about summary refs log tree commit diff
path: root/linuxthreads/mutex.c
diff options
context:
space:
mode:
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)
downloadglibc-5afdca0087dad2994ad4fcdfe7f489f4dbcab7b3.tar.gz
glibc-5afdca0087dad2994ad4fcdfe7f489f4dbcab7b3.tar.xz
glibc-5afdca0087dad2994ad4fcdfe7f489f4dbcab7b3.zip
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 0000000000..d4ebcb827a
--- /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)