New pthread_barrier algorithm with improved standards compliance.
This commit is contained in:
parent
a999deb25a
commit
8084be9f8c
|
@ -1,4 +0,0 @@
|
||||||
/.build*
|
|
||||||
/src
|
|
||||||
/glibc-*.tar.gz
|
|
||||||
/glibc-*.tar.xz
|
|
|
@ -0,0 +1,987 @@
|
||||||
|
Short description: New pthread_barrier algorithm to fulfill barrier destruction requirements.
|
||||||
|
Author(s): Torvald Riegel <triegel@redhat.com>
|
||||||
|
Origin: PATCH
|
||||||
|
Bug-RHEL: NA
|
||||||
|
Bug-Fedora: NA
|
||||||
|
Bug-Upstream: #13065
|
||||||
|
Upstream status: http://patchwork.sourceware.org/patch/10062/
|
||||||
|
# commit d6533b39f004789e0de4b7d58a29f8282ee95f7b
|
||||||
|
# Author: Torvald Riegel <triegel@redhat.com>
|
||||||
|
# Date: Wed Jun 24 14:37:32 2015 +0200
|
||||||
|
#
|
||||||
|
# New pthread_barrier algorithm to fulfill barrier destruction requirements.
|
||||||
|
#
|
||||||
|
# The previous barrier implementation did not fulfill the POSIX requirements
|
||||||
|
# for when a barrier can be destroyed. Specifically, it was possible that
|
||||||
|
# threads that haven't noticed yet that their round is complete still access
|
||||||
|
# the barrier's memory, and that those accesses can happen after the barrier
|
||||||
|
# has been legally destroyed.
|
||||||
|
# The new algorithm does not have this issue, and it avoids using a lock
|
||||||
|
# internally.
|
||||||
|
#
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/Makefile
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/Makefile
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/Makefile
|
||||||
|
@@ -243,7 +243,7 @@ tests = tst-typesizes \
|
||||||
|
tst-sem1 tst-sem2 tst-sem3 tst-sem4 tst-sem5 tst-sem6 tst-sem7 \
|
||||||
|
tst-sem8 tst-sem9 tst-sem10 tst-sem11 tst-sem12 tst-sem13 tst-sem14 \
|
||||||
|
tst-sem15 \
|
||||||
|
- tst-barrier1 tst-barrier2 tst-barrier3 tst-barrier4 \
|
||||||
|
+ tst-barrier1 tst-barrier2 tst-barrier3 tst-barrier4 tst-barrier5 \
|
||||||
|
tst-align tst-align3 \
|
||||||
|
tst-basic1 tst-basic2 tst-basic3 tst-basic4 tst-basic5 tst-basic6 \
|
||||||
|
tst-basic7 \
|
||||||
|
@@ -304,7 +304,7 @@ tests-nolibpthread = tst-unload
|
||||||
|
|
||||||
|
gen-as-const-headers = pthread-errnos.sym \
|
||||||
|
lowlevelcond.sym lowlevelrwlock.sym \
|
||||||
|
- lowlevelbarrier.sym unwindbuf.sym \
|
||||||
|
+ unwindbuf.sym \
|
||||||
|
lowlevelrobustlock.sym pthread-pi-defines.sym
|
||||||
|
|
||||||
|
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/lowlevelbarrier.sym
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/lowlevelbarrier.sym
|
||||||
|
+++ /dev/null
|
||||||
|
@@ -1,12 +0,0 @@
|
||||||
|
-#include <stddef.h>
|
||||||
|
-#include <sched.h>
|
||||||
|
-#include <bits/pthreadtypes.h>
|
||||||
|
-#include "internaltypes.h"
|
||||||
|
-
|
||||||
|
---
|
||||||
|
-
|
||||||
|
-CURR_EVENT offsetof (struct pthread_barrier, curr_event)
|
||||||
|
-MUTEX offsetof (struct pthread_barrier, lock)
|
||||||
|
-LEFT offsetof (struct pthread_barrier, left)
|
||||||
|
-INIT_COUNT offsetof (struct pthread_barrier, init_count)
|
||||||
|
-PRIVATE offsetof (struct pthread_barrier, private)
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/pthread_barrier_destroy.c
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/pthread_barrier_destroy.c
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/pthread_barrier_destroy.c
|
||||||
|
@@ -18,25 +18,44 @@
|
||||||
|
|
||||||
|
#include <errno.h>
|
||||||
|
#include "pthreadP.h"
|
||||||
|
-#include <lowlevellock.h>
|
||||||
|
+#include <atomic.h>
|
||||||
|
+#include <futex-internal.h>
|
||||||
|
|
||||||
|
|
||||||
|
int
|
||||||
|
pthread_barrier_destroy (pthread_barrier_t *barrier)
|
||||||
|
{
|
||||||
|
- struct pthread_barrier *ibarrier;
|
||||||
|
- int result = EBUSY;
|
||||||
|
+ struct pthread_barrier *bar = (struct pthread_barrier *) barrier;
|
||||||
|
|
||||||
|
- ibarrier = (struct pthread_barrier *) barrier;
|
||||||
|
+ /* Destroying a barrier is only allowed if no thread is blocked on it.
|
||||||
|
+ Thus, there is no unfinished round, and all modifications to IN will
|
||||||
|
+ have happened before us (either because the calling thread took part
|
||||||
|
+ in the most recent round and thus synchronized-with all other threads
|
||||||
|
+ entering, or the program ensured this through other synchronization).
