media: fix race condition on async release
Clear Java object state at releaseAsync(), and delete native object
upon async release complete.
Clearing CodecBase object only led to a rare race condition which
caused null pointer dereference.
Bug: 158501286
Test: atest CtsMediaTestCases:MediaCodecTest#testAsyncRelease (100 times)
Test: atest CtsMediaTestCases:MediaCodecCapabilitiesTest#testGetMaxSupportedInstances
Test: atest CtsMediaTestCases -- --module-arg CtsMediaTestCases:size:small
Change-Id: I691d39007c0ea770318f4038558ad338252bd2fb
diff --git a/media/jni/android_media_MediaCodec.cpp b/media/jni/android_media_MediaCodec.cpp
index f970b59..0b0e162 100644
--- a/media/jni/android_media_MediaCodec.cpp
+++ b/media/jni/android_media_MediaCodec.cpp
@@ -235,7 +235,10 @@
void JMediaCodec::releaseAsync() {
std::call_once(mAsyncReleaseFlag, [this] {
if (mCodec != NULL) {
- mCodec->releaseAsync(new AMessage(kWhatAsyncReleaseComplete, this));
+ sp<AMessage> notify = new AMessage(kWhatAsyncReleaseComplete, this);
+ // Hold strong reference to this until async release is complete
+ notify->setObject("this", this);
+ mCodec->releaseAsync(notify);
}
mInitStatus = NO_INIT;
});
@@ -1088,8 +1091,11 @@
}
case kWhatAsyncReleaseComplete:
{
- mCodec.clear();
- mLooper->stop();
+ if (mLooper != NULL) {
+ mLooper->unregisterHandler(id());
+ mLooper->stop();
+ mLooper.clear();
+ }
break;
}
default:
@@ -1104,7 +1110,7 @@
using namespace android;
static sp<JMediaCodec> setMediaCodec(
- JNIEnv *env, jobject thiz, const sp<JMediaCodec> &codec) {
+ JNIEnv *env, jobject thiz, const sp<JMediaCodec> &codec, bool release = true) {
sp<JMediaCodec> old = (JMediaCodec *)env->CallLongMethod(thiz, gFields.lockAndGetContextID);
if (codec != NULL) {
codec->incStrong(thiz);
@@ -1115,7 +1121,9 @@
* its message handler, doing release() from there will deadlock
* (as MediaCodec::release() post synchronous message to the same looper)
*/
- old->release();
+ if (release) {
+ old->release();
+ }
old->decStrong(thiz);
}
env->CallVoidMethod(thiz, gFields.setAndUnlockContextID, (jlong)codec.get());
@@ -1130,7 +1138,8 @@
}
static void android_media_MediaCodec_release(JNIEnv *env, jobject thiz) {
- sp<JMediaCodec> codec = getMediaCodec(env, thiz);
+ // Clear Java native reference.
+ sp<JMediaCodec> codec = setMediaCodec(env, thiz, nullptr, false /* release */);
if (codec != NULL) {
codec->releaseAsync();
}