Bug 679240 - Split total channel timeout into two discrete wait periods. Avoids aborting children after system sleep. r=bsmedberg

ipc/glue/SyncChannel.cpp

@@ -62,6 +62,7 @@ SyncChannel::SyncChannel(SyncListener* aListener)
   , mProcessingSyncMessage(false)
   , mNextSeqno(0)
   , mTimeoutMs(kNoTimeout)
+  , mInTimeoutSecondHalf(false)
 #ifdef OS_WIN
   , mTopFrame(NULL)
 #endif
@@ -283,6 +284,23 @@ SyncChannel::ShouldContinueFromTimeout()
     return cont;
 }
 
+bool
+SyncChannel::WaitResponse(bool aWaitTimedOut)
+{
+  if (aWaitTimedOut) {
+    if (mInTimeoutSecondHalf) {
+      // We've really timed out this time
+      return false;
+    }
+    // Try a second time
+    mInTimeoutSecondHalf = true;
+  } else {
+    mInTimeoutSecondHalf = false;
+  }
+  return true;
+}
+
+
 // Windows versions of the following two functions live in
 // WindowsMessageLoop.cpp.
 
@@ -301,7 +319,7 @@ SyncChannel::WaitForNotify()
 
     // if the timeout didn't expire, we know we received an event.
     // The converse is not true.
-    return !IsTimeoutExpired(waitStart, timeout);
+    return WaitResponse(IsTimeoutExpired(waitStart, timeout));
 }
 
 void

ipc/glue/SyncChannel.h

@@ -81,9 +81,13 @@ public:
     // Synchronously send |msg| (i.e., wait for |reply|)
     virtual bool Send(Message* msg, Message* reply);
 
+    // Set channel timeout value. Since this is broken up into
+    // two period, the minimum timeout value is 2ms.
     void SetReplyTimeoutMs(int32 aTimeoutMs) {
         AssertWorkerThread();
-        mTimeoutMs = (aTimeoutMs <= 0) ? kNoTimeout : aTimeoutMs;
+        mTimeoutMs = (aTimeoutMs <= 0) ? kNoTimeout :
+          // timeouts are broken up into two periods
+          (int32)ceil((double)aTimeoutMs/2.0);
     }
 
     static bool IsPumpingMessages() {
@@ -185,6 +189,12 @@ protected:
 
     static bool sIsPumpingMessages;
 
+    // Timeout periods are broken up in two to prevent system suspension from
+    // triggering an abort. This method (called by WaitForNotify with a 'did
+    // timeout' flag) decides if we should wait again for half of mTimeoutMs
+    // or give up.
+    bool WaitResponse(bool aWaitTimedOut);
+    bool mInTimeoutSecondHalf;
     int32 mTimeoutMs;
 
 #ifdef OS_WIN

ipc/glue/WindowsMessageLoop.cpp

@@ -741,7 +741,7 @@ SyncChannel::WaitForNotify()
 
   MonitorAutoUnlock unlock(*mMonitor);
 
-  bool retval = true;
+  bool timedout = false;
 
   UINT_PTR timerId = NULL;
   TimeoutData timeoutData = { 0 };
@@ -795,7 +795,7 @@ SyncChannel::WaitForNotify()
 
       if (TimeoutHasExpired(timeoutData)) {
         // A timeout was specified and we've passed it. Break out.
-        retval = false;
+        timedout = true;
         break;
       }
 
@@ -847,7 +847,7 @@ SyncChannel::WaitForNotify()
 
   SyncChannel::SetIsPumpingMessages(false);
 
-  return retval;
+  return WaitResponse(timedout);
 }
 
 bool
@@ -868,7 +868,7 @@ RPCChannel::WaitForNotify()
 
   MonitorAutoUnlock unlock(*mMonitor);
 
-  bool retval = true;
+  bool timedout = false;
 
   UINT_PTR timerId = NULL;
   TimeoutData timeoutData = { 0 };
@@ -949,7 +949,7 @@ RPCChannel::WaitForNotify()
 
     if (TimeoutHasExpired(timeoutData)) {
       // A timeout was specified and we've passed it. Break out.
-      retval = false;
+      timedout = true;
       break;
     }
 
@@ -987,7 +987,7 @@ RPCChannel::WaitForNotify()
 
   SyncChannel::SetIsPumpingMessages(false);
 
-  return retval;
+  return WaitResponse(timedout);
 }
 
 void

ipc/ipdl/test/cxx/TestHangs.cpp

@@ -73,7 +73,7 @@ TestHangsParent::ShouldContinueFromReplyTimeout()
 {
     mDetectedHang = true;
 
-    // so we've detected a timeout after 1 ms ... now we cheat and
+    // so we've detected a timeout after 2 ms ... now we cheat and
     // sleep for a long time, to allow the subprocess's reply to come
     // in
 
@@ -95,9 +95,9 @@ TestHangsParent::AnswerStackFrame()
             fail("should have timed out!");
     }
     else {
-        // minimum possible, 1 ms.  We want to detecting a hang to race
+        // minimum possible, 2 ms.  We want to detecting a hang to race
         // with the reply coming in, as reliably as possible
-        SetReplyTimeoutMs(1);
+        SetReplyTimeoutMs(2);
 
         if (CallHang())
             fail("should have timed out!");