Merge "audioflinger: Move async callback setting to onFirstRef"
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 0de7e7d..00b612f 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -2140,9 +2140,19 @@
if (!isStreamInitialized()) {
ALOGE("The stream is not open yet"); // This should not happen.
} else {
- // setEventCallback will need a strong pointer as a parameter. Calling it
- // here instead of constructor of PlaybackThread so that the onFirstRef
- // callback would not be made on an incompletely constructed object.
+ // Callbacks take strong or weak pointers as a parameter.
+ // Since PlaybackThread passes itself as a callback handler, it can only
+ // be done outside of the constructor. Creating weak and especially strong
+ // pointers to a refcounted object in its own constructor is strongly
+ // discouraged, see comments in system/core/libutils/include/utils/RefBase.h.
+ // Even if a function takes a weak pointer, it is possible that it will
+ // need to convert it to a strong pointer down the line.
+ if (mOutput->flags & AUDIO_OUTPUT_FLAG_NON_BLOCKING &&
+ mOutput->stream->setCallback(this) == OK) {
+ mUseAsyncWrite = true;
+ mCallbackThread = new AudioFlinger::AsyncCallbackThread(this);
+ }
+
if (mOutput->stream->setEventCallback(this) != OK) {
ALOGD("Failed to add event callback");
}
@@ -3007,13 +3017,6 @@
mFrameCount);
}
- if (mOutput->flags & AUDIO_OUTPUT_FLAG_NON_BLOCKING) {
- if (mOutput->stream->setCallback(this) == OK) {
- mUseAsyncWrite = true;
- mCallbackThread = new AudioFlinger::AsyncCallbackThread(this);
- }
- }
-
mHwSupportsPause = false;
if (mOutput->flags & AUDIO_OUTPUT_FLAG_DIRECT) {
bool supportsPause = false, supportsResume = false;