Update.
* sysdeps/unix/sysv/linux/i386/i486/pthread_barrier_wait.S (pthread_barrier_wait): After wakeup, release lock only when the last thread stopped using the barrier object. * sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S (pthread_barrier_wait): Likewise. * sysdeps/pthread/pthread_barrier_wait.c (pthread_barrier_wait): Likewise. * Makefile (tests): Add tst-barrier4. * tst-barrier4.c: New file.
This commit is contained in:
Ulrich Drepper
parent
dc39124662
commit
37c054c7c4
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@ -1,5 +1,14 @@
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2004-02-18 Ulrich Drepper <drepper@redhat.com>
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* sysdeps/unix/sysv/linux/i386/i486/pthread_barrier_wait.S
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(pthread_barrier_wait): After wakeup, release lock only when the
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last thread stopped using the barrier object.
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* sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S
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(pthread_barrier_wait): Likewise.
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* sysdeps/pthread/pthread_barrier_wait.c (pthread_barrier_wait):
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Likewise.
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* Makefile (tests): Add tst-barrier4.
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* tst-barrier4.c: New file.
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* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S
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(__pthread_cond_timedwait): Perform timeout test while holding
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@ -1,7 +1,7 @@
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Barriers pseudocode
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===================
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int pthread_barrier_wait(barrier_t * barrier);
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int pthread_barrier_wait(barrier_t *barrier);
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struct barrier_t {
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@ -21,29 +21,27 @@ struct barrier_t {
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pthread_barrier_wait(barrier_t *barrier)
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{
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unsigned int event;
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result = 0;
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lll_lock(barrier->lock);
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if (!--barrier->left) {
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barrier->left = barrier->init_count;
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barrier->curr_event++;
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futex_wake(&barrier->curr_event, INT_MAX)
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lll_unlock(barrier->lock);
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return BARRIER_SERIAL_THREAD;
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result = BARRIER_SERIAL_THREAD;
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} else {
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event = barrier->curr_event;
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do {
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lll_unlock(barrier->lock);
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futex_wait(&barrier->curr_event, event)
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lll_lock(barrier->lock);
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} while (event == barrier->curr_event);
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}
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event = barrier->curr_event;
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for (;;) {
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if (atomic_exchange_and_add (barrier->left, 1) == barrier->init_count - 1)
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lll_unlock(barrier->lock);
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futex_wait(&barrier->curr_event, event)
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lll_lock(barrier->lock);
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if (event != barrier->curr_event)
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break;
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}
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lll_unlock(barrier->lock);
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return 0;
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return result;
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}
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@ -201,7 +201,7 @@ tests = tst-attr1 tst-attr2 tst-attr3 \
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tst-key1 tst-key2 tst-key3 tst-key4 \
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tst-sem1 tst-sem2 tst-sem3 tst-sem4 tst-sem5 tst-sem6 tst-sem7 \
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tst-sem8 tst-sem9 \
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tst-barrier1 tst-barrier2 tst-barrier3 \
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tst-barrier1 tst-barrier2 tst-barrier3 tst-barrier4 \
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tst-align \
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tst-basic1 tst-basic2 tst-basic3 tst-basic4 tst-basic5 tst-basic6 \
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tst-kill1 tst-kill2 tst-kill3 tst-kill4 tst-kill5 tst-kill6 \
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@ -1,4 +1,4 @@
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/* Copyright (C) 2003 Free Software Foundation, Inc.