|
||||||
|
+ We must wait until all threads that entered so far have confirmed that
|
||||||
|
+ they have exited as well. To get the notification, pretend that we have
|
||||||
|
+ reached the reset threshold. */
|
||||||
|
+ unsigned int count = bar->count;
|
||||||
|
+ unsigned int max_in_before_reset = BARRIER_IN_THRESHOLD
|
||||||
|
+ - BARRIER_IN_THRESHOLD % count;
|
||||||
|
+ /* Relaxed MO sufficient because the program must have ensured that all
|
||||||
|
+ modifications happen-before this load (see above). */
|
||||||
|
+ unsigned int in = atomic_load_relaxed (&bar->in);
|
||||||
|
+ /* Trigger reset. The required acquire MO is below. */
|
||||||
|
+ if (atomic_fetch_add_relaxed (&bar->out, max_in_before_reset - in) < in)
|
||||||
|
+ {
|
||||||
|
+ /* Not all threads confirmed yet that they have exited, so another
|
||||||
|
+ thread will perform a reset. Wait until that has happened. */
|
||||||
|
+ while (in != 0)
|
||||||
|
+ {
|
||||||
|
+ futex_wait_simple (&bar->in, in, bar->shared);
|
||||||
|
+ in = atomic_load_relaxed (&bar->in);
|
||||||
|
+ }
|
||||||
|
+ }
|
||||||
|
+ /* We must ensure that memory reuse happens after all prior use of the
|
||||||
|
+ barrier (specifically, synchronize-with the reset of the barrier or the
|
||||||
|
+ confirmation of threads leaving the barrier). */
|
||||||
|
+ atomic_thread_fence_acquire ();
|
||||||
|
|
||||||
|
- lll_lock (ibarrier->lock, ibarrier->private ^ FUTEX_PRIVATE_FLAG);
|
||||||
|
-
|
||||||
|
- if (__glibc_likely (ibarrier->left == ibarrier->init_count))
|
||||||
|
- /* The barrier is not used anymore. */
|
||||||
|
- result = 0;
|
||||||
|
- else
|
||||||
|
- /* Still used, return with an error. */
|
||||||
|
- lll_unlock (ibarrier->lock, ibarrier->private ^ FUTEX_PRIVATE_FLAG);
|
||||||
|
-
|
||||||
|
- return result;
|
||||||
|
+ return 0;
|
||||||
|
}
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/pthread_barrier_init.c
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/pthread_barrier_init.c
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/pthread_barrier_init.c
|
||||||
|
@@ -18,7 +18,7 @@
|
||||||
|
|
||||||
|
#include <errno.h>
|
||||||
|
#include "pthreadP.h"
|
||||||
|
-#include <lowlevellock.h>
|
||||||
|
+#include <futex-internal.h>
|
||||||
|
#include <kernel-features.h>
|
||||||
|
|
||||||
|
|
||||||
|
@@ -34,8 +34,10 @@ __pthread_barrier_init (pthread_barrier_
|
||||||
|
{
|
||||||
|
struct pthread_barrier *ibarrier;
|
||||||
|
|
||||||
|
- /* XXX EINVAL is not specified by POSIX as a possible error code. */
|
||||||
|
- if (__glibc_unlikely (count == 0))
|
||||||
|
+ /* XXX EINVAL is not specified by POSIX as a possible error code. See
|
||||||
|
+ pthread_barrier_wait for the reason for the comparison with
|
||||||
|
+ BARRIER_IN_THRESHOLD. */
|
||||||
|
+ if (__glibc_unlikely (count == 0 || count >= BARRIER_IN_THRESHOLD))
|
||||||
|
return EINVAL;
|
||||||
|
|
||||||
|
const struct pthread_barrierattr *iattr
|
||||||
|
@@ -46,15 +48,12 @@ __pthread_barrier_init (pthread_barrier_
|
||||||
|
ibarrier = (struct pthread_barrier *) barrier;
|
||||||
|
|
||||||
|
/* Initialize the individual fields. */
|
||||||
|
- ibarrier->lock = LLL_LOCK_INITIALIZER;
|
||||||
|
- ibarrier->left = count;
|
||||||
|
- ibarrier->init_count = count;
|
||||||
|
- ibarrier->curr_event = 0;
|
||||||
|
-
|
||||||
|
- /* XXX Don't use FUTEX_SHARED or FUTEX_PRIVATE as long as there are still
|
||||||
|
- assembly implementations that expect the value determined below. */
|
||||||
|
- ibarrier->private = (iattr->pshared != PTHREAD_PROCESS_PRIVATE
|
||||||
|
- ? 0 : FUTEX_PRIVATE_FLAG);
|
||||||
|
+ ibarrier->in = 0;
|
||||||
|
+ ibarrier->out = 0;
|
||||||
|
+ ibarrier->count = count;
|
||||||
|
+ ibarrier->current_round = 0;
|
||||||
|
+ ibarrier->shared = (iattr->pshared == PTHREAD_PROCESS_PRIVATE
|
||||||
|
+ ? FUTEX_PRIVATE : FUTEX_SHARED);
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/pthread_barrier_wait.c
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/pthread_barrier_wait.c
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/pthread_barrier_wait.c
|
||||||
|
@@ -18,63 +18,206 @@
|
||||||
|
|
||||||
|
#include <errno.h>
|
||||||
|
#include <sysdep.h>
|
||||||
|
-#include <lowlevellock.h>
|
||||||
|
#include <futex-internal.h>
|
||||||
|
#include <pthreadP.h>
|
||||||
|
|
||||||
|
|
||||||
|
-/* Wait on barrier. */
|
||||||
|
+/* Wait on the barrier.
|
||||||
|
+
|
||||||
|
+ In each round, we wait for a fixed number of threads to enter the barrier
|
||||||
|
+ (COUNT). Once that has happened, exactly these threads are allowed to
|
||||||
|
+ leave the barrier. Note that POSIX does not require that only COUNT
|
||||||
|
+ threads can attempt to block using the barrier concurrently.
|
||||||
|
+
|
||||||
|
+ We count the number of threads that have entered (IN). Each thread
|
||||||
|
+ increments IN when entering, thus getting a position in the sequence of
|
||||||
|
+ threads that are or have been waiting (starting with 1, so the position
|
||||||
|
+ is the number of threads that have entered so far including the current
|
||||||
|
+ thread).
|
||||||
|
+ CURRENT_ROUND designates the most recent thread whose round has been
|
||||||
|
+ detected as complete. When a thread detects that enough threads have
|
||||||
|
+ entered to make a round complete, it finishes this round by effectively
|
||||||
|
+ adding COUNT to CURRENT_ROUND atomically. Threads that believe that their
|
||||||
|
+ round is not complete yet wait until CURRENT_ROUND is not smaller than
|
||||||
|
+ their position anymore.
|
||||||
|
+
|
||||||
|
+ A barrier can be destroyed as soon as no threads are blocked on the
|
||||||
|
+ barrier. This is already the case if just one thread from the last round
|
||||||
|
+ has stopped waiting and returned to the caller; the assumption is that
|
||||||
|
+ all threads from the round are unblocked atomically, even though they may
|
||||||
|
+ return at different times from the respective calls to
|
||||||
|
+ pthread_barrier_wait). Thus, a valid call to pthread_barrier_destroy can
|
||||||
|
+ be concurrent with other threads still figuring out that their round has
|
||||||
|
+ been completed. Therefore, threads need to confirm that they have left
|
||||||
|
+ the barrier by incrementing OUT, and pthread_barrier_destroy needs to wait
|
||||||
|
+ until OUT equals IN.
|
||||||
|
+
|
||||||
|
+ To avoid an ABA issue for futex_wait on CURRENT_ROUND and for archs with
|
||||||
|
+ 32b-only atomics, we additionally reset the barrier when IN reaches
|
||||||
|
+ a threshold to avoid overflow. We assume that the total number of threads
|
||||||
|
+ is less than INT_MAX/2, and set the threshold accordingly so that we can
|
||||||
|
+ use a simple atomic_fetch_add on IN instead of a CAS when entering. The
|
||||||
|
+ threshold is always set to the end of a round, so all threads that have
|
||||||
|
+ entered are either pre-reset threads or post-reset threads (i.e., have a
|
||||||
|
+ position larger than the threshold).
|
||||||
|
+ Pre-reset threads just run the algorithm explained above. Post-reset
|
||||||
|
+ threads wait until IN is reset to a pre-threshold value.
|
||||||
|
+ When the last pre-reset thread leaves the barrier (i.e., OUT equals the
|
||||||
|
+ threshold), it resets the barrier to its initial state. Other (post-reset)
|
||||||
|
+ threads wait for the reset to have finished by waiting until IN is less
|
||||||
|
+ than the threshold and then restart by trying to enter the barrier again.
