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From: Dave Love
Subject: [Emacs-diffs]
Date: Fri, 06 Jun 2003 05:44:20 -0400

Index: emacs/gc/os_dep.c
diff -c emacs/gc/os_dep.c:1.1 emacs/gc/os_dep.c:removed
*** emacs/gc/os_dep.c:1.1       Thu Jun  5 13:45:54 2003
--- emacs/gc/os_dep.c   Fri Jun  6 05:44:20 2003
***************
*** 1,3535 ****
- /*
-  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
-  * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
-  * Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.
-  * Copyright (c) 1999 by Hewlett-Packard Company.  All rights reserved.
-  *
-  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
-  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
-  *
-  * Permission is hereby granted to use or copy this program
-  * for any purpose,  provided the above notices are retained on all copies.
-  * Permission to modify the code and to distribute modified code is granted,
-  * provided the above notices are retained, and a notice that the code was
-  * modified is included with the above copyright notice.
-  */
- 
- # include "private/gc_priv.h"
- 
- # if defined(LINUX) && !defined(POWERPC)
- #   include <linux/version.h>
- #   if (LINUX_VERSION_CODE <= 0x10400)
-       /* Ugly hack to get struct sigcontext_struct definition.  Required      
*/
-       /* for some early 1.3.X releases.  Will hopefully go away soon. */
-       /* in some later Linux releases, asm/sigcontext.h may have to   */
-       /* be included instead.                                         */
- #     define __KERNEL__
- #     include <asm/signal.h>
- #     undef __KERNEL__
- #   else
-       /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
-       /* struct sigcontext.  libc6 (glibc2) uses "struct sigcontext" in     */
-       /* prototypes, so we have to include the top-level sigcontext.h to    */
-       /* make sure the former gets defined to be the latter if appropriate. */
- #     include <features.h>
- #     if 2 <= __GLIBC__
- #       if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__
-         /* glibc 2.1 no longer has sigcontext.h.  But signal.h        */
-         /* has the right declaration for glibc 2.1.                   */
- #         include <sigcontext.h>
- #       endif /* 0 == __GLIBC_MINOR__ */
- #     else /* not 2 <= __GLIBC__ */
-         /* libc5 doesn't have <sigcontext.h>: go directly with the kernel   */
-         /* one.  Check LINUX_VERSION_CODE to see which we should reference. */
- #       include <asm/sigcontext.h>
- #     endif /* 2 <= __GLIBC__ */
- #   endif
- # endif
- # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
-     && !defined(MSWINCE)
- #   include <sys/types.h>
- #   if !defined(MSWIN32) && !defined(SUNOS4)
- #     include <unistd.h>
- #   endif
- # endif
- 
- # include <stdio.h>
- # if defined(MSWINCE)
- #   define SIGSEGV 0 /* value is irrelevant */
- # else
- #   include <signal.h>
- # endif
- 
- /* Blatantly OS dependent routines, except for those that are related         
*/
- /* to dynamic loading.                                                        
*/
- 
- # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
- #   define NEED_FIND_LIMIT
- # endif
- 
- # if !defined(STACKBOTTOM) && defined(HEURISTIC2)
- #   define NEED_FIND_LIMIT
- # endif
- 
- # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
- #   define NEED_FIND_LIMIT
- # endif
- 
- # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
-       || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
- #   define NEED_FIND_LIMIT
- # endif
- 
- #if defined(FREEBSD) && defined(I386)
- #  include <machine/trap.h>
- #  if !defined(PCR)
- #    define NEED_FIND_LIMIT
- #  endif
- #endif
- 
- #ifdef NEED_FIND_LIMIT
- #   include <setjmp.h>
- #endif
- 
- #ifdef AMIGA
- # define GC_AMIGA_DEF
- # include "AmigaOS.c"
- # undef GC_AMIGA_DEF
- #endif
- 
- #if defined(MSWIN32) || defined(MSWINCE)
- # define WIN32_LEAN_AND_MEAN
- # define NOSERVICE
- # include <windows.h>
- #endif
- 
- #ifdef MACOS
- # include <Processes.h>
- #endif
- 
- #ifdef IRIX5
- # include <sys/uio.h>
- # include <malloc.h>   /* for locking */
- #endif
- #ifdef USE_MMAP
- # include <sys/types.h>
- # include <sys/mman.h>
- # include <sys/stat.h>
- #endif
- 
- #ifdef UNIX_LIKE
- # include <fcntl.h>
- #endif
- 
- #if defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX)
- # ifdef SUNOS5SIGS
- #  include <sys/siginfo.h>
- # endif
- # undef setjmp
- # undef longjmp
- # define setjmp(env) sigsetjmp(env, 1)
- # define longjmp(env, val) siglongjmp(env, val)
- # define jmp_buf sigjmp_buf
- #endif
- 
- #ifdef DJGPP
-   /* Apparently necessary for djgpp 2.01.  May cause problems with    */
-   /* other versions.                                                  */
-   typedef long unsigned int caddr_t;
- #endif
- 
- #ifdef PCR
- # include "il/PCR_IL.h"
- # include "th/PCR_ThCtl.h"
- # include "mm/PCR_MM.h"
- #endif
- 
- #if !defined(NO_EXECUTE_PERMISSION)
- # define OPT_PROT_EXEC PROT_EXEC
- #else
- # define OPT_PROT_EXEC 0
- #endif
- 
- #if defined(SEARCH_FOR_DATA_START)
-   /* The I386 case can be handled without a search.  The Alpha case   */
-   /* used to be handled differently as well, but the rules changed    */
-   /* for recent Linux versions.  This seems to be the easiest way to  */
-   /* cover all versions.                                              */
- 
- # ifdef LINUX
-     /* Some Linux distributions arrange to define __data_start.  Some */
-     /* define data_start as a weak symbol.  The latter is technically */
-     /* broken, since the user program may define data_start, in which */
-     /* case we lose.  Nonetheless, we try both, prefering __data_start.       
*/
-     /* We assume gcc-compatible pragmas.      */
- #   pragma weak __data_start
-     extern int __data_start[];
- #   pragma weak data_start
-     extern int data_start[];
- # endif /* LINUX */
-   extern int _end[];
- 
-   ptr_t GC_data_start;
- 
-   void GC_init_linux_data_start()
-   {
-     extern ptr_t GC_find_limit();
- 
- #   ifdef LINUX
-       /* Try the easy approaches first:       */
-       if ((ptr_t)__data_start != 0) {
-         GC_data_start = (ptr_t)(__data_start);
-         return;
-       }
-       if ((ptr_t)data_start != 0) {
-         GC_data_start = (ptr_t)(data_start);
-         return;
-       }
- #   endif /* LINUX */
-     GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
-   }
- #endif
- 
- # ifdef ECOS
- 
- # ifndef ECOS_GC_MEMORY_SIZE
- # define ECOS_GC_MEMORY_SIZE (448 * 1024)
- # endif /* ECOS_GC_MEMORY_SIZE */
- 
- // setjmp() function, as described in ANSI para 7.6.1.1
- #define setjmp( __env__ )  hal_setjmp( __env__ )
- 
- // FIXME: This is a simple way of allocating memory which is
- // compatible with ECOS early releases.  Later releases use a more
- // sophisticated means of allocating memory than this simple static
- // allocator, but this method is at least bound to work.
- static char memory[ECOS_GC_MEMORY_SIZE];
- static char *brk = memory;
- 
- static void *tiny_sbrk(ptrdiff_t increment)
- {
-   void *p = brk;
- 
-   brk += increment;
- 
-   if (brk >  memory + sizeof memory)
-     {
-       brk -= increment;
-       return NULL;
-     }
- 
-   return p;
- }
- #define sbrk tiny_sbrk
- # endif /* ECOS */
- 
- #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
-   ptr_t GC_data_start;
- 
-   void GC_init_netbsd_elf()
-   {
-     extern ptr_t GC_find_limit();
-     extern char **environ;
-       /* This may need to be environ, without the underscore, for     */
-       /* some versions.                                               */
-     GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
-   }
- #endif
- 
- # ifdef OS2
- 
- # include <stddef.h>
- 
- # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
- 
- struct exe_hdr {
-     unsigned short      magic_number;
-     unsigned short      padding[29];
-     long                new_exe_offset;
- };
- 
- #define E_MAGIC(x)      (x).magic_number
- #define EMAGIC          0x5A4D  
- #define E_LFANEW(x)     (x).new_exe_offset
- 
- struct e32_exe {
-     unsigned char       magic_number[2]; 
-     unsigned char       byte_order; 
-     unsigned char       word_order; 
-     unsigned long       exe_format_level;
-     unsigned short      cpu;       
-     unsigned short      os;
-     unsigned long       padding1[13];
-     unsigned long       object_table_offset;
-     unsigned long       object_count;    
-     unsigned long       padding2[31];
- };
- 
- #define E32_MAGIC1(x)   (x).magic_number[0]
- #define E32MAGIC1       'L'
- #define E32_MAGIC2(x)   (x).magic_number[1]
- #define E32MAGIC2       'X'
- #define E32_BORDER(x)   (x).byte_order
- #define E32LEBO         0
- #define E32_WORDER(x)   (x).word_order
- #define E32LEWO         0
- #define E32_CPU(x)      (x).cpu
- #define E32CPU286       1
- #define E32_OBJTAB(x)   (x).object_table_offset
- #define E32_OBJCNT(x)   (x).object_count
- 
- struct o32_obj {
-     unsigned long       size;  
-     unsigned long       base;
-     unsigned long       flags;  
-     unsigned long       pagemap;
-     unsigned long       mapsize; 
-     unsigned long       reserved;
- };
- 
- #define O32_FLAGS(x)    (x).flags
- #define OBJREAD         0x0001L
- #define OBJWRITE        0x0002L
- #define OBJINVALID      0x0080L
- #define O32_SIZE(x)     (x).size
- #define O32_BASE(x)     (x).base
- 
- # else  /* IBM's compiler */
- 
- /* A kludge to get around what appears to be a header file bug */
- # ifndef WORD
- #   define WORD unsigned short
- # endif
- # ifndef DWORD
- #   define DWORD unsigned long
- # endif
- 
- # define EXE386 1
- # include <newexe.h>
- # include <exe386.h>
- 
- # endif  /* __IBMC__ */
- 
- # define INCL_DOSEXCEPTIONS
- # define INCL_DOSPROCESS
- # define INCL_DOSERRORS
- # define INCL_DOSMODULEMGR
- # define INCL_DOSMEMMGR
- # include <os2.h>
- 
- 
- /* Disable and enable signals during nontrivial allocations   */
- 
- void GC_disable_signals(void)
- {
-     ULONG nest;
-     
-     DosEnterMustComplete(&nest);
-     if (nest != 1) ABORT("nested GC_disable_signals");
- }
- 
- void GC_enable_signals(void)
- {
-     ULONG nest;
-     
-     DosExitMustComplete(&nest);
-     if (nest != 0) ABORT("GC_enable_signals");
- }
- 
- 
- # else
- 
- #  if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
-       && !defined(MSWINCE) \
-       && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
-       && !defined(NOSYS) && !defined(ECOS)
- 
- #   if defined(sigmask) && !defined(UTS4) && !defined(HURD)
-       /* Use the traditional BSD interface */
- #     define SIGSET_T int
- #     define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
- #     define SIG_FILL(set)  (set) = 0x7fffffff
-         /* Setting the leading bit appears to provoke a bug in some   */
-         /* longjmp implementations.  Most systems appear not to have  */
-         /* a signal 32.                                               */
- #     define SIGSETMASK(old, new) (old) = sigsetmask(new)
- #   else
-       /* Use POSIX/SYSV interface     */
- #     define SIGSET_T sigset_t
- #     define SIG_DEL(set, signal) sigdelset(&(set), (signal))
- #     define SIG_FILL(set) sigfillset(&set)
- #     define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
- #   endif
- 
- static GC_bool mask_initialized = FALSE;
- 
- static SIGSET_T new_mask;
- 
- static SIGSET_T old_mask;
- 
- static SIGSET_T dummy;
- 
- #if defined(PRINTSTATS) && !defined(THREADS)
- # define CHECK_SIGNALS
-   int GC_sig_disabled = 0;
- #endif
- 
- void GC_disable_signals()
- {
-     if (!mask_initialized) {
-       SIG_FILL(new_mask);
- 
-       SIG_DEL(new_mask, SIGSEGV);
-       SIG_DEL(new_mask, SIGILL);
-       SIG_DEL(new_mask, SIGQUIT);
- #     ifdef SIGBUS
-           SIG_DEL(new_mask, SIGBUS);
- #     endif
- #     ifdef SIGIOT
-           SIG_DEL(new_mask, SIGIOT);
- #     endif
- #     ifdef SIGEMT
-           SIG_DEL(new_mask, SIGEMT);
- #     endif
- #     ifdef SIGTRAP
-           SIG_DEL(new_mask, SIGTRAP);
- #     endif 
-       mask_initialized = TRUE;
-     }
- #   ifdef CHECK_SIGNALS
-       if (GC_sig_disabled != 0) ABORT("Nested disables");
-       GC_sig_disabled++;
- #   endif
-     SIGSETMASK(old_mask,new_mask);
- }
- 
- void GC_enable_signals()
- {
- #   ifdef CHECK_SIGNALS
-       if (GC_sig_disabled != 1) ABORT("Unmatched enable");
-       GC_sig_disabled--;
- #   endif
-     SIGSETMASK(dummy,old_mask);
- }
- 
- #  endif  /* !PCR */
- 
- # endif /*!OS/2 */
- 
- /* Ivan Demakov: simplest way (to me) */
- #if defined (DOS4GW)
-   void GC_disable_signals() { }
-   void GC_enable_signals() { }
- #endif
- 
- /* Find the page size */
- word GC_page_size;
- 
- # if defined(MSWIN32) || defined(MSWINCE)
-   void GC_setpagesize()
-   {
-     GetSystemInfo(&GC_sysinfo);
-     GC_page_size = GC_sysinfo.dwPageSize;
-   }
- 
- # else
- #   if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
-        || defined(USE_MUNMAP)
-       void GC_setpagesize()
-       {
-           GC_page_size = GETPAGESIZE();
-       }
- #   else
-       /* It's acceptable to fake it. */
-       void GC_setpagesize()
-       {
-           GC_page_size = HBLKSIZE;
-       }
- #   endif
- # endif
- 
- /* 
-  * Find the base of the stack. 
-  * Used only in single-threaded environment.
-  * With threads, GC_mark_roots needs to know how to do this.
-  * Called with allocator lock held.
