Changeset 228152 in webkit

Timestamp:

Feb 5, 2018 10:50:24 PM (6 years ago)

Author:

Chris Dumez

Message:

Avoid unnecessarily constructing RunLoops for GC AutomaticThreads in Connection::sendMessage() after r228001
​https://bugs.webkit.org/show_bug.cgi?id=182494
<rdar://problem/37147632>

Reviewed by Ryosuke Niwa.

Somebody fixed a GC crash in r228001 by allowing RunLoop::current() to be called from a
GC thread. However, this is still unnecessarily inefficient. Calling RunLoop::current()
will construct RunLoops for background GC threads (WTF::AutomaticThreads). This patches
updates the IPC code to call isMainThread() instead of RunLoop::isMain() in
Connection::sendMessage(). This should mean the same thing since this code runs in
WebKit2 and should be more efficient as it ends up simply calling pthread_main_np(),
without constructing a RunLoop.

• Platform/IPC/Connection.cpp:

(IPC::Connection::sendMessage):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• Platform/IPC/Connection.cpp (modified) (1 diff)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2018-02-05  Chris Dumez  <cdumez@apple.com>
+
+        Avoid unnecessarily constructing RunLoops for GC AutomaticThreads in Connection::sendMessage() after r228001
+        https://bugs.webkit.org/show_bug.cgi?id=182494
+        <rdar://problem/37147632>
+
+        Reviewed by Ryosuke Niwa.
+
+        Somebody fixed a GC crash in r228001 by allowing RunLoop::current() to be called from a
+        GC thread. However, this is still unnecessarily inefficient. Calling RunLoop::current()
+        will construct RunLoops for background GC threads (WTF::AutomaticThreads). This patches
+        updates the IPC code to call isMainThread() instead of RunLoop::isMain() in
+        Connection::sendMessage(). This should mean the same thing since this code runs in
+        WebKit2 and should be more efficient as it ends up simply calling pthread_main_np(),
+        without constructing a RunLoop.
+
+        * Platform/IPC/Connection.cpp:
+        (IPC::Connection::sendMessage):
+
 2018-02-05  Ryosuke Niwa  <rniwa@webkit.org>
 

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

@@ -380 +380 @@
         return false;
 
-    if (RunLoop::isMain() && m_inDispatchMessageMarkedToUseFullySynchronousModeForTesting && !encoder->isSyncMessage() && !(encoder->messageReceiverName() == "IPC")) {
+    if (isMainThread() && m_inDispatchMessageMarkedToUseFullySynchronousModeForTesting && !encoder->isSyncMessage() && !(encoder->messageReceiverName() == "IPC")) {
         uint64_t syncRequestID;
         auto wrappedMessage = createSyncMessageEncoder("IPC", "WrappedAsyncMessageForTesting", encoder->destinationID(), syncRequestID);