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/* Copyright (C) 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
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@ -29,6 +29,7 @@ pthread_barrier_wait (barrier)
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pthread_barrier_t *barrier;
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{
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struct pthread_barrier *ibarrier = (struct pthread_barrier *) barrier;
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int result = 0;
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/* Make sure we are alone. */
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lll_lock (ibarrier->lock);
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@ -39,41 +40,42 @@ pthread_barrier_wait (barrier)
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/* Are these all? */
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if (ibarrier->left == 0)
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{
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/* Yes. Restore the barrier to be empty. */
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ibarrier->left = ibarrier->init_count;
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/* Increment the event counter to avoid invalid wake-ups and
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/* Yes. Increment the event counter to avoid invalid wake-ups and
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tell the current waiters that it is their turn. */
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++ibarrier->curr_event;
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/* Wake up everybody. */
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lll_futex_wake (&ibarrier->curr_event, INT_MAX);
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/* The barrier is open for business again. */
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lll_unlock (ibarrier->lock);
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/* This is the thread which finished the serialization. */
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return PTHREAD_BARRIER_SERIAL_THREAD;
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result = PTHREAD_BARRIER_SERIAL_THREAD;
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}
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/* The number of the event we are waiting for. The barrier's event
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number must be bumped before we continue. */
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unsigned int event = ibarrier->curr_event;
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do
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else
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{
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/* Before suspending, make the barrier available to others. */
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lll_unlock (ibarrier->lock);
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/* The number of the event we are waiting for. The barrier's event
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number must be bumped before we continue. */
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unsigned int event = ibarrier->curr_event;
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do
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{
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/* Before suspending, make the barrier available to others. */
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lll_unlock (ibarrier->lock);
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/* Wait for the event counter of the barrier to change. */
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lll_futex_wait (&ibarrier->curr_event, event);
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/* Wait for the event counter of the barrier to change. */
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lll_futex_wait (&ibarrier->curr_event, event);
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/* We are going to access shared data. */
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lll_lock (ibarrier->lock);
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/* We are going to access shared data. */
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lll_lock (ibarrier->lock);
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}
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while (event == ibarrier->curr_event);
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}
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while (event == ibarrier->curr_event);
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/* We are done, let others use the barrier. */
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lll_unlock (ibarrier->lock);
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/* Make sure the init_count is stored locally or in a register. */
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unsigned int init_count = ibarrier->init_count;
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return 0;
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/* If this was the last woken thread, unlock. */
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if (atomic_exchange_and_add (ibarrier->left, 1) == init_count - 1)
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/* We are done. */
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lll_unlock (ibarrier->lock);
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return result;
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}
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@ -1,4 +1,4 @@
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/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
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/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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@ -84,16 +84,32 @@ pthread_barrier_wait:
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#endif
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je,pn 8b
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/* Increment LEFT. If this brings the count back to the
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initial count unlock the object. */
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movl $1, %edx
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movl INIT_COUNT(%ebx), %ecx
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LOCK
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xaddl %edx, LEFT(%ebx)
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subl $1, %ecx
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cmpl %ecx, %edx
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jne,pt 10f
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/* Release the mutex. We cannot release the lock before
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waking the waiting threads since otherwise a new thread might
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arrive and gets waken up, too. */
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LOCK
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subl $1, MUTEX(%ebx)
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jne 9f
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/* Note: %esi is still zero. */
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movl %esi, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
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10: movl %esi, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
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popl %esi
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popl %ebx
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ret
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/* The necessary number of threads arrived. */
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3: movl INIT_COUNT(%ebx), %eax
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movl %eax, LEFT(%ebx)
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3:
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#if CURR_EVENT == 0
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addl $1, (%ebx)
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#else
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@ -107,6 +123,16 @@ pthread_barrier_wait:
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movl $SYS_futex, %eax
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ENTER_KERNEL
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/* Increment LEFT. If this brings the count back to the
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initial count unlock the object. */
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movl $1, %edx
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movl INIT_COUNT(%ebx), %ecx
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LOCK
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xaddl %edx, LEFT(%ebx)
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subl $1, %ecx
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cmpl %ecx, %edx
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jne,pt 5f
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/* Release the mutex. We cannot release the lock before
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waking the waiting threads since otherwise a new thread might
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arrive and gets waken up, too. */
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@ -130,4 +156,8 @@ pthread_barrier_wait:
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6: leal MUTEX(%ebx), %eax
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call __lll_mutex_unlock_wake
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jmp 7b
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9: leal MUTEX(%ebx), %eax