-  */
- # if defined(MSWIN32) || defined(MSWINCE)
- # define is_writable(prot) ((prot) == PAGE_READWRITE \
-                           || (prot) == PAGE_WRITECOPY \
-                           || (prot) == PAGE_EXECUTE_READWRITE \
-                           || (prot) == PAGE_EXECUTE_WRITECOPY)
- /* Return the number of bytes that are writable starting at p.        */
- /* The pointer p is assumed to be page aligned.                       */
- /* If base is not 0, *base becomes the beginning of the       */
- /* allocation region containing p.                            */
- word GC_get_writable_length(ptr_t p, ptr_t *base)
- {
-     MEMORY_BASIC_INFORMATION buf;
-     word result;
-     word protect;
-     
-     result = VirtualQuery(p, &buf, sizeof(buf));
-     if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
-     if (base != 0) *base = (ptr_t)(buf.AllocationBase);
-     protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
-     if (!is_writable(protect)) {
-         return(0);
-     }
-     if (buf.State != MEM_COMMIT) return(0);
-     return(buf.RegionSize);
- }
- 
- ptr_t GC_get_stack_base()
- {
-     int dummy;
-     ptr_t sp = (ptr_t)(&dummy);
-     ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
-     word size = GC_get_writable_length(trunc_sp, 0);
-    
-     return(trunc_sp + size);
- }
- 
- 
- # endif /* MS Windows */
- 
- # ifdef BEOS
- # include <kernel/OS.h>
- ptr_t GC_get_stack_base(){
-       thread_info th;
-       get_thread_info(find_thread(NULL),&th);
-       return th.stack_end;
- }
- # endif /* BEOS */
- 
- 
- # ifdef OS2
- 
- ptr_t GC_get_stack_base()
- {
-     PTIB ptib;
-     PPIB ppib;
-     
-     if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
-       GC_err_printf0("DosGetInfoBlocks failed\n");
-       ABORT("DosGetInfoBlocks failed\n");
-     }
-     return((ptr_t)(ptib -> tib_pstacklimit));
- }
- 
- # endif /* OS2 */
- 
- # ifdef AMIGA
- #   define GC_AMIGA_SB
- #   include "AmigaOS.c"
- #   undef GC_AMIGA_SB
- # endif /* AMIGA */
- 
- # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
- 
- #   ifdef __STDC__
-       typedef void (*handler)(int);
- #   else
-       typedef void (*handler)();
- #   endif
- 
- #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) || defined(HURD)
-       static struct sigaction old_segv_act;
- #     if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) || defined(HURD)
-           static struct sigaction old_bus_act;
- #     endif
- #   else
-         static handler old_segv_handler, old_bus_handler;
- #   endif
-     
- #   ifdef __STDC__
-       void GC_set_and_save_fault_handler(handler h)
- #   else
-       void GC_set_and_save_fault_handler(h)
-       handler h;
- #   endif
-     {
- #     if defined(SUNOS5SIGS) || defined(IRIX5)  \
-         || defined(OSF1) || defined(HURD)
-         struct sigaction      act;
- 
-         act.sa_handler        = h;
- #       ifdef SUNOS5SIGS
-             act.sa_flags          = SA_RESTART | SA_NODEFER;
- #         else
-             act.sa_flags          = SA_RESTART;
- #       endif
-           /* The presence of SA_NODEFER represents yet another gross    */
-           /* hack.  Under Solaris 2.3, siglongjmp doesn't appear to     */
-           /* interact correctly with -lthread.  We hide the confusion   */
-           /* by making sure that signal handling doesn't affect the     */
-           /* signal mask.                                               */
- 
-         (void) sigemptyset(&act.sa_mask);
- #       ifdef GC_IRIX_THREADS
-               /* Older versions have a bug related to retrieving and  */
-               /* and setting a handler at the same time.              */
-               (void) sigaction(SIGSEGV, 0, &old_segv_act);
-               (void) sigaction(SIGSEGV, &act, 0);
- #       else
-               (void) sigaction(SIGSEGV, &act, &old_segv_act);
- #             if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
-                  || defined(HPUX) || defined(HURD)
-                   /* Under Irix 5.x or HP/UX, we may get SIGBUS.      */
-                   /* Pthreads doesn't exist under Irix 5.x, so we     */
-                   /* don't have to worry in the threads case.         */
-                   (void) sigaction(SIGBUS, &act, &old_bus_act);
- #             endif
- #       endif /* GC_IRIX_THREADS */
- #     else
-         old_segv_handler = signal(SIGSEGV, h);
- #       ifdef SIGBUS
-           old_bus_handler = signal(SIGBUS, h);
- #       endif
- #     endif
-     }
- # endif /* NEED_FIND_LIMIT || UNIX_LIKE */
- 
- # ifdef NEED_FIND_LIMIT
-   /* Some tools to implement HEURISTIC2       */
- #   define MIN_PAGE_SIZE 256  /* Smallest conceivable page size, bytes */
-     /* static */ jmp_buf GC_jmp_buf;
-     
-     /*ARGSUSED*/
-     void GC_fault_handler(sig)
-     int sig;
-     {
-         longjmp(GC_jmp_buf, 1);
-     }
- 
-     void GC_setup_temporary_fault_handler()
-     {
-       GC_set_and_save_fault_handler(GC_fault_handler);
-     }
-     
-     void GC_reset_fault_handler()
-     {
- #       if defined(SUNOS5SIGS) || defined(IRIX5) \
-          || defined(OSF1) || defined(HURD)
-         (void) sigaction(SIGSEGV, &old_segv_act, 0);
- #       if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
-            || defined(HPUX) || defined(HURD)
-             (void) sigaction(SIGBUS, &old_bus_act, 0);
- #       endif
- #       else
-         (void) signal(SIGSEGV, old_segv_handler);
- #       ifdef SIGBUS
-           (void) signal(SIGBUS, old_bus_handler);
- #       endif
- #       endif
-     }
- 
-     /* Return the first nonaddressible location > p (up) or   */
-     /* the smallest location q s.t. [q,p) is addressable (!up).       */
-     /* We assume that p (up) or p-1 (!up) is addressable.     */
-     ptr_t GC_find_limit(p, up)
-     ptr_t p;
-     GC_bool up;
-     {
-         static VOLATILE ptr_t result;
-               /* Needs to be static, since otherwise it may not be    */
-               /* preserved across the longjmp.  Can safely be         */
-               /* static since it's only called once, with the         */
-               /* allocation lock held.                                */
- 
- 
-       GC_setup_temporary_fault_handler();
-       if (setjmp(GC_jmp_buf) == 0) {
-           result = (ptr_t)(((word)(p))
-                             & ~(MIN_PAGE_SIZE-1));
-           for (;;) {
-               if (up) {
-                   result += MIN_PAGE_SIZE;
-               } else {
-                   result -= MIN_PAGE_SIZE;
-               }
-               GC_noop1((word)(*result));
-           }
-       }
-       GC_reset_fault_handler();
-       if (!up) {
-           result += MIN_PAGE_SIZE;
-       }
-       return(result);
-     }
- # endif
- 
- #if defined(ECOS) || defined(NOSYS)
-   ptr_t GC_get_stack_base()
-   {
-     return STACKBOTTOM;
-   }
- #endif
- 
- #ifdef LINUX_STACKBOTTOM
- 
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <ctype.h>
- 
- # define STAT_SKIP 27   /* Number of fields preceding startstack      */
-                       /* field in /proc/self/stat                     */
- 
- # pragma weak __libc_stack_end
-   extern ptr_t __libc_stack_end;
- 
- # ifdef IA64
- #   pragma weak __libc_ia64_register_backing_store_base
-     extern ptr_t __libc_ia64_register_backing_store_base;
- 
-     ptr_t GC_get_register_stack_base(void)
-     {
-       if (0 != &__libc_ia64_register_backing_store_base
-         && 0 != __libc_ia64_register_backing_store_base) {
-       /* Glibc 2.2.4 has a bug such that for dynamically linked       */
-       /* executables __libc_ia64_register_backing_store_base is       */
-       /* defined but ininitialized during constructor calls.          */
-       /* Hence we check for both nonzero address and value.           */
-       return __libc_ia64_register_backing_store_base;
-       } else {
-       word result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
-       result += BACKING_STORE_ALIGNMENT - 1;
-       result &= ~(BACKING_STORE_ALIGNMENT - 1);
-       return (ptr_t)result;
-       }
-     }
- # endif
- 
-   ptr_t GC_linux_stack_base(void)
-   {
-     /* We read the stack base value from /proc/self/stat.  We do this */
-     /* using direct I/O system calls in order to avoid calling malloc   */
-     /* in case REDIRECT_MALLOC is defined.                            */ 
- #   define STAT_BUF_SIZE 4096
- #   if defined(GC_USE_LD_WRAP)
- #     define STAT_READ __real_read
- #   else
- #     define STAT_READ read
- #   endif    
-     char stat_buf[STAT_BUF_SIZE];
-     int f;
-     char c;
-     word result = 0;
-     size_t i, buf_offset = 0;
- 
-     /* First try the easy way.  This should work for glibc 2.2        */
-       if (0 != &__libc_stack_end) {
- #       ifdef IA64
-         /* Some versions of glibc set the address 16 bytes too        */
-         /* low while the initialization code is running.              */
-         if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
-           return __libc_stack_end + 0x10;
-         } /* Otherwise it's not safe to add 16 bytes and we fall      */
-           /* back to using /proc.                                     */
- #     else 
-         return __libc_stack_end;
- #     endif
-       }
-     f = open("/proc/self/stat", O_RDONLY);
-     if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
-       ABORT("Couldn't read /proc/self/stat");
-     }
-     c = stat_buf[buf_offset++];
-     /* Skip the required number of fields.  This number is hopefully  */
-     /* constant across all Linux implementations.                     */
-       for (i = 0; i < STAT_SKIP; ++i) {
-       while (isspace(c)) c = stat_buf[buf_offset++];
-       while (!isspace(c)) c = stat_buf[buf_offset++];
-       }
-     while (isspace(c)) c = stat_buf[buf_offset++];
-     while (isdigit(c)) {
-       result *= 10;
-       result += c - '0';
-       c = stat_buf[buf_offset++];
-     }
-     close(f);
-     if (result < 0x10000000) ABORT("Absurd stack bottom value");
-     return (ptr_t)result;
-   }
- 
- #endif /* LINUX_STACKBOTTOM */
- 
- #ifdef FREEBSD_STACKBOTTOM
- 
- /* This uses an undocumented sysctl call, but at least one expert     */
- /* believes it will stay.                                             */
- 
- #include <unistd.h>
- #include <sys/types.h>
- #include <sys/sysctl.h>
- 
-   ptr_t GC_freebsd_stack_base(void)
-   {
-     int nm[2] = {CTL_KERN, KERN_USRSTACK};
-     ptr_t base;
-     size_t len = sizeof(ptr_t);
-     int r = sysctl(nm, 2, &base, &len, NULL, 0);
-     
-     if (r) ABORT("Error getting stack base");
- 
-     return base;
-   }
- 
- #endif /* FREEBSD_STACKBOTTOM */
- 
- #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
-     && !defined(MSWINCE) && !defined(OS2)
- 
- ptr_t GC_get_stack_base()
- {
-     word dummy;
-     ptr_t result;
- 
- #   define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
- 
- #   ifdef STACKBOTTOM
-       return(STACKBOTTOM);
- #   else
- #     ifdef HEURISTIC1
- #        ifdef STACK_GROWS_DOWN
-            result = (ptr_t)((((word)(&dummy))
-                              + STACKBOTTOM_ALIGNMENT_M1)
-                             & ~STACKBOTTOM_ALIGNMENT_M1);
- #        else
-            result = (ptr_t)(((word)(&dummy))
-                             & ~STACKBOTTOM_ALIGNMENT_M1);
- #        endif
- #     endif /* HEURISTIC1 */
- #     ifdef LINUX_STACKBOTTOM
-          result = GC_linux_stack_base();
- #     endif
- #     ifdef FREEBSD_STACKBOTTOM
-          result = GC_freebsd_stack_base();
- #     endif
- #     ifdef HEURISTIC2
- #         ifdef STACK_GROWS_DOWN
-               result = GC_find_limit((ptr_t)(&dummy), TRUE);
- #             ifdef HEURISTIC2_LIMIT
-                   if (result > HEURISTIC2_LIMIT
-                       && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
-                           result = HEURISTIC2_LIMIT;
-                   }
- #             endif
- #         else
-               result = GC_find_limit((ptr_t)(&dummy), FALSE);
- #             ifdef HEURISTIC2_LIMIT
-                   if (result < HEURISTIC2_LIMIT
-                       && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
-                           result = HEURISTIC2_LIMIT;
-                   }
- #             endif
- #         endif
- 
- #     endif /* HEURISTIC2 */
- #     ifdef STACK_GROWS_DOWN
-           if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
- #     endif
-       return(result);
- #   endif /* STACKBOTTOM */
- }
- 
- # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS */
- 
- /*
-  * Register static data segment(s) as roots.
-  * If more data segments are added later then they need to be registered
-  * add that point (as we do with SunOS dynamic loading),
-  * or GC_mark_roots needs to check for them (as we do with PCR).
-  * Called with allocator lock held.
