$OpenBSD$

index fbb3514..61bd08c 100644
--- ipc/glue/WindowsMessageLoop.cpp.orig	Fri Feb 20 15:40:37 2015
+++ ipc/glue/WindowsMessageLoop.cpp	Fri Feb 20 15:40:37 2015
@@ -540,19 +540,6 @@ UnhookNeuteredWindows()
   gNeuteredWindows->Clear();
 }
 
-void
-Init()
-{
-  // If we aren't setup before a call to NotifyWorkerThread, we'll hang
-  // on startup.
-  if (!gUIThreadId) {
-    gUIThreadId = GetCurrentThreadId();
-  }
-  NS_ASSERTION(gUIThreadId, "ThreadId should not be 0!");
-  NS_ASSERTION(gUIThreadId == GetCurrentThreadId(),
-               "Running on different threads!");
-}
-
 // This timeout stuff assumes a sane value of mTimeoutMs (less than the overflow
 // value for GetTickCount(), which is something like 50 days). It uses the
 // cheapest (and least accurate) method supported by Windows 2000.
@@ -594,6 +581,28 @@ TimeoutHasExpired(const TimeoutData& aData)
 
 } // anonymous namespace
 
+namespace mozilla {
+namespace ipc {
+namespace windows {
+
+void
+InitUIThread()
+{
+  // If we aren't setup before a call to NotifyWorkerThread, we'll hang
+  // on startup.
+  if (!gUIThreadId) {
+    gUIThreadId = GetCurrentThreadId();
+  }
+  MOZ_ASSERT(gUIThreadId);
+  MOZ_ASSERT(gUIThreadId == GetCurrentThreadId(),
+               "Called InitUIThread multiple times on different threads!");
+}
+
+} // namespace windows
+} // namespace ipc
+} // namespace mozilla
+
+// See SpinInternalEventLoop below
 MessageChannel::SyncStackFrame::SyncStackFrame(MessageChannel* channel, bool interrupt)
   : mInterrupt(interrupt)
   , mSpinNestedEvents(false)
@@ -602,6 +611,12 @@ MessageChannel::SyncStackFrame::SyncStackFrame(MessageChannel* channel, bool int
   , mPrev(mChannel->mTopFrame)
   , mStaticPrev(sStaticTopFrame)
 {
+  // Only track stack frames when Windows message deferral behavior
+  // is request for the channel.
+  if (!(mChannel->GetChannelFlags() & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) {
+    return;
+  }
+
   mChannel->mTopFrame = this;
   sStaticTopFrame = this;
 
@@ -614,6 +629,10 @@ MessageChannel::SyncStackFrame::SyncStackFrame(MessageChannel* channel, bool int
 
 MessageChannel::SyncStackFrame::~SyncStackFrame()
 {
+  if (!(mChannel->GetChannelFlags() & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) {
+    return;
+  }
+
   NS_ASSERTION(this == mChannel->mTopFrame,
                "Mismatched interrupt stack frames");
   NS_ASSERTION(this == sStaticTopFrame,
@@ -652,6 +671,8 @@ MessageChannel::NotifyGeckoEventDispatch()
 void
 MessageChannel::ProcessNativeEventsInInterruptCall()
 {
+  NS_ASSERTION(GetCurrentThreadId() == gUIThreadId,
+               "Shouldn't be on a non-main thread in here!");
   if (!mTopFrame) {
     NS_ERROR("Spin logic error: no Interrupt frame");
     return;
@@ -721,14 +742,47 @@ MessageChannel::SpinInternalEventLoop()
   } while (true);
 }
 
+static inline bool
+IsTimeoutExpired(PRIntervalTime aStart, PRIntervalTime aTimeout)
+{
+  return (aTimeout != PR_INTERVAL_NO_TIMEOUT) &&
+    (aTimeout <= (PR_IntervalNow() - aStart));
+}
+
 bool
 MessageChannel::WaitForSyncNotify()
 {
   mMonitor->AssertCurrentThreadOwns();
 
-  // Initialize global objects used in deferred messaging.
-  Init();
+  MOZ_ASSERT(gUIThreadId, "InitUIThread was not called!");
+
+  // Use a blocking wait if this channel does not require
+  // Windows message deferral behavior.
+  if (!(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) {
+    PRIntervalTime timeout = (kNoTimeout == mTimeoutMs) ?
+                             PR_INTERVAL_NO_TIMEOUT :
+                             PR_MillisecondsToInterval(mTimeoutMs);
+    // XXX could optimize away this syscall for "no timeout" case if desired
+    PRIntervalTime waitStart = 0;
+    
+    if (timeout != PR_INTERVAL_NO_TIMEOUT) {
+      waitStart = PR_IntervalNow();
+    }
+
+    mIsSyncWaitingOnNonMainThread = true;
+
+    mMonitor->Wait(timeout);
 
+    mIsSyncWaitingOnNonMainThread = false;
+
+    // If the timeout didn't expire, we know we received an event. The
+    // converse is not true.
+    return WaitResponse(timeout == PR_INTERVAL_NO_TIMEOUT ?
+                        false : IsTimeoutExpired(waitStart, timeout));
+  }
+
+  NS_ASSERTION(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION,
+               "Shouldn't be here for channels that don't use message deferral!");
   NS_ASSERTION(mTopFrame && !mTopFrame->mInterrupt,
                "Top frame is not a sync frame!");
 
@@ -848,14 +902,21 @@ MessageChannel::WaitForInterruptNotify()
 {
   mMonitor->AssertCurrentThreadOwns();
 
+  MOZ_ASSERT(gUIThreadId, "InitUIThread was not called!");
+
+  // Re-use sync notification wait code if this channel does not require
+  // Windows message deferral behavior. 
+  if (!(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) {
+    return WaitForSyncNotify();
+  }
+
   if (!InterruptStackDepth()) {
     // There is currently no way to recover from this condition.
     NS_RUNTIMEABORT("StackDepth() is 0 in call to MessageChannel::WaitForNotify!");
   }
 
-  // Initialize global objects used in deferred messaging.
-  Init();
-
+  NS_ASSERTION(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION,
+               "Shouldn't be here for channels that don't use message deferral!");
   NS_ASSERTION(mTopFrame && mTopFrame->mInterrupt,
                "Top frame is not a sync frame!");
 
@@ -987,6 +1048,12 @@ void
 MessageChannel::NotifyWorkerThread()
 {
   mMonitor->AssertCurrentThreadOwns();
+
+  if (mIsSyncWaitingOnNonMainThread) {
+    mMonitor->Notify();
+    return;
+  }
+
   NS_ASSERTION(mEvent, "No signal event to set, this is really bad!");
   if (!SetEvent(mEvent)) {
     NS_WARNING("Failed to set NotifyWorkerThread event!");