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 #include <audio_utils/roundup.h>
18 #include "FastThreadDumpState.h"
19
20 namespace android {
21
FastThreadDumpState()22 FastThreadDumpState::FastThreadDumpState()
23 {
24 #ifdef FAST_THREAD_STATISTICS
25 increaseSamplingN(1);
26 #endif
27 }
28
29 #ifdef FAST_THREAD_STATISTICS
increaseSamplingN(uint32_t samplingN)30 void FastThreadDumpState::increaseSamplingN(uint32_t samplingN)
31 {
32 if (samplingN <= mSamplingN || samplingN > kSamplingN || roundup(samplingN) != samplingN) {
33 return;
34 }
35 const uint32_t additional = samplingN - mSamplingN;
36 // sample arrays aren't accessed atomically with respect to the bounds,
37 // so clearing reduces chance for dumpsys to read random uninitialized samples
38 memset(&mMonotonicNs[mSamplingN], 0, sizeof(mMonotonicNs[0]) * additional);
39 memset(&mLoadNs[mSamplingN], 0, sizeof(mLoadNs[0]) * additional);
40 #ifdef CPU_FREQUENCY_STATISTICS
41 memset(&mCpukHz[mSamplingN], 0, sizeof(mCpukHz[0]) * additional);
42 #endif
43 mSamplingN = samplingN;
44 }
45 #endif
46
47 } // namespace android
48