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[PATCH] Implement thread destruction
|
From: |
Richard Braun |
|
Subject: |
[PATCH] Implement thread destruction |
|
Date: |
Thu, 26 Dec 2013 17:22:58 +0100 |
This change makes libpthread release almost every resource allocated for
a thread, including the kernel thread, its send right, its reply port
and its stack. This improves resource usage after peaks of activity
during which servers can create hundreds or even thousands of threads.
To achieve it, the library relies on the recently added
thread_terminate_release one-way GNU Mach RPC, which allows threads to
release their last resources along with terminating in a single
operation. The pthread_exit function unconditionally releases all the
resources it can, including other kernel objects (namely the port used
for blocking and waking up) and signal states. When releasing the
pthread structure, a reference counter is used so that joinable threads
remain available. Once the reference counter drops to 0, the pthread
structure can be recycled. Thread local storage (TLS) is also recycled
since it needs to remain allocated while terminating the thread, as it
is there that the reply port is stored. TLS could be released too, after
grabbing the reply port name, but it is difficult to make sure no RPC
involving a reply port is used afterwards, so the simpler solution of
recycling TLS was chosen.
This patch can be applied on top of the master-threadvars branch, as
a few commits are still not present in master.
---
Makefile | 2 +-
pthread/pt-alloc.c | 21 ++--------
pthread/pt-create.c | 69 +++++++++++++++----------------
pthread/pt-dealloc.c | 5 +++
pthread/pt-detach.c | 24 +++--------
pthread/pt-exit.c | 35 ++++++++--------
pthread/pt-internal.h | 36 ++++++++++-------
pthread/pt-join.c | 18 +--------
sysdeps/mach/hurd/pt-sigstate-destroy.c | 2 +-
sysdeps/mach/hurd/pt-sigstate-init.c | 18 ++++++++-
sysdeps/mach/hurd/pt-sysdep.c | 5 +++
sysdeps/mach/hurd/pt-sysdep.h | 3 +-
sysdeps/mach/pt-thread-alloc.c | 31 ++++----------
sysdeps/mach/pt-thread-dealloc.c | 3 +-
sysdeps/mach/pt-thread-halt.c | 37 -----------------
sysdeps/mach/pt-thread-start.c | 4 +-
sysdeps/mach/pt-thread-terminate.c | 72 +++++++++++++++++++++++++++++++++
17 files changed, 194 insertions(+), 191 deletions(-)
delete mode 100644 sysdeps/mach/pt-thread-halt.c
create mode 100644 sysdeps/mach/pt-thread-terminate.c
diff --git a/Makefile b/Makefile
index c57f1a0..61e59fc 100644
--- a/Makefile
+++ b/Makefile
@@ -121,7 +121,7 @@ libpthread-routines := pt-attr pt-attr-destroy
pt-attr-getdetachstate \
pt-thread-alloc \
pt-thread-dealloc \
pt-thread-start \
- pt-thread-halt \
+ pt-thread-terminate \
pt-startup \
\
pt-getconcurrency pt-setconcurrency \
diff --git a/pthread/pt-alloc.c b/pthread/pt-alloc.c
index 604d376..aa0c9e2 100644
--- a/pthread/pt-alloc.c
+++ b/pthread/pt-alloc.c
@@ -47,7 +47,7 @@ struct __pthread *__pthread_free_threads;
pthread_mutex_t __pthread_free_threads_lock;
static inline error_t
-initialize_pthread (struct __pthread *new, int recycling)
+initialize_pthread (struct __pthread *new)
{
error_t err;
@@ -55,6 +55,7 @@ initialize_pthread (struct __pthread *new, int recycling)
if (err)
return err;
+ new->nr_refs = 1;
new->cancel_lock = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
new->cancel_hook = NULL;
new->cancel_hook_arg = NULL;
@@ -62,14 +63,6 @@ initialize_pthread (struct __pthread *new, int recycling)
new->cancel_type = PTHREAD_CANCEL_DEFERRED;
new->cancel_pending = 0;
- if (recycling)
- /* Since we are recycling PTHREAD, we can assume certains things
- about PTHREAD's current state and save some cycles by not
- rewriting the memory. */
- return 0;
-
- new->stack = 0;
-
new->state_lock = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
new->state_cond = (pthread_cond_t) PTHREAD_COND_INITIALIZER;
@@ -117,12 +110,6 @@ __pthread_alloc (struct __pthread **pthread)
if (new)
{
- /* The thread may still be running. Make sure it is stopped.