-  */
- 
- # ifdef OS2
- 
- void GC_register_data_segments()
- {
-     PTIB ptib;
-     PPIB ppib;
-     HMODULE module_handle;
- #   define PBUFSIZ 512
-     UCHAR path[PBUFSIZ];
-     FILE * myexefile;
-     struct exe_hdr hdrdos;    /* MSDOS header.        */
-     struct e32_exe hdr386;    /* Real header for my executable */
-     struct o32_obj seg;       /* Currrent segment */
-     int nsegs;
-     
-     
-     if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
-       GC_err_printf0("DosGetInfoBlocks failed\n");
-       ABORT("DosGetInfoBlocks failed\n");
-     }
-     module_handle = ppib -> pib_hmte;
-     if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
-       GC_err_printf0("DosQueryModuleName failed\n");
-       ABORT("DosGetInfoBlocks failed\n");
-     }
-     myexefile = fopen(path, "rb");
-     if (myexefile == 0) {
-         GC_err_puts("Couldn't open executable ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Failed to open executable\n");
-     }
-     if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof 
hdrdos) {
-         GC_err_puts("Couldn't read MSDOS header from ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Couldn't read MSDOS header");
-     }
-     if (E_MAGIC(hdrdos) != EMAGIC) {
-         GC_err_puts("Executable has wrong DOS magic number: ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Bad DOS magic number");
-     }
-     if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
-         GC_err_puts("Seek to new header failed in ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Bad DOS magic number");
-     }
-     if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof 
hdr386) {
-         GC_err_puts("Couldn't read MSDOS header from ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Couldn't read OS/2 header");
-     }
-     if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
-         GC_err_puts("Executable has wrong OS/2 magic number:");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Bad OS/2 magic number");
-     }
-     if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
-         GC_err_puts("Executable %s has wrong byte order: ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Bad byte order");
-     }
-     if ( E32_CPU(hdr386) == E32CPU286) {
-         GC_err_puts("GC can't handle 80286 executables: ");
-         GC_err_puts(path); GC_err_puts("\n");
-         EXIT();
-     }
-     if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
-             SEEK_SET) != 0) {
-         GC_err_puts("Seek to object table failed: ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Seek to object table failed");
-     }
-     for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
-       int flags;
-       if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
-         GC_err_puts("Couldn't read obj table entry from ");
-         GC_err_puts(path); GC_err_puts("\n");
-         ABORT("Couldn't read obj table entry");
-       }
-       flags = O32_FLAGS(seg);
-       if (!(flags & OBJWRITE)) continue;
-       if (!(flags & OBJREAD)) continue;
-       if (flags & OBJINVALID) {
-           GC_err_printf0("Object with invalid pages?\n");
-           continue;
-       } 
-       GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
-     }
- }
- 
- # else /* !OS2 */
- 
- # if defined(MSWIN32) || defined(MSWINCE)
- 
- # ifdef MSWIN32
-   /* Unfortunately, we have to handle win32s very differently from NT,        
*/
-   /* Since VirtualQuery has very different semantics.  In particular, */
-   /* under win32s a VirtualQuery call on an unmapped page returns an  */
-   /* invalid result.  Under NT, GC_register_data_segments is a noop and       
*/
-   /* all real work is done by GC_register_dynamic_libraries.  Under   */
-   /* win32s, we cannot find the data segments associated with dll's.  */
-   /* We register the main data segment here.                          */
- #  ifdef __GCC__
-   GC_bool GC_no_win32_dlls = TRUE;
-                        /* GCC can't do SEH, so we can't use VirtualQuery */
- #  else
-   GC_bool GC_no_win32_dlls = FALSE;    
- #  endif
-   
-   void GC_init_win32()
-   {
-     /* if we're running under win32s, assume that no DLLs will be loaded */
-     DWORD v = GetVersion();
-     GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
-   }
- 
-   /* Return the smallest address a such that VirtualQuery             */
-   /* returns correct results for all addresses between a and start.   */
-   /* Assumes VirtualQuery returns correct information for start.      */
-   ptr_t GC_least_described_address(ptr_t start)
-   {  
-     MEMORY_BASIC_INFORMATION buf;
-     DWORD result;
-     LPVOID limit;
-     ptr_t p;
-     LPVOID q;
-     
-     limit = GC_sysinfo.lpMinimumApplicationAddress;
-     p = (ptr_t)((word)start & ~(GC_page_size - 1));
-     for (;;) {
-       q = (LPVOID)(p - GC_page_size);
-       if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
-       result = VirtualQuery(q, &buf, sizeof(buf));
-       if (result != sizeof(buf) || buf.AllocationBase == 0) break;
-       p = (ptr_t)(buf.AllocationBase);
-     }
-     return(p);
-   }
- # endif
- 
- # ifndef REDIRECT_MALLOC
-   /* We maintain a linked list of AllocationBase values that we know  */
-   /* correspond to malloc heap sections.  Currently this is only called */
-   /* during a GC.  But there is some hope that for long running               
*/
-   /* programs we will eventually see most heap sections.              */
- 
-   /* In the long run, it would be more reliable to occasionally walk  */
-   /* the malloc heap with HeapWalk on the default heap.  But that     */
-   /* apparently works only for NT-based Windows.                      */ 
- 
-   /* In the long run, a better data structure would also be nice ...  */
-   struct GC_malloc_heap_list {
-     void * allocation_base;
-     struct GC_malloc_heap_list *next;
-   } *GC_malloc_heap_l = 0;
- 
-   /* Is p the base of one of the malloc heap sections we already know */
-   /* about?                                                           */
-   GC_bool GC_is_malloc_heap_base(ptr_t p)
-   {
-     struct GC_malloc_heap_list *q = GC_malloc_heap_l;
- 
-     while (0 != q) {
-       if (q -> allocation_base == p) return TRUE;
-       q = q -> next;
-     }
-     return FALSE;
-   }
- 
-   void *GC_get_allocation_base(void *p)
-   {
-     MEMORY_BASIC_INFORMATION buf;
-     DWORD result = VirtualQuery(p, &buf, sizeof(buf));
-     if (result != sizeof(buf)) {
-       ABORT("Weird VirtualQuery result");
-     }
-     return buf.AllocationBase;
-   }
- 
-   size_t GC_max_root_size = 100000;   /* Appr. largest root size.     */
- 
-   void GC_add_current_malloc_heap()
-   {
-     struct GC_malloc_heap_list *new_l =
-                  malloc(sizeof(struct GC_malloc_heap_list));
-     void * candidate = GC_get_allocation_base(new_l);
- 
-     if (new_l == 0) return;
-     if (GC_is_malloc_heap_base(candidate)) {
-       /* Try a little harder to find malloc heap.                     */
-       size_t req_size = 10000;
-       do {
-         void *p = malloc(req_size);
-         if (0 == p) { free(new_l); return; }
-         candidate = GC_get_allocation_base(p);
-         free(p);
-         req_size *= 2;
-       } while (GC_is_malloc_heap_base(candidate)
-                && req_size < GC_max_root_size/10 && req_size < 500000);
-       if (GC_is_malloc_heap_base(candidate)) {
-         free(new_l); return;
-       }
-     }
- #   ifdef CONDPRINT
-       if (GC_print_stats)
-         GC_printf1("Found new system malloc AllocationBase at 0x%lx\n",
-                      candidate);
- #   endif
-     new_l -> allocation_base = candidate;
-     new_l -> next = GC_malloc_heap_l;
-     GC_malloc_heap_l = new_l;
-   }
- # endif /* REDIRECT_MALLOC */
-   
-   /* Is p the start of either the malloc heap, or of one of our */
-   /* heap sections?                                           */
-   GC_bool GC_is_heap_base (ptr_t p)
-   {
-      
-      unsigned i;
-      
- #    ifndef REDIRECT_MALLOC
-        static word last_gc_no = -1;
-      
-        if (last_gc_no != GC_gc_no) {
-        GC_add_current_malloc_heap();
-        last_gc_no = GC_gc_no;
-        }
-        if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
-        if (GC_is_malloc_heap_base(p)) return TRUE;
- #    endif
-      for (i = 0; i < GC_n_heap_bases; i++) {
-          if (GC_heap_bases[i] == p) return TRUE;
-      }
-      return FALSE ;
-   }
- 
- # ifdef MSWIN32
-   void GC_register_root_section(ptr_t static_root)
-   {
-       MEMORY_BASIC_INFORMATION buf;
-       DWORD result;
-       DWORD protect;
-       LPVOID p;
-       char * base;
-       char * limit, * new_limit;
-     
-       if (!GC_no_win32_dlls) return;
-       p = base = limit = GC_least_described_address(static_root);
-       while (p < GC_sysinfo.lpMaximumApplicationAddress) {
-         result = VirtualQuery(p, &buf, sizeof(buf));
-         if (result != sizeof(buf) || buf.AllocationBase == 0
-             || GC_is_heap_base(buf.AllocationBase)) break;
-         new_limit = (char *)p + buf.RegionSize;
-         protect = buf.Protect;
-         if (buf.State == MEM_COMMIT
-             && is_writable(protect)) {
-             if ((char *)p == limit) {
-                 limit = new_limit;
-             } else {
-                 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
-                 base = p;
-                 limit = new_limit;
-             }
-         }
-         if (p > (LPVOID)new_limit /* overflow */) break;
-         p = (LPVOID)new_limit;
-       }
-       if (base != limit) GC_add_roots_inner(base, limit, FALSE);
-   }
- #endif
-   
-   void GC_register_data_segments()
-   {
- #     ifdef MSWIN32
-       static char dummy;
-       GC_register_root_section((ptr_t)(&dummy));
- #     endif
-   }
- 
- # else /* !OS2 && !Windows */
- 
- # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
-       || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
- ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
- int max_page_size;
- int * etext_addr;
- {
-     word text_end = ((word)(etext_addr) + sizeof(word) - 1)
-                   & ~(sizeof(word) - 1);
-       /* etext rounded to word boundary       */
-     word next_page = ((text_end + (word)max_page_size - 1)
-                     & ~((word)max_page_size - 1));
-     word page_offset = (text_end & ((word)max_page_size - 1));
-     VOLATILE char * result = (char *)(next_page + page_offset);
-     /* Note that this isnt equivalent to just adding          */
-     /* max_page_size to &etext if &etext is at a page boundary        */
-     
-     GC_setup_temporary_fault_handler();
-     if (setjmp(GC_jmp_buf) == 0) {
-       /* Try writing to the address.  */
-       *result = *result;
-         GC_reset_fault_handler();
-     } else {
-         GC_reset_fault_handler();
-       /* We got here via a longjmp.  The address is not readable.     */
-       /* This is known to happen under Solaris 2.4 + gcc, which place */
-       /* string constants in the text segment, but after etext.       */
-       /* Use plan B.  Note that we now know there is a gap between    */
-       /* text and data segments, so plan A bought us something.       */
-       result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
-     }
-     return((ptr_t)result);
- }
- # endif
- 
- # if defined(FREEBSD) && defined(I386) && !defined(PCR)
- /* Its unclear whether this should be identical to the above, or      */
- /* whether it should apply to non-X86 architectures.                  */
- /* For now we don't assume that there is always an empty page after   */
- /* etext.  But in some cases there actually seems to be slightly more.  */
- /* This also deals with holes between read-only data and writable data.       
*/
- ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr)
- int max_page_size;
- int * etext_addr;
- {
-     word text_end = ((word)(etext_addr) + sizeof(word) - 1)
-                    & ~(sizeof(word) - 1);
-       /* etext rounded to word boundary       */
-     VOLATILE word next_page = (text_end + (word)max_page_size - 1)
-                             & ~((word)max_page_size - 1);
-     VOLATILE ptr_t result = (ptr_t)text_end;
-     GC_setup_temporary_fault_handler();
-     if (setjmp(GC_jmp_buf) == 0) {
-       /* Try reading at the address.                          */
-       /* This should happen before there is another thread.   */
-       for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
-           *(VOLATILE char *)next_page;
-       GC_reset_fault_handler();
-     } else {
-       GC_reset_fault_handler();
-       /* As above, we go to plan B    */
-       result = GC_find_limit((ptr_t)(DATAEND), FALSE);
-     }
-     return(result);
- }
- 
- # endif
- 
- 
- #ifdef AMIGA
- 
- #  define GC_AMIGA_DS
- #  include "AmigaOS.c"
- #  undef GC_AMIGA_DS
- 
- #else /* !OS2 && !Windows && !AMIGA */
- 
- void GC_register_data_segments()
- {
- #   if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS)
- #     if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
-       /* As of Solaris 2.3, the Solaris threads implementation        */
-       /* allocates the data structure for the initial thread with     */
-       /* sbrk at process startup.  It needs to be scanned, so that    */
-       /* we don't lose some malloc allocated data structures          */
-       /* hanging from it.  We're on thin ice here ...                 */
-         extern caddr_t sbrk();
- 
-       GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
- #     else
-       GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
- #       if defined(DATASTART2)
-          GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
- #       endif
- #     endif
- #   endif
- #   if defined(MACOS)
-     {
- #   if defined(THINK_C)
-       extern void* GC_MacGetDataStart(void);
-       /* globals begin above stack and end at a5. */
-       GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
-                          (ptr_t)LMGetCurrentA5(), FALSE);
- #   else
- #     if defined(__MWERKS__)
- #       if !__POWERPC__
-         extern void* GC_MacGetDataStart(void);
-         /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
- #         if __option(far_data)
-         extern void* GC_MacGetDataEnd(void);
- #         endif
-         /* globals begin above stack and end at a5. */
-         GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
-                            (ptr_t)LMGetCurrentA5(), FALSE);
-         /* MATTHEW: Handle Far Globals */                          
- #         if __option(far_data)
-       /* Far globals follow he QD globals: */
-         GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
-                            (ptr_t)GC_MacGetDataEnd(), FALSE);
- #         endif
- #       else
-         extern char __data_start__[], __data_end__[];
-         GC_add_roots_inner((ptr_t)&__data_start__,
-                            (ptr_t)&__data_end__, FALSE);
- #       endif /* __POWERPC__ */
- #     endif /* __MWERKS__ */
- #   endif /* !THINK_C */
-     }
- #   endif /* MACOS */
- 
-     /* Dynamic libraries are added at every collection, since they may  */
-     /* change.                                                                
*/
- }
- 
- # endif  /* ! AMIGA */
- # endif  /* ! MSWIN32 && ! MSWINCE*/
- # endif  /* ! OS2 */
- 
- /*
-  * Auxiliary routines for obtaining memory from OS.
-  */
- 
- # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
-       && !defined(MSWIN32) && !defined(MSWINCE) \
-       && !defined(MACOS) && !defined(DOS4GW)
- 
- # ifdef SUNOS4
-     extern caddr_t sbrk();
- # endif
- # ifdef __STDC__
- #   define SBRK_ARG_T ptrdiff_t
- # else
- #   define SBRK_ARG_T int
- # endif
- 
- 
- # ifdef RS6000
- /* The compiler seems to generate speculative reads one past the end of       
*/
- /* an allocated object.  Hence we need to make sure that the page     */
- /* following the last heap page is also mapped.                               