|
||||||
|
+
|
||||||
|
+ We reuse the reset mechanism in pthread_barrier_destroy to get notified
|
||||||
|
+ when all threads have left the barrier: We trigger an artificial reset and
|
||||||
|
+ wait for the last pre-reset thread to finish reset, thus notifying the
|
||||||
|
+ thread that is about to destroy the barrier.
|
||||||
|
+
|
||||||
|
+ Blocking using futexes is straightforward: pre-reset threads wait for
|
||||||
|
+ completion of their round using CURRENT_ROUND as futex word, and post-reset
|
||||||
|
+ threads and pthread_barrier_destroy use IN as futex word.
|
||||||
|
+
|
||||||
|
+ Further notes:
|
||||||
|
+ * It is not simple to let some of the post-reset threads help with the
|
||||||
|
+ reset because of the ABA issues that arise; therefore, we simply make
|
||||||
|
+ the last thread to leave responsible for the reset.
|
||||||
|
+ * POSIX leaves it unspecified whether a signal handler running in a thread
|
||||||
|
+ that has been unblocked (because its round is complete) can stall all
|
||||||
|
+ other threads and prevent them from returning from the barrier. In this
|
||||||
|
+ implementation, other threads will return. However,
|
||||||
|
+ pthread_barrier_destroy will of course wait for the signal handler thread
|
||||||
|
+ to confirm that it left the barrier.
|
||||||
|
+
|
||||||
|
+ TODO We should add spinning with back-off. Once we do that, we could also
|
||||||
|
+ try to avoid the futex_wake syscall when a round is detected as finished.
|
||||||
|
+ If we do not spin, it is quite likely that at least some other threads will
|
||||||
|
+ have called futex_wait already. */
|
||||||
|
int
|
||||||
|
__pthread_barrier_wait (pthread_barrier_t *barrier)
|
||||||
|
{
|
||||||
|
- struct pthread_barrier *ibarrier = (struct pthread_barrier *) barrier;
|
||||||
|
- int result = 0;
|
||||||
|
- int lll_private = ibarrier->private ^ FUTEX_PRIVATE_FLAG;
|
||||||
|
- int futex_private = (lll_private == LLL_PRIVATE
|
||||||
|
- ? FUTEX_PRIVATE : FUTEX_SHARED);
|
||||||
|
+ struct pthread_barrier *bar = (struct pthread_barrier *) barrier;
|
||||||
|
|
||||||
|
- /* Make sure we are alone. */
|
||||||
|
- lll_lock (ibarrier->lock, lll_private);
|
||||||
|
+ /* How many threads entered so far, including ourself. */
|
||||||
|
+ unsigned int i;
|
||||||
|
|
||||||
|
- /* One more arrival. */
|
||||||
|
- --ibarrier->left;
|
||||||
|
+ reset_restart:
|
||||||
|
+ /* Try to enter the barrier. We need acquire MO to (1) ensure that if we
|
||||||
|
+ observe that our round can be completed (see below for our attempt to do
|
||||||
|
+ so), all pre-barrier-entry effects of all threads in our round happen
|
||||||
|
+ before us completing the round, and (2) to make our use of the barrier
|
||||||
|
+ happen after a potential reset. We need release MO to make sure that our
|
||||||
|
+ pre-barrier-entry effects happen before threads in this round leaving the
|
||||||
|
+ barrier. */
|
||||||
|
+ i = atomic_fetch_add_acq_rel (&bar->in, 1) + 1;
|
||||||
|
+ /* These loads are after the fetch_add so that we're less likely to first
|
||||||
|
+ pull in the cache line as shared. */
|
||||||
|
+ unsigned int count = bar->count;
|
||||||
|
+ /* This is the number of threads that can enter before we need to reset.
|
||||||
|
+ Always at the end of a round. */
|
||||||
|
+ unsigned int max_in_before_reset = BARRIER_IN_THRESHOLD
|
||||||
|
+ - BARRIER_IN_THRESHOLD % count;
|
||||||
|
|
||||||
|
- /* Are these all? */
|
||||||
|
- if (ibarrier->left == 0)
|
||||||
|
+ if (i > max_in_before_reset)
|
||||||
|
{
|
||||||
|
- /* Yes. Increment the event counter to avoid invalid wake-ups and
|
||||||
|
- tell the current waiters that it is their turn. */
|
||||||
|
- ++ibarrier->curr_event;
|
||||||
|
-
|
||||||
|
- /* Wake up everybody. */
|
||||||
|
- futex_wake (&ibarrier->curr_event, INT_MAX, futex_private);
|
||||||
|
+ /* We're in a reset round. Just wait for a reset to finish; do not
|
||||||
|
+ help finishing previous rounds because this could happen
|
||||||
|
+ concurrently with a reset. */
|
||||||
|
+ while (i > max_in_before_reset)
|
||||||
|
+ {
|
||||||
|
+ futex_wait_simple (&bar->in, i, bar->shared);
|
||||||
|
+ /* Relaxed MO is fine here because we just need an indication for
|
||||||
|
+ when we should retry to enter (which will use acquire MO, see
|
||||||
|
+ above). */
|
||||||
|
+ i = atomic_load_relaxed (&bar->in);
|
||||||
|
+ }
|
||||||
|
+ goto reset_restart;
|
||||||
|
+ }
|
||||||
|
|
||||||
|
- /* This is the thread which finished the serialization. */
|
||||||
|
- result = PTHREAD_BARRIER_SERIAL_THREAD;
|
||||||
|
+ /* Look at the current round. At this point, we are just interested in
|
||||||
|
+ whether we can complete rounds, based on the information we obtained
|
||||||
|
+ through our acquire-MO load of IN. Nonetheless, if we notice that
|
||||||
|
+ our round has been completed using this load, we use the acquire-MO
|
||||||
|
+ fence below to make sure that all pre-barrier-entry effects of all
|
||||||
|
+ threads in our round happen before us leaving the barrier. Therefore,
|
||||||
|
+ relaxed MO is sufficient. */
|
||||||
|
+ unsigned cr = atomic_load_relaxed (&bar->current_round);
|
||||||
|
+
|
||||||
|
+ /* Try to finish previous rounds and/or the current round. We simply
|
||||||
|
+ consider just our position here and do not try to do the work of threads
|
||||||
|
+ that entered more recently. */
|
||||||
|
+ while (cr + count <= i)
|
||||||
|
+ {
|
||||||
|
+ /* Calculate the new current round based on how many threads entered.
|
||||||
|
+ NEWCR must be larger than CR because CR+COUNT ends a round. */
|
||||||
|
+ unsigned int newcr = i - i % count;
|
||||||
|
+ /* Try to complete previous and/or the current round. We need release
|
||||||
|
+ MO to propagate the happens-before that we observed through reading
|
||||||
|
+ with acquire MO from IN to other threads. If the CAS fails, it
|
||||||
|
+ is like the relaxed-MO load of CURRENT_ROUND above. */
|
||||||
|
+ if (atomic_compare_exchange_weak_release (&bar->current_round, &cr,
|
||||||
|
+ newcr))
|
||||||
|
+ {
|
||||||
|
+ /* Update CR with the modification we just did. */
|
||||||
|
+ cr = newcr;
|
||||||
|
+ /* Wake threads belonging to the rounds we just finished. We may
|
||||||
|
+ wake more threads than necessary if more than COUNT threads try
|
||||||
|
+ to block concurrently on the barrier, but this is not a typical
|
||||||
|
+ use of barriers.
