1 /* 2 * Copyright (C) 2014 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_DUMP_STATE_H 18 #define ANDROID_AUDIO_FAST_MIXER_DUMP_STATE_H 19 20 #include "Configuration.h" 21 22 namespace android { 23 24 // Describes the underrun status for a single "pull" attempt 25 enum FastTrackUnderrunStatus { 26 UNDERRUN_FULL, // framesReady() is full frame count, no underrun 27 UNDERRUN_PARTIAL, // framesReady() is non-zero but < full frame count, partial underrun 28 UNDERRUN_EMPTY, // framesReady() is zero, total underrun 29 }; 30 31 // Underrun counters are not reset to zero for new tracks or if track generation changes. 32 // This packed representation is used to keep the information atomic. 33 union FastTrackUnderruns { FastTrackUnderruns()34 FastTrackUnderruns() { mAtomic = 0; 35 COMPILE_TIME_ASSERT_FUNCTION_SCOPE(sizeof(FastTrackUnderruns) == sizeof(uint32_t)); } FastTrackUnderruns(const FastTrackUnderruns & copyFrom)36 FastTrackUnderruns(const FastTrackUnderruns& copyFrom) : mAtomic(copyFrom.mAtomic) { } 37 FastTrackUnderruns& operator=(const FastTrackUnderruns& rhs) 38 { if (this != &rhs) mAtomic = rhs.mAtomic; return *this; } 39 struct { 40 #define UNDERRUN_BITS 10 41 #define UNDERRUN_MASK ((1 << UNDERRUN_BITS) - 1) 42 uint32_t mFull : UNDERRUN_BITS; // framesReady() is full frame count 43 uint32_t mPartial : UNDERRUN_BITS; // framesReady() is non-zero but < full frame count 44 uint32_t mEmpty : UNDERRUN_BITS; // framesReady() is zero 45 FastTrackUnderrunStatus mMostRecent : 2; // status of most recent framesReady() 46 } mBitFields; 47 private: 48 uint32_t mAtomic; 49 }; 50 51 // Represents the dump state of a fast track 52 struct FastTrackDump { FastTrackDumpFastTrackDump53 FastTrackDump() : mFramesReady(0) { } ~FastTrackDumpFastTrackDump54 /*virtual*/ ~FastTrackDump() { } 55 FastTrackUnderruns mUnderruns; 56 size_t mFramesReady; // most recent value only; no long-term statistics kept 57 }; 58 59 // The FastMixerDumpState keeps a cache of FastMixer statistics that can be logged by dumpsys. 60 // Each individual native word-sized field is accessed atomically. But the 61 // overall structure is non-atomic, that is there may be an inconsistency between fields. 62 // No barriers or locks are used for either writing or reading. 63 // Only POD types are permitted, and the contents shouldn't be trusted (i.e. do range checks). 64 // It has a different lifetime than the FastMixer, and so it can't be a member of FastMixer. 65 struct FastMixerDumpState : FastThreadDumpState { 66 FastMixerDumpState( 67 #ifdef FAST_MIXER_STATISTICS 68 uint32_t samplingN = kSamplingNforLowRamDevice 69 #endif 70 ); 71 /*virtual*/ ~FastMixerDumpState(); 72 73 void dump(int fd) const; // should only be called on a stable copy, not the original 74 75 uint32_t mWriteSequence; // incremented before and after each write() 76 uint32_t mFramesWritten; // total number of frames written successfully 77 uint32_t mNumTracks; // total number of active fast tracks 78 uint32_t mWriteErrors; // total number of write() errors 79 uint32_t mSampleRate; 80 size_t mFrameCount; 81 uint32_t mTrackMask; // mask of active tracks 82 FastTrackDump mTracks[FastMixerState::kMaxFastTracks]; 83 84 #ifdef FAST_MIXER_STATISTICS 85 // Compile-time constant for a "low RAM device", must be a power of 2 <= kSamplingN. 86 // This value was chosen such that each array uses 1 small page (4 Kbytes). 87 static const uint32_t kSamplingNforLowRamDevice = 0x400; 88 // Increase sampling window after construction, must be a power of 2 <= kSamplingN 89 void increaseSamplingN(uint32_t samplingN); 90 #endif 91 }; 92 93 } // android 94 95 #endif // ANDROID_AUDIO_FAST_MIXER_DUMP_STATE_H 96