- If this is the case, then the thread is either at the end of
- __pthread_dealloc or in __pthread_thread_halt. In both
- cases, we are interrupt it. */
- __pthread_thread_halt (new);
-
#ifdef ENABLE_TLS
if (new->tcb)
{
@@ -132,7 +119,7 @@ __pthread_alloc (struct __pthread **pthread)
}
#endif /* ENABLE_TLS */
- err = initialize_pthread (new, 1);
+ err = initialize_pthread (new);
if (! err)
*pthread = new;
return err;
@@ -143,7 +130,7 @@ __pthread_alloc (struct __pthread **pthread)
if (new == NULL)
return ENOMEM;
- err = initialize_pthread (new, 0);
+ err = initialize_pthread (new);
if (err)
{
free (new);
diff --git a/pthread/pt-create.c b/pthread/pt-create.c
index fd6800f..99d1b47 100644
--- a/pthread/pt-create.c
+++ b/pthread/pt-create.c
@@ -103,47 +103,30 @@ __pthread_create_internal (struct __pthread **thread,
pthread->state = (setup->detachstate == PTHREAD_CREATE_DETACHED
? PTHREAD_DETACHED : PTHREAD_JOINABLE);
- /* If the user supplied a stack, it is not our responsibility to
- setup a stack guard. */
if (setup->stackaddr)
- pthread->guardsize = 0;
- else
- pthread->guardsize = (setup->guardsize <= setup->stacksize
- ? setup->guardsize : setup->stacksize);
-
- /* Find a stack. There are several scenarios: if a detached thread
- kills itself, it has no way to deallocate its stack, thus it
- leaves PTHREAD->stack set to true. We try to reuse it here,
- however, if the user supplied a stack or changes the size,
- we cannot use the old one. Right now, we simply deallocate it. */
- if (pthread->stack)
{
- if ((setup->stackaddr && setup->stackaddr != pthread->stackaddr)
- || (setup->stacksize != pthread->stacksize))
- {
- __pthread_stack_dealloc (pthread->stackaddr,
- pthread->stacksize);
- pthread->stackaddr = setup->stackaddr;
- pthread->stacksize = setup->stacksize;
- }
+ pthread->stackaddr = setup->stackaddr;
+
+ /* If the user supplied a stack, it is not our responsibility to
+ setup a stack guard. */
+ pthread->guardsize = 0;
+ pthread->stack = 0;
}
else
{
- pthread->stacksize = setup->stacksize;
-
- if (setup->stackaddr)
- pthread->stackaddr = setup->stackaddr;
- else
- {
- err = __pthread_stack_alloc (&pthread->stackaddr,
- setup->stacksize);
- if (err)
- goto failed_stack_alloc;
-
- pthread->stack = 1;
- }
+ /* Allocate a stack. */
+ err = __pthread_stack_alloc (&pthread->stackaddr,
+ setup->stacksize);
+ if (err)
+ goto failed_stack_alloc;
+
+ pthread->guardsize = (setup->guardsize <= setup->stacksize
+ ? setup->guardsize : setup->stacksize);
+ pthread->stack = 1;
}
+ pthread->stacksize = setup->stacksize;
+
/* Allocate the kernel thread and other required resources. */
err = __pthread_thread_alloc (pthread);
if (err)
@@ -169,6 +152,10 @@ __pthread_create_internal (struct __pthread **thread,
if (err)
goto failed_sigstate;
+ /* If the new thread is joinable, add a reference for the caller. */
+ if (pthread->state == PTHREAD_JOINABLE)
+ pthread->nr_refs++;
+
/* Set the new thread's signal mask and set the pending signals to
empty. POSIX says: "The signal mask shall be inherited from the
creating thread. The set of signals pending for the new thread
@@ -216,6 +203,10 @@ __pthread_create_internal (struct __pthread **thread,
return 0;
failed_starting:
+ /* If joinable, a reference was added for the caller. */
+ if (pthread->state == PTHREAD_JOINABLE)
+ __pthread_dealloc (pthread);
+
__pthread_setid (pthread->thread, NULL);
__atomic_dec (&__pthread_total);
failed_sigstate:
@@ -227,10 +218,14 @@ __pthread_create_internal (struct __pthread **thread,
failed_thread_tls_alloc:
#endif /* ENABLE_TLS */
__pthread_thread_dealloc (pthread);
- __pthread_thread_halt (pthread);
+ __pthread_thread_terminate (pthread);
+
+ /* __pthread_thread_terminate has taken care of deallocating the stack and
+ the thread structure. */
+ goto failed;
failed_thread_alloc:
- __pthread_stack_dealloc (pthread->stackaddr, pthread->stacksize);
- pthread->stack = 0;
+ if (pthread->stack)
+ __pthread_stack_dealloc (pthread->stackaddr, pthread->stacksize);
failed_stack_alloc:
__pthread_dealloc (pthread);
failed:
diff --git a/pthread/pt-dealloc.c b/pthread/pt-dealloc.c
index 92fe1fd..e324800 100644
--- a/pthread/pt-dealloc.c
+++ b/pthread/pt-dealloc.c
@@ -23,6 +23,8 @@
#include <pt-internal.h>
+#include <bits/pt-atomic.h>
+
/* List of thread structures corresponding to free thread IDs. */
extern struct __pthread *__pthread_free_threads;
extern pthread_mutex_t __pthread_free_threads_lock;
@@ -34,6 +36,9 @@ __pthread_dealloc (struct __pthread *pthread)
{
assert (pthread->state != PTHREAD_TERMINATED);
+ if (! __atomic_dec_and_test (&pthread->nr_refs))
+ return;
+
/* Withdraw this thread from the thread ID lookup table. */
__pthread_setid (pthread->thread, NULL);
diff --git a/pthread/pt-detach.c b/pthread/pt-detach.c
index 4ed8d2c..3431f1b 100644
--- a/pthread/pt-detach.c
+++ b/pthread/pt-detach.c
@@ -50,30 +50,16 @@ pthread_detach (pthread_t thread)
consequences instead of blocking indefinitely. */
pthread_cond_broadcast (&pthread->state_cond);
__pthread_mutex_unlock (&pthread->state_lock);
+
+ __pthread_dealloc (pthread);
break;
case PTHREAD_EXITED:
- /* THREAD has already exited. Make sure that nobody can
- reference it anymore, and mark it as terminated. */
-
__pthread_mutex_unlock (&pthread->state_lock);
- /* Make sure the thread is not running before we remove its
- stack. (The only possibility is that it is in a call to
- __pthread_thread_halt itself, but that is enough to cause a
- sigsegv.) */
- __pthread_thread_halt (pthread);
-
- /* Destroy the stack, the kernel resources and the control
- block. */
- if (pthread->stack)
- {
- __pthread_stack_dealloc (pthread->stackaddr, pthread->stacksize);
- pthread->stack = 0;
- }
-
- __pthread_thread_dealloc (pthread);
-
+ /* THREAD has already exited. PTHREAD remained after the thread
+ exited in order to provide the exit status, but it turns out
+ it won't be needed. */
__pthread_dealloc (pthread);
break;
diff --git a/pthread/pt-exit.c b/pthread/pt-exit.c
index 8468b80..ea61732 100644
--- a/pthread/pt-exit.c
+++ b/pthread/pt-exit.c
@@ -48,12 +48,6 @@ __pthread_exit (void *status)
pthread_setcancelstate (oldstate, &oldstate);
- /* Destory any thread specific data. */
- __pthread_destroy_specific (self);
-
- /* Destroy any signal state. */
- __pthread_sigstate_destroy (self);
-
/* Decrease the number of threads. We use an atomic operation to
make sure that only the last thread calls `exit'. */
if (__atomic_dec_and_test (&__pthread_total))
@@ -77,15 +71,8 @@ __pthread_exit (void *status)
break;
case PTHREAD_DETACHED:
- /* Make sure that nobody can reference this thread anymore, and
- mark it as terminated. Our thread ID will immediately become
- available for re-use. For obvious reasons, we cannot
- deallocate our own stack and TLS. However, it will eventually be
- reused when this thread structure is recycled. */
__pthread_mutex_unlock (&self->state_lock);
- __pthread_dealloc (self);
-
break;
case PTHREAD_JOINABLE:
@@ -105,12 +92,22 @@ __pthread_exit (void *status)
break;
}
- /* Note that after this point the resources used by this thread can
- be freed at any moment if another thread joins or detaches us.
- This means that before freeing any resources, such a thread
- should make sure that this thread is really halted. */
-
- __pthread_thread_halt (self);
+ /* Destroy any thread specific data. */
+ __pthread_destroy_specific (self);
+
+ /* Destroy any signal state. */
+ __pthread_sigstate_destroy (self);
+
+ /* Kernel resources may be used to implement synchronization objects,
+ release them late. */
+ __pthread_thread_dealloc (self);
+
+ /* Self terminating requires TLS, so defer the release of the TCB until
+ the thread structure is reused. */
+
+ /* Terminate the kernel thread, release the stack and drop the
+ self reference. */
+ __pthread_thread_terminate (self);
/* NOTREACHED */
abort ();
diff --git a/pthread/pt-internal.h b/pthread/pt-internal.h
index aeac009..bd808f3 100644
--- a/pthread/pt-internal.h
+++ b/pthread/pt-internal.h
@@ -72,6 +72,12 @@ struct __pthread
/* Thread ID. */
pthread_t thread;
+ __atomic_t nr_refs; /* Detached threads have a self reference only,
+ while joinable threads have two references.
+ These are used to keep the structure valid at
+ thread destruction. Detaching/joining a thread
+ drops a reference. */
+
/* Cancellation. */
pthread_mutex_t cancel_lock; /* Protect cancel_xxx members. */
void (*cancel_hook)(void *); /* Called to unblock a thread blocking
@@ -208,12 +214,13 @@ extern int __pthread_create_internal (struct __pthread
**__restrict pthread,
void *__restrict arg);
/* Allocate a new thread structure and a pthread thread ID (but not a
- kernel thread or a stack). */
+ kernel thread or a stack). THREAD has one reference. */
extern int __pthread_alloc (struct __pthread **thread);
/* Deallocate the thread structure. This is the dual of
- __pthread_alloc (N.B. it does not call __pthread_stack_alloc nor
- __pthread_thread_halt). */
+ __pthread_alloc (N.B. it does not call __pthread_stack_dealloc nor
+ __pthread_thread_terminate). THREAD looses one reference and is
+ released if the reference counter drops to 0. */
extern void __pthread_dealloc (struct __pthread *thread);
@@ -238,22 +245,23 @@ extern int __pthread_setup (struct __pthread *__restrict
thread,
resources) for THREAD; it must not be placed on the run queue. */
extern int __pthread_thread_alloc (struct __pthread *thread);
-/* Deallocate any kernel resources associated with THREAD. The thread
- must not be running (that is, if __pthread_thread_start was called,
- __pthread_thread_halt must first be called). This function will
- never be called by a thread on itself. In the case that a thread
- exits, its thread structure will be cached and cleaned up
- later. */
+/* Deallocate any kernel resources associated with THREAD. */
extern void __pthread_thread_dealloc (struct __pthread *thread);
/* Start THREAD making it eligible to run. */
extern int __pthread_thread_start (struct __pthread *thread);
-/* Stop the kernel thread associated with THREAD. This function may
- be called by two threads in parallel. In particular, by the thread
- itself and another thread trying to join it. This function must be
- implemented such that this is safe. */
-extern void __pthread_thread_halt (struct __pthread *thread);
+/* Terminate the kernel thread associated with THREAD, and deallocate its
+ stack. In addition, THREAD looses one reference.
