Default values for thread-specific key handling functions.

* sysdeps/mach/bits/libc-lock.h (__libc_ctf_call): New macro.
(__libc_key_create, __libc_setspecific): Use macro above.
* sysdeps/mach/hurd/bits/libc-lock.h: (__libc_ctf_call): New macro.
(__libc_key_create, __libc_setspecific): Use macro above.
* sysdeps/mach/hurd/cthreads.c (__libc_getspecific): Call
cthread_getspecific only if pthread is present.

---
 sysdeps/mach/bits/libc-lock.h      |   11 +++++++++--
 sysdeps/mach/hurd/bits/libc-lock.h |   11 +++++++++--
 sysdeps/mach/hurd/cthreads.c       |    8 +++++---
 3 files changed, 23 insertions(+), 7 deletions(-)

Index: glibc-2.21/sysdeps/mach/bits/libc-lock.h
===================================================================
--- glibc-2.21.orig/sysdeps/mach/bits/libc-lock.h
+++ glibc-2.21/sysdeps/mach/bits/libc-lock.h
@@ -124,8 +124,15 @@ struct __libc_once
 #define __libc_mutex_unlock __mutex_unlock
 #endif
 
-#define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
-#define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
+#define __libc_ctf_call(FUNC, ARGS, ELSE) \
+  (&_cthread_init_routine && _cthread_init_routine \
+    ? FUNC ARGS : ELSE)
+
+extern void *(*_cthread_init_routine) (void) __attribute__ ((weak));
+#define __libc_key_create(KEY,DEST) \
+  __libc_ctf_call (cthread_keycreate, (KEY), 1)
+#define __libc_setspecific(KEY,VAL) \
+  __libc_ctf_call (cthread_setspecific, (KEY, VAL), 0)
 void *__libc_getspecific (__libc_key_t key);
 
 /* XXX until cthreads supports recursive locks */
Index: glibc-2.21/sysdeps/mach/hurd/bits/libc-lock.h
===================================================================
--- glibc-2.21.orig/sysdeps/mach/hurd/bits/libc-lock.h
+++ glibc-2.21/sysdeps/mach/hurd/bits/libc-lock.h
@@ -197,8 +197,15 @@ struct __libc_once
 /* Type for key of thread specific data.  */
 typedef cthread_key_t __libc_key_t;
 
-#define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
-#define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
+#define __libc_ctf_call(FUNC, ARGS, ELSE) \
+  (&_cthread_init_routine && _cthread_init_routine \
+    ? FUNC ARGS : ELSE)
+
+extern void *(*_cthread_init_routine) (void) __attribute__ ((weak));
+#define __libc_key_create(KEY,DEST) \
+  __libc_ctf_call (cthread_keycreate, (KEY), 1)
+#define __libc_setspecific(KEY,VAL) \
+  __libc_ctf_call (cthread_setspecific, (KEY, VAL), 0)
 void *__libc_getspecific (__libc_key_t key);
 
 #endif /* _CTHREADS_ */
Index: glibc-2.21/sysdeps/mach/hurd/cthreads.c
===================================================================
--- glibc-2.21.orig/sysdeps/mach/hurd/cthreads.c
+++ glibc-2.21/sysdeps/mach/hurd/cthreads.c
@@ -54,12 +54,16 @@ cthread_setspecific (key, val)
 }
 
 /* Call cthread_getspecific which gets a pointer to the return value instead
-   of just returning it.  */
+   of just returning it.
+   Follow NPTL, return NULL when pthread is not loaded. */
 void *
 __libc_getspecific (key)
      cthread_key_t key;
 {
-  void *val;
-  cthread_getspecific (key, &val);
+  void *val = NULL;
+#if !IS_IN(rtld)
+  if (&_cthread_init_routine && _cthread_init_routine)
+    cthread_getspecific (key, &val);
+#endif
   return val;
 }