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author | Ulrich Drepper <drepper@redhat.com> | 1998-03-11 12:42:25 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1998-03-11 12:42:25 +0000 |
commit | 5afdca0087dad2994ad4fcdfe7f489f4dbcab7b3 (patch) | |
tree | c9c82db2ff92537b921361a02a284b0e18a594b8 /linuxthreads/condvar.c | |
parent | 3d76e7784700c20fc222920b2a22baba006daa15 (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.c | 207 |
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; + } + } +} |