Fix issue 2553359: Pandora does not work well with Passion deskdock / Cardock.

The problem is due to a too big difference between the buffer size used at the hardware interface and at the A2DP interface.
When no resampling occurs we don't notice problems but the timing is very tight. As soon as resampling is activated, the AudioTrack underruns.
This is because the AudioTrack buffers are not resized when moving the AudioTrack from hardware to A2DP output.
The AudioTrack buffers are calculated based on a hardware output buffer size of 3072 bytes. Which is much less than the A2DP output buffer size (10240).

The solution consists in creating new tracks with new buffers in AudioFlinger when the A2DP output is opened
instead of just transfering active tracks from hardware output mixer thread to the new A2DP output mixer thread.
To avoid synchronization issues between mixer threads and client processes, this is done by invalidating tracks
by setting a flag in their control block and having AudioTrack release the handle on this track (IAudioTrack)
and create a new IAudioTrack when this flag is detected next time obtainBuffer() or start() is executed.

AudioFlinger modifications:
- invalidate the tracks when setStreamOutput() is called
- make sure that notifications of output opening/closing and change of stream type to output mapping are sent synchronously to client process.
This is necessary so that AudioSystem has the new stream to output mapping when the AudioTrack detects the invalidate flag in the client process.
Previously their were sent when the corresponding thread loop was executed.

AudioTrack modifications:
- move frame count calculation and verification from set() to createTrack() so that is is updated every time a new IAudioTrack is created.
- detect track invalidate flag in obtainBuffer() and start() and create a new IAudioTrack.

AudioTrackShared modifications
- group all flags (out, flowControlFlag, forceReady...) into a single bit filed to save space.

Change-Id: I9ac26b6192230627d35084e1449640caaf7d56ee

2 files changed, 107 insertions, 77 deletions

diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index ad037d6..fd2b1ce 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -430,7 +430,7 @@ status_t AudioRecord::openRecord(
     mCblkMemory = cblk;
     mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
     mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
-    mCblk->out = 0;
+    mCblk->flags &= ~CBLK_DIRECTION_MSK;
     mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
     mCblk->waitTimeMs = 0;
     return NO_ERROR;
@@ -644,10 +644,10 @@ bool AudioRecord::processAudioBuffer(const sp<ClientRecordThread>& thread)
 
     // Manage overrun callback
     if (mActive && (mCblk->framesAvailable_l() == 0)) {
-        LOGV("Overrun user: %x, server: %x, flowControlFlag %d", mCblk->user, mCblk->server, mCblk->flowControlFlag);
-        if (mCblk->flowControlFlag == 0) {
+        LOGV("Overrun user: %x, server: %x, flags %04x", mCblk->user, mCblk->server, mCblk->flags);
+        if ((mCblk->flags & CBLK_UNDERRUN_MSK) == CBLK_UNDERRUN_OFF) {
             mCbf(EVENT_OVERRUN, mUserData, 0);
-            mCblk->flowControlFlag = 1;
+            mCblk->flags |= CBLK_UNDERRUN_ON;
         }
     }
 
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index cd7bcd5..c350532 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -124,10 +124,6 @@ status_t AudioTrack::set(
     if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
         return NO_INIT;
     }
-    int afFrameCount;
-    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
-        return NO_INIT;
-    }
     uint32_t afLatency;
     if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
         return NO_INIT;
@@ -173,48 +169,13 @@ status_t AudioTrack::set(
         return BAD_VALUE;
     }
 
-    if (!AudioSystem::isLinearPCM(format)) {
-        if (sharedBuffer != 0) {
-            frameCount = sharedBuffer->size();
-        }
-    } else {
-        // Ensure that buffer depth covers at least audio hardware latency
-        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
-        if (minBufCount < 2) minBufCount = 2;
-
-        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
-
-        if (sharedBuffer == 0) {
-            if (frameCount == 0) {
-                frameCount = minFrameCount;
-            }
-            if (notificationFrames == 0) {
-                notificationFrames = frameCount/2;
-            }
-            // Make sure that application is notified with sufficient margin
-            // before underrun
-            if (notificationFrames > frameCount/2) {
-                notificationFrames = frameCount/2;
-            }
-            if (frameCount < minFrameCount) {
-              LOGE("Invalid buffer size: minFrameCount %d, frameCount %d", minFrameCount, frameCount);
-              return BAD_VALUE;
-            }
-        } else {
-            // Ensure that buffer alignment matches channelcount
-            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
-                LOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
-                return BAD_VALUE;
-            }
-            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
-        }
-    }
-
     mVolume[LEFT] = 1.0f;
     mVolume[RIGHT] = 1.0f;
+    mFrameCount = frameCount;
+    mNotificationFramesReq = notificationFrames;
     // create the IAudioTrack
     status_t status = createTrack(streamType, sampleRate, format, channelCount,
-                                  frameCount, flags, sharedBuffer, output);
+                                  frameCount, flags, sharedBuffer, output, true);
 
