Changeset 247239 in webkit

Timestamp:

Jul 8, 2019 4:56:45 PM (5 years ago)

Author:

Chris Dumez

Message:

Make Document::postTask() safe to call from a background thread
​https://bugs.webkit.org/show_bug.cgi?id=199585

Reviewed by Alex Christensen.

Make Document::postTask() safe to call from a background thread by not calling makeWeakPtr() on the Document.
Calling makeWeakPtr() on a document from a background thread is not safe since Document is a main thread
object. Instead, capture Document::identifier() in the lambda and lookup the document from its identifier
once we're on the main thread.

• dom/Document.cpp:

(WebCore::Document::postTask):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• dom/Document.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-07-08  Chris Dumez  <cdumez@apple.com>
+
+        Make Document::postTask() safe to call from a background thread
+        https://bugs.webkit.org/show_bug.cgi?id=199585
+
+        Reviewed by Alex Christensen.
+
+        Make Document::postTask() safe to call from a background thread by not calling makeWeakPtr() on the Document.
+        Calling makeWeakPtr() on a document from a background thread is not safe since Document is a main thread
+        object. Instead, capture Document::identifier() in the lambda and lookup the document from its identifier
+        once we're on the main thread.
+
+        * dom/Document.cpp:
+        (WebCore::Document::postTask):
+
 2019-07-08  Youenn Fablet  <youenn@apple.com>
 

trunk/Source/WebCore/dom/Document.cpp

@@ -6121 +6121 @@
 void Document::postTask(Task&& task)
 {
-    callOnMainThread([documentReference = makeWeakPtr(*this), task = WTFMove(task)]() mutable {
+    callOnMainThread([documentID = identifier(), task = WTFMove(task)]() mutable {
         ASSERT(isMainThread());
 
-        Document* document = documentReference.get();
+        auto* document = allDocumentsMap().get(documentID);
         if (!document)
             return;