commit eac3db27221c72e1a304b88fb1076c1f8c7be6ba
author Chia-I Wu <olv@google.com> Fri Sep 14 11:28:03 2018 -0700
committer Chia-I Wu <olv@google.com> Mon Oct 01 13:07:40 2018 -0700
tree 44b21f13f54e20c61b8534c1ae5864464d6d5cbf
parent 378461558c17da362bada8eaa5ddeb8b12f93fd1

surfaceflinger: use std::queue for mPendingEvents

Replace Vector by std::queue for mPendingEvents.  It is used for
pending hotplug events, which happen rarely and are consumed one by
one quickly by an RT thread.  std::queue is likely no better than
std::vector in that scenario, but is more expressive.

Bug: 115738279
Test: boots
Change-Id: Ia906a7f08ecbe6d5534cd6ec42e5af2ac865a911

services/surfaceflinger/Scheduler/EventThread.cpp

diff --git a/services/surfaceflinger/Scheduler/EventThread.cpp b/services/surfaceflinger/Scheduler/EventThread.cpp
index fa2b0a6..a75235c 100644
--- a/services/surfaceflinger/Scheduler/EventThread.cpp
+++ b/services/surfaceflinger/Scheduler/EventThread.cpp
@@ -181,7 +181,7 @@
     event.header.timestamp = systemTime();
     event.hotplug.connected = connected;
 
-    mPendingEvents.add(event);
+    mPendingEvents.push(event);
     mCondition.notify_all();
 }
 
@@ -244,11 +244,11 @@
 
         if (!timestamp) {
             // no vsync event, see if there are some other event
-            eventPending = !mPendingEvents.isEmpty();
+            eventPending = !mPendingEvents.empty();
             if (eventPending) {
                 // we have some other event to dispatch
-                *outEvent = mPendingEvents[0];
-                mPendingEvents.removeAt(0);
+                *outEvent = mPendingEvents.front();
+                mPendingEvents.pop();
             }
         }
 
@@ -384,6 +384,7 @@
         result.appendFormat("    %p: count=%d\n", connection.get(),
                             connection != nullptr ? connection->count : 0);
     }
+    result.appendFormat("  other-events-pending: %zu\n", mPendingEvents.size());
 }
 
 // ---------------------------------------------------------------------------

services/surfaceflinger/Scheduler/EventThread.h

diff --git a/services/surfaceflinger/Scheduler/EventThread.h b/services/surfaceflinger/Scheduler/EventThread.h
index 127891e..3879ae4 100644
--- a/services/surfaceflinger/Scheduler/EventThread.h
+++ b/services/surfaceflinger/Scheduler/EventThread.h
@@ -22,6 +22,7 @@
 #include <condition_variable>
 #include <cstdint>
 #include <mutex>
+#include <queue>
 #include <thread>
 
 #include <android-base/thread_annotations.h>
@@ -168,7 +169,7 @@
 
     // protected by mLock
     SortedVector<wp<Connection>> mDisplayEventConnections GUARDED_BY(mMutex);
-    Vector<DisplayEventReceiver::Event> mPendingEvents GUARDED_BY(mMutex);
+    std::queue<DisplayEventReceiver::Event> mPendingEvents GUARDED_BY(mMutex);
     std::array<DisplayEventReceiver::Event, 2> mVSyncEvent GUARDED_BY(mMutex);
     bool mUseSoftwareVSync GUARDED_BY(mMutex) = false;
     bool mVsyncEnabled GUARDED_BY(mMutex) = false;