     if (status != NO_ERROR) {
         return status;
@@ -238,10 +199,7 @@ status_t AudioTrack::set(
     mMuted = false;
     mActive = 0;
     mCbf = cbf;
-    mNotificationFrames = notificationFrames;
-    mRemainingFrames = notificationFrames;
     mUserData = user;
-    mLatency = afLatency + (1000*mFrameCount) / sampleRate;
     mLoopCount = 0;
     mMarkerPosition = 0;
     mMarkerReached = false;
@@ -281,7 +239,7 @@ int AudioTrack::channelCount() const
 
 uint32_t AudioTrack::frameCount() const
 {
-    return mFrameCount;
+    return mCblk->frameCount;
 }
 
 int AudioTrack::frameSize() const
@@ -303,6 +261,7 @@ sp<IMemory>& AudioTrack::sharedBuffer()
 void AudioTrack::start()
 {
     sp<AudioTrackThread> t = mAudioTrackThread;
+    status_t status;
 
     LOGV("start %p", this);
     if (t != 0) {
@@ -325,11 +284,18 @@ void AudioTrack::start()
             setpriority(PRIO_PROCESS, 0, THREAD_PRIORITY_AUDIO_CLIENT);
         }
 
-        status_t status = mAudioTrack->start();
+        if (mCblk->flags & CBLK_INVALID_MSK) {
+            LOGW("start() track %p invalidated, creating a new one", this);
+            // no need to clear the invalid flag as this cblk will not be used anymore
+            // force new track creation
+            status = DEAD_OBJECT;
+        } else {
+            status = mAudioTrack->start();
+        }
         if (status == DEAD_OBJECT) {
             LOGV("start() dead IAudioTrack: creating a new one");
             status = createTrack(mStreamType, mCblk->sampleRate, mFormat, mChannelCount,
-                                 mFrameCount, mFlags, mSharedBuffer, getOutput());
+                                 mFrameCount, mFlags, mSharedBuffer, getOutput(), false);
             if (status == NO_ERROR) {
                 status = mAudioTrack->start();
                 if (status == NO_ERROR) {
@@ -479,14 +445,14 @@ status_t AudioTrack::setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount
     }
 
     if (loopStart >= loopEnd ||
-        loopEnd - loopStart > mFrameCount) {
-        LOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, mFrameCount, cblk->user);
+        loopEnd - loopStart > cblk->frameCount) {
+        LOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, cblk->frameCount, cblk->user);
         return BAD_VALUE;
     }
 
-    if ((mSharedBuffer != 0) && (loopEnd   > mFrameCount)) {
+    if ((mSharedBuffer != 0) && (loopEnd   > cblk->frameCount)) {
         LOGE("setLoop invalid value: loop markers beyond data: loopStart %d, loopEnd %d, framecount %d",
-            loopStart, loopEnd, mFrameCount);
+            loopStart, loopEnd, cblk->frameCount);
         return BAD_VALUE;
     }
 
@@ -566,7 +532,7 @@ status_t AudioTrack::setPosition(uint32_t position)
     if (position > mCblk->user) return BAD_VALUE;
 
     mCblk->server = position;
-    mCblk->forceReady = 1;
+    mCblk->flags |= CBLK_FORCEREADY_ON;
 
     return NO_ERROR;
 }
@@ -586,7 +552,7 @@ status_t AudioTrack::reload()
 
     flush();
 
