1 /*
2  * Copyright (C) 2018 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 // This measures the time required to compute two different native heap size metrics that
18 // we might use to guide GC triggering.
19 
20 #include <atomic>
21 #include <err.h>
22 #include <fcntl.h>
23 #include <malloc.h>
24 #include <pthread.h>
25 #include <sched.h>
26 #include <unistd.h>
27 #include <sys/stat.h>
28 #include <sys/types.h>
29 
30 #include <benchmark/benchmark.h>
31 #include "util.h"
32 
33 static volatile size_t sink;
34 
35 static constexpr int NTHREADS = 5;
36 
37 static std::atomic<int> thread_count;
38 
thread_func(void * arg)39 static void* thread_func(void* arg) {
40   *reinterpret_cast<void**>(arg) = malloc(17);
41   thread_count++;
42   return nullptr;
43 }
44 
BM_mallinfo(benchmark::State & state)45 static void BM_mallinfo(benchmark::State& state) {
46   pthread_t t[NTHREADS];
47   void* object[NTHREADS];
48   // Create threads to populate thread-local arenas, if any.
49   thread_count = 0;
50   for (int i = 0; i < 5; i++) {
51     int res = pthread_create(t + i, NULL, thread_func, object + i);
52     if (res != 0) {
53       errx(1, "ERROR: pthread_create failed");
54     }
55   }
56   while (thread_count != NTHREADS) {
57     sched_yield();
58   }
59   for (auto _ : state) {
60     sink = mallinfo().uordblks;
61   }
62   for (int i = 0; i < 5; i++) {
63     int res = pthread_join(t[i], NULL);
64     if (res != 0) {
65       errx(1, "ERROR: pthread_join failed");
66     }
67     free(object[i]);
68   }
69 }
70 
71 BIONIC_BENCHMARK(BM_mallinfo);
72 
73 static constexpr int BUF_SIZE = 100;
74 
BM_read_statm(benchmark::State & state)75 static void BM_read_statm(benchmark::State& state) {
76   char buf[BUF_SIZE];
77   int statm_fd = open("/proc/self/statm", O_RDONLY);
78   if (statm_fd == -1) {
79     errx(1, "ERROR: Open failed");
80   }
81   for (auto _ : state) {
82     off_t result = lseek(statm_fd, 0 /* offset */, SEEK_SET);
83     if (result == (off_t) -1) {
84       errx(1, "ERROR: lseek to beginning failed");
85     }
86     ssize_t nread = read(statm_fd, buf, BUF_SIZE);
87     if (nread < 13 || nread > 50) {
88       errx(1, "ERROR: Implausible read result; result = %zd", nread);
89     }
90     // We should really add the parsing overhead for the result; but that should be < 100 nsecs
91     // if we tweak it enough.
92   }
93   if (close(statm_fd) == -1) {
94     errx(1, "ERROR: Close failed");
95   }
96 }
97 
98 BIONIC_BENCHMARK(BM_read_statm);
99