Use sp<AudioTrack> instead of raw AudioTrack *

This change prepares for the new implementation of AudioTrack client, which
will require clients to use only sp<AudioTrack>, not raw AudioTrack *.
A raw delete will cause a race condition during AudioTrack destruction.

AudioTrack was made a RefBase by commit b68a91a70bc8d0d18e7404e14443d4e4020b3635
on 2011/11/15, when it was needed by OpenSL ES (for the callback protector).
At that time, the only other client that was also converted from
AudioTrack * to sp<AudioTrack> was android.media.AudioTrack JNI in
project frameworks/base (file android_media_AudioTrack.cpp).

Details:
 * Use .clear() instead of delete followed by = NULL.
 * ALOG %p need .get().
 * sp<> don't need to be listed in constructor initializer, if initially 0.
 * Use == 0 for sp<> vs == NULL for raw pointers.
 * Use if (sp != 0) instead of if (raw).

Change-Id: Ic7cad25795d6e862e112abdc227b6d33afdfce17

1 files changed, 2 insertions, 2 deletions

diff --git a/include/media/ToneGenerator.h b/include/media/ToneGenerator.h
index 2183fbe..98c4332 100644
--- a/include/media/ToneGenerator.h
+++ b/include/media/ToneGenerator.h
@@ -160,7 +160,7 @@ public:
     bool isInited() { return (mState == TONE_IDLE)?false:true;}
 
     // returns the audio session this ToneGenerator belongs to or 0 if an error occured.
-    int getSessionId() { return (mpAudioTrack == NULL) ? 0 : mpAudioTrack->getSessionId(); }
+    int getSessionId() { return (mpAudioTrack == 0) ? 0 : mpAudioTrack->getSessionId(); }
 
 private:
 
@@ -264,7 +264,7 @@ private:
     unsigned short mLoopCounter; // Current tone loopback count
 
     uint32_t mSamplingRate;  // AudioFlinger Sampling rate
-    AudioTrack *mpAudioTrack;  // Pointer to audio track used for playback
+    sp<AudioTrack> mpAudioTrack;  // Pointer to audio track used for playback
     Mutex mLock;  // Mutex to control concurent access to ToneGenerator object from audio callback and application API
     Mutex mCbkCondLock; // Mutex associated to mWaitCbkCond
     Condition mWaitCbkCond; // condition enabling interface to wait for audio callback completion after a change is requested