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Diffstat (limited to 'nptl/pthread_cond_timedwait.c')
-rw-r--r--nptl/pthread_cond_timedwait.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/nptl/pthread_cond_timedwait.c b/nptl/pthread_cond_timedwait.c
new file mode 100644
index 0000000000..fdbf43eae8
--- /dev/null
+++ b/nptl/pthread_cond_timedwait.c
@@ -0,0 +1,214 @@
+/* Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <endian.h>
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <pthread.h>
+#include <pthreadP.h>
+
+#include <shlib-compat.h>
+
+
+/* Cleanup handler, defined in pthread_cond_wait.c. */
+extern void __condvar_cleanup (void *arg)
+ __attribute__ ((visibility ("hidden")));
+
+struct _condvar_cleanup_buffer
+{
+ int oldtype;
+ pthread_cond_t *cond;
+ pthread_mutex_t *mutex;
+ unsigned int bc_seq;
+};
+
+int
+__pthread_cond_timedwait (cond, mutex, abstime)
+ pthread_cond_t *cond;
+ pthread_mutex_t *mutex;
+ const struct timespec *abstime;
+{
+ struct _pthread_cleanup_buffer buffer;
+ struct _condvar_cleanup_buffer cbuffer;
+ int result = 0;
+
+ /* Catch invalid parameters. */
+ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+ return EINVAL;
+
+ /* Make sure we are along. */
+ lll_mutex_lock (cond->__data.__lock);
+
+ /* Now we can release the mutex. */
+ int err = __pthread_mutex_unlock_usercnt (mutex, 0);
+ if (err)
+ {
+ lll_mutex_unlock (cond->__data.__lock);
+ return err;
+ }
+
+ /* We have one new user of the condvar. */
+ ++cond->__data.__total_seq;
+ ++cond->__data.__futex;
+ cond->__data.__nwaiters += 1 << COND_CLOCK_BITS;
+
+ /* Remember the mutex we are using here. If there is already a
+ different address store this is a bad user bug. Do not store
+ anything for pshared condvars. */
+ if (cond->__data.__mutex != (void *) ~0l)
+ cond->__data.__mutex = mutex;
+
+ /* Prepare structure passed to cancellation handler. */
+ cbuffer.cond = cond;
+ cbuffer.mutex = mutex;
+
+ /* Before we block we enable cancellation. Therefore we have to
+ install a cancellation handler. */
+ __pthread_cleanup_push (&buffer, __condvar_cleanup, &cbuffer);
+
+ /* The current values of the wakeup counter. The "woken" counter
+ must exceed this value. */
+ unsigned long long int val;
+ unsigned long long int seq;
+ val = seq = cond->__data.__wakeup_seq;
+ /* Remember the broadcast counter. */
+ cbuffer.bc_seq = cond->__data.__broadcast_seq;
+
+ while (1)
+ {
+ struct timespec rt;
+ {
+#ifdef __NR_clock_gettime
+ INTERNAL_SYSCALL_DECL (err);
+ int ret;
+ ret = INTERNAL_SYSCALL (clock_gettime, err, 2,
+ (cond->__data.__nwaiters
+ & ((1 << COND_CLOCK_BITS) - 1)),
+ &rt);
+# ifndef __ASSUME_POSIX_TIMERS
+ if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (ret, err), 0))
+ {
+ struct timeval tv;
+ (void) gettimeofday (&tv, NULL);
+
+ /* Convert the absolute timeout value to a relative timeout. */
+ rt.tv_sec = abstime->tv_sec - tv.tv_sec;
+ rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+ }
+ else
+# endif
+ {
+ /* Convert the absolute timeout value to a relative timeout. */
+ rt.tv_sec = abstime->tv_sec - rt.tv_sec;
+ rt.tv_nsec = abstime->tv_nsec - rt.tv_nsec;
+ }
+#else
+ /* Get the current time. So far we support only one clock. */
+ struct timeval tv;
+ (void) gettimeofday (&tv, NULL);
+
+ /* Convert the absolute timeout value to a relative timeout. */
+ rt.tv_sec = abstime->tv_sec - tv.tv_sec;
+ rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+#endif
+ }
+ if (rt.tv_nsec < 0)
+ {
+ rt.tv_nsec += 1000000000;
+ --rt.tv_sec;
+ }
+ /* Did we already time out? */
+ if (__builtin_expect (rt.tv_sec < 0, 0))
+ {
+ if (cbuffer.bc_seq != cond->__data.__broadcast_seq)
+ goto bc_out;
+
+ goto timeout;
+ }
+
+ unsigned int futex_val = cond->__data.__futex;
+
+ /* Prepare to wait. Release the condvar futex. */
+ lll_mutex_unlock (cond->__data.__lock);
+
+ /* Enable asynchronous cancellation. Required by the standard. */
+ cbuffer.oldtype = __pthread_enable_asynccancel ();
+
+ /* Wait until woken by signal or broadcast. */
+ err = lll_futex_timed_wait (&cond->__data.__futex,
+ futex_val, &rt);
+
+ /* Disable asynchronous cancellation. */
+ __pthread_disable_asynccancel (cbuffer.oldtype);
+
+ /* We are going to look at shared data again, so get the lock. */
+ lll_mutex_lock(cond->__data.__lock);
+
+ /* If a broadcast happened, we are done. */
+ if (cbuffer.bc_seq != cond->__data.__broadcast_seq)
+ goto bc_out;
+
+ /* Check whether we are eligible for wakeup. */
+ val = cond->__data.__wakeup_seq;
+ if (val != seq && cond->__data.__woken_seq != val)
+ break;
+
+ /* Not woken yet. Maybe the time expired? */
+ if (__builtin_expect (err == -ETIMEDOUT, 0))
+ {
+ timeout:
+ /* Yep. Adjust the counters. */
+ ++cond->__data.__wakeup_seq;
+ ++cond->__data.__futex;
+
+ /* The error value. */
+ result = ETIMEDOUT;
+ break;
+ }
+ }
+
+ /* Another thread woken up. */
+ ++cond->__data.__woken_seq;
+
+ bc_out:
+
+ cond->__data.__nwaiters -= 1 << COND_CLOCK_BITS;
+
+ /* If pthread_cond_destroy was called on this variable already,
+ notify the pthread_cond_destroy caller all waiters have left
+ and it can be successfully destroyed. */
+ if (cond->__data.__total_seq == -1ULL
+ && cond->__data.__nwaiters < (1 << COND_CLOCK_BITS))
+ lll_futex_wake (&cond->__data.__nwaiters, 1);
+
+ /* We are done with the condvar. */
+ lll_mutex_unlock (cond->__data.__lock);
+
+ /* The cancellation handling is back to normal, remove the handler. */
+ __pthread_cleanup_pop (&buffer, 0);
+
+ /* Get the mutex before returning. */
+ err = __pthread_mutex_cond_lock (mutex);
+
+ return err ?: result;
+}
+
+versioned_symbol (libpthread, __pthread_cond_timedwait, pthread_cond_timedwait,
+ GLIBC_2_3_2);