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 void *helper_thread_main(void *data)
 132 {
 133         struct helper_data *hd = data;
 134         unsigned int msec_to_next_event, next_log, next_si;
 135         unsigned int next_ss = STEADYSTATE_MSEC;
 136         struct timespec ts, last_du, last_ss, last_si;
 137         char action;
 138         int ret = 0;
 139
 140         sk_out_assign(hd->sk_out);
 141
 142 #ifdef HAVE_PTHREAD_SIGMASK
 143         {
 144         sigset_t sigmask;
 145
 146         /* Let another thread handle signals. */
 147         ret = pthread_sigmask(SIG_UNBLOCK, NULL, &sigmask);
 148         assert(ret == 0);
 149         ret = pthread_sigmask(SIG_BLOCK, &sigmask, NULL);
 150         assert(ret == 0);
 151         }
 152 #endif
 153
 154 #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
 155         clock_gettime(CLOCK_MONOTONIC, &ts);
 156 #else
 157         clock_gettime(CLOCK_REALTIME, &ts);
 158 #endif
 159         memcpy(&last_du, &ts, sizeof(ts));
 160         memcpy(&last_ss, &ts, sizeof(ts));
 161         memcpy(&last_si, &ts, sizeof(ts));
 162
 163         fio_sem_up(hd->startup_sem);
 164
 165         msec_to_next_event = DISK_UTIL_MSEC;
 166         while (!ret && !hd->exit) {
 167                 uint64_t since_du, since_si, since_ss = 0;
 168                 struct timeval timeout = {
 169                         .tv_sec  = msec_to_next_event / 1000,
 170                         .tv_usec = (msec_to_next_event % 1000) * 1000,
 171                 };
 172                 fd_set rfds, efds;
 173
 174                 if (read_from_pipe(hd->pipe[0], &action, sizeof(action)) < 0) {
 175                         FD_ZERO(&rfds);
 176                         FD_SET(hd->pipe[0], &rfds);
 177                         FD_ZERO(&efds);
 178                         FD_SET(hd->pipe[0], &efds);
 179                         ret = select(1, &rfds, NULL, &efds, &timeout);
 180                         if (ret < 0)
 181                                 log_err("fio: select() call in helper thread failed: %s",
 182                                         strerror(errno));
 183                         if (read_from_pipe(hd->pipe[0], &action, sizeof(action)) <
 184                             0)
 185                                 action = 0;
 186                 }
 187
 188 #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
 189                 clock_gettime(CLOCK_MONOTONIC, &ts);
 190 #else
 191                 clock_gettime(CLOCK_REALTIME, &ts);
 192 #endif
 193
 194                 if (action == A_RESET) {
 195                         last_du = ts;
 196                         last_ss = ts;
 197                 }
 198
 199                 since_du = mtime_since(&last_du, &ts);
 200                 if (since_du >= DISK_UTIL_MSEC || DISK_UTIL_MSEC - since_du < 10) {
 201                         ret = update_io_ticks();
 202                         timespec_add_msec(&last_du, DISK_UTIL_MSEC);
 203                         msec_to_next_event = DISK_UTIL_MSEC;
 204                         if (since_du >= DISK_UTIL_MSEC)
 205                                 msec_to_next_event -= (since_du - DISK_UTIL_MSEC);
 206                 } else
 207                         msec_to_next_event = DISK_UTIL_MSEC - since_du;
 208
 209                 if (action == A_DO_STAT)
 210                         __show_running_run_stats();
 211
 212                 if (status_interval) {
 213                         since_si = mtime_since(&last_si, &ts);
 214                         if (since_si >= status_interval || status_interval - since_si < 10) {
 215                                 __show_running_run_stats();
 216                                 timespec_add_msec(&last_si, since_si);
 217                                 if (since_si > status_interval)
 218                                         next_si = status_interval - (since_si - status_interval);
 219                                 else
 220                                         next_si = status_interval;
 221                         } else
 222                                 next_si = status_interval - since_si;
