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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/condvar.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/condvar.c')
-rw-r--r--linuxthreads/condvar.c207
1 files changed, 207 insertions, 0 deletions
diff --git a/linuxthreads/condvar.c b/linuxthreads/condvar.c
new file mode 100644
index 0000000000..6807522edc
--- /dev/null
+++ b/linuxthreads/condvar.c
@@ -0,0 +1,207 @@
+/* Linuxthreads - a simple clone()-based implementation of Posix        */
+/* threads for Linux.                                                   */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
+/* and Pavel Krauz (krauz@fsid.cvut.cz).                                */
+/*                                                                      */
+/* 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.                 */
+
+/* Condition variables */
+
+#include <errno.h>
+#include <sched.h>
+#include <stddef.h>
+#include <sys/time.h>
+#include "pthread.h"
+#include "internals.h"
+#include "spinlock.h"
+#include "queue.h"
+#include "restart.h"
+
+static void remove_from_queue(pthread_queue * q, pthread_descr th);
+
+int pthread_cond_init(pthread_cond_t *cond,
+                      const pthread_condattr_t *cond_attr)
+{
+  cond->c_spinlock = 0;
+  queue_init(&cond->c_waiting);
+  return 0;
+}
+
+int pthread_cond_destroy(pthread_cond_t *cond)
+{
+  pthread_descr head;
+
+  acquire(&cond->c_spinlock);
+  head = cond->c_waiting.head;
+  release(&cond->c_spinlock);
+  if (head != NULL) return EBUSY;
+  return 0;
+}
+
+int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
+{
+  volatile pthread_descr self = thread_self();
+  acquire(&cond->c_spinlock);
+  enqueue(&cond->c_waiting, self);
+  release(&cond->c_spinlock);
+  pthread_mutex_unlock(mutex);
+  suspend_with_cancellation(self);
+  pthread_mutex_lock(mutex);
+  /* This is a cancellation point */
+  if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
+    /* Remove ourselves from the waiting queue if we're still on it */
+    acquire(&cond->c_spinlock);
+    remove_from_queue(&cond->c_waiting, self);
+    release(&cond->c_spinlock);
+    pthread_exit(PTHREAD_CANCELED);
+  }
+  return 0;
+}
+
+static inline int
+pthread_cond_timedwait_relative(pthread_cond_t *cond,
+				pthread_mutex_t *mutex,
+				const struct timespec * reltime)
+{
+  volatile pthread_descr self = thread_self();
+  sigset_t unblock, initial_mask;
+  int retsleep;
+  sigjmp_buf jmpbuf;
+
+  /* Wait on the condition */
+  acquire(&cond->c_spinlock);
+  enqueue(&cond->c_waiting, self);
+  release(&cond->c_spinlock);
+  pthread_mutex_unlock(mutex);
+  /* Set up a longjmp handler for the restart signal */
+  /* No need to save the signal mask, since PTHREAD_SIG_RESTART will be
+     blocked when doing the siglongjmp, and we'll just leave it blocked. */
+  if (sigsetjmp(jmpbuf, 0) == 0) {
+    self->p_signal_jmp = &jmpbuf;
+    self->p_signal = 0;
+    /* Check for cancellation */
+    if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
+      retsleep = -1;
+    } else {
+      /* Unblock the restart signal */
+      sigemptyset(&unblock);
+      sigaddset(&unblock, PTHREAD_SIG_RESTART);
+      sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask);
+      /* Sleep for the required duration */
+      retsleep = __libc_nanosleep(reltime, NULL);
+      /* Block the restart signal again */
+      sigprocmask(SIG_SETMASK, &initial_mask, NULL);
+    }
+  } else {
+    retsleep = -1;
+  }
+  self->p_signal_jmp = NULL;
+  /* Here, either the condition was signaled (self->p_signal != 0)
+                   or we got canceled (self->p_canceled != 0)
+                   or the timeout occurred (retsleep == 0)
+                   or another interrupt occurred (retsleep == -1) */
+  /* Re-acquire the spinlock */
+  acquire(&cond->c_spinlock);
+  /* This is a cancellation point */
+  if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
+    remove_from_queue(&cond->c_waiting, self);
+    release(&cond->c_spinlock);
+    pthread_mutex_lock(mutex);
+    pthread_exit(PTHREAD_CANCELED);
+  }
+  /* If not signaled: also remove ourselves and return an error code */
+  if (self->p_signal == 0) {
+    remove_from_queue(&cond->c_waiting, self);
+    release(&cond->c_spinlock);
+    pthread_mutex_lock(mutex);
+    return retsleep == 0 ? ETIMEDOUT : EINTR;
+  }
+  /* Otherwise, return normally */
+  release(&cond->c_spinlock);
+  pthread_mutex_lock(mutex);
+  return 0;
+}
+
+int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
+                           const struct timespec * abstime)
+{
+  struct timeval now;
+  struct timespec reltime;
+  /* Compute a time offset relative to now */
+  __gettimeofday(&now, NULL);
+  reltime.tv_sec = abstime->tv_sec - now.tv_sec;
+  reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000;
+  if (reltime.tv_nsec < 0) {
+    reltime.tv_nsec += 1000000000;
+    reltime.tv_sec -= 1;
+  }
+  if (reltime.tv_sec < 0) return ETIMEDOUT;
+  return pthread_cond_timedwait_relative(cond, mutex, &reltime);
+}
+
+int pthread_cond_signal(pthread_cond_t *cond)
+{
+  pthread_descr th;
+
+  acquire(&cond->c_spinlock);
+  th = dequeue(&cond->c_waiting);
+  release(&cond->c_spinlock);
+  if (th != NULL) restart(th);
+  return 0;
+}
+
+int pthread_cond_broadcast(pthread_cond_t *cond)
+{
+  pthread_queue tosignal;
+  pthread_descr th;
+
+  acquire(&cond->c_spinlock);
+  /* Copy the current state of the waiting queue and empty it */
+  tosignal = cond->c_waiting;
+  queue_init(&cond->c_waiting);
+  release(&cond->c_spinlock);
+  /* Now signal each process in the queue */
+  while ((th = dequeue(&tosignal)) != NULL) restart(th);
+  return 0;
+}
+
+int pthread_condattr_init(pthread_condattr_t *attr)
+{
+  return 0;
+}
+
+int pthread_condattr_destroy(pthread_condattr_t *attr)
+{
+  return 0;
+}
+
+/* Auxiliary function on queues */
+
+static void remove_from_queue(pthread_queue * q, pthread_descr th)
+{
+  pthread_descr t;
+
+  if (q->head == NULL) return;
+  if (q->head == th) {
+    q->head = th->p_nextwaiting;
+    if (q->head == NULL) q->tail = NULL;
+    th->p_nextwaiting = NULL;
+    return;
+  }
+  for (t = q->head; t->p_nextwaiting != NULL; t = t->p_nextwaiting) {
+    if (t->p_nextwaiting == th) {
+      t->p_nextwaiting = th->p_nextwaiting;
+      if (th->p_nextwaiting == NULL) q->tail = t;
+      th->p_nextwaiting = NULL;
+      return;
+    }
+  }
+}