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authorUlrich Drepper <drepper@redhat.com>1998-03-11 12:42:25 +0000
committerUlrich Drepper <drepper@redhat.com>1998-03-11 12:42:25 +0000
commit5afdca0087dad2994ad4fcdfe7f489f4dbcab7b3 (patch)
treec9c82db2ff92537b921361a02a284b0e18a594b8 /linuxthreads/man/pthread_key_create.man
parent3d76e7784700c20fc222920b2a22baba006daa15 (diff)
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LinuxThreads library.
1998-03-11 00:42  Wolfram Gloger  <wmglo@dent.med.uni-muenchen.de>
	* linuxthreads/manager.c: Enable resetting of the thread
	scheduling policy to SCHED_OTHER when the parent thread
	has a different one.
1998-02-01 13:51  Ulrich Drepper  <drepper@cygnus.com>
	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
	_POSIX_ASYNCHRONOUS_IO.
	* sysdeps/pthread/pthread.h: Define bits for Unix98 variants of
	mutexes.
	* mutex.c: Implement new mutex types.
	* internals.h: Include <signal.h>.
	* libpthread.map: Add __erno_location and __h_errno_location.
	* errno.c: Return pointer to variable actually in use.  This might
	not be the one in the thread structure.
	* internals.h (struct _pthread_descr_struct): Add new fields p_errnop
	and p_h_errnop.
	* manager.c (__pthread_manager): Set p_errnop and p_h_errnop member
	of manager thread structure.
	(pthread_handle_create): Set p_errnop and p_h_errnop members for new
	thread.
	* pthread.c: Adapt initializer for thread structures.
	(__pthread_initial_thread): Set p_errnop and p_h_errnop member.
	(__pthread_reset_main_thread): Reset p_errnop and p_h_errnop of
	current thread to global variables.
1998-01-31 17:27  Ulrich Drepper  <drepper@cygnus.com>
	* rwlock.c: New file.
	* Makefile (libpthread-routines): Add rwlock.
	* sysdeps/pthread/pthread.h: Define data structures and declare
	functions.
	* libpthread.map: Add new functions.
1997-12-18 13:50  Philip Blundell  <pb@nexus.co.uk>
	* sysdeps/arm/pt-machine.h: New file; add ARM support.
	* sysdeps/arm/Implies: likewise.
	* README: Document it.
1997-12-13  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* signals.c: Remove unneeded initializer for sigwaited, saving a
1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* semaphore.c (sem_init): Set sem_spinlock only if available.
1997-12-04 01:48  Ulrich Drepper  <drepper@cygnus.com>
	* mutex.c: Implement PTHREAD_MUTEX_CHECKERROR.
	* sysdeps/pthread/pthread.h: Define PTHREAD_MUTEX_CHECKERROR.
	* Makefile: Update from LinuxThreads 0.7.
	* internals.h. Likewise.
	* manager.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* Examples/ex3.c: Likewise.
1997-11-20 18:13  Ulrich Drepper  <drepper@cygnus.com>
	* pthread.c (__pthread_reset_main_thread): Close pipe only if still
	open.
1997-10-29 05:38  Ulrich Drepper  <drepper@cygnus.com>

	* wrapsyscall.c: Add socket functions which are also cancelation
	points.

1997-10-19 21:40  Wolfram Gloger  <wg@wolfram.dent.med.uni-muenchen.de>

	* specific.c (__libc_internal_tsd_set, __libc_internal_tsd_get):
	New functions for fast thread specific data within libc.

	* internals.h: Add new array p_libc_specific to struct
	_pthread_descr_struct.

	* sysdeps/pthread/bits/libc-lock.h: Declare new functions.

1997-10-13 05:39  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.h: Add __BEGIN_DECLS/__END_DECLS.
	Reported by Ralf Corsepius <corsepiu@faw.uni-ulm.de>.