*/
- ptr_t GC_unix_get_mem(bytes)
- word bytes;
- {
-     caddr_t cur_brk = (caddr_t)sbrk(0);
-     caddr_t result;
-     SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
-     static caddr_t my_brk_val = 0;
-     
-     if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
-     if (lsbs != 0) {
-         if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
-     }
-     if (cur_brk == my_brk_val) {
-       /* Use the extra block we allocated last time. */
-         result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
-         if (result == (caddr_t)(-1)) return(0);
-         result -= GC_page_size;
-     } else {
-         result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
-         if (result == (caddr_t)(-1)) return(0);
-     }
-     my_brk_val = result + bytes + GC_page_size;       /* Always page aligned 
*/
-     return((ptr_t)result);
- }
- 
- #else  /* Not RS6000 */
- 
- #if defined(USE_MMAP)
- /* Tested only under Linux, IRIX5 and Solaris 2 */
- 
- #ifdef USE_MMAP_FIXED
- #   define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
-       /* Seems to yield better performance on Solaris 2, but can      */
-       /* be unreliable if something is already mapped at the address. */
- #else
- #   define GC_MMAP_FLAGS MAP_PRIVATE
- #endif
- 
- #ifndef HEAP_START
- #   define HEAP_START 0
- #endif
- 
- ptr_t GC_unix_get_mem(bytes)
- word bytes;
- {
-     void *result;
-     static ptr_t last_addr = HEAP_START;
- 
- #   ifndef USE_MMAP_ANON
-       static GC_bool initialized = FALSE;
-       static int fd;
- 
-       if (!initialized) {
-         fd = open("/dev/zero", O_RDONLY);
-         fcntl(fd, F_SETFD, FD_CLOEXEC);
-         initialized = TRUE;
-       }
- #   endif
- 
-     if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
- #   ifdef USE_MMAP_ANON
-       result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
-                   GC_MMAP_FLAGS | MAP_ANON, -1, 0/* offset */);
- #   else
-       result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
-                   GC_MMAP_FLAGS, fd, 0/* offset */);
- #   endif
-     if (result == MAP_FAILED) return(0);
-     last_addr = (ptr_t)result + bytes + GC_page_size - 1;
-     last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
- #   if !defined(LINUX)
-       if (last_addr == 0) {
-         /* Oops.  We got the end of the address space.  This isn't    */
-       /* usable by arbitrary C code, since one-past-end pointers      */
-       /* don't work, so we discard it and try again.                  */
-       munmap(result, (size_t)(-GC_page_size) - (size_t)result);
-                       /* Leave last page mapped, so we can't repeat. */
-       return GC_unix_get_mem(bytes);
-       }
- #   else
-       GC_ASSERT(last_addr != 0);
- #   endif
-     return((ptr_t)result);
- }
- 
- #else /* Not RS6000, not USE_MMAP */
- ptr_t GC_unix_get_mem(bytes)
- word bytes;
- {
-   ptr_t result;
- # ifdef IRIX5
-     /* Bare sbrk isn't thread safe.  Play by malloc rules.    */
-     /* The equivalent may be needed on other systems as well.         */
-     __LOCK_MALLOC();
- # endif
-   {
-     ptr_t cur_brk = (ptr_t)sbrk(0);
-     SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
-     
-     if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
-     if (lsbs != 0) {
-         if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0);
-     }
-     result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
-     if (result == (ptr_t)(-1)) result = 0;
-   }
- # ifdef IRIX5
-     __UNLOCK_MALLOC();
- # endif
-   return(result);
- }
- 
- #endif /* Not USE_MMAP */
- #endif /* Not RS6000 */
- 
- # endif /* UN*X */
- 
- # ifdef OS2
- 
- void * os2_alloc(size_t bytes)
- {
-     void * result;
- 
-     if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
-                                   PAG_WRITE | PAG_COMMIT)
-                   != NO_ERROR) {
-       return(0);
-     }
-     if (result == 0) return(os2_alloc(bytes));
-     return(result);
- }
- 
- # endif /* OS2 */
- 
- 
- # if defined(MSWIN32) || defined(MSWINCE)
- SYSTEM_INFO GC_sysinfo;
- # endif
- 
- # ifdef MSWIN32
- 
- # ifdef USE_GLOBAL_ALLOC
- #   define GLOBAL_ALLOC_TEST 1
- # else
- #   define GLOBAL_ALLOC_TEST GC_no_win32_dlls
- # endif
- 
- word GC_n_heap_bases = 0;
- 
- ptr_t GC_win32_get_mem(bytes)
- word bytes;
- {
-     ptr_t result;
- 
-     if (GLOBAL_ALLOC_TEST) {
-       /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE.    */
-       /* There are also unconfirmed rumors of other           */
-       /* problems, so we dodge the issue.                     */
-         result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
-         result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
-     } else {
-       /* VirtualProtect only works on regions returned by a   */
-       /* single VirtualAlloc call.  Thus we allocate one      */
-       /* extra page, which will prevent merging of blocks     */
-       /* in separate regions, and eliminate any temptation    */
-       /* to call VirtualProtect on a range spanning regions.  */
-       /* This wastes a small amount of memory, and risks      */
-       /* increased fragmentation.  But better alternatives    */
-       /* would require effort.                                */
-         result = (ptr_t) VirtualAlloc(NULL, bytes + 1,
-                                     MEM_COMMIT | MEM_RESERVE,
-                                     PAGE_EXECUTE_READWRITE);
-     }
-     if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
-       /* If I read the documentation correctly, this can      */
-       /* only happen if HBLKSIZE > 64k or not a power of 2.   */
-     if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
-     GC_heap_bases[GC_n_heap_bases++] = result;
-     return(result);                     
- }
- 
- void GC_win32_free_heap ()
- {
-     if (GC_no_win32_dlls) {
-       while (GC_n_heap_bases > 0) {
-           GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
-           GC_heap_bases[GC_n_heap_bases] = 0;
-       }
-     }
- }
- # endif
- 
- #ifdef AMIGA
- # define GC_AMIGA_AM
- # include "AmigaOS.c"
- # undef GC_AMIGA_AM
- #endif
- 
- 
- # ifdef MSWINCE
- word GC_n_heap_bases = 0;
- 
- ptr_t GC_wince_get_mem(bytes)
- word bytes;
- {
-     ptr_t result;
-     word i;
- 
-     /* Round up allocation size to multiple of page size */
-     bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
- 
-     /* Try to find reserved, uncommitted pages */
-     for (i = 0; i < GC_n_heap_bases; i++) {
-       if (((word)(-(signed_word)GC_heap_lengths[i])
-            & (GC_sysinfo.dwAllocationGranularity-1))
-           >= bytes) {
-           result = GC_heap_bases[i] + GC_heap_lengths[i];
-           break;
-       }
-     }
- 
-     if (i == GC_n_heap_bases) {
-       /* Reserve more pages */
-       word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
-                        & ~(GC_sysinfo.dwAllocationGranularity-1);
-       /* If we ever support MPROTECT_VDB here, we will probably need to       
*/
-       /* ensure that res_bytes is strictly > bytes, so that VirtualProtect    
*/
-       /* never spans regions.  It seems to be OK for a VirtualFree argument   
*/
-       /* to span regions, so we should be OK for now.                         
*/
-       result = (ptr_t) VirtualAlloc(NULL, res_bytes,
-                                     MEM_RESERVE | MEM_TOP_DOWN,
-                                     PAGE_EXECUTE_READWRITE);
-       if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
-           /* If I read the documentation correctly, this can  */
-           /* only happen if HBLKSIZE > 64k or not a power of 2.       */
-       if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
-       GC_heap_bases[GC_n_heap_bases] = result;
-       GC_heap_lengths[GC_n_heap_bases] = 0;
-       GC_n_heap_bases++;
-     }
- 
-     /* Commit pages */
-     result = (ptr_t) VirtualAlloc(result, bytes,
-                                 MEM_COMMIT,
-                                 PAGE_EXECUTE_READWRITE);
-     if (result != NULL) {
-       if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
-       GC_heap_lengths[i] += bytes;
-     }
- 
-     return(result);                     
- }
- # endif
- 
- #ifdef USE_MUNMAP
- 
- /* For now, this only works on Win32/WinCE and some Unix-like */
- /* systems.  If you have something else, don't define         */
- /* USE_MUNMAP.                                                        */
- /* We assume ANSI C to support this feature.                  */
- 
- #if !defined(MSWIN32) && !defined(MSWINCE)
- 
- #include <unistd.h>
- #include <sys/mman.h>
- #include <sys/stat.h>
- #include <sys/types.h>
- 
- #endif
- 
- /* Compute a page aligned starting address for the unmap      */
- /* operation on a block of size bytes starting at start.      */
- /* Return 0 if the block is too small to make this feasible.  */
- ptr_t GC_unmap_start(ptr_t start, word bytes)
- {
-     ptr_t result = start;
-     /* Round start to next page boundary.       */
-         result += GC_page_size - 1;
-         result = (ptr_t)((word)result & ~(GC_page_size - 1));
-     if (result + GC_page_size > start + bytes) return 0;
-     return result;
- }
- 
- /* Compute end address for an unmap operation on the indicated        */
- /* block.                                                     */
- ptr_t GC_unmap_end(ptr_t start, word bytes)
- {
-     ptr_t end_addr = start + bytes;
-     end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
-     return end_addr;
- }
- 
- /* Under Win32/WinCE we commit (map) and decommit (unmap)     */
- /* memory using       VirtualAlloc and VirtualFree.  These functions  */
- /* work on individual allocations of virtual memory, made     */
- /* previously using VirtualAlloc with the MEM_RESERVE flag.   */
- /* The ranges we need to (de)commit may span several of these */
- /* allocations; therefore we use VirtualQuery to check                */
- /* allocation lengths, and split up the range as necessary.   */
- 
- /* We assume that GC_remap is called on exactly the same range        */
- /* as a previous call to GC_unmap.  It is safe to consistently        */
- /* round the endpoints in both places.                                */
- void GC_unmap(ptr_t start, word bytes)
- {
-     ptr_t start_addr = GC_unmap_start(start, bytes);
-     ptr_t end_addr = GC_unmap_end(start, bytes);
-     word len = end_addr - start_addr;
-     if (0 == start_addr) return;
- #   if defined(MSWIN32) || defined(MSWINCE)
-       while (len != 0) {
-           MEMORY_BASIC_INFORMATION mem_info;
-         GC_word free_len;
-         if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
-             != sizeof(mem_info))
-             ABORT("Weird VirtualQuery result");
-         free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
-         if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
-             ABORT("VirtualFree failed");
-         GC_unmapped_bytes += free_len;
-         start_addr += free_len;
-         len -= free_len;
-       }
- #   else
-       if (munmap(start_addr, len) != 0) ABORT("munmap failed");
-       GC_unmapped_bytes += len;
- #   endif
- }
- 
- 
- void GC_remap(ptr_t start, word bytes)
- {
-     static int zero_descr = -1;
-     ptr_t start_addr = GC_unmap_start(start, bytes);
-     ptr_t end_addr = GC_unmap_end(start, bytes);
-     word len = end_addr - start_addr;
-     ptr_t result;
- 
- #   if defined(MSWIN32) || defined(MSWINCE)
-       if (0 == start_addr) return;
-       while (len != 0) {
-           MEMORY_BASIC_INFORMATION mem_info;
-         GC_word alloc_len;
-         if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
-             != sizeof(mem_info))
-             ABORT("Weird VirtualQuery result");
-         alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
-         result = VirtualAlloc(start_addr, alloc_len,
-                               MEM_COMMIT,
-                               PAGE_EXECUTE_READWRITE);
-         if (result != start_addr) {
-             ABORT("VirtualAlloc remapping failed");
-         }
-         GC_unmapped_bytes -= alloc_len;
-         start_addr += alloc_len;
-         len -= alloc_len;
-       }
- #   else
-       if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR);
-       fcntl(zero_descr, F_SETFD, FD_CLOEXEC);
-       if (0 == start_addr) return;
-       result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
-                   MAP_FIXED | MAP_PRIVATE, zero_descr, 0);
-       if (result != start_addr) {
-         ABORT("mmap remapping failed");
-       }
-       GC_unmapped_bytes -= len;
- #   endif
- }
- 
- /* Two adjacent blocks have already been unmapped and are about to    */
- /* be merged.  Unmap the whole block.  This typically requires                
*/
- /* that we unmap a small section in the middle that was not previously        
*/
- /* unmapped due to alignment constraints.                             */
- void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
- {
-     ptr_t start1_addr = GC_unmap_start(start1, bytes1);
-     ptr_t end1_addr = GC_unmap_end(start1, bytes1);
-     ptr_t start2_addr = GC_unmap_start(start2, bytes2);
-     ptr_t end2_addr = GC_unmap_end(start2, bytes2);
-     ptr_t start_addr = end1_addr;
-     ptr_t end_addr = start2_addr;
-     word len;
-     GC_ASSERT(start1 + bytes1 == start2);
-     if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + 
bytes2);
-     if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
-     if (0 == start_addr) return;
-     len = end_addr - start_addr;
- #   if defined(MSWIN32) || defined(MSWINCE)
-       while (len != 0) {
-           MEMORY_BASIC_INFORMATION mem_info;
-         GC_word free_len;
-         if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
-             != sizeof(mem_info))
-             ABORT("Weird VirtualQuery result");
-         free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
-         if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
-             ABORT("VirtualFree failed");
-         GC_unmapped_bytes += free_len;
-         start_addr += free_len;
-         len -= free_len;
-       }
- #   else
-       if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
-       GC_unmapped_bytes += len;
- #   endif
- }
- 
- #endif /* USE_MUNMAP */
- 
- /* Routine for pushing any additional roots.  In THREADS      */
- /* environment, this is also responsible for marking from     */
- /* thread stacks.                                             */
- #ifndef THREADS
- void (*GC_push_other_roots)() = 0;
- #else /* THREADS */
- 
- # ifdef PCR
- PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
- {
-     struct PCR_ThCtl_TInfoRep info;
-     PCR_ERes result;
-     
-     info.ti_stkLow = info.ti_stkHi = 0;
-     result = PCR_ThCtl_GetInfo(t, &info);
-     GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
-     return(result);
- }
- 
- /* Push the contents of an old object. We treat this as stack */
- /* data only becasue that makes it robust against mark stack  */
- /* overflow.                                                  */
- PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
- {
-     GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
-     return(PCR_ERes_okay);
- }
- 
- 
- void GC_default_push_other_roots GC_PROTO((void))
- {
-     /* Traverse data allocated by previous memory managers.           */
-       {
-         extern struct PCR_MM_ProcsRep * GC_old_allocator;
-         
-         if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
-                                                  GC_push_old_obj, 0)
-             != PCR_ERes_okay) {
-             ABORT("Old object enumeration failed");
-         }
-       }
-     /* Traverse all thread stacks. */
-       if (PCR_ERes_IsErr(
-                 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
-               || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 
0))) {
-               ABORT("Thread stack marking failed\n");
-       }
- }
- 
- # endif /* PCR */
- 
- # ifdef SRC_M3
- 
- # ifdef ALL_INTERIOR_POINTERS
-     --> misconfigured
- # endif
- 
- void GC_push_thread_structures GC_PROTO((void))
- {
-     /* Not our responsibibility. */
- }
- 
- extern void ThreadF__ProcessStacks();
- 
- void GC_push_thread_stack(start, stop)
- word start, stop;
- {
-    GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
- }
- 
- /* Push routine with M3 specific calling convention. */
- GC_m3_push_root(dummy1, p, dummy2, dummy3)
- word *p;
- ptr_t dummy1, dummy2;
- int dummy3;
- {
-     word q = *p;
-     
-     GC_PUSH_ONE_STACK(q, p);
- }
- 
- /* M3 set equivalent to RTHeap.TracedRefTypes */
- typedef struct { int elts[1]; }  RefTypeSet;
- RefTypeSet GC_TracedRefTypes = {{0x1}};
- 
- void GC_default_push_other_roots GC_PROTO((void))
- {
-     /* Use the M3 provided routine for finding static roots.   */
-     /* This is a bit dubious, since it presumes no C roots.    */
-     /* We handle the collector roots explicitly in GC_push_roots */
-               RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
-       if (GC_words_allocd > 0) {
-           ThreadF__ProcessStacks(GC_push_thread_stack);
-       }
-       /* Otherwise this isn't absolutely necessary, and we have       */
-       /* startup ordering problems.                                   */
- }
- 
- # endif /* SRC_M3 */
- 
- # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
-      defined(GC_WIN32_THREADS)
- 
- extern void GC_push_all_stacks();
- 
- void GC_default_push_other_roots GC_PROTO((void))
- {
-     GC_push_all_stacks();
- }
- 
- # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
- 
- void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
- 
- #endif /* THREADS */
- 
- /*
-  * Routines for accessing dirty  bits on virtual pages.