|
||||||
|
+ Note that we can still access SHARED because we haven't yet
|
||||||
|
+ confirmed to have left the barrier. */
|
||||||
|
+ futex_wake (&bar->current_round, INT_MAX, bar->shared);
|
||||||
|
+ /* We did as much as we could based on our position. If we advanced
|
||||||
|
+ the current round to a round sufficient for us, do not wait for
|
||||||
|
+ that to happen and skip the acquire fence (we already
|
||||||
|
+ synchronize-with all other threads in our round through the
|
||||||
|
+ initial acquire MO fetch_add of IN. */
|
||||||
|
+ if (i <= cr)
|
||||||
|
+ goto ready_to_leave;
|
||||||
|
+ else
|
||||||
|
+ break;
|
||||||
|
+ }
|
||||||
|
}
|
||||||
|
- else
|
||||||
|
+
|
||||||
|
+ /* Wait until the current round is more recent than the round we are in. */
|
||||||
|
+ while (i > cr)
|
||||||
|
{
|
||||||
|
- /* The number of the event we are waiting for. The barrier's event
|
||||||
|
- number must be bumped before we continue. */
|
||||||
|
- unsigned int event = ibarrier->curr_event;
|
||||||
|
-
|
||||||
|
- /* Before suspending, make the barrier available to others. */
|
||||||
|
- lll_unlock (ibarrier->lock, lll_private);
|
||||||
|
-
|
||||||
|
- /* Wait for the event counter of the barrier to change. */
|
||||||
|
- do
|
||||||
|
- futex_wait_simple (&ibarrier->curr_event, event, futex_private);
|
||||||
|
- while (event == ibarrier->curr_event);
|
||||||
|
+ /* Wait for the current round to finish. */
|
||||||
|
+ futex_wait_simple (&bar->current_round, cr, bar->shared);
|
||||||
|
+ /* See the fence below. */
|
||||||
|
+ cr = atomic_load_relaxed (&bar->current_round);
|
||||||
|
}
|
||||||
|
|
||||||
|
- /* Make sure the init_count is stored locally or in a register. */
|
||||||
|
- unsigned int init_count = ibarrier->init_count;
|
||||||
|
+ /* Our round finished. Use the acquire MO fence to synchronize-with the
|
||||||
|
+ thread that finished the round, either through the initial load of
|
||||||
|
+ CURRENT_ROUND above or a failed CAS in the loop above. */
|
||||||
|
+ atomic_thread_fence_acquire ();
|
||||||
|
+
|
||||||
|
+ /* Now signal that we left. */
|
||||||
|
+ unsigned int o;
|
||||||
|
+ ready_to_leave:
|
||||||
|
+ /* We need release MO here so that our use of the barrier happens before
|
||||||
|
+ reset or memory reuse after pthread_barrier_destroy. */
|
||||||
|
+ o = atomic_fetch_add_release (&bar->out, 1) + 1;
|
||||||
|
+ if (o == max_in_before_reset)
|
||||||
|
+ {
|
||||||
|
+ /* Perform a reset if we are the last pre-reset thread leaving. All
|
||||||
|
+ other threads accessing the barrier are post-reset threads and are
|
||||||
|
+ incrementing or spinning on IN. Thus, resetting IN as the last step
|
||||||
|
+ of reset ensures that the reset is not concurrent with actual use of
|
||||||
|
+ the barrier. We need the acquire MO fence so that the reset happens
|
||||||
|
+ after use of the barrier by all earlier pre-reset threads. */
|
||||||
|
+ atomic_thread_fence_acquire ();
|
||||||
|
+ atomic_store_relaxed (&bar->current_round, 0);
|
||||||
|
+ atomic_store_relaxed (&bar->out, 0);
|
||||||
|
+ /* When destroying the barrier, we wait for a reset to happen. Thus,
|
||||||
|
+ we must load SHARED now so that this happens before the barrier is
|
||||||
|
+ destroyed. */
|
||||||
|
+ int shared = bar->shared;
|
||||||
|
+ atomic_store_release (&bar->in, 0);
|
||||||
|
+ futex_wake (&bar->in, INT_MAX, shared);
|
||||||
|
|
||||||
|
- /* If this was the last woken thread, unlock. */
|
||||||
|
- if (atomic_increment_val (&ibarrier->left) == init_count)
|
||||||
|
- /* We are done. */
|
||||||
|
- lll_unlock (ibarrier->lock, lll_private);
|
||||||
|
+ }
|
||||||
|
|
||||||
|
- return result;
|
||||||
|
+ /* Return a special value for exactly one thread per round. */
|
||||||
|
+ return i % count == 0 ? PTHREAD_BARRIER_SERIAL_THREAD : 0;
|
||||||
|
}
|
||||||
|
weak_alias (__pthread_barrier_wait, pthread_barrier_wait)
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/pthread_barrierattr_setpshared.c
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/pthread_barrierattr_setpshared.c
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/pthread_barrierattr_setpshared.c
|
||||||
|
@@ -24,15 +24,11 @@
|
||||||
|
int
|
||||||
|
pthread_barrierattr_setpshared (pthread_barrierattr_t *attr, int pshared)
|
||||||
|
{
|
||||||
|
- struct pthread_barrierattr *iattr;
|
||||||
|
-
|
||||||
|
int err = futex_supports_pshared (pshared);
|
||||||
|
if (err != 0)
|
||||||
|
return err;
|
||||||
|
|
||||||
|
- iattr = (struct pthread_barrierattr *) attr;
|
||||||
|
-
|
||||||
|
- iattr->pshared = pshared;
|
||||||
|
+ ((struct pthread_barrierattr *) attr)->pshared = pshared;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/tst-barrier4.c
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/nptl/tst-barrier4.c
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/tst-barrier4.c
|
||||||
|
@@ -16,7 +16,7 @@
|
||||||
|
License along with the GNU C Library; if not, see
|
||||||
|
<http://www.gnu.org/licenses/>. */
|
||||||
|
|
||||||
|
-/* This is a test for behavior not guaranteed by POSIX. */
|
||||||
|
+/* This tests destruction of a barrier right after waiting on it. */
|
||||||
|
#include <errno.h>
|
||||||
|
#include <pthread.h>
|
||||||
|
#include <stdio.h>
|
||||||
|
Index: glibc-2.22-621-g90c400b/nptl/tst-barrier5.c
|
||||||
|
===================================================================
|
||||||
|
--- /dev/null
|
||||||
|
+++ glibc-2.22-621-g90c400b/nptl/tst-barrier5.c
|
||||||
|
@@ -0,0 +1,145 @@
|
||||||
|
+/* Copyright (C) 2004-2015 Free Software Foundation, Inc.
|
||||||
|
+ This file is part of the GNU C Library.