+
+ This function can be called by any thread, including the target thread.
+ Since some resources that are destroyed along the kernel thread are
+ stored in thread-local variables, the conditions required for this
+ function to behave correctly are a bit unusual : as long as the target
+ thread hasn't been started, any thread can terminate it, but once it
+ has started, no other thread can terminate it, so that thread-local
+ variables created by that thread are correctly released. */
+extern void __pthread_thread_terminate (struct __pthread *thread);
/* Called by a thread just before it calls the provided start
diff --git a/pthread/pt-join.c b/pthread/pt-join.c
index 417f433..122d130 100644
--- a/pthread/pt-join.c
+++ b/pthread/pt-join.c
@@ -50,27 +50,11 @@ pthread_join (pthread_t thread, void **status)
switch (pthread->state)
{
case PTHREAD_EXITED:
- __pthread_mutex_unlock (&pthread->state_lock);
-
/* THREAD has already exited. Salvage its exit status. */
if (status)
*status = pthread->status;
- /* Make sure the thread is not running before we remove its
- stack. (The only possibility is that it is in a call to
- __pthread_thread_halt itself, but that is enough to cause a
- sigsegv.) */
- __pthread_thread_halt (pthread);
-
- /* Destroy the stack, the kernel resources and the control
- block. */
- if (pthread->stack)
- {
- __pthread_stack_dealloc (pthread->stackaddr, pthread->stacksize);
- pthread->stack = 0;
- }
-
- __pthread_thread_dealloc (pthread);
+ __pthread_mutex_unlock (&pthread->state_lock);
__pthread_dealloc (pthread);
break;
diff --git a/sysdeps/mach/hurd/pt-sigstate-destroy.c
b/sysdeps/mach/hurd/pt-sigstate-destroy.c
index 8e56c5c..d5e28d2 100644
--- a/sysdeps/mach/hurd/pt-sigstate-destroy.c
+++ b/sysdeps/mach/hurd/pt-sigstate-destroy.c
@@ -24,5 +24,5 @@
void
__pthread_sigstate_destroy (struct __pthread *thread)
{
- /* Nothing to do. */
+ _hurd_sigstate_delete (thread->kernel_thread);
}
diff --git a/sysdeps/mach/hurd/pt-sigstate-init.c
b/sysdeps/mach/hurd/pt-sigstate-init.c
index dd56d90..500b4d4 100644
--- a/sysdeps/mach/hurd/pt-sigstate-init.c
+++ b/sysdeps/mach/hurd/pt-sigstate-init.c
@@ -23,6 +23,22 @@
error_t
__pthread_sigstate_init (struct __pthread *thread)
{
- /* Nothing to do. */
+ static int do_init_global;
+
+ /* Mark the thread as a global signal receiver so as to conform with
+ the pthread semantics. However, we must be careful. The first
+ pthread created is the main thread, during libpthread initialization.