-  * We plan to eventually implement four strategies for doing so:
-  * DEFAULT_VDB:       A simple dummy implementation that treats every page
-  *            as possibly dirty.  This makes incremental collection
-  *            useless, but the implementation is still correct.
-  * PCR_VDB:   Use PPCRs virtual dirty bit facility.
-  * PROC_VDB:  Use the /proc facility for reading dirty bits.  Only
-  *            works under some SVR4 variants.  Even then, it may be
-  *            too slow to be entirely satisfactory.  Requires reading
-  *            dirty bits for entire address space.  Implementations tend
-  *            to assume that the client is a (slow) debugger.
-  * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
-  *            dirtied pages.  The implementation (and implementability)
-  *            is highly system dependent.  This usually fails when system
-  *            calls write to a protected page.  We prevent the read system
-  *            call from doing so.  It is the clients responsibility to
-  *            make sure that other system calls are similarly protected
-  *            or write only to the stack.
-  */
-  
- GC_bool GC_dirty_maintained = FALSE;
- 
- # ifdef DEFAULT_VDB
- 
- /* All of the following assume the allocation lock is held, and       */
- /* signals are disabled.                                      */
- 
- /* The client asserts that unallocated pages in the heap are never    */
- /* written.                                                           */
- 
- /* Initialize virtual dirty bit implementation.                       */
- void GC_dirty_init()
- {
-     GC_dirty_maintained = TRUE;
- }
- 
- /* Retrieve system dirty bits for heap to a local buffer.     */
- /* Restore the systems notion of which pages are dirty.               */
- void GC_read_dirty()
- {}
- 
- /* Is the HBLKSIZE sized page at h marked dirty in the local buffer?  */
- /* If the actual page size is different, this returns TRUE if any     */
- /* of the pages overlapping h are dirty.  This routine may err on the */
- /* side of labelling pages as dirty (and this implementation does).   */
- /*ARGSUSED*/
- GC_bool GC_page_was_dirty(h)
- struct hblk *h;
- {
-     return(TRUE);
- }
- 
- /*
-  * The following two routines are typically less crucial.  They matter
-  * most with large dynamic libraries, or if we can't accurately identify
-  * stacks, e.g. under Solaris 2.X.  Otherwise the following default
-  * versions are adequate.
-  */
-  
- /* Could any valid GC heap pointer ever have been written to this page?       
*/
- /*ARGSUSED*/
- GC_bool GC_page_was_ever_dirty(h)
- struct hblk *h;
- {
-     return(TRUE);
- }
- 
- /* Reset the n pages starting at h to "was never dirty" status.       */
- void GC_is_fresh(h, n)
- struct hblk *h;
- word n;
- {
- }
- 
- /* A call that:                                               */
- /* I) hints that [h, h+nblocks) is about to be written.       */
- /* II) guarantees that protection is removed.         */
- /* (I) may speed up some dirty bit implementations.   */
- /* (II) may be essential if we need to ensure that    */
- /* pointer-free system call buffers in the heap are   */
- /* not protected.                                     */
- /*ARGSUSED*/
- void GC_remove_protection(h, nblocks, is_ptrfree)
- struct hblk *h;
- word nblocks;
- GC_bool is_ptrfree;
- {
- }
- 
- # endif /* DEFAULT_VDB */
- 
- 
- # ifdef MPROTECT_VDB
- 
- /*
-  * See DEFAULT_VDB for interface descriptions.
-  */
- 
- /*
-  * This implementation maintains dirty bits itself by catching write
-  * faults and keeping track of them.  We assume nobody else catches
-  * SIGBUS or SIGSEGV.  We assume no write faults occur in system calls.
-  * This means that clients must ensure that system calls don't write
-  * to the write-protected heap.  Probably the best way to do this is to
-  * ensure that system calls write at most to POINTERFREE objects in the
-  * heap, and do even that only if we are on a platform on which those
-  * are not protected.  Another alternative is to wrap system calls
-  * (see example for read below), but the current implementation holds
-  * a lock across blocking calls, making it problematic for multithreaded
-  * applications. 
-  * We assume the page size is a multiple of HBLKSIZE.
-  * We prefer them to be the same.  We avoid protecting POINTERFREE
-  * objects only if they are the same.
-  */
- 
- # if !defined(MSWIN32) && !defined(MSWINCE)
- 
- #   include <sys/mman.h>
- #   include <signal.h>
- #   include <sys/syscall.h>
- 
- #   define PROTECT(addr, len) \
-         if (mprotect((caddr_t)(addr), (size_t)(len), \
-                      PROT_READ | OPT_PROT_EXEC) < 0) { \
-           ABORT("mprotect failed"); \
-         }
- #   define UNPROTECT(addr, len) \
-         if (mprotect((caddr_t)(addr), (size_t)(len), \
-                      PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
-           ABORT("un-mprotect failed"); \
-         }
-         
- # else
- 
- #   ifndef MSWINCE
- #     include <signal.h>
- #   endif
- 
-     static DWORD protect_junk;
- #   define PROTECT(addr, len) \
-         if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
-                             &protect_junk)) { \
-           DWORD last_error = GetLastError(); \
-           GC_printf1("Last error code: %lx\n", last_error); \
-           ABORT("VirtualProtect failed"); \
-         }
- #   define UNPROTECT(addr, len) \
-         if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
-                             &protect_junk)) { \
-           ABORT("un-VirtualProtect failed"); \
-         }
-         
- # endif
- 
- #if defined(SUNOS4) || defined(FREEBSD)
-     typedef void (* SIG_PF)();
- #endif
- #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
-     || defined(MACOSX) || defined(HURD)
- # ifdef __STDC__
-     typedef void (* SIG_PF)(int);
- # else
-     typedef void (* SIG_PF)();
- # endif
- #endif
- #if defined(MSWIN32)
-     typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
- #   undef SIG_DFL
- #   define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
- #endif
- #if defined(MSWINCE)
-     typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
- #   undef SIG_DFL
- #   define SIG_DFL (SIG_PF) (-1)
- #endif
- 
- #if defined(IRIX5) || defined(OSF1) || defined(HURD)
-     typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
- #endif
- #if defined(SUNOS5SIGS)
- # ifdef HPUX
- #   define SIGINFO __siginfo
- # else
- #   define SIGINFO siginfo
- # endif
- # ifdef __STDC__
-     typedef void (* REAL_SIG_PF)(int, struct SIGINFO *, void *);
- # else
-     typedef void (* REAL_SIG_PF)();
- # endif
- #endif
- #if defined(LINUX)
- #   if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
-       typedef struct sigcontext s_c;
- #   else  /* glibc < 2.2 */
- #     include <linux/version.h>
- #     if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) 
|| defined(ARM32)
-         typedef struct sigcontext s_c;
- #     else
-         typedef struct sigcontext_struct s_c;
- #     endif
- #   endif  /* glibc < 2.2 */
- #   if defined(ALPHA) || defined(M68K)
-       typedef void (* REAL_SIG_PF)(int, int, s_c *);
- #   else
- #     if defined(IA64) || defined(HP_PA)
-         typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
- #     else
-         typedef void (* REAL_SIG_PF)(int, s_c);
- #     endif
- #   endif
- #   ifdef ALPHA
-     /* Retrieve fault address from sigcontext structure by decoding   */
-     /* instruction.                                                   */
-     char * get_fault_addr(s_c *sc) {
-         unsigned instr;
-       word faultaddr;
- 
-       instr = *((unsigned *)(sc->sc_pc));
-       faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
-       faultaddr += (word) (((int)instr << 16) >> 16);
-       return (char *)faultaddr;
-     }
- #   endif /* !ALPHA */
- # endif
- 
- # if defined(MACOSX) /* Should also test for PowerPC? */
-     typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
- 
- /* Decodes the machine instruction which was responsible for the sending of 
the
-    SIGBUS signal. Sadly this is the only way to find the faulting address 
because
-    the signal handler doesn't get it directly from the kernel (although it is
-    available on the Mach level, but droppped by the BSD personality before it
-    calls our signal handler...)
-    This code should be able to deal correctly with all PPCs starting from the
-    601 up to and including the G4s (including Velocity Engine). */
- #define EXTRACT_OP1(iw)     (((iw) & 0xFC000000) >> 26)
- #define EXTRACT_OP2(iw)     (((iw) & 0x000007FE) >> 1)
- #define EXTRACT_REGA(iw)    (((iw) & 0x001F0000) >> 16)
- #define EXTRACT_REGB(iw)    (((iw) & 0x03E00000) >> 21)
- #define EXTRACT_REGC(iw)    (((iw) & 0x0000F800) >> 11)
- #define EXTRACT_DISP(iw)    ((short *) &(iw))[1]
- 
- static char *get_fault_addr(struct sigcontext *scp)
- {
-    unsigned int   instr = *((unsigned int *) scp->sc_ir);
-    unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
-    int            disp = 0, tmp;
-    unsigned int   baseA = 0, baseB = 0;
-    unsigned int   addr, alignmask = 0xFFFFFFFF;
- 
- #ifdef GC_DEBUG_DECODER
-    GC_err_printf1("Instruction: 0x%lx\n", instr);
-    GC_err_printf1("Opcode 1: d\n", (int)EXTRACT_OP1(instr));
- #endif
-    switch(EXTRACT_OP1(instr)) {
-       case 38:   /* stb */
-       case 39:   /* stbu */
-       case 54:   /* stfd */
-       case 55:   /* stfdu */
-       case 52:   /* stfs */
-       case 53:   /* stfsu */
-       case 44:   /* sth */
-       case 45:   /* sthu */
-       case 47:   /* stmw */
-       case 36:   /* stw */
-       case 37:   /* stwu */
-             tmp = EXTRACT_REGA(instr);
-             if(tmp > 0)
-                baseA = regs[tmp];
-             disp = EXTRACT_DISP(instr);
-             break;
-       case 31:
- #ifdef GC_DEBUG_DECODER
-             GC_err_printf1("Opcode 2: %d\n", (int)EXTRACT_OP2(instr));
- #endif
-             switch(EXTRACT_OP2(instr)) {
-                case 86:    /* dcbf */
-                case 54:    /* dcbst */
-                case 1014:  /* dcbz */
-                case 247:   /* stbux */
-                case 215:   /* stbx */
-                case 759:   /* stfdux */
-                case 727:   /* stfdx */
-                case 983:   /* stfiwx */
-                case 695:   /* stfsux */
-                case 663:   /* stfsx */
-                case 918:   /* sthbrx */
-                case 439:   /* sthux */
-                case 407:   /* sthx */
-                case 661:   /* stswx */
-                case 662:   /* stwbrx */
-                case 150:   /* stwcx. */
-                case 183:   /* stwux */
-                case 151:   /* stwx */
-                case 135:   /* stvebx */
-                case 167:   /* stvehx */
-                case 199:   /* stvewx */
-                case 231:   /* stvx */
-                case 487:   /* stvxl */
-                      tmp = EXTRACT_REGA(instr);
-                      if(tmp > 0)
-                         baseA = regs[tmp];
-                         baseB = regs[EXTRACT_REGC(instr)];
-                         /* determine Altivec alignment mask */
-                         switch(EXTRACT_OP2(instr)) {
-                            case 167:   /* stvehx */
-                                  alignmask = 0xFFFFFFFE;
-                                  break;
-                            case 199:   /* stvewx */
-                                  alignmask = 0xFFFFFFFC;
-                                  break;
-                            case 231:   /* stvx */
-                                  alignmask = 0xFFFFFFF0;
-                                  break;
-                            case 487:  /* stvxl */
-                                  alignmask = 0xFFFFFFF0;
-                                  break;
-                         }
-                         break;
-                case 725:   /* stswi */
-                      tmp = EXTRACT_REGA(instr);
-                      if(tmp > 0)
-                         baseA = regs[tmp];
-                         break;
-                default:   /* ignore instruction */
- #ifdef GC_DEBUG_DECODER
-                      GC_err_printf("Ignored by inner handler\n");
- #endif
-                      return NULL;
-                     break;
-             }
-             break;
-       default:   /* ignore instruction */
- #ifdef GC_DEBUG_DECODER
-             GC_err_printf("Ignored by main handler\n");
- #endif
-             return NULL;
-             break;
-    }
-       
-    addr = (baseA + baseB) + disp;
-   addr &= alignmask;
- #ifdef GC_DEBUG_DECODER
-    GC_err_printf1("BaseA: %d\n", baseA);
-    GC_err_printf1("BaseB: %d\n", baseB);
-    GC_err_printf1("Disp:  %d\n", disp);
-    GC_err_printf1("Address: %d\n", addr);
- #endif
-    return (char *)addr;
- }
- #endif /* MACOSX */
- 
- SIG_PF GC_old_bus_handler;
- SIG_PF GC_old_segv_handler;   /* Also old MSWIN32 ACCESS_VIOLATION filter */
- 
- #ifdef THREADS
