cc: Do not allow CCScheduler::processScheduledActions to recurse

BUG=151420


Review URL: https://chromiumcodereview.appspot.com/10969027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158913 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 13 insertions, 15 deletions

diff --git a/cc/CCScheduler.cpp b/cc/CCScheduler.cpp
index 78fcca8..d9d4ea0 100644
--- a/cc/CCScheduler.cpp
+++ b/cc/CCScheduler.cpp
@@ -7,6 +7,7 @@
 #include "CCScheduler.h"
 
 #include "TraceEvent.h"
+#include <base/auto_reset.h>
 
 namespace cc {
 
@@ -14,6 +15,7 @@ CCScheduler::CCScheduler(CCSchedulerClient* client, PassOwnPtr<CCFrameRateContro
     : m_client(client)
     , m_frameRateController(frameRateController)
     , m_updateResourcesCompletePending(false)
+    , m_insideProcessScheduledActions(false)
 {
     ASSERT(m_client);
     m_frameRateController->setClient(this);
@@ -40,11 +42,7 @@ void CCScheduler::setVisible(bool visible)
 void CCScheduler::setCanDraw(bool canDraw)
 {
     m_stateMachine.setCanDraw(canDraw);
-
-    // Defer processScheduleActions so we don't recurse and commit/draw
-    // multiple frames. We can call processScheduledActions directly
-    // once it is no longer re-entrant.
-    m_frameRateController->setActive(m_stateMachine.vsyncCallbackNeeded());
+    processScheduledActions();
 }
 
 void CCScheduler::setNeedsCommit()
@@ -149,17 +147,15 @@ void CCScheduler::updateResourcesComplete()
 
 void CCScheduler::processScheduledActions()
 {
-    // Early out so we don't spam TRACE_EVENTS with useless processScheduledActions.
-    if (m_stateMachine.nextAction() == CCSchedulerStateMachine::ACTION_NONE) {
-        m_frameRateController->setActive(m_stateMachine.vsyncCallbackNeeded());
+    // We do not allow processScheduledActions to be recursive.
+    // The top-level call will iteratively execute the next action for us anyway.
+    if (m_insideProcessScheduledActions)
         return;
-    }
 
-    // This function can re-enter itself. For example, draw may call
-    // setNeedsCommit. Proceeed with caution.
-    CCSchedulerStateMachine::Action action;
-    do {
-        action = m_stateMachine.nextAction();
+    AutoReset<bool> markInside(&m_insideProcessScheduledActions, true);
+
+    CCSchedulerStateMachine::Action action = m_stateMachine.nextAction();
+    while (action != CCSchedulerStateMachine::ACTION_NONE) {
         m_stateMachine.updateState(action);
         TRACE_EVENT1("cc", "CCScheduler::processScheduledActions()", "action", action);
 
@@ -196,7 +192,8 @@ void CCScheduler::processScheduledActions()
             m_client->scheduledActionAcquireLayerTexturesForMainThread();
             break;
         }
-    } while (action != CCSchedulerStateMachine::ACTION_NONE);
+        action = m_stateMachine.nextAction();
+    }
 
     // Activate or deactivate the frame rate controller.
     m_frameRateController->setActive(m_stateMachine.vsyncCallbackNeeded());
diff --git a/cc/CCScheduler.h b/cc/CCScheduler.h
index 2d276a6..2600f780 100644
--- a/cc/CCScheduler.h
+++ b/cc/CCScheduler.h
@@ -100,6 +100,7 @@ private:
     OwnPtr<CCFrameRateController> m_frameRateController;
     CCSchedulerStateMachine m_stateMachine;
     bool m_updateResourcesCompletePending;
+    bool m_insideProcessScheduledActions;
 };
 
 }