|
||||||
|
+
|
||||||
|
+ 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, see
|
||||||
|
+ <http://www.gnu.org/licenses/>. */
|
||||||
|
+
|
||||||
|
+/* This tests the barrier reset mechanism. */
|
||||||
|
+#include <errno.h>
|
||||||
|
+#include <pthread.h>
|
||||||
|
+#include <stdio.h>
|
||||||
|
+#include <stdlib.h>
|
||||||
|
+#include <internaltypes.h>
|
||||||
|
+
|
||||||
|
+
|
||||||
|
+static pthread_barrier_t b1;
|
||||||
|
+static pthread_barrier_t b2;
|
||||||
|
+
|
||||||
|
+
|
||||||
|
+#define N 20
|
||||||
|
+#define ROUNDS_PER_RUN 20
|
||||||
|
+#define START ((BARRIER_IN_THRESHOLD / N - ROUNDS_PER_RUN / 2) * N)
|
||||||
|
+
|
||||||
|
+static void *
|
||||||
|
+tf (void *arg)
|
||||||
|
+{
|
||||||
|
+ int runs = 0;
|
||||||
|
+
|
||||||
|
+ while (runs++ < 30)
|
||||||
|
+ {
|
||||||
|
+ /* In each run, we execute a number of rounds and initialize the barrier
|
||||||
|
+ so that we will go over the reset threshold with those rounds. */
|
||||||
|
+ for (int rounds = 0; rounds < ROUNDS_PER_RUN; rounds++)
|
||||||
|
+ pthread_barrier_wait (&b1);
|
||||||
|
+
|
||||||
|
+ if (pthread_barrier_wait (&b1) == PTHREAD_BARRIER_SERIAL_THREAD)
|
||||||
|
+ {
|
||||||
|
+ pthread_barrier_destroy (&b1);
|
||||||
|
+ if (pthread_barrier_init (&b1, NULL, N) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("tf: 1st barrier_init failed");
|
||||||
|
+ exit (1);
|
||||||
|
+ }
|
||||||
|
+ puts ("b1 reinitialized");
|
||||||
|
+ /* Trigger a reset. */
|
||||||
|
+ struct pthread_barrier *bar = (struct pthread_barrier *) &b1;
|
||||||
|
+ bar->in = START;
|
||||||
|
+ bar->out = START;
|
||||||
|
+ /* We deliberately don't set bar->current_round so that we also
|
||||||
|
+ test whether the helping for the updates of current_round
|
||||||
|
+ works correctly. */
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ /* Same as above, just for b2. */
|
||||||
|
+ for (int rounds = 0; rounds < ROUNDS_PER_RUN; rounds++)
|
||||||
|
+ pthread_barrier_wait (&b2);
|
||||||
|
+
|
||||||
|
+ if (pthread_barrier_wait (&b2) == PTHREAD_BARRIER_SERIAL_THREAD)
|
||||||
|
+ {
|
||||||
|
+ pthread_barrier_destroy (&b2);
|
||||||
|
+ if (pthread_barrier_init (&b2, NULL, N) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("tf: 2nd barrier_init failed");
|
||||||
|
+ exit (1);
|
||||||
|
+ }
|
||||||
|
+ puts ("b2 reinitialized");
|
||||||
|
+ /* Trigger a reset. See above. */
|
||||||
|
+ struct pthread_barrier *bar = (struct pthread_barrier *) &b2;
|
||||||
|
+ bar->in = START;
|
||||||
|
+ bar->out = START;
|
||||||
|
+ }
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ return NULL;
|
||||||
|
+}
|
||||||
|
+
|
||||||
|
+
|
||||||
|
+static int
|
||||||
|
+do_test (void)
|
||||||
|
+{
|
||||||
|
+ pthread_attr_t at;
|
||||||
|
+ int cnt;
|
||||||
|
+
|
||||||
|
+ if (pthread_attr_init (&at) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("attr_init failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ if (pthread_attr_setstacksize (&at, 1 * 1024 * 1024) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("attr_setstacksize failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ if (pthread_barrier_init (&b1, NULL, N) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("1st barrier_init failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ if (pthread_barrier_init (&b2, NULL, N) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("2nd barrier_init failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ pthread_t th[N - 1];
|
||||||
|
+ for (cnt = 0; cnt < N - 1; ++cnt)
|
||||||
|
+ if (pthread_create (&th[cnt], &at, tf, NULL) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("pthread_create failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ if (pthread_attr_destroy (&at) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("attr_destroy failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ tf (NULL);
|
||||||
|
+
|
||||||
|
+ for (cnt = 0; cnt < N - 1; ++cnt)
|
||||||
|
+ if (pthread_join (th[cnt], NULL) != 0)
|
||||||
|
+ {
|
||||||
|
+ puts ("pthread_join failed");
|
||||||
|
+ return 1;
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
+ return 0;
|
||||||
|
+}
|
||||||
|
+
|
||||||
|
+#define TEST_FUNCTION do_test ()
|
||||||
|
+#include "../test-skeleton.c"
|
||||||
|
Index: glibc-2.22-621-g90c400b/sysdeps/nptl/internaltypes.h
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/sysdeps/nptl/internaltypes.h
|
||||||
|
+++ glibc-2.22-621-g90c400b/sysdeps/nptl/internaltypes.h
|
||||||
|
@@ -95,12 +95,13 @@ struct pthread_rwlockattr
|
||||||
|
/* Barrier data structure. */
|
||||||
|
struct pthread_barrier
|
||||||
|
{
|
||||||
|
- unsigned int curr_event;
|
||||||
|
- int lock;
|
||||||
|
- unsigned int left;
|
||||||
|
- unsigned int init_count;
|
||||||
|
- int private;
|
||||||
|
+ unsigned int in;
|
||||||
|
+ unsigned int current_round;
|
||||||
|
+ unsigned int count;
|
||||||
|
+ int shared;
|
||||||
|
+ unsigned int out;
|
||||||
|
};
|
||||||
|
+#define BARRIER_IN_THRESHOLD (UINT_MAX/2)
|
||||||
|
|
||||||
|
|
||||||
|
/* Barrier variable attribute data structure. */
|
||||||
|
Index: glibc-2.22-621-g90c400b/sysdeps/unix/sysv/linux/i386/pthread_barrier_wait.S
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/sysdeps/unix/sysv/linux/i386/pthread_barrier_wait.S
|
||||||
|
+++ /dev/null
|
||||||
|
@@ -1,187 +0,0 @@
|
||||||
|
-/* Copyright (C) 2002-2015 Free Software Foundation, Inc.
|
||||||
|
- This file is part of the GNU C Library.
