1 files changed, 14 insertions, 4 deletions

diff --git a/media/jni/soundpool/StreamManager.cpp b/media/jni/soundpool/StreamManager.cpp
index 8b84bf3eb8d8..49c2b39f8904 100644
--- a/media/jni/soundpool/StreamManager.cpp
+++ b/media/jni/soundpool/StreamManager.cpp
@@ -43,6 +43,14 @@ static constexpr bool kPlayOnCallingThread = true;
 // Amount of time for a StreamManager thread to wait before closing.
 static constexpr int64_t kWaitTimeBeforeCloseNs = 9 * NANOS_PER_SECOND;
 
+// Debug flag:
+// kForceLockStreamManagerStop is set to true to force lock the StreamManager
+// worker thread during stop. This limits concurrency of Stream processing.
+// Normally we lock the StreamManager worker thread during stop ONLY
+// for SoundPools configured with a single Stream.
+//
+static constexpr bool kForceLockStreamManagerStop = false;
+
 ////////////
 
 StreamMap::StreamMap(int32_t streams) {
@@ -103,6 +111,7 @@ StreamManager::StreamManager(
     : StreamMap(streams)
     , mAttributes(*attributes)
     , mOpPackageName(std::move(opPackageName))
+    , mLockStreamManagerStop(streams == 1 || kForceLockStreamManagerStop)
 {
     ALOGV("%s(%d, %zu, ...)", __func__, streams, threads);
     forEach([this](Stream *stream) {
@@ -113,7 +122,8 @@ StreamManager::StreamManager(
     });
 
     mThreadPool = std::make_unique<ThreadPool>(
-            std::min(threads, (size_t)std::thread::hardware_concurrency()),
+            std::min((size_t)streams,  // do not make more threads than streams to play
+                    std::min(threads, (size_t)std::thread::hardware_concurrency())),
             "SoundPool_");
 }
 
@@ -375,12 +385,12 @@ void StreamManager::run(int32_t id)
             }
             mRestartStreams.erase(it);
             mProcessingStreams.emplace(stream);
-            lock.unlock();
+            if (!mLockStreamManagerStop) lock.unlock();
             stream->stop();
             ALOGV("%s(%d) stopping streamID:%d", __func__, id, stream->getStreamID());
             if (Stream* nextStream = stream->playPairStream()) {
                 ALOGV("%s(%d) starting streamID:%d", __func__, id, nextStream->getStreamID());
-                lock.lock();
+                if (!mLockStreamManagerStop) lock.lock();
                 if (nextStream->getStopTimeNs() > 0) {
                     // the next stream was stopped before we can move it to the active queue.
                     ALOGV("%s(%d) stopping started streamID:%d",
@@ -390,7 +400,7 @@ void StreamManager::run(int32_t id)
                     addToActiveQueue_l(nextStream);
                 }
             } else {
-                lock.lock();
+                if (!mLockStreamManagerStop) lock.lock();
                 mAvailableStreams.insert(stream);
             }
             mProcessingStreams.erase(stream);