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_THREAD_H
18 #define ANDROID_AUDIO_FAST_THREAD_H
19 
20 #include "Configuration.h"
21 #ifdef CPU_FREQUENCY_STATISTICS
22 #include <cpustats/ThreadCpuUsage.h>
23 #endif
24 #include <utils/Thread.h>
25 #include "FastThreadState.h"
26 
27 namespace android {
28 
29 // FastThread is the common abstract base class of FastMixer and FastCapture
30 class FastThread : public Thread {
31 
32 public:
33             FastThread(const char *cycleMs, const char *loadUs);
34     virtual ~FastThread();
35 
36 private:
37     // implement Thread::threadLoop()
38     virtual bool threadLoop();
39 
40 protected:
41     // callouts to subclass in same lexical order as they were in original FastMixer.cpp
42     // FIXME need comments
43     virtual const FastThreadState *poll() = 0;
setNBLogWriter(NBLog::Writer * logWriter __unused)44     virtual void setNBLogWriter(NBLog::Writer *logWriter __unused) { }
45     virtual void onIdle() = 0;
46     virtual void onExit() = 0;
47     virtual bool isSubClassCommand(FastThreadState::Command command) = 0;
48     virtual void onStateChange() = 0;
49     virtual void onWork() = 0;
50 
51     // FIXME these former local variables need comments
52     const FastThreadState*  mPrevious;
53     const FastThreadState*  mCurrent;
54     struct timespec mOldTs;
55     bool            mOldTsValid;
56     long            mSleepNs;       // -1: busy wait, 0: sched_yield, > 0: nanosleep
57     long            mPeriodNs;      // expected period; the time required to render one mix buffer
58     long            mUnderrunNs;    // underrun likely when write cycle is greater than this value
59     long            mOverrunNs;     // overrun likely when write cycle is less than this value
60     long            mForceNs;       // if overrun detected,
61                                     // force the write cycle to take this much time
62     long            mWarmupNsMin;   // warmup complete when write cycle is greater than or equal to
63                                     // this value
64     long            mWarmupNsMax;   // and less than or equal to this value
65     FastThreadDumpState* mDummyDumpState;
66     FastThreadDumpState* mDumpState;
67     bool            mIgnoreNextOverrun;     // used to ignore initial overrun and first after an
68                                             // underrun
69 #ifdef FAST_THREAD_STATISTICS
70     struct timespec mOldLoad;       // previous value of clock_gettime(CLOCK_THREAD_CPUTIME_ID)
71     bool            mOldLoadValid;  // whether oldLoad is valid
72     uint32_t        mBounds;
73     bool            mFull;          // whether we have collected at least mSamplingN samples
74 #ifdef CPU_FREQUENCY_STATISTICS
75     ThreadCpuUsage  mTcu;           // for reading the current CPU clock frequency in kHz
76 #endif
77 #endif
78     unsigned        mColdGen;       // last observed mColdGen
79     bool            mIsWarm;        // true means ready to mix,
80                                     // false means wait for warmup before mixing
81     struct timespec   mMeasuredWarmupTs;  // how long did it take for warmup to complete
82     uint32_t          mWarmupCycles;  // counter of number of loop cycles during warmup phase
83     uint32_t          mWarmupConsecutiveInRangeCycles;    // number of consecutive cycles in range
84     const sp<NBLog::Writer> mDummyNBLogWriter{new NBLog::Writer()};
85     status_t          mTimestampStatus;
86 
87     FastThreadState::Command mCommand;
88     bool            mAttemptedWrite;
89 
90     char            mCycleMs[16];   // cycle_ms + suffix
91     char            mLoadUs[16];    // load_us + suffix
92 
93 };  // class FastThread
94 
95 }   // android
96 
97 #endif  // ANDROID_AUDIO_FAST_THREAD_H
98