helper_thread: Introduce the wait_for_action() function
[fio.git] / helper_thread.c
CommitLineData
c31092b8 1#include <signal.h>
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2#ifdef CONFIG_VALGRIND_DEV
3#include <valgrind/drd.h>
4#else
5#define DRD_IGNORE_VAR(x) do { } while (0)
6#endif
7
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8#include "fio.h"
9#include "smalloc.h"
10#include "helper_thread.h"
16e56d25 11#include "steadystate.h"
ae626d4e 12#include "pshared.h"
a39fb9ea 13
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14enum action {
15 A_EXIT = 1,
16 A_RESET = 2,
17 A_DO_STAT = 3,
18};
19
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20static struct helper_data {
21 volatile int exit;
52a552e2 22 int pipe[2]; /* 0: read end; 1: write end. */
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23 struct sk_out *sk_out;
24 pthread_t thread;
971caeb1 25 struct fio_sem *startup_sem;
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26} *helper_data;
27
28void helper_thread_destroy(void)
29{
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30 if (!helper_data)
31 return;
32
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33 close(helper_data->pipe[0]);
34 close(helper_data->pipe[1]);
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35 sfree(helper_data);
36}
37
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38#ifdef _WIN32
39static void sock_init(void)
a39fb9ea 40{
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41 WSADATA wsaData;
42 int res;
a39fb9ea 43
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44 /* It is allowed to call WSAStartup() more than once. */
45 res = WSAStartup(MAKEWORD(2, 2), &wsaData);
46 assert(res == 0);
47}
a39fb9ea 48
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49static int make_nonblocking(int fd)
50{
51 unsigned long arg = 1;
dda11987 52
52a552e2 53 return ioctlsocket(fd, FIONBIO, &arg);
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54}
55
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56static int write_to_pipe(int fd, const void *buf, size_t len)
57{
58 return send(fd, buf, len, 0);
59}
60
61static int read_from_pipe(int fd, void *buf, size_t len)
62{
63 return recv(fd, buf, len, 0);
64}
65#else
66static void sock_init(void)
67{
68}
69
70static int make_nonblocking(int fd)
71{
72 return fcntl(fd, F_SETFL, O_NONBLOCK);
73}
74
75static int write_to_pipe(int fd, const void *buf, size_t len)
76{
77 return write(fd, buf, len);
78}
79
80static int read_from_pipe(int fd, void *buf, size_t len)
81{
82 return read(fd, buf, len);
83}
84#endif
85
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86static void block_signals(void)
87{
88#ifdef HAVE_PTHREAD_SIGMASK
89 sigset_t sigmask;
90
91 ret = pthread_sigmask(SIG_UNBLOCK, NULL, &sigmask);
92 assert(ret == 0);
93 ret = pthread_sigmask(SIG_BLOCK, &sigmask, NULL);
94 assert(ret == 0);
95#endif
96}
97
52a552e2 98static void submit_action(enum action a)
a39fb9ea 99{
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100 const char data = a;
101 int ret;
102
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103 if (!helper_data)
104 return;
105
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106 ret = write_to_pipe(helper_data->pipe[1], &data, sizeof(data));
107 assert(ret == 1);
108}
109
110void helper_reset(void)
111{
112 submit_action(A_RESET);
113}
114
115/*
116 * May be invoked in signal handler context and hence must only call functions
117 * that are async-signal-safe. See also
118 * https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04_03.
119 */
120void helper_do_stat(void)
121{
122 submit_action(A_DO_STAT);
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123}
124
125bool helper_should_exit(void)
126{
127 if (!helper_data)
128 return true;
129
130 return helper_data->exit;
131}
132
133void helper_thread_exit(void)
134{
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135 if (!helper_data)
136 return;
137
a39fb9ea 138 helper_data->exit = 1;
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139 submit_action(A_EXIT);
140 pthread_join(helper_data->thread, NULL);
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141}
142
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143/*
144 * Waits for an action from fd during at least timeout_ms. `fd` must be in
145 * non-blocking mode.
