Changeset 182980 in webkit

Timestamp:

Apr 17, 2015, 6:04:24 PM (10 years ago)

Author:

timothy_horton@apple.com

Message:

Clients sometimes block for 500ms in waitForPossibleGeometryUpdates
​https://bugs.webkit.org/show_bug.cgi?id=143901
<rdar://problem/20488655>

Reviewed by Anders Carlsson.

• Platform/IPC/Connection.cpp:

(IPC::Connection::waitForMessage):
InterruptWaitingIfSyncMessageArrives already cancels waitForMessage if
a sync message arrives while waiting, but it should also avoid waiting
if there's a sync message already in the queue when the waiting starts,
as that will have the same nasty effect.

• UIProcess/mac/TiledCoreAnimationDrawingAreaProxy.mm:

(WebKit::TiledCoreAnimationDrawingAreaProxy::waitForPossibleGeometryUpdate):
If a synchronous message comes in from the Web process while we're waiting,
cancel our synchronous wait for DidUpdateGeometry. This will cause the size
change to not synchronize with the Web process' painting, but that is better
than pointlessly blocking for 500ms.

Location:

trunk/Source/WebKit2

Files:

• ChangeLog (modified) (1 diff)
• Platform/IPC/Connection.cpp (modified) (3 diffs)
• UIProcess/mac/TiledCoreAnimationDrawingAreaProxy.mm (modified) (1 diff)

trunk/Source/WebKit2/ChangeLog

@@ +1 @@
+2015-04-17  Tim Horton  <timothy_horton@apple.com>
+
+        Clients sometimes block for 500ms in waitForPossibleGeometryUpdates
+        https://bugs.webkit.org/show_bug.cgi?id=143901
+        <rdar://problem/20488655>
+
+        Reviewed by Anders Carlsson.
+
+        * Platform/IPC/Connection.cpp:
+        (IPC::Connection::waitForMessage):
+        InterruptWaitingIfSyncMessageArrives already cancels waitForMessage if
+        a sync message arrives while waiting, but it should also avoid waiting
+        if there's a sync message already in the queue when the waiting starts,
+        as that will have the same nasty effect.
+
+        * UIProcess/mac/TiledCoreAnimationDrawingAreaProxy.mm:
+        (WebKit::TiledCoreAnimationDrawingAreaProxy::waitForPossibleGeometryUpdate):
+        If a synchronous message comes in from the Web process while we're waiting,
+        cancel our synchronous wait for DidUpdateGeometry. This will cause the size
+        change to not synchronize with the Web process' painting, but that is better
+        than pointlessly blocking for 500ms.
+
 2015-04-17  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebKit2/Platform/IPC/Connection.cpp

@@ -419 +419 @@
     ASSERT(&m_clientRunLoop == &RunLoop::current());
 
+    bool hasIncomingSynchronousMessage = false;
+
     // First, check if this message is already in the incoming messages queue.
     {
@@ -432 +434 @@
                 return returnedMessage;
             }
+
+            if (message->isSyncMessage())
+                hasIncomingSynchronousMessage = true;
         }
+    }
+
+    // Don't even start waiting if we have InterruptWaitingIfSyncMessageArrives and there's a sync message already in the queue.
+    if (hasIncomingSynchronousMessage && waitForMessageFlags & InterruptWaitingIfSyncMessageArrives) {
+        m_waitingForMessage = nullptr;
+        return nullptr;
     }
 
@@ -445 +456 @@
         m_waitingForMessage = &waitingForMessage;
     }
-    
+
     // Now wait for it to be set.
     while (true) {

trunk/Source/WebKit2/UIProcess/mac/TiledCoreAnimationDrawingAreaProxy.mm

@@ -77 +77 @@
         return;
 
-    m_webPageProxy.process().connection()->waitForAndDispatchImmediately<Messages::DrawingAreaProxy::DidUpdateGeometry>(m_webPageProxy.pageID(), timeout);
+    m_webPageProxy.process().connection()->waitForAndDispatchImmediately<Messages::DrawingAreaProxy::DidUpdateGeometry>(m_webPageProxy.pageID(), timeout, InterruptWaitingIfSyncMessageArrives);
 }