1997-08-29 03:05  Ulrich Drepper  <drepper@cygnus.com>

	* internals.h (struct _pthread_descr_struct): Add definitions for
	two-level specific key handling.
	* manager.c (pthread_handle_create): Initialize specific memory array.
	* specific.c: Implement two-level key handling.
	* weaks.c: Don't provide dummy key handling.
	* sysdeps/pthread/bits/libc-lock.h: Typedef __libc_lock_t (no #define).
	Add definition of __libc_key_t.
	* sysdeps/unix/sysv/linux/bits/local_lim.h: Define PTHREAD_KEYS_MAX
	as 1024.
	Add definition of _POSIX_THREAD_DESTRUCTOR_ITERATIONS and
	PTHREAD_DESTRUCTOR_ITERATIONS.

	* manager.c (pthread_handle_create): Compare mmap result with
	MAP_FAILED.

	* ptfork.c: Rename to __pthread_atfork and make old name a weak alias.
	* sysdeps/pthread/bits/pthread.h: Add prototype for __pthread_atfork.

1997-08-22 19:04  Richard Henderson  <rth@cygnus.com>

	sysdeps/sparc -> sysdeps/sparc/sparc32
	sysdeps/sparc64 -> sysdeps/sparc/sparc64

	* internals.h: Change definition of THREAD_SELF to be an expression,
	not a statement that did a return.
	* sysdeps/alpha/pt-machine.h (THREAD_SELF): Update accordingly.
	* sysdeps/sparc/sparc32/pt-machine.h (THREAD_SELF, INIT_THREAD_SELF):
	Follow Solaris and use a "system reserved" register (%g6) to hold
	the thread descriptor.
	* sysdeps/sparc/sparc64/pt-machine.h: Likewise.

1997-08-03 00:09  Ulrich Drepper  <drepper@cygnus.com>

	* mutex.c: Correct pthread_once.  Patch by Xavier Leroy.
	* sysdeps/pthread/pthread.h: Add prototype for __pthread_once.
	* sysdeps/pthread/bits/pthread.h: Add macros for __libc_once.

	* semaphore.c: Include spinlock.h only when needed.

	* specific.c (__pthread_setsepcific, __pthread_getspecific): Reject
	keys for entries not in use.

	* weaks.c: Implement key handling functions for real.

1997-06-29  01:04  Richard Henderson  <richard@gnu.ai.mit.edu>

	Initial sparc64-linux support:
	* linuxthreads/sysdeps/sparc64/Implies: New file.
	* linuxthreads/sysdeps/sparc64/pt-machine.h: Likewise.

1997-06-29 00:48  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.c: Include spinlock.h at correct place.
	Patch by HJ Lu.

1997-06-13 10:06  Richard Henderson  <rth@tamu.edu>

	The Great Bit File Move:
	* sysdeps/alpha/semaphorebits.h: -> .../bits/semaphore.h.
	* sysdeps/powerpc/semaphorebits.h: Likewise.
	* sysdeps/pthread/cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/no-cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/libc-lock.h: -> bits/
	* sysdeps/pthread/stdio-lock.h: Likewise.
	* sysdeps/unix/sysv/linux/local_lim.h: Likewise.
	* sysdeps/unix/sysv/linux/posix_opt.h: Likewise.
	* semaphore.h: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* lockfile.c: <foo.h> -> <bits/foo.h>.
	* semaphore.h: Likewise.

	* Makefile: (headers): foo.h -> bits/foo.h.
	* sysdeps/pthread/Makefile: Likewise.

1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* semaphore.c (sem_init): Set sem_spinlock only if available.

	* sysdeps/m68k/pt-machine.h (testandset, __compare_and_swap): Fix
	asm constraints.

1997-04-09 03:00  Ulrich Drepper  <drepper@cygnus.com>

	Update from LinuxThreads 0.6.

	* attr.c (pthread_attr_getdetachstate): Use __sched_get_priority_max
	and __sched_get_priority_min instead of names without `__'.

	* manager.c: Rewrite large parts to implement opaque pthread_t.

	* cancel.c: Adapt for opaque pthread_t type.
	* condvar.c: Likewise.
	* errno.c: Likewise.
	* join.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* restart.h: Likewise.
	* queue.h: Likewise.
	* Examples/ex3.c: Likewise.
	* Examples/ex4.c: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* pthread.c: Accumulate time for all threads in thread manager.

	* semaphore.c: Implement fallback implementation for architectures
	sometimes missing compare-exchange operations.

