Fix slow AudioTrack and AudioRecord destruction

There were two causes for the slowness:

When thread was paused, it used nanosleep and sleep.  These usually
run to completion (except for POSIX signal, which we avoid because it
is low-level).  Instead, replace the nanosleep and sleep by condition
timed wait, as that can be made to return early by a condition signal.
Another advantage of condition timed wait is that a condition wait was
already being used at top of thread loop, so it is a simpler change.

The AudioRecord destructor was missing a proxy interrupt that was correct
in AudioTrack.  This proxy interrupt is needed in case another thread
is blocked in proxy obtainBuffer.

Does not address the 1 second polling for NS_WHENEVER.

Bug: 10822765
Change-Id: Id665994551e87e4d7da9c7b015f424fd7a0b5560

2 files changed, 12 insertions, 8 deletions

diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index 62f0c64..052064d 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -398,18 +398,20 @@ private:
 
                 void        pause();    // suspend thread from execution at next loop boundary
                 void        resume();   // allow thread to execute, if not requested to exit
-                void        pauseConditional();
-                                        // like pause(), but only if prior resume() wasn't latched
 
     private:
+                void        pauseInternal(nsecs_t ns = 0LL);
+                                        // like pause(), but only used internally within thread
+
         friend class AudioRecord;
         virtual bool        threadLoop();
         AudioRecord&        mReceiver;
         virtual ~AudioRecordThread();
         Mutex               mMyLock;    // Thread::mLock is private
         Condition           mMyCond;    // Thread::mThreadExitedCondition is private
-        bool                mPaused;    // whether thread is currently paused
-        bool                mResumeLatch;   // whether next pauseConditional() will be a nop
+        bool                mPaused;    // whether thread is requested to pause at next loop entry
+        bool                mPausedInt; // whether thread internally requests pause
+        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
     };
 
             // body of AudioRecordThread::threadLoop()
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index 453c106..22ad57e 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -598,18 +598,20 @@ protected:
 
                 void        pause();    // suspend thread from execution at next loop boundary
                 void        resume();   // allow thread to execute, if not requested to exit
-                void        pauseConditional();
-                                        // like pause(), but only if prior resume() wasn't latched
 
     private:
+                void        pauseInternal(nsecs_t ns = 0LL);
+                                        // like pause(), but only used internally within thread
+
         friend class AudioTrack;
         virtual bool        threadLoop();
         AudioTrack&         mReceiver;
         virtual ~AudioTrackThread();
         Mutex               mMyLock;    // Thread::mLock is private
         Condition           mMyCond;    // Thread::mThreadExitedCondition is private
-        bool                mPaused;    // whether thread is currently paused
-        bool                mResumeLatch;   // whether next pauseConditional() will be a nop
+        bool                mPaused;    // whether thread is requested to pause at next loop entry
+        bool                mPausedInt; // whether thread internally requests pause
+        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
     };
 
             // body of AudioTrackThread::threadLoop()