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call __lll_mutex_unlock_wake
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jmp 10b
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.size pthread_barrier_wait,.-pthread_barrier_wait
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@ -1,4 +1,4 @@
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/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
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/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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@ -78,14 +78,29 @@ pthread_barrier_wait:
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#endif
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je 8b
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/* Note: %esi is still zero. */
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movl %esi, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
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/* Increment LEFT. If this brings the count back to the
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initial count unlock the object. */
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movl $1, %edx
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movl INIT_COUNT(%rdi), %eax
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LOCK
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xaddl %edx, LEFT(%rdi)
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subl $1, %eax
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cmpl %eax, %edx
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jne,pt 10f
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/* Release the mutex. We cannot release the lock before
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waking the waiting threads since otherwise a new thread might
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arrive and gets waken up, too. */
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LOCK
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decl MUTEX(%rdi)
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jne 9f
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10: xorl %eax, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
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retq
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/* The necessary number of threads arrived. */
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3: movl INIT_COUNT(%rdi), %eax
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movl %eax, LEFT(%rdi)
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3:
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#if CURR_EVENT == 0
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incl (%rdi)
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#else
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@ -99,6 +114,16 @@ pthread_barrier_wait:
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movq $SYS_futex, %rax
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syscall
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/* Increment LEFT. If this brings the count back to the
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initial count unlock the object. */
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movl $1, %edx
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movl INIT_COUNT(%rdi), %eax
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LOCK
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xaddl %edx, LEFT(%rdi)
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subl $1, %eax
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cmpl %eax, %edx
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jne,pt 5f
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/* Release the mutex. We cannot release the lock before
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waking the waiting threads since otherwise a new thread might
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arrive and gets waken up, too. */
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@ -117,11 +142,14 @@ pthread_barrier_wait:
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4: addq $MUTEX, %rdi
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callq __lll_mutex_unlock_wake
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subq $MUTEX, %rdi
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jmp 5b
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6: addq $MUTEX, %rdi
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callq __lll_mutex_unlock_wake
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subq $MUTEX, %rdi
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jmp 7b
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9: addq $MUTEX, %rdi
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callq __lll_mutex_unlock_wake
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jmp 10b
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.size pthread_barrier_wait,.-pthread_barrier_wait
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@ -0,0 +1,102 @@
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/* Copyright (C) 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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/* This is a test for behavior not guaranteed by POSIX. */
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#include <errno.h>
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#include <pthread.h>
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#include <stdio.h>
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static pthread_barrier_t b1;
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static pthread_barrier_t b2;
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#define N 20
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static void *
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tf (void *arg)
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{
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int round = 0;
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while (round++ < 30)
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{
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if (pthread_barrier_wait (&b1) == PTHREAD_BARRIER_SERIAL_THREAD)
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{
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pthread_barrier_destroy (&b1);
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if (pthread_barrier_init (&b1, NULL, N) != 0)
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{
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puts ("tf: 1st barrier_init failed");
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exit (1);
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}
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}
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if (pthread_barrier_wait (&b2) == PTHREAD_BARRIER_SERIAL_THREAD)
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{
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pthread_barrier_destroy (&b2);
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if (pthread_barrier_init (&b2, NULL, N) != 0)
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{
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puts ("tf: 2nd barrier_init failed");
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exit (1);
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}
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}
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}
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return NULL;
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}
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static int
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do_test (void)
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{
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int cnt;
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if (pthread_barrier_init (&b1, NULL, N) != 0)
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{
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puts ("1st barrier_init failed");
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return 1;
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}
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if (pthread_barrier_init (&b2, NULL, N) != 0)
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{
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puts ("2nd barrier_init failed");
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return 1;
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}
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pthread_t th[N - 1];
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for (cnt = 0; cnt < N - 1; ++cnt)
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if (pthread_create (&th[cnt], NULL, tf, NULL) != 0)
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{
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puts ("pthread_create failed");
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return 1;
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}
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tf (NULL);
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for (cnt = 0; cnt < N - 1; ++cnt)
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if (pthread_join (th[cnt], NULL) != 0)
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{
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puts ("pthread_join failed");
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return 1;
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}
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return 0;
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}
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#define TEST_FUNCTION do_test ()
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#include "../test-skeleton.c"
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Loading…
Reference in New Issue