From 0e44976aa425b0c2a0dcf6ec8db918e6a6f51b1a Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Tue, 1 Dec 2009 17:23:28 -0800
Subject: [PATCH] fix [2297155] SurfaceFlinger's freeze-timeout doesn't work

There was bug in the logic that calculated the relative timeout, the start time was
reset each time an event was received, which caused the timeout to never occur if
an application was constantly redrawing.

Now we always check for a timeout when we come back from the waitEvent() and
process the "anti-freeze" if needed, regardless of whether an event was received.
---
 libs/surfaceflinger/SurfaceFlinger.cpp | 29 +++++++++++++++-----------
 libs/surfaceflinger/SurfaceFlinger.h   |  6 +++++-
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/libs/surfaceflinger/SurfaceFlinger.cpp b/libs/surfaceflinger/SurfaceFlinger.cpp
index 9694cf1f20fd3..965b7dd28f320 100644
--- a/libs/surfaceflinger/SurfaceFlinger.cpp
+++ b/libs/surfaceflinger/SurfaceFlinger.cpp
@@ -417,9 +417,9 @@ void SurfaceFlinger::waitForEvent()
 {
     while (true) {
         nsecs_t timeout = -1;
+        const nsecs_t freezeDisplayTimeout = ms2ns(5000);
         if (UNLIKELY(isFrozen())) {
             // wait 5 seconds
-            const nsecs_t freezeDisplayTimeout = ms2ns(5000);
             const nsecs_t now = systemTime();
             if (mFreezeDisplayTime == 0) {
                 mFreezeDisplayTime = now;
@@ -429,23 +429,27 @@ void SurfaceFlinger::waitForEvent()
         }
 
         MessageList::value_type msg = mEventQueue.waitMessage(timeout);
+
+        // see if we timed out
+        if (isFrozen()) {
+            const nsecs_t now = systemTime();
+            nsecs_t frozenTime = (now - mFreezeDisplayTime);
+            if (frozenTime >= freezeDisplayTimeout) {
+                // we timed out and are still frozen
+                LOGW("timeout expired mFreezeDisplay=%d, mFreezeCount=%d",
+                        mFreezeDisplay, mFreezeCount);
+                mFreezeDisplayTime = 0;
+                mFreezeCount = 0;
+                mFreezeDisplay = false;
+            }
+        }
+
         if (msg != 0) {
-            mFreezeDisplayTime = 0;
             switch (msg->what) {
                 case MessageQueue::INVALIDATE:
                     // invalidate message, just return to the main loop
                     return;
             }
-        } else {
-            // we timed out
-            if (isFrozen()) {
-                // we timed out and are still frozen
-                LOGW("timeout expired mFreezeDisplay=%d, mFreezeCount=%d",
-                        mFreezeDisplay, mFreezeCount);
-                mFreezeCount = 0;
-                mFreezeDisplay = false;
-                return;
-            }
         }
     }
 }
@@ -1646,6 +1650,7 @@ status_t SurfaceFlinger::onTransact(
             }
             case 1007: // set mFreezeCount
                 mFreezeCount = data.readInt32();
+                mFreezeDisplayTime = 0;
                 return NO_ERROR;
             case 1010:  // interrogate.
                 reply->writeInt32(0);
diff --git a/libs/surfaceflinger/SurfaceFlinger.h b/libs/surfaceflinger/SurfaceFlinger.h
index f9bfe6c7c3016..c0ab73d891228 100644
--- a/libs/surfaceflinger/SurfaceFlinger.h
+++ b/libs/surfaceflinger/SurfaceFlinger.h
@@ -291,7 +291,11 @@ private:
 
             friend class FreezeLock;
             sp<FreezeLock> getFreezeLock() const;
-            inline void incFreezeCount() { mFreezeCount++; }
+            inline void incFreezeCount() {
+                if (mFreezeCount == 0)
+                    mFreezeDisplayTime = 0;
+                mFreezeCount++;
+            }
             inline void decFreezeCount() { if (mFreezeCount > 0) mFreezeCount--; }
             inline bool hasFreezeRequest() const { return mFreezeDisplay; }
             inline bool isFrozen() const {