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 
BM_unistd_getpid(int iters)22 static void BM_unistd_getpid(int iters) {
23   StartBenchmarkTiming();
24 
25   for (int i = 0; i < iters; ++i) {
26     getpid();
27   }
28 
29   StopBenchmarkTiming();
30 }
31 BENCHMARK(BM_unistd_getpid);
32 
BM_unistd_getpid_syscall(int iters)33 static void BM_unistd_getpid_syscall(int iters) {
34   StartBenchmarkTiming();
35 
36   for (int i = 0; i < iters; ++i) {
37     syscall(__NR_getpid);
38   }
39 
40   StopBenchmarkTiming();
41 }
42 BENCHMARK(BM_unistd_getpid_syscall);
43 
44 // Stop GCC optimizing out our pure function.
45 /* Must not be static! */ pid_t (*gettid_fp)() = gettid;
46 
BM_unistd_gettid(int iters)47 static void BM_unistd_gettid(int iters) {
48   StartBenchmarkTiming();
49 
50   for (int i = 0; i < iters; ++i) {
51     gettid_fp();
52   }
53 
54   StopBenchmarkTiming();
55 }
56 BENCHMARK(BM_unistd_gettid);
57 
BM_unistd_gettid_syscall(int iters)58 static void BM_unistd_gettid_syscall(int iters) {
59   StartBenchmarkTiming();
60 
61   for (int i = 0; i < iters; ++i) {
62     syscall(__NR_gettid);
63   }
64 
65   StopBenchmarkTiming();
66 }
67 BENCHMARK(BM_unistd_gettid_syscall);
68