Changeset 282011 in webkit

Timestamp:

Sep 3, 2021, 12:11:25 PM (5 years ago)

Author:

Chris Dumez

Message:

Fix race in RemoteRenderingBackend::allowsExitUnderMemoryPressure()
​https://bugs.webkit.org/show_bug.cgi?id=229870
<rdar://82459484>

Reviewed by David Kilzer.

RemoteRenderingBackend::m_remoteResourceCache should only be used safely from RemoteRenderingBackend's work queue.
RemoteRenderingBackend::allowsExitUnderMemoryPressure() gets called on the main thread so we need to make sure we
dispatch to RemoteRenderingBackend's work queue before accessing m_remoteResourceCache.

• GPUProcess/graphics/RemoteRenderingBackend.cpp:

(WebKit::RemoteRenderingBackend::allowsExitUnderMemoryPressure const):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• GPUProcess/graphics/RemoteRenderingBackend.cpp (modified) (1 diff)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2021-09-03  Chris Dumez  <cdumez@apple.com>
+
+        Fix race in RemoteRenderingBackend::allowsExitUnderMemoryPressure()
+        https://bugs.webkit.org/show_bug.cgi?id=229870
+        <rdar://82459484>
+
+        Reviewed by David Kilzer.
+
+        RemoteRenderingBackend::m_remoteResourceCache should only be used safely from RemoteRenderingBackend's work queue.
+        RemoteRenderingBackend::allowsExitUnderMemoryPressure() gets called on the main thread so we need to make sure we
+        dispatch to RemoteRenderingBackend's work queue before accessing m_remoteResourceCache.
+
+        * GPUProcess/graphics/RemoteRenderingBackend.cpp:
+        (WebKit::RemoteRenderingBackend::allowsExitUnderMemoryPressure const):
+
 2021-09-03  Alex Christensen  <achristensen@webkit.org>
 

trunk/Source/WebKit/GPUProcess/graphics/RemoteRenderingBackend.cpp

@@ -682 +682 @@
 bool RemoteRenderingBackend::allowsExitUnderMemoryPressure() const
 {
-    return m_remoteResourceCache.imageBuffers().isEmpty() && m_remoteResourceCache.nativeImages().isEmpty();
+    ASSERT(isMainRunLoop());
+    bool hasActiveDrawables = false;
+    m_workQueue->dispatchSync([this, &hasActiveDrawables] {
+        hasActiveDrawables = !m_remoteResourceCache.imageBuffers().isEmpty() || !m_remoteResourceCache.nativeImages().isEmpty();
+    });
+    return !hasActiveDrawables;
 }