From 4594eee516213158662b6b279bd77ba8b4aaad1e Mon Sep 17 00:00:00 2001
From: Cameron Kaiser <classilla@floodgap.com>
Date: Mon, 25 Mar 2019 20:48:57 -0700
Subject: [PATCH] #446 + #334: trim refresh driver further; restore old Tele
 removal

---
 layout/base/nsRefreshDriver.cpp  | 34 +++++++++++++++++++++-----------
 toolkit/xre/nsEmbedFunctions.cpp |  6 ++++++
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/layout/base/nsRefreshDriver.cpp b/layout/base/nsRefreshDriver.cpp
index ac5a414a2..b446e4583 100644
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -430,9 +430,11 @@ private:
 
     void OnTimerStart()
     {
+#if(0)
       if (!XRE_IsParentProcess()) {
         mLastChildTick = TimeStamp::Now();
       }
+#endif
     }
 
   private:
@@ -440,6 +442,7 @@ private:
 
     void RecordTelemetryProbes(TimeStamp aVsyncTimestamp)
     {
+#if(0)
       MOZ_ASSERT(NS_IsMainThread());
     #ifndef ANDROID  /* bug 1142079 */
       if (XRE_IsParentProcess()) {
@@ -467,20 +470,23 @@ private:
         mVsyncRate = mVsyncRefreshDriverTimer->mVsyncChild->GetVsyncRate();
       }
     #endif
+#endif
     }
 
     void TickRefreshDriver(TimeStamp aVsyncTimestamp)
     {
       MOZ_ASSERT(NS_IsMainThread());
 
-      RecordTelemetryProbes(aVsyncTimestamp);
-      if (XRE_IsParentProcess()) {
+      //RecordTelemetryProbes(aVsyncTimestamp);
+      //if (XRE_IsParentProcess()) {
+      { // Make sure the lock expires before we leave this block.
         MonitorAutoLock lock(mRefreshTickLock);
         aVsyncTimestamp = mRecentVsync;
         mProcessedVsync = true;
-      } else {
-        mLastChildTick = TimeStamp::Now();
       }
+      //} else {
+      //  mLastChildTick = TimeStamp::Now();
+      //}
       MOZ_ASSERT(aVsyncTimestamp <= TimeStamp::Now());
 
       // We might have a problem that we call ~VsyncRefreshDriverTimer() before
@@ -504,9 +510,10 @@ private:
 
   virtual ~VsyncRefreshDriverTimer()
   {
-    if (XRE_IsParentProcess()) {
+    //if (XRE_IsParentProcess()) {
       mVsyncDispatcher->SetParentRefreshTimer(nullptr);
       mVsyncDispatcher = nullptr;
+#if(0)
     } else {
       // Since the PVsyncChild actors live through the life of the process, just
       // send the unobserveVsync message to disable vsync event. We don't need
@@ -516,6 +523,7 @@ private:
       mVsyncChild->SetVsyncObserver(nullptr);
       mVsyncChild = nullptr;
     }
+#endif
 
     // Detach current vsync timer from this VsyncObserver. The observer will no
     // longer tick this timer.
@@ -531,12 +539,12 @@ private:
     mLastFireEpoch = JS_Now();
     mLastFireTime = TimeStamp::Now();
 
-    if (XRE_IsParentProcess()) {
+    //if (XRE_IsParentProcess()) {
       mVsyncDispatcher->SetParentRefreshTimer(mVsyncObserver);
-    } else {
-      Unused << mVsyncChild->SendObserve();
-      mVsyncObserver->OnTimerStart();
-    }
+    //} else {
+    //  Unused << mVsyncChild->SendObserve();
+    //  mVsyncObserver->OnTimerStart();
+    //}
 
     ++sActiveVsyncTimers;
   }
@@ -832,14 +840,14 @@ CreateVsyncRefreshTimer()
     return;
   }
 
-  if (XRE_IsParentProcess()) {
+  //if (XRE_IsParentProcess()) {
     // Make sure all vsync systems are ready.
     gfxPlatform::GetPlatform();
     // In parent process, we don't need to use ipc. We can create the
     // VsyncRefreshDriverTimer directly.
     sRegularRateTimer = new VsyncRefreshDriverTimer();
     return;
-  }
+  //}
 
 #ifdef MOZ_NUWA_PROCESS
   // NUWA process will just use software timer. Use NuwaAddFinalConstructor()
@@ -1878,8 +1886,10 @@ nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
     }
   }
 
+#if(0)
 #ifndef ANDROID  /* bug 1142079 */
   mozilla::Telemetry::AccumulateTimeDelta(mozilla::Telemetry::REFRESH_DRIVER_TICK, mTickStart);
+#endif
 #endif
 
   nsTObserverArray<nsAPostRefreshObserver*>::ForwardIterator iter(mPostRefreshObservers);
diff --git a/toolkit/xre/nsEmbedFunctions.cpp b/toolkit/xre/nsEmbedFunctions.cpp
index e735bf626..c8d07b0df 100644
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -237,6 +237,12 @@ XRE_SetProcessType(const char* aProcessTypeString)
        i < (int) ArrayLength(kGeckoProcessTypeString);
        ++i) {
     if (!strcmp(kGeckoProcessTypeString[i], aProcessTypeString)) {
+      // For purposes of TenFourFox issue 446, assert that we never, ever
+      // launch a child process (it would immediately crash anyway due to
+      // defective IPC, but let's be paranoid and make it crash predictably).
+      if (MOZ_UNLIKELY(static_cast<GeckoProcessType>(i) != GeckoProcessType_Default))
+        MOZ_CRASH("TenFourFox does not support E10S child processes.");
+
       sChildProcessType = static_cast<GeckoProcessType>(i);
       return;
     }