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 constexpr int NTHREADS = 5;
34 
35 static std::atomic<int> thread_count;
36 
thread_func(void * arg)37 static void* thread_func(void* arg) {
38   *reinterpret_cast<void**>(arg) = malloc(17);
39   thread_count++;
40   return nullptr;
41 }
42 
BM_mallinfo(benchmark::State & state)43 static void BM_mallinfo(benchmark::State& state) {
44   pthread_t t[NTHREADS];
45   void* object[NTHREADS];
46   // Create threads to populate thread-local arenas, if any.
47   thread_count = 0;
48   for (int i = 0; i < 5; i++) {
49     int res = pthread_create(t + i, NULL, thread_func, object + i);
50     if (res != 0) {
51       errx(1, "ERROR: pthread_create failed");
52     }
53   }
54   while (thread_count != NTHREADS) {
55     sched_yield();
56   }
57   for (auto _ : state) {
58     benchmark::DoNotOptimize(mallinfo().uordblks);
59   }
60   for (int i = 0; i < 5; i++) {
61     int res = pthread_join(t[i], NULL);
62     if (res != 0) {
63       errx(1, "ERROR: pthread_join failed");
64     }
65     free(object[i]);
66   }
67 }
68 
69 BIONIC_BENCHMARK(BM_mallinfo);
70 
71 static constexpr int BUF_SIZE = 100;
72 
BM_read_statm(benchmark::State & state)73 static void BM_read_statm(benchmark::State& state) {
74   char buf[BUF_SIZE];
75   int statm_fd = open("/proc/self/statm", O_RDONLY);
76   if (statm_fd == -1) {
77     errx(1, "ERROR: Open failed");
78   }
79   for (auto _ : state) {
80     off_t result = lseek(statm_fd, 0 /* offset */, SEEK_SET);
81     if (result == (off_t) -1) {
82       errx(1, "ERROR: lseek to beginning failed");
83     }
84     ssize_t nread = read(statm_fd, buf, BUF_SIZE);
85     if (nread < 13 || nread > 50) {
86       errx(1, "ERROR: Implausible read result; result = %zd", nread);
87     }
88     // We should really add the parsing overhead for the result; but that should be < 100 nsecs
89     // if we tweak it enough.
90   }
91   if (close(statm_fd) == -1) {
92     errx(1, "ERROR: Close failed");
93   }
94 }
95 
96 BIONIC_BENCHMARK(BM_read_statm);
97