MediaPlayer(十)--release()流程

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我是靠谱客的博主老实发带，最近开发中收集的这篇文章主要介绍MediaPlayer(十)--release()流程，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

release相比reset流程，多了一些处理

MediaPlayer层将MediaPlayer的各种listener置为null
jni层减少了对surface的引用
jni层销毁了mediaplayer的实例
这里先偷懒，没详细分析


/**
* Releases resources associated with this MediaPlayer object.
* It is considered good practice to call this method when you're
* done using the MediaPlayer. In particular, whenever an Activity
* of an application is paused (its onPause() method is called),
* or stopped (its onStop() method is called), this method should be
* invoked to release the MediaPlayer object, unless the application
* has a special need to keep the object around. In addition to
* unnecessary resources (such as memory and instances of codecs)
* being held, failure to call this method immediately if a
* MediaPlayer object is no longer needed may also lead to
* continuous battery consumption for mobile devices, and playback
* failure for other applications if no multiple instances of the
* same codec are supported on a device. Even if multiple instances
* of the same codec are supported, some performance degradation
* may be expected when unnecessary multiple instances are used
* at the same time.
*/
public void release() {
baseRelease();
stayAwake(false);
updateSurfaceScreenOn();
mOnPreparedListener = null;
mOnBufferingUpdateListener = null;
mOnCompletionListener = null;
mOnSeekCompleteListener = null;
mOnErrorListener = null;
mOnInfoListener = null;
mOnVideoSizeChangedListener = null;
mOnTimedTextListener = null;
if (mTimeProvider != null) {
mTimeProvider.close();
mTimeProvider = null;
}
mOnSubtitleDataListener = null;
// Modular DRM clean up
mOnDrmConfigHelper = null;
mOnDrmInfoHandlerDelegate = null;
mOnDrmPreparedHandlerDelegate = null;
resetDrmState();
_release();
}
private native void _release();

static void
android_media_MediaPlayer_release(JNIEnv *env, jobject thiz)
{
ALOGV("release");
decVideoSurfaceRef(env, thiz);
sp<MediaPlayer> mp = setMediaPlayer(env, thiz, 0);
if (mp != NULL) {
// this prevents native callbacks after the object is released
mp->setListener(0);
mp->disconnect();
}
}

void MediaPlayer::disconnect()
{
ALOGV("disconnect");
sp<IMediaPlayer> p;
{
Mutex::Autolock _l(mLock);
p = mPlayer;
mPlayer.clear();
}
if (p != 0) {
p->disconnect();
}
}

void MediaPlayerService::Client::disconnect()
{
ALOGV("disconnect(%d) from pid %d", mConnId, mPid);
// grab local reference and clear main reference to prevent future
// access to object
sp<MediaPlayerBase> p;
{
Mutex::Autolock l(mLock);
p = mPlayer;
mClient.clear();
mPlayer.clear();
}
// clear the notification to prevent callbacks to dead client
// and reset the player. We assume the player will serialize
// access to itself if necessary.
if (p != 0) {
p->setNotifyCallback(0, 0);
#if CALLBACK_ANTAGONIZER
ALOGD("kill Antagonizer");
mAntagonizer->kill();
#endif
p->reset();
}
{
Mutex::Autolock l(mLock);
disconnectNativeWindow_l();
}
IPCThreadState::self()->flushCommands();
}