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

1 files changed, 8 insertions, 3 deletions

diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index fa0b3d8ee1da..4be06e43d112 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -278,17 +278,20 @@ void InputReader::loopOnce() {
 
     { // 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::dump(String8& dump) {
 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