|
||||||
|
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
||||||
|
-
|
||||||
|
- 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, see
|
||||||
|
- <http://www.gnu.org/licenses/>. */
|
||||||
|
-
|
||||||
|
-#include <sysdep.h>
|
||||||
|
-#include <lowlevellock.h>
|
||||||
|
-#include <lowlevelbarrier.h>
|
||||||
|
-
|
||||||
|
- .text
|
||||||
|
-
|
||||||
|
- .globl __pthread_barrier_wait
|
||||||
|
- .type __pthread_barrier_wait,@function
|
||||||
|
- .align 16
|
||||||
|
-__pthread_barrier_wait:
|
||||||
|
- cfi_startproc
|
||||||
|
- pushl %ebx
|
||||||
|
- cfi_adjust_cfa_offset(4)
|
||||||
|
- cfi_offset(%ebx, -8)
|
||||||
|
-
|
||||||
|
- movl 8(%esp), %ebx
|
||||||
|
-
|
||||||
|
- /* Get the mutex. */
|
||||||
|
- movl $1, %edx
|
||||||
|
- xorl %eax, %eax
|
||||||
|
- LOCK
|
||||||
|
- cmpxchgl %edx, MUTEX(%ebx)
|
||||||
|
- jnz 1f
|
||||||
|
-
|
||||||
|
- /* One less waiter. If this was the last one needed wake
|
||||||
|
- everybody. */
|
||||||
|
-2: subl $1, LEFT(%ebx)
|
||||||
|
- je 3f
|
||||||
|
-
|
||||||
|
- /* There are more threads to come. */
|
||||||
|
- pushl %esi
|
||||||
|
- cfi_adjust_cfa_offset(4)
|
||||||
|
- cfi_offset(%esi, -12)
|
||||||
|
-
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- movl (%ebx), %edx
|
||||||
|
-#else
|
||||||
|
- movl CURR_EVENT(%ebx), %edx
|
||||||
|
-#endif
|
||||||
|
-
|
||||||
|
- /* Release the mutex. */
|
||||||
|
- LOCK
|
||||||
|
- subl $1, MUTEX(%ebx)
|
||||||
|
- jne 6f
|
||||||
|
-
|
||||||
|
- /* Wait for the remaining threads. The call will return immediately
|
||||||
|
- if the CURR_EVENT memory has meanwhile been changed. */
|
||||||
|
-7:
|
||||||
|
-#if FUTEX_WAIT == 0
|
||||||
|
- movl PRIVATE(%ebx), %ecx
|
||||||
|
-#else
|
||||||
|
- movl $FUTEX_WAIT, %ecx
|
||||||
|
- orl PRIVATE(%ebx), %ecx
|
||||||
|
-#endif
|
||||||
|
- xorl %esi, %esi
|
||||||
|
-8: movl $SYS_futex, %eax
|
||||||
|
- ENTER_KERNEL
|
||||||
|
-
|
||||||
|
- /* Don't return on spurious wakeups. The syscall does not change
|
||||||
|
- any register except %eax so there is no need to reload any of
|
||||||
|
- them. */
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- cmpl %edx, (%ebx)
|
||||||
|
-#else
|
||||||
|
- cmpl %edx, CURR_EVENT(%ebx)
|
||||||
|
-#endif
|
||||||
|
- je 8b
|
||||||
|
-
|
||||||
|
- /* Increment LEFT. If this brings the count back to the
|
||||||
|
- initial count unlock the object. */
|
||||||
|
- movl $1, %edx
|
||||||
|
- movl INIT_COUNT(%ebx), %ecx
|
||||||
|
- LOCK
|
||||||
|
- xaddl %edx, LEFT(%ebx)
|
||||||
|
- subl $1, %ecx
|
||||||
|
- cmpl %ecx, %edx
|
||||||
|
- jne 10f
|
||||||
|
-
|
||||||
|
- /* Release the mutex. We cannot release the lock before
|
||||||
|
- waking the waiting threads since otherwise a new thread might
|
||||||
|
- arrive and gets waken up, too. */
|
||||||
|
- LOCK
|
||||||
|
- subl $1, MUTEX(%ebx)
|
||||||
|
- jne 9f
|
||||||
|
-
|
||||||
|
- /* Note: %esi is still zero. */
|
||||||
|
-10: movl %esi, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
|
||||||
|
-
|
||||||
|
- popl %esi
|
||||||
|
- cfi_adjust_cfa_offset(-4)
|
||||||
|
- cfi_restore(%esi)
|
||||||
|
- popl %ebx
|
||||||
|
- cfi_adjust_cfa_offset(-4)
|
||||||
|
- cfi_restore(%ebx)
|
||||||
|
- ret
|
||||||
|
-
|
||||||
|
- cfi_adjust_cfa_offset(4)
|
||||||
|
- cfi_offset(%ebx, -8)
|
||||||
|
-
|
||||||
|
- /* The necessary number of threads arrived. */
|
||||||
|
-3:
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- addl $1, (%ebx)
|
||||||
|
-#else
|
||||||
|
- addl $1, CURR_EVENT(%ebx)
|
||||||
|
-#endif
|
||||||
|
-
|
||||||
|
- /* Wake up all waiters. The count is a signed number in the kernel
|
||||||
|
- so 0x7fffffff is the highest value. */
|
||||||
|
- movl $0x7fffffff, %edx
|
||||||
|
- movl $FUTEX_WAKE, %ecx
|
||||||
|
- orl PRIVATE(%ebx), %ecx
|
||||||
|
- movl $SYS_futex, %eax
|
||||||
|
- ENTER_KERNEL
|
||||||
|
-
|
||||||
|
- /* Increment LEFT. If this brings the count back to the
|
||||||
|
- initial count unlock the object. */
|
||||||
|
- movl $1, %edx
|
||||||
|
- movl INIT_COUNT(%ebx), %ecx
|
||||||
|
- LOCK
|
||||||
|
- xaddl %edx, LEFT(%ebx)
|
||||||
|
- subl $1, %ecx
|
||||||
|
- cmpl %ecx, %edx
|
||||||
|
- jne 5f
|
||||||
|
-
|
||||||
|
- /* Release the mutex. We cannot release the lock before
|
||||||
|
- waking the waiting threads since otherwise a new thread might
|
||||||
|
- arrive and gets waken up, too. */
|
||||||
|
- LOCK
|
||||||
|
- subl $1, MUTEX(%ebx)
|
||||||
|
- jne 4f
|
||||||
|
-
|
||||||
|
-5: orl $-1, %eax /* == PTHREAD_BARRIER_SERIAL_THREAD */
|
||||||
|
-
|
||||||
|
- popl %ebx
|
||||||
|
- cfi_adjust_cfa_offset(-4)
|
||||||
|
- cfi_restore(%ebx)
|
||||||
|
- ret
|
||||||
|
-
|
||||||
|
- cfi_adjust_cfa_offset(4)
|
||||||
|
- cfi_offset(%ebx, -8)
|
||||||
|
-1: movl PRIVATE(%ebx), %ecx
|
||||||
|
- leal MUTEX(%ebx), %edx
|
||||||
|
- xorl $LLL_SHARED, %ecx
|
||||||
|
- call __lll_lock_wait
|
||||||
|
- jmp 2b
|
||||||
|
-
|
||||||
|
-4: movl PRIVATE(%ebx), %ecx
|
||||||
|
- leal MUTEX(%ebx), %eax
|
||||||
|
- xorl $LLL_SHARED, %ecx
|
||||||
|
- call __lll_unlock_wake
|
||||||
|
- jmp 5b
|
||||||
|
-
|
||||||
|
- cfi_adjust_cfa_offset(4)
|
||||||
|
- cfi_offset(%esi, -12)
|
||||||
|
-6: movl PRIVATE(%ebx), %ecx
|
||||||
|
- leal MUTEX(%ebx), %eax
|
||||||
|
- xorl $LLL_SHARED, %ecx
|
||||||
|
- call __lll_unlock_wake
|
||||||
|
- jmp 7b
|
||||||
|
-
|
||||||
|
-9: movl PRIVATE(%ebx), %ecx
|
||||||
|
- leal MUTEX(%ebx), %eax
|
||||||
|
- xorl $LLL_SHARED, %ecx
|
||||||
|
- call __lll_unlock_wake
|
||||||
|
- jmp 10b
|
||||||
|
- cfi_endproc
|
||||||
|
- .size __pthread_barrier_wait,.-__pthread_barrier_wait
|
||||||
|
-weak_alias (__pthread_barrier_wait, pthread_barrier_wait)
|
||||||
|
Index: glibc-2.22-621-g90c400b/sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S
|
||||||
|
===================================================================
|
||||||
|
--- glibc-2.22-621-g90c400b.orig/sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S
|
||||||
|
+++ /dev/null
|
||||||
|
@@ -1,161 +0,0 @@
|
||||||
|
-/* Copyright (C) 2002-2015 Free Software Foundation, Inc.
