commit a77869d964afe3915ae6dfcb1b832a7ccb1fe308
author Phil Burk <philburk@google.com> Thu May 07 10:39:47 2020 -0700
committer Phil Burk <philburk@google.com> Thu May 07 14:33:39 2020 -0700
tree 37a516c20dbd10c7575cbe1ce90cb352dd6b49a5
parent 686dac0cdb04834b889b1264f7a41c5d6ce25d2a

aaudio: process callbacks asynchronously

Spawn a thread to handle the disconnects for onRoutingChanged()
and onTearDown(). This is to prevent deadlocks when calling back into
AudioFlinger.

Bug: 155819038
Test: See bug for repro steps with OboeTester
Test: Also run TEST DISCONNECT in OboeTester. It was failing.
Test: atest CtsNativeMediaAAudioTestCases
Change-Id: I83212fea140d3b6beca9aa737606a77a7c97b007

services/oboeservice/AAudioServiceEndpointMMAP.cpp

diff --git a/services/oboeservice/AAudioServiceEndpointMMAP.cpp b/services/oboeservice/AAudioServiceEndpointMMAP.cpp
index 9dab770..0843e0b 100644
--- a/services/oboeservice/AAudioServiceEndpointMMAP.cpp
+++ b/services/oboeservice/AAudioServiceEndpointMMAP.cpp
@@ -23,10 +23,10 @@
 #include <map>
 #include <mutex>
 #include <sstream>
+#include <thread>
 #include <utils/Singleton.h>
 #include <vector>
 
-
 #include "AAudioEndpointManager.h"
 #include "AAudioServiceEndpoint.h"
 
@@ -36,7 +36,6 @@
 #include "AAudioServiceEndpointPlay.h"
 #include "AAudioServiceEndpointMMAP.h"
 
-
 #define AAUDIO_BUFFER_CAPACITY_MIN    4 * 512
 #define AAUDIO_SAMPLE_RATE_DEFAULT    48000
 
@@ -48,7 +47,6 @@
 using namespace android;  // TODO just import names needed
 using namespace aaudio;   // TODO just import names needed
 
-
 AAudioServiceEndpointMMAP::AAudioServiceEndpointMMAP(AAudioService &audioService)
         : mMmapStream(nullptr)
         , mAAudioService(audioService) {}
@@ -318,9 +316,8 @@
     return 0; // TODO
 }
 
-// This is called by AudioFlinger when it wants to destroy a stream.
-void AAudioServiceEndpointMMAP::onTearDown(audio_port_handle_t portHandle) {
-    ALOGD("%s(portHandle = %d) called", __func__, portHandle);
+// This is called by onTearDown() in a separate thread to avoid deadlocks.
+void AAudioServiceEndpointMMAP::handleTearDownAsync(audio_port_handle_t portHandle) {
     // Are we tearing down the EXCLUSIVE MMAP stream?
     if (isStreamRegistered(portHandle)) {
         ALOGD("%s(%d) tearing down this entire MMAP endpoint", __func__, portHandle);
@@ -333,6 +330,13 @@
     }
 };
 
+// This is called by AudioFlinger when it wants to destroy a stream.
+void AAudioServiceEndpointMMAP::onTearDown(audio_port_handle_t portHandle) {
+    ALOGD("%s(portHandle = %d) called", __func__, portHandle);
+    std::thread asyncTask(&AAudioServiceEndpointMMAP::handleTearDownAsync, this, portHandle);
+    asyncTask.detach();
+}
+
 void AAudioServiceEndpointMMAP::onVolumeChanged(audio_channel_mask_t channels,
                                               android::Vector<float> values) {
     // TODO Do we really need a different volume for each channel?
@@ -345,12 +349,20 @@
     }
 };
 
-void AAudioServiceEndpointMMAP::onRoutingChanged(audio_port_handle_t deviceId) {
+void AAudioServiceEndpointMMAP::onRoutingChanged(audio_port_handle_t portHandle) {
+    const int32_t deviceId = static_cast<int32_t>(portHandle);
     ALOGD("%s() called with dev %d, old = %d", __func__, deviceId, getDeviceId());
-    if (getDeviceId() != AUDIO_PORT_HANDLE_NONE  && getDeviceId() != deviceId) {
-        disconnectRegisteredStreams();
+    if (getDeviceId() != deviceId) {
+        if (getDeviceId() != AUDIO_PORT_HANDLE_NONE) {
+            std::thread asyncTask([this, deviceId]() {
+                disconnectRegisteredStreams();
+                setDeviceId(deviceId);
+            });
+            asyncTask.detach();
+        } else {
+            setDeviceId(deviceId);
+        }
     }
-    setDeviceId(deviceId);
 };
 
 /**