Fix race while setting ASyncNotify callback
Holding mAsyncCallbackLock while setCallback() in
mediacodec can cause deadlock. setCallback() is done without lock
but the ASyncCallback and userdata assignments are done within
the lock so that we can respond to async callback immediatly
bug: 236908959
Change-Id: Id0d2befa8520cbd35b6265037e6481276dcb1bfc
diff --git a/media/ndk/NdkMediaCodec.cpp b/media/ndk/NdkMediaCodec.cpp
index 38e422d..7495082 100644
--- a/media/ndk/NdkMediaCodec.cpp
+++ b/media/ndk/NdkMediaCodec.cpp
@@ -529,22 +529,31 @@
AMediaCodecOnAsyncNotifyCallback callback,
void *userdata) {
- Mutex::Autolock _l(mData->mAsyncCallbackLock);
-
- if (mData->mAsyncNotify == NULL) {
- mData->mAsyncNotify = new AMessage(kWhatAsyncNotify, mData->mHandler);
+ {
+ Mutex::Autolock _l(mData->mAsyncCallbackLock);
+ if (mData->mAsyncNotify == NULL) {
+ mData->mAsyncNotify = new AMessage(kWhatAsyncNotify, mData->mHandler);
+ }
+ // we set this ahead so that we can be ready
+ // to receive callbacks as soon as the next call is a
+ // success.
+ mData->mAsyncCallback = callback;
+ mData->mAsyncCallbackUserData = userdata;
}
// always call, codec may have been reset/re-configured since last call.
status_t err = mData->mCodec->setCallback(mData->mAsyncNotify);
if (err != OK) {
+ {
+ //The setup gone wrong. clean up the pointers.
+ Mutex::Autolock _l(mData->mAsyncCallbackLock);
+ mData->mAsyncCallback = {};
+ mData->mAsyncCallbackUserData = nullptr;
+ }
ALOGE("setAsyncNotifyCallback: err(%d), failed to set async callback", err);
return translate_error(err);
}
- mData->mAsyncCallback = callback;
- mData->mAsyncCallbackUserData = userdata;
-
return AMEDIA_OK;
}