146 */
147static uint8_t wait_for_action(int fd, unsigned int timeout_ms)
148{
149 struct timeval timeout = {
150 .tv_sec = timeout_ms / 1000,
151 .tv_usec = (timeout_ms % 1000) * 1000,
152 };
153 fd_set rfds, efds;
154 uint8_t action = 0;
155 int res;
156
157 res = read_from_pipe(fd, &action, sizeof(action));
158 if (res > 0 || timeout_ms == 0)
159 return action;
160 FD_ZERO(&rfds);
161 FD_SET(fd, &rfds);
162 FD_ZERO(&efds);
163 FD_SET(fd, &efds);
164 res = select(fd + 1, &rfds, NULL, &efds, &timeout);
165 if (res < 0) {
166 log_err("fio: select() call in helper thread failed: %s",
167 strerror(errno));
168 return A_EXIT;
169 }
170 if (FD_ISSET(fd, &rfds))
171 read_from_pipe(fd, &action, sizeof(action));
172 return action;
173}
174
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175static unsigned int task_helper(struct timespec *last, struct timespec *now, unsigned int period, void do_task())
176{
177 unsigned int next, since;
178
179 since = mtime_since(last, now);
180 if (since >= period || period - since < 10) {
181 do_task();
182 timespec_add_msec(last, since);
183 if (since > period)
184 next = period - (since - period);
185 else
186 next = period;
187 } else
188 next = period - since;
189
190 return next;
191}
192
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193static void *helper_thread_main(void *data)
194{
195 struct helper_data *hd = data;
3da71e37 196 unsigned int msec_to_next_event, next_log, next_si = status_interval;
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197 unsigned int next_ss = STEADYSTATE_MSEC;
198 struct timespec ts, last_du, last_ss, last_si;
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199 int ret = 0;
200
201 sk_out_assign(hd->sk_out);
202
c31092b8 203 /* Let another thread handle signals. */
2575407f 204 block_signals();
c31092b8 205
69212fc4 206 fio_get_mono_time(&ts);
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207 memcpy(&last_du, &ts, sizeof(ts));
208 memcpy(&last_ss, &ts, sizeof(ts));
0f77d30d 209 memcpy(&last_si, &ts, sizeof(ts));
a39fb9ea 210
971caeb1 211 fio_sem_up(hd->startup_sem);
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212
213 msec_to_next_event = DISK_UTIL_MSEC;
214 while (!ret && !hd->exit) {
3da71e37 215 uint64_t since_du;
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216 uint8_t action;
217
218 action = wait_for_action(hd->pipe[0], msec_to_next_event);
219 if (action == A_EXIT)
220 break;
a39fb9ea 221
69212fc4 222 fio_get_mono_time(&ts);
a39fb9ea 223
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224 if (action == A_RESET) {
225 last_du = ts;
226 last_ss = ts;
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227 }
228
8b6a404c 229 since_du = mtime_since(&last_du, &ts);
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230 if (since_du >= DISK_UTIL_MSEC || DISK_UTIL_MSEC - since_du < 10) {
231 ret = update_io_ticks();
8b6a404c 232 timespec_add_msec(&last_du, DISK_UTIL_MSEC);
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233 msec_to_next_event = DISK_UTIL_MSEC;
234 if (since_du >= DISK_UTIL_MSEC)
235 msec_to_next_event -= (since_du - DISK_UTIL_MSEC);
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236 } else
237 msec_to_next_event = DISK_UTIL_MSEC - since_du;
a39fb9ea 238
52a552e2 239 if (action == A_DO_STAT)
a39fb9ea 240 __show_running_run_stats();
a39fb9ea 241
0f77d30d 242 if (status_interval) {
3da71e37 243 next_si = task_helper(&last_si, &ts, status_interval, __show_running_run_stats);
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244 msec_to_next_event = min(next_si, msec_to_next_event);
245 }
246
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247 next_log = calc_log_samples();
248 if (!next_log)
249 next_log = DISK_UTIL_MSEC;
250
84784e07 251 if (steadystate_enabled) {
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252 next_ss = task_helper(&last_ss, &ts, STEADYSTATE_MSEC, steadystate_check);
253 msec_to_next_event = min(next_ss, msec_to_next_event);
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254 }
255
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256 msec_to_next_event = min(next_log, msec_to_next_event);
257 dprint(FD_HELPERTHREAD, "next_si: %u, next_ss: %u, next_log: %u, msec_to_next_event: %u\n",
258 next_si, next_ss, next_log, msec_to_next_event);
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259
260 if (!is_backend)
261 print_thread_status();
262 }
263
264 fio_writeout_logs(false);
265
266 sk_out_drop();
267 return NULL;
268}
269
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270/*
271 * Connect two sockets to each other to emulate the pipe() system call on Windows.
