1 /* 2 * Copyright (C) 2012 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 #ifndef ANDROID_AUDIO_FAST_MIXER_H 18 #define ANDROID_AUDIO_FAST_MIXER_H 19 20 #include <utils/Debug.h> 21 #include <utils/Thread.h> 22 extern "C" { 23 #include "../private/bionic_futex.h" 24 } 25 #include "StateQueue.h" 26 #include "FastMixerState.h" 27 28 namespace android { 29 30 typedef StateQueue<FastMixerState> FastMixerStateQueue; 31 32 class FastMixer : public Thread { 33 34 public: 35 FastMixer() : Thread(false /*canCallJava*/) { } 36 virtual ~FastMixer() { } 37 38 FastMixerStateQueue* sq() { return &mSQ; } 39 40 private: 41 virtual bool threadLoop(); 42 FastMixerStateQueue mSQ; 43 44 }; // class FastMixer 45 46 // Describes the underrun status for a single "pull" attempt 47 enum FastTrackUnderrunStatus { 48 UNDERRUN_FULL, // framesReady() is full frame count, no underrun 49 UNDERRUN_PARTIAL, // framesReady() is non-zero but < full frame count, partial underrun 50 UNDERRUN_EMPTY, // framesReady() is zero, total underrun 51 }; 52 53 // Underrun counters are not reset to zero for new tracks or if track generation changes. 54 // This packed representation is used to keep the information atomic. 55 union FastTrackUnderruns { 56 FastTrackUnderruns() { mAtomic = 0; 57 COMPILE_TIME_ASSERT_FUNCTION_SCOPE(sizeof(FastTrackUnderruns) == sizeof(uint32_t)); } 58 FastTrackUnderruns(const FastTrackUnderruns& copyFrom) : mAtomic(copyFrom.mAtomic) { } 59 FastTrackUnderruns& operator=(const FastTrackUnderruns& rhs) 60 { if (this != &rhs) mAtomic = rhs.mAtomic; return *this; } 61 struct { 62 #define UNDERRUN_BITS 10 63 #define UNDERRUN_MASK ((1 << UNDERRUN_BITS) - 1) 64 uint32_t mFull : UNDERRUN_BITS; // framesReady() is full frame count 65 uint32_t mPartial : UNDERRUN_BITS; // framesReady() is non-zero but < full frame count 66 uint32_t mEmpty : UNDERRUN_BITS; // framesReady() is zero 67 FastTrackUnderrunStatus mMostRecent : 2; // status of most recent framesReady() 68 } mBitFields; 69 private: 70 uint32_t mAtomic; 71 }; 72 73 // Represents the dump state of a fast track 74 struct FastTrackDump { 75 FastTrackDump() : mFramesReady(0) { } 76 /*virtual*/ ~FastTrackDump() { } 77 FastTrackUnderruns mUnderruns; 78 size_t mFramesReady; // most recent value only; no long-term statistics kept 79 }; 80 81 // The FastMixerDumpState keeps a cache of FastMixer statistics that can be logged by dumpsys. 82 // Each individual native word-sized field is accessed atomically. But the 83 // overall structure is non-atomic, that is there may be an inconsistency between fields. 84 // No barriers or locks are used for either writing or reading. 85 // Only POD types are permitted, and the contents shouldn't be trusted (i.e. do range checks). 86 // It has a different lifetime than the FastMixer, and so it can't be a member of FastMixer. 87 struct FastMixerDumpState { 88 FastMixerDumpState( 89 #ifdef FAST_MIXER_STATISTICS 90 uint32_t samplingN = kSamplingNforLowRamDevice 91 #endif 92 ); 93 /*virtual*/ ~FastMixerDumpState(); 94 95 void dump(int fd) const; // should only be called on a stable copy, not the original 96 97 FastMixerState::Command mCommand; // current command 98 uint32_t mWriteSequence; // incremented before and after each write() 99 uint32_t mFramesWritten; // total number of frames written successfully 100 uint32_t mNumTracks; // total number of active fast tracks 101 uint32_t mWriteErrors; // total number of write() errors 102 uint32_t mUnderruns; // total number of underruns 103 uint32_t mOverruns; // total number of overruns 104 uint32_t mSampleRate; 105 size_t mFrameCount; 106 struct timespec mMeasuredWarmupTs; // measured warmup time 107 uint32_t mWarmupCycles; // number of loop cycles required to warmup 108 uint32_t mTrackMask; // mask of active tracks 109 FastTrackDump mTracks[FastMixerState::kMaxFastTracks]; 110 111 #ifdef FAST_MIXER_STATISTICS 112 // Recently collected samples of per-cycle monotonic time, thread CPU time, and CPU frequency. 113 // kSamplingN is max size of sampling frame (statistics), and must be a power of 2 <= 0x8000. 114 // The sample arrays are virtually allocated based on this compile-time constant, 115 // but are only initialized and used based on the runtime parameter mSamplingN. 116 static const uint32_t kSamplingN = 0x8000; 117 // Compile-time constant for a "low RAM device", must be a power of 2 <= kSamplingN. 118 // This value was chosen such that each array uses 1 small page (4 Kbytes). 119 static const uint32_t kSamplingNforLowRamDevice = 0x400; 120 // Corresponding runtime maximum size of sample arrays, must be a power of 2 <= kSamplingN. 121 uint32_t mSamplingN; 122 // The bounds define the interval of valid samples, and are represented as follows: 123 // newest open (excluded) endpoint = lower 16 bits of bounds, modulo N 124 // oldest closed (included) endpoint = upper 16 bits of bounds, modulo N 125 // Number of valid samples is newest - oldest. 126 uint32_t mBounds; // bounds for mMonotonicNs, mThreadCpuNs, and mCpukHz 127 // The elements in the *Ns arrays are in units of nanoseconds <= 3999999999. 128 uint32_t mMonotonicNs[kSamplingN]; // delta monotonic (wall clock) time 129 uint32_t mLoadNs[kSamplingN]; // delta CPU load in time 130 #ifdef CPU_FREQUENCY_STATISTICS 131 uint32_t mCpukHz[kSamplingN]; // absolute CPU clock frequency in kHz, bits 0-3 are CPU# 132 #endif 133 // Increase sampling window after construction, must be a power of 2 <= kSamplingN 134 void increaseSamplingN(uint32_t samplingN); 135 #endif 136 }; 137 138 } // namespace android 139 140 #endif // ANDROID_AUDIO_FAST_MIXER_H 141
