1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "AAudioService"
18 //#define LOG_NDEBUG 0
19 #include <utils/Log.h>
20 
21 #include <assert.h>
22 #include <map>
23 #include <mutex>
24 #include <utils/Singleton.h>
25 
26 #include "AAudioEndpointManager.h"
27 #include "AAudioServiceEndpoint.h"
28 #include <algorithm>
29 #include <mutex>
30 #include <vector>
31 
32 #include "core/AudioStreamBuilder.h"
33 #include "AAudioServiceEndpoint.h"
34 #include "AAudioServiceStreamShared.h"
35 #include "AAudioServiceEndpointPlay.h"
36 
37 using namespace android;  // TODO just import names needed
38 using namespace aaudio;   // TODO just import names needed
39 
40 #define BURSTS_PER_BUFFER_DEFAULT   2
41 
AAudioServiceEndpointPlay(AAudioService & audioService)42 AAudioServiceEndpointPlay::AAudioServiceEndpointPlay(AAudioService &audioService)
43         : mStreamInternalPlay(audioService, true) {
44 }
45 
~AAudioServiceEndpointPlay()46 AAudioServiceEndpointPlay::~AAudioServiceEndpointPlay() {
47 }
48 
open(int32_t deviceId)49 aaudio_result_t AAudioServiceEndpointPlay::open(int32_t deviceId) {
50     aaudio_result_t result = AAudioServiceEndpoint::open(deviceId);
51     if (result == AAUDIO_OK) {
52         mMixer.allocate(getStreamInternal()->getSamplesPerFrame(),
53                         getStreamInternal()->getFramesPerBurst());
54 
55         int32_t burstsPerBuffer = AAudioProperty_getMixerBursts();
56         if (burstsPerBuffer == 0) {
57             mLatencyTuningEnabled = true;
58             burstsPerBuffer = BURSTS_PER_BUFFER_DEFAULT;
59         }
60         ALOGD("AAudioServiceEndpoint(): burstsPerBuffer = %d", burstsPerBuffer);
61         int32_t desiredBufferSize = burstsPerBuffer * getStreamInternal()->getFramesPerBurst();
62         getStreamInternal()->setBufferSize(desiredBufferSize);
63     }
64     return result;
65 }
66 
67 // Mix data from each application stream and write result to the shared MMAP stream.
callbackLoop()68 void *AAudioServiceEndpointPlay::callbackLoop() {
69     ALOGD("AAudioServiceEndpointPlay(): callbackLoop() entering");
70     int32_t underflowCount = 0;
71 
72     aaudio_result_t result = getStreamInternal()->requestStart();
73 
74     int64_t timeoutNanos = getStreamInternal()->calculateReasonableTimeout();
75 
76     // result might be a frame count
77     while (mCallbackEnabled.load() && getStreamInternal()->isActive() && (result >= 0)) {
78         // Mix data from each active stream.
79         mMixer.clear();
80         { // use lock guard
81             std::lock_guard <std::mutex> lock(mLockStreams);
82             for (AAudioServiceStreamShared *sharedStream : mRunningStreams) {
83                 FifoBuffer *fifo = sharedStream->getDataFifoBuffer();
84                 float volume = 0.5; // TODO get from system
85                 bool underflowed = mMixer.mix(fifo, volume);
86                 underflowCount += underflowed ? 1 : 0;
87                 // TODO log underflows in each stream
88                 sharedStream->markTransferTime(AudioClock::getNanoseconds());
89             }
90         }
91 
92         // Write mixer output to stream using a blocking write.
93         result = getStreamInternal()->write(mMixer.getOutputBuffer(),
94                                             getFramesPerBurst(), timeoutNanos);
95         if (result == AAUDIO_ERROR_DISCONNECTED) {
96             disconnectRegisteredStreams();
97             break;
98         } else if (result != getFramesPerBurst()) {
99             ALOGW("AAudioServiceEndpoint(): callbackLoop() wrote %d / %d",
100                   result, getFramesPerBurst());
101             break;
102         }
103     }
104 
105     result = getStreamInternal()->requestStop();
106 
107     ALOGD("AAudioServiceEndpointPlay(): callbackLoop() exiting, %d underflows", underflowCount);
108     return NULL; // TODO review
109 }
110