272 */
273int pipe_over_loopback(int fd[2])
274{
275 struct sockaddr_in addr = { .sin_family = AF_INET };
276 socklen_t len = sizeof(addr);
277 int res;
278
279 addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
280
281 sock_init();
282
283 fd[0] = socket(AF_INET, SOCK_STREAM, 0);
284 if (fd[0] < 0)
285 goto err;
286 fd[1] = socket(AF_INET, SOCK_STREAM, 0);
287 if (fd[1] < 0)
288 goto close_fd_0;
289 res = bind(fd[0], (struct sockaddr *)&addr, len);
290 if (res < 0)
291 goto close_fd_1;
292 res = getsockname(fd[0], (struct sockaddr *)&addr, &len);
293 if (res < 0)
294 goto close_fd_1;
295 res = listen(fd[0], 1);
296 if (res < 0)
297 goto close_fd_1;
298 res = connect(fd[1], (struct sockaddr *)&addr, len);
299 if (res < 0)
300 goto close_fd_1;
301 res = accept(fd[0], NULL, NULL);
302 if (res < 0)
303 goto close_fd_1;
304 close(fd[0]);
305 fd[0] = res;
306 return 0;
307
308close_fd_1:
309 close(fd[1]);
310
311close_fd_0:
312 close(fd[0]);
313
314err:
315 return -1;
316}
317
971caeb1 318int helper_thread_create(struct fio_sem *startup_sem, struct sk_out *sk_out)
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319{
320 struct helper_data *hd;
321 int ret;
322
b3090ff4 323 hd = scalloc(1, sizeof(*hd));
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324
325 setup_disk_util();
16e56d25 326 steadystate_setup();
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327
328 hd->sk_out = sk_out;
34febb23 329
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330#if defined(CONFIG_PIPE2)
331 ret = pipe2(hd->pipe, O_CLOEXEC);
332#elif defined(CONFIG_PIPE)
333 ret = pipe(hd->pipe);
334#else
335 ret = pipe_over_loopback(hd->pipe);
336#endif
34febb23 337 if (ret)
f9e5b5ee 338 return 1;
34febb23 339
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340 ret = make_nonblocking(hd->pipe[0]);
341 assert(ret >= 0);
342
971caeb1 343 hd->startup_sem = startup_sem;
a39fb9ea 344
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345 DRD_IGNORE_VAR(helper_data);
346
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347 ret = pthread_create(&hd->thread, NULL, helper_thread_main, hd);
348 if (ret) {
349 log_err("Can't create helper thread: %s\n", strerror(ret));
350 return 1;
351 }
352
353 helper_data = hd;
354
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355 dprint(FD_MUTEX, "wait on startup_sem\n");
356 fio_sem_down(startup_sem);
357 dprint(FD_MUTEX, "done waiting on startup_sem\n");
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358 return 0;
359}