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_DUMP_STATE_H
18#define ANDROID_AUDIO_FAST_THREAD_DUMP_STATE_H
19
20#include "Configuration.h"
21#include "FastThreadState.h"
22
23namespace android {
24
25// The FastThreadDumpState keeps a cache of FastThread statistics that can be logged by dumpsys.
26// Each individual native word-sized field is accessed atomically.  But the
27// overall structure is non-atomic, that is there may be an inconsistency between fields.
28// No barriers or locks are used for either writing or reading.
29// Only POD types are permitted, and the contents shouldn't be trusted (i.e. do range checks).
30// It has a different lifetime than the FastThread, and so it can't be a member of FastThread.
31struct FastThreadDumpState {
32    FastThreadDumpState();
33    /*virtual*/ ~FastThreadDumpState();
34
35    FastThreadState::Command mCommand;   // current command
36    uint32_t mUnderruns;        // total number of underruns
37    uint32_t mOverruns;         // total number of overruns
38    struct timespec mMeasuredWarmupTs;  // measured warmup time
39    uint32_t mWarmupCycles;     // number of loop cycles required to warmup
40
41#ifdef FAST_THREAD_STATISTICS
42    // Recently collected samples of per-cycle monotonic time, thread CPU time, and CPU frequency.
43    // kSamplingN is max size of sampling frame (statistics), and must be a power of 2 <= 0x8000.
44    // The sample arrays are virtually allocated based on this compile-time constant,
45    // but are only initialized and used based on the runtime parameter mSamplingN.
46    static const uint32_t kSamplingN = 0x8000;
47    // Compile-time constant for a "low RAM device", must be a power of 2 <= kSamplingN.
48    // This value was chosen such that each array uses 1 small page (4 Kbytes).
49    static const uint32_t kSamplingNforLowRamDevice = 0x400;
50    // Corresponding runtime maximum size of sample arrays, must be a power of 2 <= kSamplingN.
51    uint32_t mSamplingN;
52    // The bounds define the interval of valid samples, and are represented as follows:
53    //      newest open (excluded) endpoint   = lower 16 bits of bounds, modulo N
54    //      oldest closed (included) endpoint = upper 16 bits of bounds, modulo N
55    // Number of valid samples is newest - oldest.
56    uint32_t mBounds;                   // bounds for mMonotonicNs, mThreadCpuNs, and mCpukHz
57    // The elements in the *Ns arrays are in units of nanoseconds <= 3999999999.
58    uint32_t mMonotonicNs[kSamplingN];  // delta monotonic (wall clock) time
59    uint32_t mLoadNs[kSamplingN];       // delta CPU load in time
60#ifdef CPU_FREQUENCY_STATISTICS
61    uint32_t mCpukHz[kSamplingN];       // absolute CPU clock frequency in kHz, bits 0-3 are CPU#
62#endif
63
64    // Increase sampling window after construction, must be a power of 2 <= kSamplingN
65    void    increaseSamplingN(uint32_t samplingN);
66#endif
67
68};  // struct FastThreadDumpState
69
70}   // android
71
72#endif  // ANDROID_AUDIO_FAST_THREAD_DUMP_STATE_H
73