 223                         msec_to_next_event = min(next_si, msec_to_next_event);
 224                 }
 225
 226                 next_log = calc_log_samples();
 227                 if (!next_log)
 228                         next_log = DISK_UTIL_MSEC;
 229
 230                 if (steadystate_enabled) {
 231                         since_ss = mtime_since(&last_ss, &ts);
 232                         if (since_ss >= STEADYSTATE_MSEC || STEADYSTATE_MSEC - since_ss < 10) {
 233                                 steadystate_check();
 234                                 timespec_add_msec(&last_ss, since_ss);
 235                                 if (since_ss > STEADYSTATE_MSEC)
 236                                         next_ss = STEADYSTATE_MSEC - (since_ss - STEADYSTATE_MSEC);
 237                                 else
 238                                         next_ss = STEADYSTATE_MSEC;
 239                         } else
 240                                 next_ss = STEADYSTATE_MSEC - since_ss;
 241                 }
 242
 243                 msec_to_next_event = min(min(next_log, msec_to_next_event), next_ss);
 244                 dprint(FD_HELPERTHREAD, "since_ss: %llu, next_ss: %u, next_log: %u, msec_to_next_event: %u\n", (unsigned long long)since_ss, next_ss, next_log, msec_to_next_event);
 245
 246                 if (!is_backend)
 247                         print_thread_status();
 248         }
 249
 250         fio_writeout_logs(false);
 251
 252         sk_out_drop();
 253         return NULL;
 254 }
 255
 256 /*
 257  * Connect two sockets to each other to emulate the pipe() system call on Windows.
 258  */
 259 int pipe_over_loopback(int fd[2])
 260 {
 261         struct sockaddr_in addr = { .sin_family = AF_INET };
 262         socklen_t len = sizeof(addr);
 263         int res;
 264
 265         addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 266
 267         sock_init();
 268
 269         fd[0] = socket(AF_INET, SOCK_STREAM, 0);
 270         if (fd[0] < 0)
 271                 goto err;
 272         fd[1] = socket(AF_INET, SOCK_STREAM, 0);
 273         if (fd[1] < 0)
 274                 goto close_fd_0;
 275         res = bind(fd[0], (struct sockaddr *)&addr, len);
 276         if (res < 0)
 277                 goto close_fd_1;
 278         res = getsockname(fd[0], (struct sockaddr *)&addr, &len);
 279         if (res < 0)
 280                 goto close_fd_1;
 281         res = listen(fd[0], 1);
 282         if (res < 0)
 283                 goto close_fd_1;
 284         res = connect(fd[1], (struct sockaddr *)&addr, len);
 285         if (res < 0)
 286                 goto close_fd_1;
 287         res = accept(fd[0], NULL, NULL);
 288         if (res < 0)
 289                 goto close_fd_1;
 290         close(fd[0]);
 291         fd[0] = res;
 292         return 0;
 293
 294 close_fd_1:
 295         close(fd[1]);
 296
 297 close_fd_0:
 298         close(fd[0]);
 299
 300 err:
 301         return -1;
 302 }
 303
 304 int helper_thread_create(struct fio_sem *startup_sem, struct sk_out *sk_out)
 305 {
 306         struct helper_data *hd;
 307         int ret;
 308
 309         hd = scalloc(1, sizeof(*hd));
 310
 311         setup_disk_util();
 312         steadystate_setup();
 313
 314         hd->sk_out = sk_out;
 315
 316 #if defined(CONFIG_PIPE2)
 317         ret = pipe2(hd->pipe, O_CLOEXEC);
 318 #elif defined(CONFIG_PIPE)
 319         ret = pipe(hd->pipe);
 320 #else
 321         ret = pipe_over_loopback(hd->pipe);
 322 #endif
 323         if (ret)
 324                 return 1;
 325
 326         ret = make_nonblocking(hd->pipe[0]);
 327         assert(ret >= 0);
 328
 329         hd->startup_sem = startup_sem;
 330
 331         DRD_IGNORE_VAR(helper_data);
 332
 333         ret = pthread_create(&hd->thread, NULL, helper_thread_main, hd);
 334         if (ret) {
 335                 log_err("Can't create helper thread: %s\n", strerror(ret));
 336                 return 1;
 337         }
 338
 339         helper_data = hd;
 340
 341         dprint(FD_MUTEX, "wait on startup_sem\n");
 342         fio_sem_down(startup_sem);
 343         dprint(FD_MUTEX, "done waiting on startup_sem\n");
 344         return 0;
 345 }