+ We must not mark it, otherwise the sigprocmask call in
+ __pthread_create would try to access _hurd_global_sigstate,
+ which is not initialized yet. When glibc runs _hurdsig_init later
+ on, the message thread is created, which must not be marked either. */
+ if (do_init_global)
+ {
+ struct hurd_sigstate *ss = _hurd_thread_sigstate (thread->kernel_thread);
+ _hurd_sigstate_set_global_rcv (ss);
+ }
+ else if (__pthread_num_threads >= 2)
+ do_init_global = 1;
+
return 0;
}
diff --git a/sysdeps/mach/hurd/pt-sysdep.c b/sysdeps/mach/hurd/pt-sysdep.c
index 09f0dcb..fd71aba 100644
--- a/sysdeps/mach/hurd/pt-sysdep.c
+++ b/sysdeps/mach/hurd/pt-sysdep.c
@@ -65,6 +65,11 @@ init_routine (void)
err = __pthread_create_internal (&thread, 0, 0, 0);
assert_perror (err);
+ /* XXX The caller copies the command line arguments and the environment
+ to the new stack. Pretend it wasn't allocated so that it remains
+ valid if the main thread terminates. */
+ thread->stack = 0;
+
___pthread_self = thread;
/* Decrease the number of threads, to take into account that the
diff --git a/sysdeps/mach/hurd/pt-sysdep.h b/sysdeps/mach/hurd/pt-sysdep.h
index 89592f9..35912a3 100644
--- a/sysdeps/mach/hurd/pt-sysdep.h
+++ b/sysdeps/mach/hurd/pt-sysdep.h
@@ -30,8 +30,7 @@
#define PTHREAD_SYSDEP_MEMBERS \
thread_t kernel_thread; \
- mach_msg_header_t wakeupmsg; \
- int have_kernel_resources;
+ mach_msg_header_t wakeupmsg;
extern __thread struct __pthread *___pthread_self;
#define _pthread_self() \
diff --git a/sysdeps/mach/pt-thread-alloc.c b/sysdeps/mach/pt-thread-alloc.c
index 794f63e..77aa933 100644
--- a/sysdeps/mach/pt-thread-alloc.c
+++ b/sysdeps/mach/pt-thread-alloc.c
@@ -67,44 +67,29 @@ create_wakeupmsg (struct __pthread *thread)
int
__pthread_thread_alloc (struct __pthread *thread)
{
- if (thread->have_kernel_resources)
- return 0;
-
+ static int do_create;
error_t err;
err = create_wakeupmsg (thread);
if (err)
return err;
- /* If there are no pthreads in the system then the pthread library
- is bootstrapping and the main thread must create initialize
- itself. The thread itself is already running, it just has not
- pthread context. We want to reuse what it already has (including
- the kernel thread), however, we must determine which thread is
- the main thread.
-
- We cannot test if __pthread_total is one as we later decrement
- before creating the signal thread. Currently, we check if
- __pthread_num_threads--the number of allocated thread
- structures--is one. __pthread_alloc has already been called in
- __pthread_create_internal for us. This predicate could be improved,
- however, it is sufficient for now. */
- if (__pthread_num_threads == 1)
+ if (! do_create)
{
assert (__pthread_total == 0);
thread->kernel_thread = __mach_thread_self ();
- /* We implicitly hold a reference drop the one that we just
- acquired. */
- __mach_port_deallocate (__mach_task_self (), thread->kernel_thread);
+ do_create = 1;
}
else
{
err = __thread_create (__mach_task_self (), &thread->kernel_thread);
if (err)
- return EAGAIN;
+ {
+ __mach_port_destroy (__mach_task_self (),
+ thread->wakeupmsg.msgh_remote_port);
+ return EAGAIN;
+ }
}
- thread->have_kernel_resources = 1;
-
return 0;
}
diff --git a/sysdeps/mach/pt-thread-dealloc.c b/sysdeps/mach/pt-thread-dealloc.c
index 55d8c4d..e977c3f 100644
--- a/sysdeps/mach/pt-thread-dealloc.c
+++ b/sysdeps/mach/pt-thread-dealloc.c
@@ -24,8 +24,7 @@
#include <pt-internal.h>
/* Deallocate any kernel resources associated with THREAD except don't
- halt the thread itself. On return, the thread will be marked as
- dead and __pthread_halt will be called. */
+ terminate the thread itself. */
void
__pthread_thread_dealloc (struct __pthread *thread)
{
diff --git a/sysdeps/mach/pt-thread-halt.c b/sysdeps/mach/pt-thread-halt.c
deleted file mode 100644
index 973cde1..0000000
--- a/sysdeps/mach/pt-thread-halt.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Deallocate the kernel thread resources. Mach version.
