Hi!
This is the minimal fix for the issue mentioned in
http://gcc.gnu.org/ml/gcc-patches/2013-10/msg00333.html
that is being fixed as part of gomp-4_0-branch merge to trunk,
but for 4.8 I've applied this fix instead.
The testcase also includes the follow-up fix from
http://gcc.gnu.org/ml/gcc-patches/2013-10/msg00497.html
Bootstrapped/regtested on x86_64-linux and i686-linux, committed
to 4.8 branch.
2013-10-09 Jakub Jelinek <ja...@redhat.com>
* parallel.c (GOMP_parallel_end): Remember team->nthreads and call
gomp_team_end before adjusting gomp_remaining_threads_count, increment
gomp_remaining_threads_count instead of decrementing it again.
* testsuite/libgomp.c/thread-limit-1.c: New test.
--- libgomp/parallel.c.jj 2013-03-16 08:07:43.000000000 +0100
+++ libgomp/parallel.c 2013-10-09 09:10:38.215245390 +0200
@@ -115,19 +115,22 @@ GOMP_parallel_end (void)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
- if (team && team->nthreads > 1)
+ unsigned int nthreads = team ? team->nthreads : 1;
+ gomp_team_end ();
+ if (nthreads > 1)
{
#ifdef HAVE_SYNC_BUILTINS
__sync_fetch_and_add (&gomp_remaining_threads_count,
- 1UL - team->nthreads);
+ nthreads - 1);
#else
gomp_mutex_lock (&gomp_remaining_threads_lock);
- gomp_remaining_threads_count -= team->nthreads - 1;
+ gomp_remaining_threads_count += nthreads - 1;
gomp_mutex_unlock (&gomp_remaining_threads_lock);
#endif
}
}
- gomp_team_end ();
+ else
+ gomp_team_end ();
}
--- libgomp/testsuite/libgomp.c/thread-limit-1.c.jj 2013-10-09
09:05:35.702854964 +0200
+++ libgomp/testsuite/libgomp.c/thread-limit-1.c 2013-10-08
20:30:47.000000000 +0200
@@ -0,0 +1,41 @@
+/* { dg-do run } */
+/* { dg-set-target-env-var OMP_THREAD_LIMIT "6" } */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+int
+main ()
+{
+ if (omp_get_thread_limit () != 6)
+ return 0;
+ omp_set_dynamic (0);
+ omp_set_nested (1);
+ #pragma omp parallel num_threads (3)
+ if (omp_get_num_threads () != 3)
+ abort ();
+ #pragma omp parallel num_threads (3)
+ if (omp_get_num_threads () != 3)
+ abort ();
+ #pragma omp parallel num_threads (8)
+ if (omp_get_num_threads () > 6)
+ abort ();
+ #pragma omp parallel num_threads (6)
+ if (omp_get_num_threads () != 6)
+ abort ();
+ int cnt = 0;
+ #pragma omp parallel num_threads (5)
+ #pragma omp parallel num_threads (5)
+ #pragma omp parallel num_threads (2)
+ {
+ int v;
+ #pragma omp atomic capture
+ v = ++cnt;
+ if (v > 6)
+ abort ();
+ usleep (10000);
+ #pragma omp atomic
+ --cnt;
+ }
+ return 0;
+}
Jakub