-    mCblk->stepUser(mFrameCount);
+    mCblk->stepUser(mCblk->frameCount);
 
     return NO_ERROR;
 }
@@ -607,7 +573,8 @@ status_t AudioTrack::createTrack(
         int frameCount,
         uint32_t flags,
         const sp<IMemory>& sharedBuffer,
-        audio_io_handle_t output)
+        audio_io_handle_t output,
+        bool enforceFrameCount)
 {
     status_t status;
     const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
@@ -616,6 +583,61 @@ status_t AudioTrack::createTrack(
        return NO_INIT;
     }
 
+    int afSampleRate;
+    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
+        return NO_INIT;
+    }
+    int afFrameCount;
+    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
+        return NO_INIT;
+    }
+    uint32_t afLatency;
+    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
+        return NO_INIT;
+    }
+
+    mNotificationFramesAct = mNotificationFramesReq;
+    if (!AudioSystem::isLinearPCM(format)) {
+        if (sharedBuffer != 0) {
+            frameCount = sharedBuffer->size();
+        }
+    } else {
+        // Ensure that buffer depth covers at least audio hardware latency
+        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
+        if (minBufCount < 2) minBufCount = 2;
+
+        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
+
+        if (sharedBuffer == 0) {
+            if (frameCount == 0) {
+                frameCount = minFrameCount;
+            }
+            if (mNotificationFramesAct == 0) {
+                mNotificationFramesAct = frameCount/2;
+            }
+            // Make sure that application is notified with sufficient margin
+            // before underrun
+            if (mNotificationFramesAct > (uint32_t)frameCount/2) {
+                mNotificationFramesAct = frameCount/2;
+            }
+            if (frameCount < minFrameCount) {
+                if (enforceFrameCount) {
+                    LOGE("Invalid buffer size: minFrameCount %d, frameCount %d", minFrameCount, frameCount);
+                    return BAD_VALUE;
+                } else {
+                    frameCount = minFrameCount;
+                }
+            }
+        } else {
+            // Ensure that buffer alignment matches channelcount
+            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
+                LOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
+                return BAD_VALUE;
+            }
+            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
+        }
+    }
+
     sp<IAudioTrack> track = audioFlinger->createTrack(getpid(),
                                                       streamType,
                                                       sampleRate,
@@ -641,20 +663,20 @@ status_t AudioTrack::createTrack(
     mCblkMemory.clear();
     mCblkMemory = cblk;
     mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
-    mCblk->out = 1;
-    // Update buffer size in case it has been limited by AudioFlinger during track creation
-    mFrameCount = mCblk->frameCount;
+    mCblk->flags |= CBLK_DIRECTION_OUT;
     if (sharedBuffer == 0) {
         mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
     } else {
         mCblk->buffers = sharedBuffer->pointer();
          // Force buffer full condition as data is already present in shared memory
-        mCblk->stepUser(mFrameCount);
+        mCblk->stepUser(mCblk->frameCount);
     }
 
     mCblk->volumeLR = (int32_t(int16_t(mVolume[LEFT] * 0x1000)) << 16) | int16_t(mVolume[RIGHT] * 0x1000);
     mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
     mCblk->waitTimeMs = 0;
+    mRemainingFrames = mNotificationFramesAct;
+    mLatency = afLatency + (1000*mCblk->frameCount) / sampleRate;
     return NO_ERROR;
 }
 
@@ -685,8 +707,15 @@ status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
                 cblk->lock.unlock();
                 return WOULD_BLOCK;
             }
-
-            result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
+            if (!(cblk->flags & CBLK_INVALID_MSK)) {
+                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
+            }
+            if (cblk->flags & CBLK_INVALID_MSK) {
+                LOGW("obtainBuffer() track %p invalidated, creating a new one", this);
+                // no need to clear the invalid flag as this cblk will not be used anymore
+                cblk->lock.unlock();
+                goto create_new_track;
+            }
             if (__builtin_expect(result!=NO_ERROR, false)) {
                 cblk->waitTimeMs += waitTimeMs;
                 if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
@@ -700,8 +729,9 @@ status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
                         result = mAudioTrack->start();
                         if (result == DEAD_OBJECT) {
                             LOGW("obtainBuffer() dead IAudioTrack: creating a new one");
+create_new_track:
                             result = createTrack(mStreamType, cblk->sampleRate, mFormat, mChannelCount,
-                                                 mFrameCount, mFlags, mSharedBuffer, getOutput());
+                                                 mFrameCount, mFlags, mSharedBuffer, getOutput(), false);
                             if (result == NO_ERROR) {
                                 cblk = mCblk;
                                 cblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
@@ -826,13 +856,13 @@ bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
 