- /* We need to lock around the bitmap update in the write fault handler        
*/
- /* in order to avoid the risk of losing a bit.  We do this with a     */
- /* test-and-set spin lock if we know how to do that.  Otherwise we    */
- /* check whether we are already in the handler and use the dumb but   */
- /* safe fallback algorithm of setting all bits in the word.           */
- /* Contention should be very rare, so we do the minimum to handle it  */
- /* correctly.                                                         */
- #ifdef GC_TEST_AND_SET_DEFINED
-   static VOLATILE unsigned int fault_handler_lock = 0;
-   void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) 
{
-     while (GC_test_and_set(&fault_handler_lock)) {}
-     /* Could also revert to set_pht_entry_from_index_safe if initial  */
-     /* GC_test_and_set fails.                                         */
-     set_pht_entry_from_index(db, index);
-     GC_clear(&fault_handler_lock);
-   }
- #else /* !GC_TEST_AND_SET_DEFINED */
-   /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong,        
*/
-   /* just before we notice the conflict and correct it. We may end up   */
-   /* looking at it while it's wrong.  But this requires contention    */
-   /* exactly when a GC is triggered, which seems far less likely to   */
-   /* fail than the old code, which had no reported failures.  Thus we */
-   /* leave it this way while we think of something better, or support */
-   /* GC_test_and_set on the remaining platforms.                      */
-   static VOLATILE word currently_updating = 0;
-   void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) 
{
-     unsigned int update_dummy;
-     currently_updating = (word)(&update_dummy);
-     set_pht_entry_from_index(db, index);
-     /* If we get contention in the 10 or so instruction window here,  */
-     /* and we get stopped by a GC between the two updates, we lose!   */
-     if (currently_updating != (word)(&update_dummy)) {
-       set_pht_entry_from_index_safe(db, index);
-       /* We claim that if two threads concurrently try to update the  */
-       /* dirty bit vector, the first one to execute UPDATE_START      */
-       /* will see it changed when UPDATE_END is executed.  (Note that */
-       /* &update_dummy must differ in two distinct threads.)  It      */
-       /* will then execute set_pht_entry_from_index_safe, thus        */
-       /* returning us to a safe state, though not soon enough.        */
-     }
-   }
- #endif /* !GC_TEST_AND_SET_DEFINED */
- #else /* !THREADS */
- # define async_set_pht_entry_from_index(db, index) \
-       set_pht_entry_from_index(db, index)
- #endif /* !THREADS */
- 
- /*ARGSUSED*/
- # if defined (SUNOS4) || defined(FREEBSD)
-     void GC_write_fault_handler(sig, code, scp, addr)
-     int sig, code;
-     struct sigcontext *scp;
-     char * addr;
- #   ifdef SUNOS4
- #     define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
- #     define CODE_OK (FC_CODE(code) == FC_PROT \
-                           || (FC_CODE(code) == FC_OBJERR \
-                              && FC_ERRNO(code) == FC_PROT))
- #   endif
- #   ifdef FREEBSD
- #     define SIG_OK (sig == SIGBUS)
- #     define CODE_OK (code == BUS_PAGE_FAULT)
- #   endif
- # endif
- # if defined(IRIX5) || defined(OSF1) || defined(HURD)
- #   include <errno.h>
-     void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
- #   ifdef OSF1
- #     define SIG_OK (sig == SIGSEGV)
- #     define CODE_OK (code == 2 /* experimentally determined */)
- #   endif
- #   ifdef IRIX5
- #     define SIG_OK (sig == SIGSEGV)
- #     define CODE_OK (code == EACCES)
- #   endif
- #   ifdef HURD
- #     define SIG_OK (sig == SIGBUS || sig == SIGSEGV)         
- #     define CODE_OK  TRUE
- #   endif
- # endif
- # if defined(LINUX)
- #   if defined(ALPHA) || defined(M68K)
-       void GC_write_fault_handler(int sig, int code, s_c * sc)
- #   else
- #     if defined(IA64) || defined(HP_PA)
-         void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
- #     else
- #       if defined(ARM32)
-           void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc)
- #       else
-           void GC_write_fault_handler(int sig, s_c sc)
- #       endif
- #     endif
- #   endif
- #   define SIG_OK (sig == SIGSEGV)
- #   define CODE_OK TRUE
-       /* Empirically c.trapno == 14, on IA32, but is that useful?     */
-       /* Should probably consider alignment issues on other           */
-       /* architectures.                                               */
- # endif
- # if defined(SUNOS5SIGS)
- #  ifdef __STDC__
-     void GC_write_fault_handler(int sig, struct SIGINFO *scp, void * context)
- #  else
-     void GC_write_fault_handler(sig, scp, context)
-     int sig;
-     struct SIGINFO *scp;
-     void * context;
- #  endif
- #   ifdef HPUX
- #     define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
- #     define CODE_OK (scp -> si_code == SEGV_ACCERR) \
-                    || (scp -> si_code == BUS_ADRERR) \
-                    || (scp -> si_code == BUS_UNKNOWN) \
-                    || (scp -> si_code == SEGV_UNKNOWN) \
-                    || (scp -> si_code == BUS_OBJERR)
- #   else
- #     define SIG_OK (sig == SIGSEGV)
- #     define CODE_OK (scp -> si_code == SEGV_ACCERR)
- #   endif
- # endif
- 
- # if defined(MACOSX)
-     void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
- #   define SIG_OK (sig == SIGBUS)
- #   define CODE_OK (code == 0 /* experimentally determined */)
- # endif
- 
- # if defined(MSWIN32) || defined(MSWINCE)
-     LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
- #   define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
-                       STATUS_ACCESS_VIOLATION)
- #   define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 
1)
-                       /* Write fault */
- # endif
- {
-     register unsigned i;
- #   if defined(HURD) 
-       char *addr = (char *) code;
- #   endif
- #   ifdef IRIX5
-       char * addr = (char *) (size_t) (scp -> sc_badvaddr);
- #   endif
- #   if defined(OSF1) && defined(ALPHA)
-       char * addr = (char *) (scp -> sc_traparg_a0);
- #   endif
- #   ifdef SUNOS5SIGS
-       char * addr = (char *) (scp -> si_addr);
- #   endif
- #   ifdef LINUX
- #     if defined(I386) || defined (X86_64)
-       char * addr = (char *) (sc.cr2);
- #     else
- #     if defined(M68K)
-           char * addr = NULL;
- 
-         struct sigcontext *scp = (struct sigcontext *)(sc);
- 
-         int format = (scp->sc_formatvec >> 12) & 0xf;
-         unsigned long *framedata = (unsigned long *)(scp + 1); 
-         unsigned long ea;
- 
-         if (format == 0xa || format == 0xb) {
-               /* 68020/030 */
-               ea = framedata[2];
-         } else if (format == 7) {
-               /* 68040 */
-               ea = framedata[3];
-               if (framedata[1] & 0x08000000) {
-                       /* correct addr on misaligned access */
-                       ea = (ea+4095)&(~4095);
-               }
-         } else if (format == 4) {
-               /* 68060 */
-               ea = framedata[0];
-               if (framedata[1] & 0x08000000) {
-                       /* correct addr on misaligned access */
-                       ea = (ea+4095)&(~4095);
-               }
-         }     
-         addr = (char *)ea;
- #     else
- #       ifdef ALPHA
-             char * addr = get_fault_addr(sc);
- #       else
- #         if defined(IA64) || defined(HP_PA)
-             char * addr = si -> si_addr;
-             /* I believe this is claimed to work on all platforms for */
-             /* Linux 2.3.47 and later.  Hopefully we don't have to    */
-             /* worry about earlier kernels on IA64.                   */
- #         else
- #             if defined(POWERPC)
-                 char * addr = (char *) (sc.regs->dar);
- #           else
- #               if defined(ARM32)
-                   char * addr = (char *)sc.fault_address;
- #               else
-                 --> architecture not supported
- #               endif
- #           endif
- #         endif
- #       endif
- #     endif
- #     endif
- #   endif
- #   if defined(MACOSX)
-         char * addr = get_fault_addr(scp);
- #   endif
- #   if defined(MSWIN32) || defined(MSWINCE)
-       char * addr = (char *) (exc_info -> ExceptionRecord
-                               -> ExceptionInformation[1]);
- #     define sig SIGSEGV
- #   endif
-     
-     if (SIG_OK && CODE_OK) {
-         register struct hblk * h =
-                       (struct hblk *)((word)addr & ~(GC_page_size-1));
-         GC_bool in_allocd_block;
-         
- #     ifdef SUNOS5SIGS
-           /* Address is only within the correct physical page.        */
-           in_allocd_block = FALSE;
-             for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
-               if (HDR(h+i) != 0) {
-                 in_allocd_block = TRUE;
-               }
-             }
- #     else
-           in_allocd_block = (HDR(addr) != 0);
- #     endif
-         if (!in_allocd_block) {
-           /* Heap blocks now begin and end on page boundaries */
-             SIG_PF old_handler;
-             
-             if (sig == SIGSEGV) {
-               old_handler = GC_old_segv_handler;
-             } else {
-                 old_handler = GC_old_bus_handler;
-             }
-             if (old_handler == SIG_DFL) {
- #             if !defined(MSWIN32) && !defined(MSWINCE)
-                   GC_err_printf1("Segfault at 0x%lx\n", addr);
-                     ABORT("Unexpected bus error or segmentation fault");
- #             else
-                   return(EXCEPTION_CONTINUE_SEARCH);
- #             endif
-             } else {
- #             if defined (SUNOS4) || defined(FREEBSD)
-                   (*old_handler) (sig, code, scp, addr);
-                   return;
- #             endif
- #             if defined (SUNOS5SIGS)
-                   (*(REAL_SIG_PF)old_handler) (sig, scp, context);
-                   return;
- #             endif
- #             if defined (LINUX)
- #                 if defined(ALPHA) || defined(M68K)
-                       (*(REAL_SIG_PF)old_handler) (sig, code, sc);
- #                 else 
- #                   if defined(IA64) || defined(HP_PA)
-                       (*(REAL_SIG_PF)old_handler) (sig, si, scp);
- #                   else
-                       (*(REAL_SIG_PF)old_handler) (sig, sc);
- #                   endif
- #                 endif
-                   return;
- #             endif
- #             if defined (IRIX5) || defined(OSF1) || defined(HURD)
-                   (*(REAL_SIG_PF)old_handler) (sig, code, scp);
-                   return;
- #             endif
- #             ifdef MACOSX
-                   (*(REAL_SIG_PF)old_handler) (sig, code, scp);
- #             endif
- #             ifdef MSWIN32
-                   return((*old_handler)(exc_info));
- #             endif
-             }
-         }
-         UNPROTECT(h, GC_page_size);
-       /* We need to make sure that no collection occurs between       */
-       /* the UNPROTECT and the setting of the dirty bit.  Otherwise   */
-       /* a write by a third thread might go unnoticed.  Reversing     */
-       /* the order is just as bad, since we would end up unprotecting */
-       /* a page in a GC cycle during which it's not marked.           */
-       /* Currently we do this by disabling the thread stopping        */
-       /* signals while this handler is running.  An alternative might */
-       /* be to record the fact that we're about to unprotect, or      */
-       /* have just unprotected a page in the GC's thread structure,   */
-       /* and then to have the thread stopping code set the dirty      */
-       /* flag, if necessary.                                          */
-         for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
-             register int index = PHT_HASH(h+i);
-             
-             async_set_pht_entry_from_index(GC_dirty_pages, index);
-         }
- #     if defined(OSF1)
-           /* These reset the signal handler each time by default. */
-           signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
- #     endif
-       /* The write may not take place before dirty bits are read.     */
-       /* But then we'll fault again ...                               */
- #     if defined(MSWIN32) || defined(MSWINCE)
-           return(EXCEPTION_CONTINUE_EXECUTION);
- #     else
-           return;
- #     endif
-     }
- #if defined(MSWIN32) || defined(MSWINCE)
-     return EXCEPTION_CONTINUE_SEARCH;
- #else
-     GC_err_printf1("Segfault at 0x%lx\n", addr);
-     ABORT("Unexpected bus error or segmentation fault");
- #endif
- }
- 
- /*
-  * We hold the allocation lock.  We expect block h to be written
-  * shortly.  Ensure that all pages containing any part of the n hblks
-  * starting at h are no longer protected.  If is_ptrfree is false,
-  * also ensure that they will subsequently appear to be dirty.
