Changeset 95961 in webkit

Timestamp:

Sep 26, 2011 10:36:19 AM (13 years ago)

Author:

mrowe@apple.com

Message:

<​http://webkit.org/b/68809> IconDatabase::syncThreadMainLoop can assert if wakeSyncThread is called before thread starts executing

If wakeSyncThread is called before syncThreadMainLoop starts executing then m_syncThreadHasWorkToDo would be set
while executing the body of the sync thread loop, causing us to skip blocking on the condition variable. This would
lead to us hitting the assertion failure due to m_disabledSuddenTerminationForSyncThread being false, unless the main
thread happened to call wakeSyncThread a second time while the first loop iteration was executing.

Reviewed by Anders Carlsson.

• loader/icon/IconDatabase.cpp:

(WebCore::IconDatabase::syncThreadMainLoop): Clear m_syncThreadHasWorkToDo to indicate that we're about to perform
all pending work.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• loader/icon/IconDatabase.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2011-09-26  Mark Rowe  <mrowe@apple.com>
+
+        <http://webkit.org/b/68809> IconDatabase::syncThreadMainLoop can assert if wakeSyncThread is called before thread starts executing
+
+        If wakeSyncThread is called before syncThreadMainLoop starts executing then m_syncThreadHasWorkToDo would be set
+        while executing the body of the sync thread loop, causing us to skip blocking on the condition variable. This would
+        lead to us hitting the assertion failure due to m_disabledSuddenTerminationForSyncThread being false, unless the main
+        thread happened to call wakeSyncThread a second time while the first loop iteration was executing.
+
+        Reviewed by Anders Carlsson.
+
+        * loader/icon/IconDatabase.cpp:
+        (WebCore::IconDatabase::syncThreadMainLoop): Clear m_syncThreadHasWorkToDo to indicate that we're about to perform
+        all pending work.
+
 2011-09-26  Antaryami Pandia  <antaryami.pandia@motorola.com>
 

trunk/Source/WebCore/loader/icon/IconDatabase.cpp

@@ -1357 +1357 @@
     bool shouldReenableSuddenTermination = m_disabledSuddenTerminationForSyncThread;
     m_disabledSuddenTerminationForSyncThread = false;
+
+    // We'll either do any pending work on our first pass through the loop, or we'll terminate
+    // without doing any work. Either way we're dealing with any currently-pending work.
+    m_syncThreadHasWorkToDo = false;
 
     // It's possible thread termination is requested before the main loop even starts - in that case, just skip straight to cleanup