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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/mutex.c
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/mutex.c')
-rw-r--r--linuxthreads/mutex.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/linuxthreads/mutex.c b/linuxthreads/mutex.c
new file mode 100644
index 0000000..d4ebcb8
--- /dev/null
+++ b/linuxthreads/mutex.c
@@ -0,0 +1,234 @@
+/* Linuxthreads - a simple clone()-based implementation of Posix */
+/* threads for Linux. */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
+/* */
+/* This program 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. */
+/* */
+/* This program 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. */
+
+/* Mutexes */
+
+#include <errno.h>
+#include <sched.h>
+#include <stddef.h>
+#include "pthread.h"
+#include "internals.h"
+#include "spinlock.h"
+#include "queue.h"
+#include "restart.h"
+
+int __pthread_mutex_init(pthread_mutex_t * mutex,
+ const pthread_mutexattr_t * mutex_attr)
+{
+ mutex->m_spinlock = 0;
+ mutex->m_count = 0;
+ mutex->m_owner = NULL;
+ mutex->m_kind =
+ mutex_attr == NULL ? PTHREAD_MUTEX_FAST_NP : mutex_attr->mutexkind;
+ queue_init(&mutex->m_waiting);
+ return 0;
+}
+weak_alias (__pthread_mutex_init, pthread_mutex_init)
+
+int __pthread_mutex_destroy(pthread_mutex_t * mutex)
+{
+ int count;
+ acquire(&mutex->m_spinlock);
+ count = mutex->m_count;
+ release(&mutex->m_spinlock);
+ if (count > 0) return EBUSY;
+ return 0;
+}
+weak_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
+
+int __pthread_mutex_trylock(pthread_mutex_t * mutex)
+{
+ pthread_descr self;
+
+ acquire(&mutex->m_spinlock);
+ switch(mutex->m_kind) {
+ case PTHREAD_MUTEX_FAST_NP:
+ if (mutex->m_count == 0) {
+ mutex->m_count = 1;
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ break;
+ case PTHREAD_MUTEX_RECURSIVE_NP:
+ self = thread_self();
+ if (mutex->m_count == 0 || mutex->m_owner == self) {
+ mutex->m_count++;
+ mutex->m_owner = self;
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ break;
+ case PTHREAD_MUTEX_ERRORCHECK_NP:
+ self = thread_self();
+ if (mutex->m_count == 0) {
+ mutex->m_count = 1;
+ mutex->m_owner = self;
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ break;
+ default:
+ release(&mutex->m_spinlock);
+ return EINVAL;
+ }
+ release(&mutex->m_spinlock);
+ return EBUSY;
+}
+weak_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
+
+int __pthread_mutex_lock(pthread_mutex_t * mutex)
+{
+ pthread_descr self;
+
+ while(1) {
+ acquire(&mutex->m_spinlock);
+ switch(mutex->m_kind) {
+ case PTHREAD_MUTEX_FAST_NP:
+ if (mutex->m_count == 0) {
+ mutex->m_count = 1;
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ self = thread_self();
+ break;
+ case PTHREAD_MUTEX_RECURSIVE_NP:
+ self = thread_self();
+ if (mutex->m_count == 0 || mutex->m_owner == self) {
+ mutex->m_count++;
+ mutex->m_owner = self;
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ break;
+ case PTHREAD_MUTEX_ERRORCHECK_NP:
+ self = thread_self();
+ if (mutex->m_count == 0) {
+ mutex->m_count = 1;
+ mutex->m_owner = self;
+ release(&mutex->m_spinlock);
+ return 0;
+ } else if (mutex->m_owner == self) {
+ release(&mutex->m_spinlock);
+ return EDEADLK;
+ }
+ break;
+ default:
+ release(&mutex->m_spinlock);
+ return EINVAL;
+ }
+ /* Suspend ourselves, then try again */
+ enqueue(&mutex->m_waiting, self);
+ release(&mutex->m_spinlock);
+ suspend(self); /* This is not a cancellation point */
+ }
+}
+weak_alias (__pthread_mutex_lock, pthread_mutex_lock)
+
+int __pthread_mutex_unlock(pthread_mutex_t * mutex)
+{
+ pthread_descr th;
+
+ acquire(&mutex->m_spinlock);
+ switch (mutex->m_kind) {
+ case PTHREAD_MUTEX_FAST_NP:
+ mutex->m_count = 0;
+ break;
+ case PTHREAD_MUTEX_RECURSIVE_NP:
+ mutex->m_count--;
+ if (mutex->m_count > 0) {
+ release(&mutex->m_spinlock);
+ return 0;
+ }
+ mutex->m_count = 0; /* so that excess unlocks do not break everything */
+ break;
+ case PTHREAD_MUTEX_ERRORCHECK_NP:
+ if (mutex->m_count == 0 || mutex->m_owner != thread_self()) {
+ release(&mutex->m_spinlock);
+ return EPERM;
+ }
+ mutex->m_count = 0;
+ break;
+ default:
+ release(&mutex->m_spinlock);
+ return EINVAL;
+ }
+ th = dequeue(&mutex->m_waiting);
+ release(&mutex->m_spinlock);
+ if (th != NULL) restart(th);
+ return 0;
+}
+weak_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
+
+int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
+{
+ attr->mutexkind = PTHREAD_MUTEX_FAST_NP;
+ return 0;
+}
+weak_alias (__pthread_mutexattr_init, pthread_mutexattr_init)
+
+int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
+{
+ return 0;
+}
+weak_alias (__pthread_mutexattr_destroy, pthread_mutexattr_destroy)
+
+int __pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind)
+{
+ if (kind != PTHREAD_MUTEX_FAST_NP
+ && kind != PTHREAD_MUTEX_RECURSIVE_NP
+ && kind != PTHREAD_MUTEX_ERRORCHECK_NP)
+ return EINVAL;
+ attr->mutexkind = kind;
+ return 0;
+}
+weak_alias (__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np)
+
+int __pthread_mutexattr_getkind_np(const pthread_mutexattr_t *attr, int *kind)
+{
+ *kind = attr->mutexkind;
+ return 0;
+}
+weak_alias (__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np)
+
+/* Once-only execution */
+
+static pthread_mutex_t once_masterlock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t once_finished = PTHREAD_COND_INITIALIZER;
+
+enum { NEVER = 0, IN_PROGRESS = 1, DONE = 2 };
+
+int __pthread_once(pthread_once_t * once_control, void (*init_routine)(void))
+{
+ /* Test without locking first for speed */
+ if (*once_control == DONE) return 0;
+ /* Lock and test again */
+ pthread_mutex_lock(&once_masterlock);
+ /* If init_routine is being called from another routine, wait until
+ it completes. */
+ while (*once_control == IN_PROGRESS) {
+ pthread_cond_wait(&once_finished, &once_masterlock);
+ }
+ /* Here *once_control is stable and either NEVER or DONE. */
+ if (*once_control == NEVER) {
+ *once_control = IN_PROGRESS;
+ pthread_mutex_unlock(&once_masterlock);
+ init_routine();
+ pthread_mutex_lock(&once_masterlock);
+ *once_control = DONE;
+ pthread_cond_broadcast(&once_finished);
+ }
+ pthread_mutex_unlock(&once_masterlock);
+ return 0;
+}
+weak_alias (__pthread_once, pthread_once)