-  */
- void GC_remove_protection(h, nblocks, is_ptrfree)
- struct hblk *h;
- word nblocks;
- GC_bool is_ptrfree;
- {
-     struct hblk * h_trunc;  /* Truncated to page boundary */
-     struct hblk * h_end;    /* Page boundary following block end */
-     struct hblk * current;
-     GC_bool found_clean;
-     
-     if (!GC_dirty_maintained) return;
-     h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
-     h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
-                           & ~(GC_page_size-1));
-     found_clean = FALSE;
-     for (current = h_trunc; current < h_end; ++current) {
-         int index = PHT_HASH(current);
-             
-         if (!is_ptrfree || current < h || current >= h + nblocks) {
-             async_set_pht_entry_from_index(GC_dirty_pages, index);
-         }
-     }
-     UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
- }
- 
- void GC_dirty_init()
- {
- #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
-        defined(OSF1) || defined(HURD)
-       struct sigaction        act, oldact;
-       /* We should probably specify SA_SIGINFO for Linux, and handle  */
-       /* the different architectures more uniformly.                  */
- #     if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD)
-       act.sa_flags    = SA_RESTART;
-         act.sa_handler  = (SIG_PF)GC_write_fault_handler;
- #     else
-       act.sa_flags    = SA_RESTART | SA_SIGINFO;
-         act.sa_sigaction = GC_write_fault_handler;
- #     endif
-       (void)sigemptyset(&act.sa_mask);
- #     ifdef SIG_SUSPEND
-         /* Arrange to postpone SIG_SUSPEND while we're in a write fault       
*/
-         /* handler.  This effectively makes the handler atomic w.r.t. */
-         /* stopping the world for GC.                                 */
-         (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
- #     endif /* SIG_SUSPEND */
- #    endif
- #   if defined(MACOSX)
-       struct sigaction act, oldact;
- 
-       act.sa_flags = SA_RESTART;
-       act.sa_handler = GC_write_fault_handler;
-       sigemptyset(&act.sa_mask);
- #   endif
- #   ifdef PRINTSTATS
-       GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
- #   endif
-     GC_dirty_maintained = TRUE;
-     if (GC_page_size % HBLKSIZE != 0) {
-         GC_err_printf0("Page size not multiple of HBLKSIZE\n");
-         ABORT("Page size not multiple of HBLKSIZE");
-     }
- #   if defined(SUNOS4) || defined(FREEBSD)
-       GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
-       if (GC_old_bus_handler == SIG_IGN) {
-         GC_err_printf0("Previously ignored bus error!?");
-         GC_old_bus_handler = SIG_DFL;
-       }
-       if (GC_old_bus_handler != SIG_DFL) {
- #     ifdef PRINTSTATS
-           GC_err_printf0("Replaced other SIGBUS handler\n");
- #     endif
-       }
- #   endif
- #   if defined(SUNOS4)
-       GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
-       if (GC_old_segv_handler == SIG_IGN) {
-         GC_err_printf0("Previously ignored segmentation violation!?");
-         GC_old_segv_handler = SIG_DFL;
-       }
-       if (GC_old_segv_handler != SIG_DFL) {
- #     ifdef PRINTSTATS
-           GC_err_printf0("Replaced other SIGSEGV handler\n");
- #     endif
-       }
- #   endif
- #   if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \
-        || defined(OSF1) || defined(HURD)
-       /* SUNOS5SIGS includes HPUX */
- #     if defined(GC_IRIX_THREADS)
-               sigaction(SIGSEGV, 0, &oldact);
-               sigaction(SIGSEGV, &act, 0);
- #     else
-               sigaction(SIGSEGV, &act, &oldact);
- #     endif
- #     if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO)
-       /* This is Irix 5.x, not 6.x.  Irix 5.x does not have   */
-       /* sa_sigaction.                                        */
-       GC_old_segv_handler = oldact.sa_handler;
- #     else /* Irix 6.x or SUNOS5SIGS or LINUX */
-         if (oldact.sa_flags & SA_SIGINFO) {
-           GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
-         } else {
-           GC_old_segv_handler = oldact.sa_handler;
-         }
- #     endif
-       if (GC_old_segv_handler == SIG_IGN) {
-            GC_err_printf0("Previously ignored segmentation violation!?");
-            GC_old_segv_handler = SIG_DFL;
-       }
-       if (GC_old_segv_handler != SIG_DFL) {
- #       ifdef PRINTSTATS
-         GC_err_printf0("Replaced other SIGSEGV handler\n");
- #       endif
-       }
- #   endif
- #   if defined(MACOSX) || defined(HPUX) || defined(LINUX) || defined(HURD)
-       sigaction(SIGBUS, &act, &oldact);
-       GC_old_bus_handler = oldact.sa_handler;
-       if (GC_old_bus_handler == SIG_IGN) {
-            GC_err_printf0("Previously ignored bus error!?");
-            GC_old_bus_handler = SIG_DFL;
-       }
-       if (GC_old_bus_handler != SIG_DFL) {
- #       ifdef PRINTSTATS
-         GC_err_printf0("Replaced other SIGBUS handler\n");
- #       endif
-       }
- #   endif /* MACOS || HPUX || LINUX */
- #   if defined(MSWIN32)
-       GC_old_segv_handler = 
SetUnhandledExceptionFilter(GC_write_fault_handler);
-       if (GC_old_segv_handler != NULL) {
- #     ifdef PRINTSTATS
-           GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
- #     endif
-       } else {
-           GC_old_segv_handler = SIG_DFL;
-       }
- #   endif
- }
- 
- int GC_incremental_protection_needs()
- {
-     if (GC_page_size == HBLKSIZE) {
-       return GC_PROTECTS_POINTER_HEAP;
-     } else {
-       return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
-     }
- }
- 
- #define HAVE_INCREMENTAL_PROTECTION_NEEDS
- 
- #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
- 
- #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
- void GC_protect_heap()
- {
-     ptr_t start;
-     word len;
-     struct hblk * current;
-     struct hblk * current_start;  /* Start of block to be protected. */
-     struct hblk * limit;
-     unsigned i;
-     GC_bool protect_all = 
-         (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
-     for (i = 0; i < GC_n_heap_sects; i++) {
-         start = GC_heap_sects[i].hs_start;
-         len = GC_heap_sects[i].hs_bytes;
-       if (protect_all) {
-           PROTECT(start, len);
-       } else {
-         GC_ASSERT(PAGE_ALIGNED(len))
-         GC_ASSERT(PAGE_ALIGNED(start))
-         current_start = current = (struct hblk *)start;
-         limit = (struct hblk *)(start + len);
-         while (current < limit) {
-             hdr * hhdr;
-           word nhblks;
-           GC_bool is_ptrfree;
- 
-           GC_ASSERT(PAGE_ALIGNED(current));
-           GET_HDR(current, hhdr);
-           if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
-             /* This can happen only if we're at the beginning of a    */
-             /* heap segment, and a block spans heap segments.         */
-             /* We will handle that block as part of the preceding     */
-             /* segment.                                               */
-             GC_ASSERT(current_start == current);
-             current_start = ++current;
-             continue;
-           }
-           if (HBLK_IS_FREE(hhdr)) {
-             GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
-             nhblks = divHBLKSZ(hhdr -> hb_sz);
-             is_ptrfree = TRUE;        /* dirty on alloc */
-           } else {
-             nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
-             is_ptrfree = IS_PTRFREE(hhdr);
-           }
-           if (is_ptrfree) {
-             if (current_start < current) {
-               PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
-             }
-             current_start = (current += nhblks);
-           } else {
-             current += nhblks;
-           }
-         } 
-         if (current_start < current) {
-           PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
-         }
-       }
-     }
- }
- 
- /* We assume that either the world is stopped or its OK to lose dirty */
- /* bits while this is happenning (as in GC_enable_incremental).               
*/
- void GC_read_dirty()
- {
-     BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
-           (sizeof GC_dirty_pages));
-     BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
-     GC_protect_heap();
- }
- 
- GC_bool GC_page_was_dirty(h)
- struct hblk * h;
- {
-     register word index = PHT_HASH(h);
-     
-     return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
- }
- 
- /*
-  * Acquiring the allocation lock here is dangerous, since this
-  * can be called from within GC_call_with_alloc_lock, and the cord
-  * package does so.  On systems that allow nested lock acquisition, this
-  * happens to work.
-  * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
-  */
- 
- static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
-  
- void GC_begin_syscall()
- {
-     if (!I_HOLD_LOCK()) {
-       LOCK();
-       syscall_acquired_lock = TRUE;
-     }
- }
- 
- void GC_end_syscall()
- {
-     if (syscall_acquired_lock) {
-       syscall_acquired_lock = FALSE;
-       UNLOCK();
-     }
- }
- 
- void GC_unprotect_range(addr, len)
- ptr_t addr;
- word len;
- {
-     struct hblk * start_block;
-     struct hblk * end_block;
-     register struct hblk *h;
-     ptr_t obj_start;
-     
-     if (!GC_dirty_maintained) return;
-     obj_start = GC_base(addr);
-     if (obj_start == 0) return;
-     if (GC_base(addr + len - 1) != obj_start) {
-         ABORT("GC_unprotect_range(range bigger than object)");
-     }
-     start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
-     end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
-     end_block += GC_page_size/HBLKSIZE - 1;
-     for (h = start_block; h <= end_block; h++) {
-         register word index = PHT_HASH(h);
-         
-         async_set_pht_entry_from_index(GC_dirty_pages, index);
-     }
-     UNPROTECT(start_block,
-             ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
- }
- 
- #if 0
- 
- /* We no longer wrap read by default, since that was causing too many */
- /* problems.  It is preferred that the client instead avoids writing  */
- /* to the write-protected heap with a system call.                    */
- /* This still serves as sample code if you do want to wrap system calls.*/
- 
- #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
- /* Replacement for UNIX system call.                                    */
- /* Other calls that write to the heap should be handled similarly.      */
- /* Note that this doesn't work well for blocking reads:  It will hold   */
- /* the allocation lock for the entire duration of the call. Multithreaded */
- /* clients should really ensure that it won't block, either by setting        
  */
- /* the descriptor nonblocking, or by calling select or poll first, to   */
- /* make sure that input is available.                                   */
- /* Another, preferred alternative is to ensure that system calls never        
  */
- /* write to the protected heap (see above).                             */
- # if defined(__STDC__) && !defined(SUNOS4)
- #   include <unistd.h>
- #   include <sys/uio.h>
-     ssize_t read(int fd, void *buf, size_t nbyte)
- # else
- #   ifndef LINT
-       int read(fd, buf, nbyte)
- #   else
-       int GC_read(fd, buf, nbyte)
- #   endif
-     int fd;
-     char *buf;
-     int nbyte;
- # endif
- {
-     int result;
-     
-     GC_begin_syscall();
-     GC_unprotect_range(buf, (word)nbyte);
- #   if defined(IRIX5) || defined(GC_LINUX_THREADS)
-       /* Indirect system call may not always be easily available.     */
-       /* We could call _read, but that would interfere with the       */
-       /* libpthread interception of read.                             */
-       /* On Linux, we have to be careful with the linuxthreads        */
-       /* read interception.                                           */
-       {
-           struct iovec iov;
- 
-           iov.iov_base = buf;
-           iov.iov_len = nbyte;
-           result = readv(fd, &iov, 1);
-       }
- #   else
- #     if defined(HURD)        
-       result = __read(fd, buf, nbyte);
- #     else
-       /* The two zero args at the end of this list are because one
-          IA-64 syscall() implementation actually requires six args
-          to be passed, even though they aren't always used. */
-       result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
- #     endif /* !HURD */
- #   endif
-     GC_end_syscall();
-     return(result);
- }
- #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
- 
- #if defined(GC_USE_LD_WRAP) && !defined(THREADS)
-     /* We use the GNU ld call wrapping facility.                      */
-     /* This requires that the linker be invoked with "--wrap read".   */
-     /* This can be done by passing -Wl,"--wrap read" to gcc.          */
-     /* I'm not sure that this actually wraps whatever version of read */
-     /* is called by stdio.  That code also mentions __read.           */
- #   include <unistd.h>
-     ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
-     {
-       int result;
- 
-       GC_begin_syscall();
-       GC_unprotect_range(buf, (word)nbyte);
-       result = __real_read(fd, buf, nbyte);
-       GC_end_syscall();
-       return(result);
-     }
- 
-     /* We should probably also do this for __read, or whatever stdio  */
-     /* actually calls.                                                        
*/
- #endif
- 
- #endif /* 0 */
- 
- /*ARGSUSED*/
- GC_bool GC_page_was_ever_dirty(h)
- struct hblk *h;
- {
-     return(TRUE);
- }
- 
- /* Reset the n pages starting at h to "was never dirty" status.       */
- /*ARGSUSED*/
- void GC_is_fresh(h, n)
- struct hblk *h;
- word n;
- {
- }
- 
- # else /* !MPROTECT_VDB */
- 
- #   ifdef GC_USE_LD_WRAP
-       ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
-       { return __real_read(fd, buf, nbyte); }
- #   endif
- 
- # endif /* MPROTECT_VDB */
- 
- # ifdef PROC_VDB
- 
- /*
-  * See DEFAULT_VDB for interface descriptions.
-  */
-  
- /*
-  * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
-  * from which we can read page modified bits.  This facility is far from
-  * optimal (e.g. we would like to get the info for only some of the
-  * address space), but it avoids intercepting system calls.
