Suppress a benign/false-positive race in ThreadCollisionWarner and a benign race in CookieMonster Histogram handling

For the first race, the reports look like this:
WARNING: Possible data race during write of size 4 at 0080F90C: {{{
   T26 (L{}):
    #0  base::subtle::NoBarrier_Store base/atomicops_internals_x86_msvc.h:67
    #1  base::ThreadCollisionWarner::Leave base/thread_collision_warner.cc:60
           ...
  Concurrent write(s) happened at (OR AFTER) these points:
   T27 (L{}):
    #0  base::subtle::NoBarrier_Store base/atomicops_internals_x86_msvc.h:66
    #1  base::ThreadCollisionWarner::Leave base/thread_collision_warner.cc:60

And the code is:
void ThreadCollisionWarner::Leave() {
  if (subtle::Barrier_AtomicIncrement(&counter_, -1) == 0) {
    subtle::NoBarrier_Store(&valid_thread_id_, 0);
  }
}

TBR=glider
BUG=62694
Review URL: http://codereview.chromium.org/4837004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65941 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 0 deletions

diff --git a/tools/valgrind/tsan/suppressions.txt b/tools/valgrind/tsan/suppressions.txt
index d4f54dd..36dda56 100644
--- a/tools/valgrind/tsan/suppressions.txt
+++ b/tools/valgrind/tsan/suppressions.txt
@@ -63,6 +63,16 @@
 }
 
 ############################
+# Benign races
+{
+  bug_62694 [benign race in Histogram]
+  ThreadSanitizer:Race
+  ...
+  fun:base::Histogram::Add
+  fun:net::CookieMonster::*
+}
+
+############################
 # Real races in third_party
 {
   bug_23244 (libevent)
@@ -253,6 +263,13 @@
    fun:*TOOLS_SANITY_TEST_CONCURRENT_THREAD*ThreadMain*
 }
 
+{
+   Benign race (or even a false positive) on atomics in ThreadCollisionWarner
+   ThreadSanitizer:Race
+   fun:base::subtle::NoBarrier_Store
+   fun:base::ThreadCollisionWarner::Leave
+}
+
 ############################
 # Benign races in ICU
 {