|
||||||
|
- This file is part of the GNU C Library.
|
||||||
|
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
||||||
|
-
|
||||||
|
- 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, see
|
||||||
|
- <http://www.gnu.org/licenses/>. */
|
||||||
|
-
|
||||||
|
-#include <sysdep.h>
|
||||||
|
-#include <lowlevellock.h>
|
||||||
|
-#include <lowlevelbarrier.h>
|
||||||
|
-
|
||||||
|
-
|
||||||
|
- .text
|
||||||
|
-
|
||||||
|
- .globl __pthread_barrier_wait
|
||||||
|
- .type __pthread_barrier_wait,@function
|
||||||
|
- .align 16
|
||||||
|
-__pthread_barrier_wait:
|
||||||
|
- /* Get the mutex. */
|
||||||
|
- xorl %eax, %eax
|
||||||
|
- movl $1, %esi
|
||||||
|
- LOCK
|
||||||
|
- cmpxchgl %esi, MUTEX(%rdi)
|
||||||
|
- jnz 1f
|
||||||
|
-
|
||||||
|
- /* One less waiter. If this was the last one needed wake
|
||||||
|
- everybody. */
|
||||||
|
-2: decl LEFT(%rdi)
|
||||||
|
- je 3f
|
||||||
|
-
|
||||||
|
- /* There are more threads to come. */
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- movl (%rdi), %edx
|
||||||
|
-#else
|
||||||
|
- movl CURR_EVENT(%rdi), %edx
|
||||||
|
-#endif
|
||||||
|
-
|
||||||
|
- /* Release the mutex. */
|
||||||
|
- LOCK
|
||||||
|
- decl MUTEX(%rdi)
|
||||||
|
- jne 6f
|
||||||
|
-
|
||||||
|
- /* Wait for the remaining threads. The call will return immediately
|
||||||
|
- if the CURR_EVENT memory has meanwhile been changed. */
|
||||||
|
-7:
|
||||||
|
-#if FUTEX_WAIT == 0
|
||||||
|
- movl PRIVATE(%rdi), %esi
|
||||||
|
-#else
|
||||||
|
- movl $FUTEX_WAIT, %esi
|
||||||
|
- orl PRIVATE(%rdi), %esi
|
||||||
|
-#endif
|
||||||
|
- xorq %r10, %r10
|
||||||
|
-8: movl $SYS_futex, %eax
|
||||||
|
- syscall
|
||||||
|
-
|
||||||
|
- /* Don't return on spurious wakeups. The syscall does not change
|
||||||
|
- any register except %eax so there is no need to reload any of
|
||||||
|
- them. */
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- cmpl %edx, (%rdi)
|
||||||
|
-#else
|
||||||
|
- cmpl %edx, CURR_EVENT(%rdi)
|
||||||
|
-#endif
|
||||||
|
- je 8b
|
||||||
|
-
|
||||||
|
- /* Increment LEFT. If this brings the count back to the
|
||||||
|
- initial count unlock the object. */
|
||||||
|
- movl $1, %edx
|
||||||
|
- movl INIT_COUNT(%rdi), %eax
|
||||||
|
- LOCK
|
||||||
|
- xaddl %edx, LEFT(%rdi)
|
||||||
|
- subl $1, %eax
|
||||||
|
- cmpl %eax, %edx
|
||||||
|
- jne,pt 10f
|
||||||
|
-
|
||||||
|
- /* Release the mutex. We cannot release the lock before
|
||||||
|
- waking the waiting threads since otherwise a new thread might
|
||||||
|
- arrive and gets waken up, too. */
|
||||||
|
- LOCK
|
||||||
|
- decl MUTEX(%rdi)
|
||||||
|
- jne 9f
|
||||||
|
-
|
||||||
|
-10: xorl %eax, %eax /* != PTHREAD_BARRIER_SERIAL_THREAD */
|
||||||
|
-
|
||||||
|
- retq
|
||||||
|
-
|
||||||
|
- /* The necessary number of threads arrived. */
|
||||||
|
-3:
|
||||||
|
-#if CURR_EVENT == 0
|
||||||
|
- incl (%rdi)
|
||||||
|
-#else
|
||||||
|
- incl CURR_EVENT(%rdi)
|
||||||
|
-#endif
|
||||||
|
-
|
||||||
|
- /* Wake up all waiters. The count is a signed number in the kernel
|
||||||
|
- so 0x7fffffff is the highest value. */
|
||||||
|
- movl $0x7fffffff, %edx
|
||||||
|
- movl $FUTEX_WAKE, %esi
|
||||||
|
- orl PRIVATE(%rdi), %esi
|
||||||
|
- movl $SYS_futex, %eax
|
||||||
|
- syscall
|
||||||
|
-
|
||||||
|
- /* Increment LEFT. If this brings the count back to the
|
||||||
|
- initial count unlock the object. */
|
||||||
|
- movl $1, %edx
|
||||||
|
- movl INIT_COUNT(%rdi), %eax
|
||||||
|
- LOCK
|
||||||
|
- xaddl %edx, LEFT(%rdi)
|
||||||
|
- subl $1, %eax
|
||||||
|
- cmpl %eax, %edx
|
||||||
|
- jne,pt 5f
|
||||||
|
-
|
||||||
|
- /* Release the mutex. We cannot release the lock before
|
||||||
|
- waking the waiting threads since otherwise a new thread might
|
||||||
|
- arrive and gets waken up, too. */
|
||||||
|
- LOCK
|
||||||
|
- decl MUTEX(%rdi)
|
||||||
|
- jne 4f
|
||||||
|
-
|
||||||
|
-5: orl $-1, %eax /* == PTHREAD_BARRIER_SERIAL_THREAD */
|
||||||
|
-
|
||||||
|
- retq
|
||||||
|
-
|
||||||
|
-1: movl PRIVATE(%rdi), %esi
|
||||||
|
- addq $MUTEX, %rdi
|
||||||
|
- xorl $LLL_SHARED, %esi
|
||||||
|
- callq __lll_lock_wait
|
||||||
|
- subq $MUTEX, %rdi
|
||||||
|
- jmp 2b
|
||||||
|
-
|
||||||
|
-4: movl PRIVATE(%rdi), %esi
|
||||||
|
- addq $MUTEX, %rdi
|
||||||
|
- xorl $LLL_SHARED, %esi
|
||||||
|
- callq __lll_unlock_wake
|
||||||
|
- jmp 5b
|
||||||
|
-
|
||||||
|
-6: movl PRIVATE(%rdi), %esi
|
||||||
|
- addq $MUTEX, %rdi
|
||||||
|
- xorl $LLL_SHARED, %esi
|
||||||
|
- callq __lll_unlock_wake
|
||||||
|
- subq $MUTEX, %rdi
|
||||||
|
- jmp 7b
|
||||||
|
-
|
||||||
|
-9: movl PRIVATE(%rdi), %esi
|
||||||
|
- addq $MUTEX, %rdi