-  */
- 
- #include <errno.h>
- #include <sys/types.h>
- #include <sys/signal.h>
- #include <sys/fault.h>
- #include <sys/syscall.h>
- #include <sys/procfs.h>
- #include <sys/stat.h>
- 
- #define INITIAL_BUF_SZ 4096
- word GC_proc_buf_size = INITIAL_BUF_SZ;
- char *GC_proc_buf;
- 
- #ifdef GC_SOLARIS_THREADS
- /* We don't have exact sp values for threads.  So we count on */
- /* occasionally declaring stack pages to be fresh.  Thus we   */
- /* need a real implementation of GC_is_fresh.  We can't clear */
- /* entries in GC_written_pages, since that would declare all  */
- /* pages with the given hash address to be fresh.             */
- #   define MAX_FRESH_PAGES 8*1024     /* Must be power of 2 */
-     struct hblk ** GC_fresh_pages;    /* A direct mapped cache.       */
-                                       /* Collisions are dropped.      */
- 
- #   define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
- #   define ADD_FRESH_PAGE(h) \
-       GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
- #   define PAGE_IS_FRESH(h) \
-       (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
- #endif
- 
- /* Add all pages in pht2 to pht1 */
- void GC_or_pages(pht1, pht2)
- page_hash_table pht1, pht2;
- {
-     register int i;
-     
-     for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
- }
- 
- int GC_proc_fd;
- 
- void GC_dirty_init()
- {
-     int fd;
-     char buf[30];
- 
-     GC_dirty_maintained = TRUE;
-     if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
-       register int i;
-     
-         for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
- #       ifdef PRINTSTATS
-           GC_printf1("Allocated words:%lu:all pages may have been written\n",
-                      (unsigned long)
-                               (GC_words_allocd + GC_words_allocd_before_gc));
- #     endif       
-     }
-     sprintf(buf, "/proc/%d", getpid());
-     fd = open(buf, O_RDONLY);
-     if (fd < 0) {
-       ABORT("/proc open failed");
-     }
-     GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
-     close(fd);
-     syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
-     if (GC_proc_fd < 0) {
-       ABORT("/proc ioctl failed");
-     }
-     GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
- #   ifdef GC_SOLARIS_THREADS
-       GC_fresh_pages = (struct hblk **)
-         GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
-       if (GC_fresh_pages == 0) {
-           GC_err_printf0("No space for fresh pages\n");
-           EXIT();
-       }
-       BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
- #   endif
- }
- 
- /* Ignore write hints. They don't help us here.       */
- /*ARGSUSED*/
- void GC_remove_protection(h, nblocks, is_ptrfree)
- struct hblk *h;
- word nblocks;
- GC_bool is_ptrfree;
- {
- }
- 
- #ifdef GC_SOLARIS_THREADS
- #   define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
- #else
- #   define READ(fd,buf,nbytes) read(fd, buf, nbytes)
- #endif
- 
- void GC_read_dirty()
- {
-     unsigned long ps, np;
-     int nmaps;
-     ptr_t vaddr;
-     struct prasmap * map;
-     char * bufp;
-     ptr_t current_addr, limit;
-     int i;
- int dummy;
- 
-     BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
-     
-     bufp = GC_proc_buf;
-     if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
- #     ifdef PRINTSTATS
-             GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
-                      GC_proc_buf_size);
- #     endif       
-         {
-             /* Retry with larger buffer. */
-             word new_size = 2 * GC_proc_buf_size;
-             char * new_buf = GC_scratch_alloc(new_size);
-             
-             if (new_buf != 0) {
-                 GC_proc_buf = bufp = new_buf;
-                 GC_proc_buf_size = new_size;
-             }
-             if (syscall(SYS_read, GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
-                 WARN("Insufficient space for /proc read\n", 0);
-                 /* Punt:      */
-               memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
-               memset(GC_written_pages, 0xff, sizeof(page_hash_table));
- #             ifdef GC_SOLARIS_THREADS
-                   BZERO(GC_fresh_pages,
-                         MAX_FRESH_PAGES * sizeof (struct hblk *)); 
- #             endif
-               return;
-             }
-         }
-     }
-     /* Copy dirty bits into GC_grungy_pages */
-       nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
-       /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
-                    nmaps, PG_REFERENCED, PG_MODIFIED); */
-       bufp = bufp + sizeof(struct prpageheader);
-       for (i = 0; i < nmaps; i++) {
-           map = (struct prasmap *)bufp;
-           vaddr = (ptr_t)(map -> pr_vaddr);
-           ps = map -> pr_pagesize;
-           np = map -> pr_npage;
-           /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
-           limit = vaddr + ps * np;
-           bufp += sizeof (struct prasmap);
-           for (current_addr = vaddr;
-                current_addr < limit; current_addr += ps){
-               if ((*bufp++) & PG_MODIFIED) {
-                   register struct hblk * h = (struct hblk *) current_addr;
-                   
-                   while ((ptr_t)h < current_addr + ps) {
-                       register word index = PHT_HASH(h);
-                       
-                       set_pht_entry_from_index(GC_grungy_pages, index);
- #                     ifdef GC_SOLARIS_THREADS
-                         {
-                           register int slot = FRESH_PAGE_SLOT(h);
-                           
-                           if (GC_fresh_pages[slot] == h) {
-                               GC_fresh_pages[slot] = 0;
-                           }
-                         }
- #                     endif
-                       h++;
-                   }
-               }
-           }
-           bufp += sizeof(long) - 1;
-           bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
-       }
-     /* Update GC_written_pages. */
-         GC_or_pages(GC_written_pages, GC_grungy_pages);
- #   ifdef GC_SOLARIS_THREADS
-       /* Make sure that old stacks are considered completely clean    */
-       /* unless written again.                                                
*/
-       GC_old_stacks_are_fresh();
- #   endif
- }
- 
- #undef READ
- 
- GC_bool GC_page_was_dirty(h)
- struct hblk *h;
- {
-     register word index = PHT_HASH(h);
-     register GC_bool result;
-     
-     result = get_pht_entry_from_index(GC_grungy_pages, index);
- #   ifdef GC_SOLARIS_THREADS
-       if (result && PAGE_IS_FRESH(h)) result = FALSE;
-       /* This happens only if page was declared fresh since   */
-       /* the read_dirty call, e.g. because it's in an unused  */
-       /* thread stack.  It's OK to treat it as clean, in      */
-       /* that case.  And it's consistent with                 */
-       /* GC_page_was_ever_dirty.                              */
- #   endif
-     return(result);
- }
- 
- GC_bool GC_page_was_ever_dirty(h)
- struct hblk *h;
- {
-     register word index = PHT_HASH(h);
-     register GC_bool result;
-     
-     result = get_pht_entry_from_index(GC_written_pages, index);
- #   ifdef GC_SOLARIS_THREADS
-       if (result && PAGE_IS_FRESH(h)) result = FALSE;
- #   endif
-     return(result);
- }
- 
- /* Caller holds allocation lock.      */
- void GC_is_fresh(h, n)
- struct hblk *h;
- word n;
- {
- 
-     register word index;
-     
- #   ifdef GC_SOLARIS_THREADS
-       register word i;
-       
-       if (GC_fresh_pages != 0) {
-         for (i = 0; i < n; i++) {
-           ADD_FRESH_PAGE(h + i);
-         }
-       }
- #   endif
- }
- 
- # endif /* PROC_VDB */
- 
- 
- # ifdef PCR_VDB
- 
- # include "vd/PCR_VD.h"
- 
- # define NPAGES (32*1024)     /* 128 MB */
- 
- PCR_VD_DB  GC_grungy_bits[NPAGES];
- 
- ptr_t GC_vd_base;     /* Address corresponding to GC_grungy_bits[0]   */
-                       /* HBLKSIZE aligned.                            */
- 
- void GC_dirty_init()
- {
-     GC_dirty_maintained = TRUE;
-     /* For the time being, we assume the heap generally grows up */
-     GC_vd_base = GC_heap_sects[0].hs_start;
-     if (GC_vd_base == 0) {
-       ABORT("Bad initial heap segment");
-     }
-     if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
-       != PCR_ERes_okay) {
-       ABORT("dirty bit initialization failed");
-     }
- }
- 
- void GC_read_dirty()
- {
-     /* lazily enable dirty bits on newly added heap sects */
-     {
-         static int onhs = 0;
-         int nhs = GC_n_heap_sects;
-         for( ; onhs < nhs; onhs++ ) {
-             PCR_VD_WriteProtectEnable(
-                     GC_heap_sects[onhs].hs_start,
-                     GC_heap_sects[onhs].hs_bytes );
-         }
-     }
- 
- 
-     if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
-         != PCR_ERes_okay) {
-       ABORT("dirty bit read failed");
-     }
- }
- 
- GC_bool GC_page_was_dirty(h)
- struct hblk *h;
- {
-     if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
-       return(TRUE);
-     }
-     return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & 
PCR_VD_DB_dirtyBit);
- }
- 
- /*ARGSUSED*/
- void GC_remove_protection(h, nblocks, is_ptrfree)
- struct hblk *h;
- word nblocks;
- GC_bool is_ptrfree;
- {
-     PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
-     PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
- }
- 
- # endif /* PCR_VDB */
- 
- # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
-   int GC_incremental_protection_needs()
-   {
-     return GC_PROTECTS_NONE;
-   }
- # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
- 
- /*
-  * Call stack save code for debugging.
-  * Should probably be in mach_dep.c, but that requires reorganization.
-  */
- 
- /* I suspect the following works for most X86 *nix variants, so       */
- /* long as the frame pointer is explicitly stored.  In the case of gcc,       
*/
- /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is.        
*/
- #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
- #   include <features.h>
- 
-     struct frame {
-       struct frame *fr_savfp;
-       long    fr_savpc;
-         long  fr_arg[NARGS];  /* All the arguments go here.   */
-     };
- #endif
- 
- #if defined(SPARC)
- #  if defined(LINUX)
- #    include <features.h>
- 
-      struct frame {
-       long    fr_local[8];
-       long    fr_arg[6];
-       struct frame *fr_savfp;
-       long    fr_savpc;
- #       ifndef __arch64__
-         char  *fr_stret;
- #       endif
-       long    fr_argd[6];
-       long    fr_argx[0];
-      };
- #  else
- #    if defined(SUNOS4)
- #      include <machine/frame.h>
- #    else
- #      if defined (DRSNX)
- #      include <sys/sparc/frame.h>
- #      else
- #      if defined(OPENBSD) || defined(NETBSD)
- #        include <frame.h>
- #      else
- #        include <sys/frame.h>
- #      endif
- #      endif
- #    endif
- #  endif
- #  if NARGS > 6
-       --> We only know how to to get the first 6 arguments
- #  endif
- #endif /* SPARC */
- 
- #ifdef  NEED_CALLINFO
- /* Fill in the pc and argument information for up to NFRAMES of my    */
- /* callers.  Ignore my frame and my callers frame.                    */
- 
- #ifdef LINUX
- #   include <unistd.h>
- #endif
- 
- #endif /* NEED_CALLINFO */
- 
- #ifdef SAVE_CALL_CHAIN
- 
- #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
-     && defined(GC_HAVE_BUILTIN_BACKTRACE)
- 
- #include <execinfo.h>
- 
- void GC_save_callers (info) 
- struct callinfo info[NFRAMES];
- {
-   void * tmp_info[NFRAMES + 1];
-   int npcs, i;
- # define IGNORE_FRAMES 1
-   
-   /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
-   /* points to our own frame.                                         */
-   GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
-   npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
-   BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void 
*));
-   for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
- }
- 
- #else /* No builtin backtrace; do it ourselves */
- 
- #if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC)
- #  define FR_SAVFP fr_fp
- #  define FR_SAVPC fr_pc
- #else
- #  define FR_SAVFP fr_savfp
- #  define FR_SAVPC fr_savpc
- #endif
- 
- #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
- #   define BIAS 2047
- #else
- #   define BIAS 0
- #endif
- 
- void GC_save_callers (info) 
- struct callinfo info[NFRAMES];
- {
-   struct frame *frame;
-   struct frame *fp;
-   int nframes = 0;
- # ifdef I386
-     /* We assume this is turned on only with gcc as the compiler. */
-     asm("movl %%ebp,%0" : "=r"(frame));
-     fp = frame;
- # else
-     word GC_save_regs_in_stack();
- 
-     frame = (struct frame *) GC_save_regs_in_stack ();
-     fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
- #endif
-   
-    for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
-          && (nframes < NFRAMES));
-        fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
-       register int i;
-       
-       info[nframes].ci_pc = fp->FR_SAVPC;
- #     if NARGS > 0
-         for (i = 0; i < NARGS; i++) {
-         info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
-         }
- #     endif /* NARGS > 0 */
-   }
-   if (nframes < NFRAMES) info[nframes].ci_pc = 0;
- }
- 
- #endif /* No builtin backtrace */
- 
- #endif /* SAVE_CALL_CHAIN */
- 
- #ifdef NEED_CALLINFO
- 
- /* Print info to stderr.  We do NOT hold the allocation lock */
- void GC_print_callers (info)
- struct callinfo info[NFRAMES];
- {
-     register int i;
-     static int reentry_count = 0;
-     GC_bool stop = FALSE;
- 
-     LOCK();
-       ++reentry_count;
-     UNLOCK();
-     
- #   if NFRAMES == 1
-       GC_err_printf0("\tCaller at allocation:\n");
- #   else
-       GC_err_printf0("\tCall chain at allocation:\n");
- #   endif
-     for (i = 0; i < NFRAMES && !stop ; i++) {
-       if (info[i].ci_pc == 0) break;
- #     if NARGS > 0
-       {
-         int j;
- 
-         GC_err_printf0("\t\targs: ");
-         for (j = 0; j < NARGS; j++) {
-           if (j != 0) GC_err_printf0(", ");
-           GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
-                                       ~(info[i].ci_arg[j]));
-         }
-         GC_err_printf0("\n");
-       }
- #     endif
-         if (reentry_count > 1) {
-           /* We were called during an allocation during       */
-           /* a previous GC_print_callers call; punt.          */
-           GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
-           continue;
-       }
-       {
- #       ifdef LINUX
-           FILE *pipe;
- #       endif
- #       if defined(GC_HAVE_BUILTIN_BACKTRACE)
-           char **sym_name =
-             backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
-           char *name = sym_name[0];
- #       else
-           char buf[40];
-           char *name = buf;
-           sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
- #       endif
- #       if defined(LINUX) && !defined(SMALL_CONFIG)
-           /* Try for a line number. */
-           {
- #             define EXE_SZ 100
-               static char exe_name[EXE_SZ];
- #             define CMD_SZ 200
-               char cmd_buf[CMD_SZ];
- #             define RESULT_SZ 200
-               static char result_buf[RESULT_SZ];
-               size_t result_len;
-               static GC_bool found_exe_name = FALSE;
-               static GC_bool will_fail = FALSE;
-               int ret_code;
-               /* Try to get it via a hairy and expensive scheme.      */
-               /* First we get the name of the executable:             */
-               if (will_fail) goto out;
-               if (!found_exe_name) { 
-                 ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
-                 if (ret_code < 0 || ret_code >= EXE_SZ
-                     || exe_name[0] != '/') {
-                   will_fail = TRUE;   /* Dont try again. */
-                   goto out;
-                 }
-                 exe_name[ret_code] = '\0';
-                 found_exe_name = TRUE;
-               }
-               /* Then we use popen to start addr2line -e <exe> <addr> */
-               /* There are faster ways to do this, but hopefully this */
-               /* isn't time critical.                                 */
-               sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
-                                (unsigned long)info[i].ci_pc);
-               pipe = popen(cmd_buf, "r");
-               if (pipe == NULL
-                   || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
-                      == 0) {
-                 if (pipe != NULL) pclose(pipe);
-                 will_fail = TRUE;
-                 goto out;
-               }
-               if (result_buf[result_len - 1] == '\n') --result_len;
-               result_buf[result_len] = 0;
-               if (result_buf[0] == '?'
-                   || result_buf[result_len-2] == ':' 
-                      && result_buf[result_len-1] == '0') {
-                   pclose(pipe);
-                   goto out;
-               }
-               /* Get rid of embedded newline, if any.  Test for "main" */
-               {
-                  char * nl = strchr(result_buf, '\n');
-                  if (nl != NULL && nl < result_buf + result_len) {
-                    *nl = ':';
-                  }
-                  if (strncmp(result_buf, "main", nl - result_buf) == 0) {
-                    stop = TRUE;
-                  }
-               }
-               if (result_len < RESULT_SZ - 25) {
-                 /* Add in hex address */
-                   sprintf(result_buf + result_len, " [0x%lx]",
-                         (unsigned long)info[i].ci_pc);
-               }
-               name = result_buf;
-               pclose(pipe);
-               out:
-           }
- #       endif /* LINUX */
-         GC_err_printf1("\t\t%s\n", name);
- #       if defined(GC_HAVE_BUILTIN_BACKTRACE)
-           free(sym_name);  /* May call GC_free; that's OK */
- #         endif
-       }
-     }
-     LOCK();
-       --reentry_count;
-     UNLOCK();
- }
- 
- #endif /* NEED_CALLINFO */
- 
- #if defined(LINUX) && defined(__ELF__) && \
-     (!defined(SMALL_CONFIG) || defined(USE_PROC_FOR_LIBRARIES))
- #ifdef GC_USE_LD_WRAP
- #   define READ __real_read
- #else
- #   define READ read
- #endif
- 
- 
- /* Repeatedly perform a read call until the buffer is filled or       */
- /* we encounter EOF.                                          */
- ssize_t GC_repeat_read(int fd, char *buf, size_t count)
- {
-     ssize_t num_read = 0;
-     ssize_t result;
-     
-     while (num_read < count) {
-       result = READ(fd, buf + num_read, count - num_read);
-       if (result < 0) return result;
-       if (result == 0) break;
-       num_read += result;
-     }
-     return num_read;
- }
- #endif /* LINUX && ... */
- 
- 
- #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
- 
- /* Dump /proc/self/maps to GC_stderr, to enable looking up names for
-    addresses in FIND_LEAK output. */
- 
- void GC_print_address_map()
- {
-     int f;
-     int result;
-     char maps_temp[32768];
-     GC_err_printf0("---------- Begin address map ----------\n");
-         f = open("/proc/self/maps", O_RDONLY);
-         if (-1 == f) ABORT("Couldn't open /proc/self/maps");
-       do {
-           result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
-           if (result <= 0) ABORT("Couldn't read /proc/self/maps");
-           GC_err_write(maps_temp, result);
-       } while (result == sizeof(maps_temp));
-       close(f);     
-     GC_err_printf0("---------- End address map ----------\n");
- }
- 
- #endif
- 
- 
--- 0 ----




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