	* cancel.c (pthread_cancel): Validate handle argument.
	* join.c (pthread_join): Likewise.
	(pthread_detach): Likewise.
	* signals.c (pthread_kill): Likewise.

	* spinlock.h (acquire): Use __sched_yield not sched_yield.

	* queue.h (enqueue): Enqueue thread according to priority.

	* internals.c (struct pthread_start_args): New struct for passing
	args to cloning function.
	(struct _pthread): Rename to _pthread_descr_struct and adapt for
	opaque pthread_t.

	* Examples/Makefile (clean): Pass -f option to rm.

	* sysdeps/i386/pt-machine.h: Add check for compare-exchange instruction
	and define TEST_FOR_COMPARE_AND_SWAP.
	* sysdeps/i386/i486/pt-machine.h: Removed.

	* sysdeps/unix/sysv/linux/local_lim.h (PTHREAD_THREADS_MAX): Increase
	to 1024.

1997-04-04 16:38  Ulrich Drepper  <drepper@cygnus.com>

	* restart.h (suspend): Clear p_signal before suspending.
	(suspend_with_cancellation): Likewise.
	Patch by Xavier Leroy <Xavier.Leroy@inria.fr>.

	* weaks.c: Make __pthread_key_create return 1.
	* sysdeps/pthread/libc-lock.h: Define __libc_key_create,
	__libc_getspecific, __libc_setspecific, and __libc_key_t.
	* sysdeps/pthread/stdio-lock.h: Don't care for implementation not
	using libio.

1997-03-19 15:13  Miguel de Icaza  <miguel@nuclecu.unam.mx>

	* sysdeps/sparc/pt-machine (RELEASE): Fix.

1997-03-01 07:55  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/Implies: Added.
	* sysdeps/powerpc/pt-machine.h: Added.
	* sysdeps/powerpc/semaphorebits.h: Added.

1997-01-22 01:22  Ulrich Drepper  <drepper@cygnus.com>

	* linuxtheads/pthread.c (__pthread_initial_thread): Correct
	initializer.
	(__pthread_manager_thread): Likewise.
	Reported by Andreas Jaeger.

1997-01-18 22:15  Richard Henderson  <rth@tamu.edu>

	Since sigset_t no longer fits in a register, we can't pass in the
	thread's initial mask so easily.  Take this opportunity to simplify
	the clone implementation by only accepting a single void* argument.