|
||||||
|
- xorl $LLL_SHARED, %esi
|
||||||
|
- callq __lll_unlock_wake
|
||||||
|
- jmp 10b
|
||||||
|
- .size __pthread_barrier_wait,.-__pthread_barrier_wait
|
||||||
|
-weak_alias (__pthread_barrier_wait, pthread_barrier_wait)
|
|
@ -1,6 +1,6 @@
|
||||||
%define glibcsrcdir glibc-2.22-621-g90c400b
|
%define glibcsrcdir glibc-2.22-621-g90c400b
|
||||||
%define glibcversion 2.22.90
|
%define glibcversion 2.22.90
|
||||||
%define glibcrelease 28%{?dist}
|
%define glibcrelease 29%{?dist}
|
||||||
# Pre-release tarballs are pulled in from git using a command that is
|
# Pre-release tarballs are pulled in from git using a command that is
|
||||||
# effectively:
|
# effectively:
|
||||||
#
|
#
|
||||||
|
@ -291,6 +291,9 @@ Patch2034: glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch
|
||||||
# Group Merge Patch:
|
# Group Merge Patch:
|
||||||
Patch2035: glibc-nsswitch-Add-group-merging-support.patch
|
Patch2035: glibc-nsswitch-Add-group-merging-support.patch
|
||||||
|
|
||||||
|
# New pthread_barrier algorithm:
|
||||||
|
Patch2036: glibc-pthread-barrier.patch
|
||||||
|
|
||||||
##############################################################################
|
##############################################################################
|
||||||
#
|
#
|
||||||
# Benchmark comparison patches.
|
# Benchmark comparison patches.
|
||||||
|
@ -683,6 +686,7 @@ cat /proc/meminfo
|
||||||
%patch0058 -p1
|
%patch0058 -p1
|
||||||
%patch0059 -p1
|
%patch0059 -p1
|
||||||
%patch2035 -p1
|
%patch2035 -p1
|
||||||
|
%patch2036 -p1
|
||||||
|
|
||||||
##############################################################################
|
##############################################################################
|
||||||
# %%prep - Additional prep required...
|
# %%prep - Additional prep required...
|
||||||
|
@ -1941,6 +1945,9 @@ rm -f *.filelist*
|
||||||
%endif
|
%endif
|
||||||
|
|
||||||
%changelog
|
%changelog
|
||||||
|
* Wed Jan 13 2016 Carlos O'Donell <carlos@redhat.com> - 2.22.90-29
|
||||||
|
- New pthread_barrier algorithm with improved standards compliance.
|
||||||
|
|
||||||
* Wed Jan 13 2016 Carlos O'Donell <carlos@redhat.com> - 2.22.90-28
|
* Wed Jan 13 2016 Carlos O'Donell <carlos@redhat.com> - 2.22.90-28
|
||||||
- Add group merging support for distributed management (#1146822).
|
- Add group merging support for distributed management (#1146822).
|
||||||
|
|
||||||
|
|
9
series
9
series
|
@ -20,7 +20,6 @@ glibc-fedora-localedata-rh61908.patch -p1 --fuzz=0
|
||||||
glibc-fedora-uname-getrlimit.patch -p1 --fuzz=0
|
glibc-fedora-uname-getrlimit.patch -p1 --fuzz=0
|
||||||
glibc-fedora-__libc_multiple_libcs.patch -p1 --fuzz=0
|
glibc-fedora-__libc_multiple_libcs.patch -p1 --fuzz=0
|
||||||
glibc-fedora-elf-ORIGIN.patch -p1 --fuzz=0
|
glibc-fedora-elf-ORIGIN.patch -p1 --fuzz=0
|
||||||
glibc-fedora-elf-init-hidden_undef.patch -p1 --fuzz=0
|
|
||||||
glibc-rh952799.patch -p1 --fuzz=0
|
glibc-rh952799.patch -p1 --fuzz=0
|
||||||
glibc-rh1009145.patch -p1 --fuzz=0
|
glibc-rh1009145.patch -p1 --fuzz=0
|
||||||
glibc-rh1013801.patch -p1 --fuzz=0
|
glibc-rh1013801.patch -p1 --fuzz=0
|
||||||
|
@ -31,15 +30,11 @@ glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch -p1 --fuzz=0
|
||||||
glibc-disable-rwlock-elision.patch -p1 --fuzz=0
|
glibc-disable-rwlock-elision.patch -p1 --fuzz=0
|
||||||
glibc-cs-path.patch -p1 --fuzz=0
|
glibc-cs-path.patch -p1 --fuzz=0
|
||||||
glibc-bench-build.patch -p1 --fuzz=0
|
glibc-bench-build.patch -p1 --fuzz=0
|
||||||
glibc-new-condvar.patch -p1 --fuzz=0
|
|
||||||
glibc-rh1238412-remove-duplicate-transliterations.patch -p1 --fuzz=0
|
|
||||||
glibc-rh1238412-addition-and-fixes-for-translit_neutral.patch -p1 --fuzz=0
|
|
||||||
glibc-rh1238412-update-the-translit-files-to-unicode-7.0.0.patch -p1 --fuzz=0
|
|
||||||
glibc-rh1238412-add-translit-rules-for-da-nb-nn-sv-locales.patch -p1 --fuzz=0
|
|
||||||
glibc-rh1238412-unicode-8.0.0-update.patch -p1 --fuzz=0
|
|
||||||
glibc-res-hconf-gcc5.patch -p1 --fuzz=0
|
glibc-res-hconf-gcc5.patch -p1 --fuzz=0
|
||||||
glibc-ld-ctype-gcc5.patch -p1 --fuzz=0
|
glibc-ld-ctype-gcc5.patch -p1 --fuzz=0
|
||||||
glibc-gethnamaddr-gcc5.patch -p1 --fuzz=0
|
glibc-gethnamaddr-gcc5.patch -p1 --fuzz=0
|
||||||
glibc-dns-host-gcc5.patch -p1 --fuzz=0
|
glibc-dns-host-gcc5.patch -p1 --fuzz=0
|
||||||
glibc-bug-regex-gcc5.patch -p1 --fuzz=0
|
glibc-bug-regex-gcc5.patch -p1 --fuzz=0
|
||||||
glibc-c-utf8-locale.patch -p1 --fuzz=0
|
glibc-c-utf8-locale.patch -p1 --fuzz=0
|
||||||
|
glibc-nsswitch-Add-group-merging-support.patch -p1 --fuzz=0
|
||||||
|
glibc-pthread-barrier.patch --fuzz=0
|
||||||
|
|
Loading…
Reference in New Issue