Ensure that |Thread::id_| is only accessed when an happens-after relationship has been established …

base/synchronization/waitable_event_win.cc

 // Copyright (c) 2011 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 <windows.h>
 #include <stddef.h>
 
 #include <utility>
@@ skipping 44 matching lines @@
   DWORD result = WaitForSingleObject(handle_.Get(), INFINITE);
   // It is most unexpected that this should ever fail.  Help consumers learn
   // about it if it should ever fail.
   DCHECK_EQ(WAIT_OBJECT_0, result) << "WaitForSingleObject failed";
 }
 
 bool WaitableEvent::TimedWait(const TimeDelta& max_time) {
   // Record the event that this thread is blocking upon (for hang diagnosis).
   base::debug::ScopedEventWaitActivity event_activity(this);
 
-  base::ThreadRestrictions::AssertWaitAllowed();
   DCHECK_GE(max_time, TimeDelta());
+  if (!max_time.is_zero())
+    base::ThreadRestrictions::AssertWaitAllowed();
+
   // Truncate the timeout to milliseconds. The API specifies that this method
   // can return in less than |max_time| (when returning false), as the argument
   // is the maximum time that a caller is willing to wait.
   DWORD timeout = saturated_cast<DWORD>(max_time.InMilliseconds());
 
   DWORD result = WaitForSingleObject(handle_.Get(), timeout);
   switch (result) {
     case WAIT_OBJECT_0:
       return true;
     case WAIT_TIMEOUT:
@@ skipping 28 matching lines @@
                              INFINITE);  // no timeout
   if (result >= WAIT_OBJECT_0 + count) {
     DPLOG(FATAL) << "WaitForMultipleObjects failed";
     return 0;
   }
 
   return result - WAIT_OBJECT_0;
 }
 
 }  // namespace base