1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
// Copyright (c) 2014 Baidu, Inc.
// Author: Ge,Jun (gejun@baidu.com)
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <gflags/gflags.h>
#include <gtest/gtest.h>
#include "base/time.h"
#include "base/macros.h"
#include "base/errno.h"
#include <bthread/sys_futex.h>
#include <bthread/butex.h>
#include "bthread/bthread.h"
#include "base/atomicops.h"
namespace {
DEFINE_int32(thread_num, 1, "#pairs of threads doing ping pong");
DEFINE_bool(loop, false, "run until ctrl-C is pressed");
DEFINE_bool(use_futex, false, "use futex instead of pipe");
DEFINE_bool(use_butex, false, "use butex instead of pipe");
void (*ignore_sigpipe)(int) = signal(SIGPIPE, SIG_IGN);
volatile bool stop = false;
void quit_handler(int) {
stop = true;
}
struct BAIDU_CACHELINE_ALIGNMENT AlignedIntWrapper {
int value;
};
struct BAIDU_CACHELINE_ALIGNMENT PlayerArg {
int read_fd;
int write_fd;
int* wait_addr;
int* wake_addr;
long counter;
long wakeup;
};
void* pipe_player(void* void_arg) {
PlayerArg* arg = static_cast<PlayerArg*>(void_arg);
char dummy = '\0';
while (1) {
ssize_t nr = read(arg->read_fd, &dummy, 1);
if (nr <= 0) {
if (nr == 0) {
printf("[%lu] EOF\n", pthread_self());
break;
}
if (errno != EINTR) {
printf("[%lu] bad read, %m\n", pthread_self());
break;
}
continue;
}
if (1L != write(arg->write_fd, &dummy, 1)) {
printf("[%lu] bad write, %m\n", pthread_self());
break;
}
++arg->counter;
}
return NULL;
}
static const int INITIAL_FUTEX_VALUE = 0;
void* futex_player(void* void_arg) {
PlayerArg* arg = static_cast<PlayerArg*>(void_arg);
int counter = INITIAL_FUTEX_VALUE;
while (!stop) {
int rc = bthread::futex_wait_private(arg->wait_addr, counter, NULL);
++counter;
++*arg->wake_addr;
bthread::futex_wake_private(arg->wake_addr, 1);
++arg->counter;
arg->wakeup += (rc == 0);
}
return NULL;
}
void* butex_player(void* void_arg) {
PlayerArg* arg = static_cast<PlayerArg*>(void_arg);
int counter = INITIAL_FUTEX_VALUE;
while (!stop) {
int rc = bthread::butex_wait(arg->wait_addr, counter, NULL);
++counter;
++*arg->wake_addr;
bthread::butex_wake(arg->wake_addr);
++arg->counter;
arg->wakeup += (rc == 0);
}
return NULL;
}
TEST(PingPongTest, ping_pong) {
signal(SIGINT, quit_handler);
stop = false;
PlayerArg* args[FLAGS_thread_num];
for (int i = 0; i < FLAGS_thread_num; ++i) {
int pipe1[2];
int pipe2[2];
if (!FLAGS_use_futex && !FLAGS_use_butex) {
ASSERT_EQ(0, pipe(pipe1));
ASSERT_EQ(0, pipe(pipe2));
}
PlayerArg* arg1 = new PlayerArg;
if (!FLAGS_use_futex && !FLAGS_use_butex) {
arg1->read_fd = pipe1[0];
arg1->write_fd = pipe2[1];
} else if (FLAGS_use_futex) {
AlignedIntWrapper* w1 = new AlignedIntWrapper;
w1->value = INITIAL_FUTEX_VALUE;
AlignedIntWrapper* w2 = new AlignedIntWrapper;
w2->value = INITIAL_FUTEX_VALUE;
arg1->wait_addr = &w1->value;
arg1->wake_addr = &w2->value;
} else if (FLAGS_use_butex) {
arg1->wait_addr = bthread::butex_create_checked<int>();
*arg1->wait_addr = INITIAL_FUTEX_VALUE;
arg1->wake_addr = bthread::butex_create_checked<int>();
*arg1->wake_addr = INITIAL_FUTEX_VALUE;
} else {
ASSERT_TRUE(false);
}
arg1->counter = 0;
arg1->wakeup = 0;
args[i] = arg1;
PlayerArg* arg2 = new PlayerArg;
if (!FLAGS_use_futex && !FLAGS_use_butex) {
arg2->read_fd = pipe2[0];
arg2->write_fd = pipe1[1];
} else {
arg2->wait_addr = arg1->wake_addr;
arg2->wake_addr = arg1->wait_addr;
}
arg2->counter = 0;
arg2->wakeup = 0;
pthread_t th1;
pthread_t th2;
if (!FLAGS_use_futex && !FLAGS_use_butex) {
ASSERT_EQ(0, pthread_create(&th1, NULL, pipe_player, arg1));
ASSERT_EQ(0, pthread_create(&th2, NULL, pipe_player, arg2));
} else if (FLAGS_use_futex) {
ASSERT_EQ(0, pthread_create(&th1, NULL, futex_player, arg1));
ASSERT_EQ(0, pthread_create(&th2, NULL, futex_player, arg2));
} else if (FLAGS_use_butex) {
ASSERT_EQ(0, bthread_start_background(&th1, NULL, butex_player, arg1));
ASSERT_EQ(0, bthread_start_background(&th2, NULL, butex_player, arg2));
} else {
ASSERT_TRUE(false);
}
if (!FLAGS_use_futex && !FLAGS_use_butex) {
// send the seed data.
char seed = 255;
ASSERT_EQ(1L, write(pipe1[1], &seed, 1));
} else if (FLAGS_use_futex) {
++*arg1->wait_addr;
bthread::futex_wake_private(arg1->wait_addr, 1);
} else if (FLAGS_use_butex) {
++*arg1->wait_addr;
bthread::butex_wake(arg1->wait_addr);
} else {
ASSERT_TRUE(false);
}
}
long last_counter = 0;
long last_wakeup = 0;
while (!stop) {
base::Timer tm;
tm.start();
sleep(1);
tm.stop();
long cur_counter = 0;
long cur_wakeup = 0;
for (int i = 0; i < FLAGS_thread_num; ++i) {
cur_counter += args[i]->counter;
cur_wakeup += args[i]->wakeup;
}
if (FLAGS_use_futex || FLAGS_use_butex) {
printf("pingpong-ed %ld/s, wakeup=%ld/s\n",
(cur_counter - last_counter) * 1000L / tm.m_elapsed(),
(cur_wakeup - last_wakeup) * 1000L / tm.m_elapsed());
} else {
printf("pingpong-ed %ld/s\n",
(cur_counter - last_counter) * 1000L / tm.m_elapsed());
}
last_counter = cur_counter;
last_wakeup = cur_wakeup;
if (!FLAGS_loop) {
break;
}
}
stop = true;
// Program quits, Let resource leak.
}
} // namespace