Bug 1315570, vsync handling in parent process' main thread should use high priority runnables, r=ehsan

--HG-- extra : rebase_source : db5995cace3ed5e8d8dd2d095c725c3ce9f5c4e2
2017-02-11 16:59:36 +02:00 · 2017-02-11 16:59:36 +02:00 · 6a96b12f98
--- a/devtools/client/commandline/test/browser_cmd_highlight_04.js
+++ b/devtools/client/commandline/test/browser_cmd_highlight_04.js
@ -7,6 +7,8 @@

 // Tests the various highlight command parameters and options

+requestLongerTimeout(3);
+
 // Creating a test page with many elements to test the --showall option
 var TEST_PAGE = "data:text/html;charset=utf-8,<body><ul>";
 for (let i = 0; i < 101; i++) {
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@ -493,6 +493,34 @@ private:
      MOZ_ASSERT(NS_IsMainThread());
    }

+    class ParentProcessVsyncNotifier final: public Runnable,
+                                            public nsIRunnablePriority
+    {
+    public:
+      ParentProcessVsyncNotifier(RefreshDriverVsyncObserver* aObserver,
+                                 TimeStamp aVsyncTimestamp)
+        : mObserver(aObserver), mVsyncTimestamp(aVsyncTimestamp) {}
+
+      NS_DECL_ISUPPORTS_INHERITED
+
+      NS_IMETHOD Run() override
+      {
+        mObserver->TickRefreshDriver(mVsyncTimestamp);
+        return NS_OK;
+      }
+
+      NS_IMETHOD GetPriority(uint32_t* aPriority) override
+      {
+        *aPriority = nsIRunnablePriority::PRIORITY_HIGH;
+        return NS_OK;
+      }
+
+    private:
+      ~ParentProcessVsyncNotifier() {}
+      RefPtr<RefreshDriverVsyncObserver> mObserver;
+      TimeStamp mVsyncTimestamp;
+    };
+
    bool NotifyVsync(TimeStamp aVsyncTimestamp) override
    {
      if (!NS_IsMainThread()) {
@ -510,9 +538,7 @@ private:
        }

        nsCOMPtr<nsIRunnable> vsyncEvent =
-             NewRunnableMethod<TimeStamp>(this,
-                                          &RefreshDriverVsyncObserver::TickRefreshDriver,
-                                          aVsyncTimestamp);
+          new ParentProcessVsyncNotifier(this, aVsyncTimestamp);
        NS_DispatchToMainThread(vsyncEvent);
      } else {
        TickRefreshDriver(aVsyncTimestamp);
@ -706,6 +732,11 @@ private:
  TimeDuration mVsyncRate;
 }; // VsyncRefreshDriverTimer

+NS_IMPL_ISUPPORTS_INHERITED(VsyncRefreshDriverTimer::
+                            RefreshDriverVsyncObserver::
+                            ParentProcessVsyncNotifier,
+                            Runnable, nsIRunnablePriority)
+
 /**
 * Since the content process takes some time to setup
 * the vsync IPC connection, this timer is used