re PR libgomp/66761 (libgomp: ThreadSanitizer: data race in libgomp)

        PR libgomp/66761
        PR libgomp/67303
        * iter.c (gomp_iter_dynamic_next): Employ an atomic load.
        (gomp_iter_guided_next): Idem.
        * iter_ull.c (gomp_iter_ull_dynamic_next): Idem.
        (gomp_iter_ull_guided_next): Idem.
        * config/linux/wait.h (do_spin): Idem.

From-SVN: r227119

diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog
index 1d265b62e99abb01ab2987030bcbbbe52dfc7018..bd9111b86a9d1d6c4a0cdd504b13435e2e16101f 100644 (file)
--- a/libgomp/ChangeLog
+++ b/libgomp/ChangeLog
@@ -1,3 +1,13 @@
+2015-08-24  Joost VandeVondele  <vondele@gnu.gcc.org>
+
+       PR libgomp/66761
+       PR libgomp/67303
+       * iter.c (gomp_iter_dynamic_next): Employ an atomic load.
+       (gomp_iter_guided_next): Idem.
+       * iter_ull.c (gomp_iter_ull_dynamic_next): Idem.
+       (gomp_iter_ull_guided_next): Idem.
+       * config/linux/wait.h (do_spin): Idem.
+
 2015-08-10  Thomas Schwinge  <thomas@codesourcery.com>
 
        * libgomp-plugin.h (enum offload_target_type): Remove

diff --git a/libgomp/config/linux/wait.h b/libgomp/config/linux/wait.h
index 7f57454a510fab834e210b0e4a8e91da07e3bf2e..e561c2ddf6ba17cc45f1f5854c78f412f2e7320e 100644 (file)
--- a/libgomp/config/linux/wait.h
+++ b/libgomp/config/linux/wait.h
@@ -49,7 +49,9 @@ static inline int do_spin (int *addr, int val)
 {
   unsigned long long i, count = gomp_spin_count_var;
 
-  if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0))
+  if (__builtin_expect (__atomic_load_n (&gomp_managed_threads,
+                                         MEMMODEL_RELAXED)
+                        > gomp_available_cpus, 0))
     count = gomp_throttled_spin_count_var;
   for (i = 0; i < count; i++)
     if (__builtin_expect (__atomic_load_n (addr, MEMMODEL_RELAXED) != val, 0))

diff --git a/libgomp/iter.c b/libgomp/iter.c
index 0ceb41d909e29cff866caba66b777a836cc1031e..1def8bde06617b849e7639134952141fb56060fc 100644 (file)
--- a/libgomp/iter.c
+++ b/libgomp/iter.c
@@ -218,7 +218,7 @@ gomp_iter_dynamic_next (long *pstart, long *pend)
        }
     }
 
-  start = ws->next;
+  start = __atomic_load_n (&ws->next, MEMMODEL_RELAXED);
   while (1)
     {
       long left = end - start;
@@ -301,7 +301,7 @@ gomp_iter_guided_next (long *pstart, long *pend)
   long start, end, nend, incr;
   unsigned long chunk_size;
 
-  start = ws->next;
+  start = __atomic_load_n (&ws->next, MEMMODEL_RELAXED);
   end = ws->end;
   incr = ws->incr;
   chunk_size = ws->chunk_size;

diff --git a/libgomp/iter_ull.c b/libgomp/iter_ull.c
index b1cad84d4c868aa5adc283147e53a14fe4dadbc1..1c2d118b63180cdac2edf95018805f499c193f6c 100644 (file)
--- a/libgomp/iter_ull.c
+++ b/libgomp/iter_ull.c
@@ -219,7 +219,7 @@ gomp_iter_ull_dynamic_next (gomp_ull *pstart, gomp_ull *pend)
        }
     }
 
-  start = ws->next_ull;
+  start = __atomic_load_n (&ws->next_ull, MEMMODEL_RELAXED);
   while (1)
     {
       gomp_ull left = end - start;
@@ -305,7 +305,7 @@ gomp_iter_ull_guided_next (gomp_ull *pstart, gomp_ull *pend)
   gomp_ull start, end, nend, incr;
   gomp_ull chunk_size;
 
-  start = ws->next_ull;
+  start = __atomic_load_n (&ws->next_ull, MEMMODEL_RELAXED);
   end = ws->end_ull;
   incr = ws->incr_ull;
   chunk_size = ws->chunk_size_ull;