     // Manage underrun callback
     if (mActive && (mCblk->framesReady() == 0)) {
-        LOGV("Underrun user: %x, server: %x, flowControlFlag %d", mCblk->user, mCblk->server, mCblk->flowControlFlag);
-        if (mCblk->flowControlFlag == 0) {
+        LOGV("Underrun user: %x, server: %x, flags %04x", mCblk->user, mCblk->server, mCblk->flags);
+        if ((mCblk->flags & CBLK_UNDERRUN_MSK) == CBLK_UNDERRUN_OFF) {
             mCbf(EVENT_UNDERRUN, mUserData, 0);
             if (mCblk->server == mCblk->frameCount) {
                 mCbf(EVENT_BUFFER_END, mUserData, 0);
             }
-            mCblk->flowControlFlag = 1;
+            mCblk->flags |= CBLK_UNDERRUN_ON;
             if (mSharedBuffer != 0) return false;
         }
     }
@@ -932,7 +962,7 @@ bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
     while (frames);
 
     if (frames == 0) {
-        mRemainingFrames = mNotificationFrames;
+        mRemainingFrames = mNotificationFramesAct;
     } else {
         mRemainingFrames = frames;
     }
@@ -949,7 +979,7 @@ status_t AudioTrack::dump(int fd, const Vector<String16>& args) const
     result.append(" AudioTrack::dump\n");
     snprintf(buffer, 255, "  stream type(%d), left - right volume(%f, %f)\n", mStreamType, mVolume[0], mVolume[1]);
     result.append(buffer);
-    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mFrameCount);
+    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mCblk->frameCount);
     result.append(buffer);
     snprintf(buffer, 255, "  sample rate(%d), status(%d), muted(%d)\n", (mCblk == 0) ? 0 : mCblk->sampleRate, mStatus, mMuted);
     result.append(buffer);
@@ -986,7 +1016,7 @@ audio_track_cblk_t::audio_track_cblk_t()
     : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
     userBase(0), serverBase(0), buffers(0), frameCount(0),
     loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0),
-    flowControlFlag(1), forceReady(0)
+    flags(0)
 {
 }
 
@@ -996,7 +1026,7 @@ uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
 
     u += frameCount;
     // Ensure that user is never ahead of server for AudioRecord
-    if (out) {
+    if (flags & CBLK_DIRECTION_MSK) {
         // If stepServer() has been called once, switch to normal obtainBuffer() timeout period
         if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS-1) {
             bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
@@ -1013,7 +1043,7 @@ uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
     this->user = u;
 
     // Clear flow control error condition as new data has been written/read to/from buffer.
-    flowControlFlag = 0;
+    flags &= ~CBLK_UNDERRUN_MSK;
 
     return u;
 }
@@ -1038,7 +1068,7 @@ bool audio_track_cblk_t::stepServer(uint32_t frameCount)
     uint32_t s = this->server;
 
     s += frameCount;
-    if (out) {
+    if (flags & CBLK_DIRECTION_MSK) {
         // Mark that we have read the first buffer so that next time stepUser() is called
         // we switch to normal obtainBuffer() timeout period
         if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS) {
@@ -1089,7 +1119,7 @@ uint32_t audio_track_cblk_t::framesAvailable_l()
     uint32_t u = this->user;
     uint32_t s = this->server;
 
-    if (out) {
+    if (flags & CBLK_DIRECTION_MSK) {
         uint32_t limit = (s < loopStart) ? s : loopStart;
         return limit + frameCount - u;
     } else {
@@ -1102,7 +1132,7 @@ uint32_t audio_track_cblk_t::framesReady()
     uint32_t u = this->user;
     uint32_t s = this->server;
 
-    if (out) {
+    if (flags & CBLK_DIRECTION_MSK) {
         if (u < loopEnd) {
             return u - s;
         } else {