Take extra lock in base::WaitableEvent::WaitMany.

base/synchronization/waitable_event_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/synchronization/waitable_event.h"
 
 #include "base/compiler_specific.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 61 matching lines @@
 }
 
 class WaitableEventSignaler : public PlatformThread::Delegate {
  public:
   WaitableEventSignaler(double seconds, WaitableEvent* ev)
       : seconds_(seconds),
         ev_(ev) {
   }
 
   virtual void ThreadMain() OVERRIDE {
-    PlatformThread::Sleep(TimeDelta::FromSeconds(static_cast<int>(seconds_)));
+    PlatformThread::Sleep(TimeDelta::FromSecondsD(seconds_));
     ev_->Signal();
   }
 
  private:
   const double seconds_;
   WaitableEvent *const ev_;
 };
 
+TEST(WaitableEventTest, WaitAndDelete) {
+  // This test tests that if a WaitableEvent can be safely deleted
+  // when |Wait| is done without additional synchrnization.
+  // If this test crashes, it is a bug.
+
+  WaitableEvent* ev = new WaitableEvent(false, false);
+
+  WaitableEventSignaler signaler(0.01, ev);
+  PlatformThreadHandle thread;
+  PlatformThread::Create(0, &signaler, &thread);
+
+  ev->Wait();
+  delete ev;
+
+  PlatformThread::Join(thread);
+}
+
 TEST(WaitableEventTest, WaitMany) {
+  // This test tests that if a WaitableEvent can be safely deleted
+  // when |WaitMany| is done without additional synchrnization.
+  // If this test crashes, it is a bug.
+
   WaitableEvent* ev[5];
   for (unsigned i = 0; i < 5; ++i)
     ev[i] = new WaitableEvent(false, false);
 
-  WaitableEventSignaler signaler(0.1, ev[2]);
+  WaitableEventSignaler signaler(0.01, ev[2]);
   PlatformThreadHandle thread;
   PlatformThread::Create(0, &signaler, &thread);
 
-  EXPECT_EQ(WaitableEvent::WaitMany(ev, 5), 2u);
-
-  PlatformThread::Join(thread);
+  size_t index = WaitableEvent::WaitMany(ev, 5);
 
   for (unsigned i = 0; i < 5; ++i)
     delete ev[i];
+
+  PlatformThread::Join(thread);
+  EXPECT_EQ(2u, index);
 }
 
 }  // namespace base