helper_thread.c

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