- Copyright (C) 2000, 2002, 2005 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
-
-#include <assert.h>
-#include <errno.h>
-#include <mach.h>
-
-#include <pt-internal.h>
-
-/* Stop the kernel thread associated with THREAD. If NEED_DEALLOC is
- true, the function must call __pthread_dealloc on THREAD.
-
- NB: The thread executing this function may be the thread which is
- being halted, thus the last action should be halting the thread
- itself. */
-void
-__pthread_thread_halt (struct __pthread *thread)
-{
- error_t err = __thread_terminate (thread->kernel_thread);
- assert_perror (err);
-}
diff --git a/sysdeps/mach/pt-thread-start.c b/sysdeps/mach/pt-thread-start.c
index 11b017f..df490ab 100644
--- a/sysdeps/mach/pt-thread-start.c
+++ b/sysdeps/mach/pt-thread-start.c
@@ -27,9 +27,10 @@
int
__pthread_thread_start (struct __pthread *thread)
{
+ static int do_start;
error_t err;
- if (__pthread_num_threads == 1)
+ if (! do_start)
{
/* The main thread is already running: do nothing. */
assert (__pthread_total == 1);
@@ -38,6 +39,7 @@ __pthread_thread_start (struct __pthread *thread)
__mach_port_deallocate (__mach_task_self (),
thread->kernel_thread);
ok; }));
+ do_start = 1;
}
else
{
diff --git a/sysdeps/mach/pt-thread-terminate.c
b/sysdeps/mach/pt-thread-terminate.c
new file mode 100644
index 0000000..a89e505
--- /dev/null
+++ b/sysdeps/mach/pt-thread-terminate.c
@@ -0,0 +1,72 @@
+/* Deallocate the kernel thread resources. Mach version.
+ Copyright (C) 2000, 2002, 2005 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <assert.h>
+#include <errno.h>
+#include <mach.h>
+
+#include <mach/mig_support.h>
+
+#include <pt-internal.h>
+
+/* Terminate the kernel thread associated with THREAD, and deallocate its
+ right reference and its stack. The function also drops a reference
+ on THREAD. */
+void
+__pthread_thread_terminate (struct __pthread *thread)
+{
+ thread_t kernel_thread, self_ktid;
+ mach_port_t reply_port;
+ void *stackaddr;
+ size_t stacksize;
+ error_t err;
+
+ kernel_thread = thread->kernel_thread;
+
+ if (thread->stack)
+ {
+ stackaddr = thread->stackaddr;
+ stacksize = thread->stacksize;
+ }
+ else
+ {
+ stackaddr = NULL;
+ stacksize = 0;
+ }
+
+ /* Each thread has its own reply port, allocated from MiG stub code calling
+ __mig_get_reply_port. Destroying it is a bit tricky because the calls
+ involved are also RPCs, causing the creation of a new reply port if
+ currently null. The __thread_terminate_release call is actually a one way
+ simple routine designed not to require a reply port. */
+ self_ktid = __mach_thread_self ();
+ reply_port = (self_ktid == kernel_thread)
+ ? __mig_get_reply_port ()
+ : MACH_PORT_NULL;
+ __mach_port_deallocate (__mach_task_self (), self_ktid);
+
+ /* Finally done with the thread structure. */
+ __pthread_dealloc (thread);
+
+ /* Terminate and release all that's left. */
+ err = __thread_terminate_release (kernel_thread, mach_task_self (),
+ kernel_thread, reply_port,
+ stackaddr, stacksize);
+ assert_perror (err);
+}
--
1.8.5.2
- [PATCH] Implement thread destruction,
Richard Braun <=