	* linuxthreads/manager.c (__pthread_manager): Put thread vitals
	in the thread struct instead of as arguments through clone.
	(pthread_start_thread): Look for them there.
	* linuxthreads/internals.h (struct _pthread): Add p_initial_fn,
	p_initial_fn_arg, p_initial_mask.  Fix __pthread_manager proto.
	* linuxthreads/pthread.c (pthread_initialize_manager): Revise
	clone invocation.
Diffstat (limited to 'linuxthreads/man/pthread_key_create.man')
-rw-r--r--linuxthreads/man/pthread_key_create.man151
1 files changed, 151 insertions, 0 deletions
diff --git a/linuxthreads/man/pthread_key_create.man b/linuxthreads/man/pthread_key_create.man
new file mode 100644
index 0000000000..6823e304c9
--- /dev/null
+++ b/linuxthreads/man/pthread_key_create.man
@@ -0,0 +1,151 @@
+.TH PTHREAD_SPECIFIC 3 LinuxThreads
+
+.SH NAME
+pthread_key_create, pthread_key_delete, pthread_setspecific, pthread_getspecific \- management of thread-specific data
+
+.SH SYNOPSIS
+#include <pthread.h>
+
+int pthread_key_create(pthread_key_t *key, void (*destr_function) (void *));
+
+int pthread_key_delete(pthread_key_t key);
+
+int pthread_setspecific(pthread_key_t key, const void *pointer);
+
+void * pthread_getspecific(pthread_key_t key);
+
+.SH DESCRIPTION
+
+Programs often need global or static variables that have different
+values in different threads. Since threads share one memory space,
+this cannot be achieved with regular variables. Thread-specific data
+is the POSIX threads answer to this need.
+
+Each thread possesses a private memory block, the thread-specific data
+area, or TSD area for short. This area is indexed by TSD keys. The TSD
+area associates values of type !void *! to TSD keys. TSD keys are
+common to all threads, but the value associated with a given TSD key
+can be different in each thread.
+
+For concreteness, the TSD areas can be viewed as arrays of !void *!
+pointers, TSD keys as integer indices into these arrays, and the value
+of a TSD key as the value of the corresponding array element in the
+calling thread.
+
+When a thread is created, its TSD area initially associates !NULL!
+with all keys.
+
+!pthread_key_create! allocates a new TSD key. The key is stored in the
+location pointed to by |key|. There is a limit of !PTHREAD_KEYS_MAX!
+on the number of keys allocated at a given time. The value initially
+associated with the returned key is !NULL! in all currently executing
+threads.
+
+The |destr_function| argument, if not !NULL!, specifies a destructor
+function associated with the key. When a thread terminates via
+!pthread_exit! or by cancellation, |destr_function| is called with
+arguments the value associated with the key in that thread. The
+|destr_function| is not called if that value is !NULL!. The order in
+which destructor functions are called at thread termination time is
+unspecified.
+
+Before the destructor function is called, the !NULL! value is
+associated with the key in the current thread.  A destructor function
+might, however, re-associate non-!NULL! values to that key or some
+other key.  To deal with this, if after all the destructors have been
+called for all non-!NULL! values, there are still some non-!NULL!
+values with associated destructors, then the process is repeated.  The
+LinuxThreads implementation stops the process after
+!PTHREAD_DESTRUCTOR_ITERATIONS! iterations, even if some non-!NULL!
+values with associated descriptors remain.  Other implementations may
+loop indefinitely.
+
+!pthread_key_delete! deallocates a TSD key. It does not check whether
+non-!NULL! values are associated with that key in the currently
+executing threads, nor call the destructor function associated with
+the key.
+
+!pthread_setspecific! changes the value associated with |key| in the
+calling thread, storing the given |pointer| instead.
+
+!pthread_getspecific! returns the value currently associated with
+|key| in the calling thread.
+
+.SH "RETURN VALUE"
+
+!pthread_key_create!, !pthread_key_delete!, and !pthread_setspecific!
+return 0 on success and a non-zero error code on failure. If
+successful, !pthread_key_create! stores the newly allocated key in the
+location pointed to by its |key| argument.
+
+!pthread_getspecific! returns the value associated with |key| on
+success, and !NULL! on error.
+
+.SH ERRORS
+!pthread_key_create! returns the following error code on error:
+.RS
+.TP
+!EAGAIN!
+!PTHREAD_KEYS_MAX! keys are already allocated
+.RE
+
+!pthread_key_delete! and !pthread_setspecific! return the following
+error code on error:
+.RS
+.TP
+!EINVAL!
+|key| is not a valid, allocated TSD key
+.RE
+
+!pthread_getspecific! returns !NULL! if |key| is not a valid,
+allocated TSD key.
+
+.SH AUTHOR
+Xavier Leroy <Xavier.Leroy@inria.fr>
+
+.SH "SEE ALSO"
+pthread_create(3), pthread_exit(3), pthread_testcancel(3).
+
+.SH EXAMPLE
+
+The following code fragment allocates a thread-specific array of 100
+characters, with automatic reclaimation at thread exit:
+
+.RS
+.ft 3
+.nf
+.sp
+/* Key for the thread-specific buffer */
+static pthread_key_t buffer_key;
+
+/* Once-only initialisation of the key */
+static pthread_once_t buffer_key_once = PTHREAD_ONCE_INIT;
+
+/* Allocate the thread-specific buffer */
+void buffer_alloc(void)
+{
+  pthread_once(&buffer_key_once, buffer_key_alloc);
+  pthread_setspecific(buffer_key, malloc(100));
+}
+
+/* Return the thread-specific buffer */
+char * get_buffer(void)
+{
+  return (char *) pthread_getspecific(buffer_key);
+}
+
+/* Allocate the key */
+static void buffer_key_alloc()
+{
+  pthread_key_create(&buffer_key, buffer_destroy);
+}
+
+/* Free the thread-specific buffer */
+static void buffer_destroy(void * buf)
+{
+  free(buf);
+}
+.ft
+.LP
+.RE
+.fi