Merge "Bound pending write events queue to avoid OOM"
am: 6cbd36f357

Change-Id: Ice70a28b24275e9463d2f3750fa39c0f5d811f00
diff --git a/sensors/2.0/multihal/HalProxy.cpp b/sensors/2.0/multihal/HalProxy.cpp
index 49c5a0d..03ff605 100644
--- a/sensors/2.0/multihal/HalProxy.cpp
+++ b/sensors/2.0/multihal/HalProxy.cpp
@@ -150,6 +150,7 @@
 
     // Clears the queue if any events were pending write before.
     mPendingWriteEventsQueue = std::queue<std::pair<std::vector<Event>, size_t>>();
+    mSizePendingWriteEventsQueue = 0;
 
     // Clears previously connected dynamic sensors
     mDynamicSensors.clear();
@@ -287,7 +288,7 @@
            << " ms ago" << std::endl;
     // TODO(b/142969448): Add logging for history of wakelock acquisition per subhal.
     stream << "  Wakelock ref count: " << mWakelockRefCount << std::endl;
-    stream << "  Size of pending write events queue: " << mPendingWriteEventsQueue.size()
+    stream << "  # of events on pending write writes queue: " << mSizePendingWriteEventsQueue
            << std::endl;
     if (!mPendingWriteEventsQueue.empty()) {
         stream << "  Size of events list on front of pending writes queue: "
@@ -490,8 +491,10 @@
                 // all the events ahead of it down to fill gap off array at front after the erase.
                 pendingWriteEvents.erase(pendingWriteEvents.begin(),
                                          pendingWriteEvents.begin() + eventQueueSize);
+                mSizePendingWriteEventsQueue -= eventQueueSize;
             } else {
                 mPendingWriteEventsQueue.pop();
+                mSizePendingWriteEventsQueue -= pendingWriteEvents.size();
             }
         }
     }
@@ -563,11 +566,12 @@
             }
         }
     }
-    if (numToWrite < events.size()) {
-        // TODO(b/143302327): Bound the mPendingWriteEventsQueue so that we do not trigger OOMs if
-        // framework stalls
+    size_t numLeft = events.size() - numToWrite;
+    if (numToWrite < events.size() &&
+        mSizePendingWriteEventsQueue + numLeft <= kMaxSizePendingWriteEventsQueue) {
         std::vector<Event> eventsLeft(events.begin() + numToWrite, events.end());
         mPendingWriteEventsQueue.push({eventsLeft, numWakeupEvents});
+        mSizePendingWriteEventsQueue += numLeft;
         mEventQueueWriteCV.notify_one();
     }
 }
diff --git a/sensors/2.0/multihal/include/HalProxy.h b/sensors/2.0/multihal/include/HalProxy.h
index b1dd737..ce28e67 100644
--- a/sensors/2.0/multihal/include/HalProxy.h
+++ b/sensors/2.0/multihal/include/HalProxy.h
@@ -200,6 +200,12 @@
      */
     std::queue<std::pair<std::vector<Event>, size_t>> mPendingWriteEventsQueue;
 
+    //! The max number of events allowed in the pending write events queue
+    static constexpr size_t kMaxSizePendingWriteEventsQueue = 100000;
+
+    //! The number of events in the pending write events queue
+    size_t mSizePendingWriteEventsQueue = 0;
+
     //! The mutex protecting writing to the fmq and the pending events queue
     std::mutex mEventQueueWriteMutex;