unistd_benchmark.cpp revision b27a840f4b520bfa095db99b0a2e5205634b0003 
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 "benchmark.h"
18
19#include <sys/syscall.h>
20#include <unistd.h>
21
22static void BM_unistd_getpid(int iters) {
23  StartBenchmarkTiming();
24
25  for (int i = 0; i < iters; ++i) {
26    getpid();
27  }
28
29  StopBenchmarkTiming();
30}
31BENCHMARK(BM_unistd_getpid);
32
33// Stop GCC optimizing out our pure function.
34/* Must not be static! */ pid_t (*gettid_fp)() = gettid;
35
36static void BM_unistd_gettid(int iters) {
37  StartBenchmarkTiming();
38
39  for (int i = 0; i < iters; ++i) {
40    gettid_fp();
41  }
42
43  StopBenchmarkTiming();
44}
45BENCHMARK(BM_unistd_gettid);
46
47static void BM_unistd_gettid_syscall(int iters) {
48  StartBenchmarkTiming();
49
50  for (int i = 0; i < iters; ++i) {
51    syscall(__NR_gettid);
52  }
53
54  StopBenchmarkTiming();
55}
56BENCHMARK(BM_unistd_gettid_syscall);
57