commit b0abafbf0a6174e8c8933cc5fb19501a2d22c53b
author Mikhail Naganov <mnaganov@google.com> Tue Jan 31 17:24:48 2017 -0800
committer Mikhail Naganov <mnaganov@google.com> Thu Feb 02 17:00:42 2017 -0800
tree d119b77826ef8b5b1190886dab505360c86f4f2e
parent bbd6adda5af693692c889b47ef1394a578c5baea

audiohal: Make closing of effects and streams fast

There were two problems:

1. Joining of reader / writer / process threads (the threads that
   interact with HAL) was taking up to 1 second because the thread
   was usually waiting for an event flag to be toggled, or a 1s
   timeout.

2. Calling IStream.close or IEffect.close shouldn't tax the caller.
   Changed the code so a call to close only signals the thread that
   it's time to exit, and then the thread is only joined in the
   effect or stream destructor.

Bug: 34800063
Bug: 34499806
Test: see repro steps in the bugs
Change-Id: Ife20524a1eba4ec9a78152e89862526e8cd5c960

audio/2.0/default/StreamOut.cpp

diff --git a/audio/2.0/default/StreamOut.cpp b/audio/2.0/default/StreamOut.cpp
index 1948b68..bfd592c 100644
--- a/audio/2.0/default/StreamOut.cpp
+++ b/audio/2.0/default/StreamOut.cpp
@@ -16,10 +16,12 @@
 
 #define LOG_TAG "StreamOutHAL"
 //#define LOG_NDEBUG 0
+#define ATRACE_TAG ATRACE_TAG_AUDIO
 
 #include <android/log.h>
 #include <hardware/audio.h>
 #include <mediautils/SchedulingPolicyService.h>
+#include <utils/Trace.h>
 
 #include "StreamOut.h"
 
@@ -121,7 +123,19 @@
 }
 
 StreamOut::~StreamOut() {
+    ATRACE_CALL();
     close();
+    if (mWriteThread.get()) {
+        ATRACE_NAME("mWriteThread->join");
+        status_t status = mWriteThread->join();
+        ALOGE_IF(status, "write thread exit error: %s", strerror(-status));
+    }
+    if (mEfGroup) {
+        status_t status = EventFlag::deleteEventFlag(&mEfGroup);
+        ALOGE_IF(status, "write MQ event flag deletion error: %s", strerror(-status));
+    }
+    mCallback.clear();
+    mDevice->close_output_stream(mDevice, mStream);
     mStream = nullptr;
     mDevice = nullptr;
 }
@@ -225,15 +239,10 @@
     mIsClosed = true;
     if (mWriteThread.get()) {
         mStopWriteThread.store(true, std::memory_order_release);
-        status_t status = mWriteThread->requestExitAndWait();
-        ALOGE_IF(status, "write thread exit error: %s", strerror(-status));
     }
     if (mEfGroup) {
-        status_t status = EventFlag::deleteEventFlag(&mEfGroup);
-        ALOGE_IF(status, "write MQ event flag deletion error: %s", strerror(-status));
+        mEfGroup->wake(static_cast<uint32_t>(MessageQueueFlagBits::NOT_EMPTY));
     }
-    mCallback.clear();
-    mDevice->close_output_stream(mDevice, mStream);
     return Result::OK;
 }