commit 112b5f52c5a4b6743eeb7b26a8896c7636c74455
author Jeff Brown <jeffbrown@google.com> Fri Jan 27 17:32:06 2012 -0800
committer Jeff Brown <jeffbrown@google.com> Fri Jan 27 17:33:42 2012 -0800
tree b9e6ce9e78630475cea99044392dbb3c183626c4
parent 75ea64fc54f328d37b115cfb1ded1e45c30380ed

Improve watchdog monitor for InputReader and InputDispatcher.

Try harder to test for liveness.  There are situations where
the lock might not be held but the input system is stuck in
a callback into the window manager policy that has hung.

Bug: 5094994
Change-Id: Iff88655512a5dc8bbb4615be65f4115e975c020b

services/input/InputDispatcher.cpp

diff --git a/services/input/InputDispatcher.cpp b/services/input/InputDispatcher.cpp
index 9f09062..ad64ccd 100644
--- a/services/input/InputDispatcher.cpp
+++ b/services/input/InputDispatcher.cpp
@@ -238,6 +238,8 @@
     nsecs_t nextWakeupTime = LONG_LONG_MAX;
     { // acquire lock
         AutoMutex _l(mLock);
+        mDispatcherIsAliveCondition.broadcast();
+
         dispatchOnceInnerLocked(&nextWakeupTime);
 
         if (runCommandsLockedInterruptible()) {
@@ -4086,6 +4088,8 @@
 void InputDispatcher::monitor() {
     // Acquire and release the lock to ensure that the dispatcher has not deadlocked.
     mLock.lock();
+    mLooper->wake();
+    mDispatcherIsAliveCondition.wait(mLock);
     mLock.unlock();
 }
 

services/input/InputDispatcher.h

diff --git a/services/input/InputDispatcher.h b/services/input/InputDispatcher.h
index 1478d67..a1d42e1 100644
--- a/services/input/InputDispatcher.h
+++ b/services/input/InputDispatcher.h
@@ -862,6 +862,8 @@
 
     Mutex mLock;
 
+    Condition mDispatcherIsAliveCondition;
+
     sp<Looper> mLooper;
 
     EventEntry* mPendingEvent;

services/input/InputReader.cpp

diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index fa0b3d8..4be06e4 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -278,17 +278,20 @@
 
     { // acquire lock
         AutoMutex _l(mLock);
+        mReaderIsAliveCondition.broadcast();
 
         if (count) {
             processEventsLocked(mEventBuffer, count);
         }
         if (!count || timeoutMillis == 0) {
             nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+            if (now >= mNextTimeout) {
 #if DEBUG_RAW_EVENTS
-            ALOGD("Timeout expired, latency=%0.3fms", (now - mNextTimeout) * 0.000001f);
+                ALOGD("Timeout expired, latency=%0.3fms", (now - mNextTimeout) * 0.000001f);
 #endif
-            mNextTimeout = LLONG_MAX;
-            timeoutExpiredLocked(now);
+                mNextTimeout = LLONG_MAX;
+                timeoutExpiredLocked(now);
+            }
         }
     } // release lock
 
@@ -772,6 +775,8 @@
 void InputReader::monitor() {
     // Acquire and release the lock to ensure that the reader has not deadlocked.
     mLock.lock();
+    mEventHub->wake();
+    mReaderIsAliveCondition.wait(mLock);
     mLock.unlock();
 
     // Check the EventHub

services/input/InputReader.h

diff --git a/services/input/InputReader.h b/services/input/InputReader.h
index a122c97..ad89a22 100644
--- a/services/input/InputReader.h
+++ b/services/input/InputReader.h
@@ -363,6 +363,8 @@
 private:
     Mutex mLock;
 
+    Condition mReaderIsAliveCondition;
+
     sp<EventHubInterface> mEventHub;
     sp<InputReaderPolicyInterface> mPolicy;
     sp<QueuedInputListener> mQueuedListener;