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                         ret = select(1, &rfds, NULL, &efds, &timeout);
 198                         if (ret < 0)
 199                                 log_err("fio: select() call in helper thread failed: %s",
 200                                         strerror(errno));
 201                         if (read_from_pipe(hd->pipe[0], &action, sizeof(action)) <
 202                             0)
 203                                 action = 0;
 204                 }
 205
 206 #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
 207                 clock_gettime(CLOCK_MONOTONIC, &ts);
 208 #else
 209                 clock_gettime(CLOCK_REALTIME, &ts);
 210 #endif
 211
 212                 if (action == A_RESET) {
 213                         last_du = ts;
 214                         last_ss = ts;
 215                 }
 216
 217                 since_du = mtime_since(&last_du, &ts);
 218                 if (since_du >= DISK_UTIL_MSEC || DISK_UTIL_MSEC - since_du < 10) {
 219                         ret = update_io_ticks();
 220                         timespec_add_msec(&last_du, DISK_UTIL_MSEC);
 221                         msec_to_next_event = DISK_UTIL_MSEC;
 222                         if (since_du >= DISK_UTIL_MSEC)
 223                                 msec_to_next_event -= (since_du - DISK_UTIL_MSEC);
 224                 } else
 225                         msec_to_next_event = DISK_UTIL_MSEC - since_du;
 226
 227                 if (action == A_DO_STAT)
 228                         __show_running_run_stats();
 229
 230                 if (status_interval) {
 231                         next_si = task_helper(&last_si, &ts, status_interval, __show_running_run_stats);
 232                         msec_to_next_event = min(next_si, msec_to_next_event);
 233                 }
 234
 235                 next_log = calc_log_samples();
 236                 if (!next_log)
 237                         next_log = DISK_UTIL_MSEC;
 238
 239                 if (steadystate_enabled) {
 240                         next_ss = task_helper(&last_ss, &ts, STEADYSTATE_MSEC, steadystate_check);
 241                         msec_to_next_event = min(next_ss, msec_to_next_event);
 242                 }
 243
 244                 msec_to_next_event = min(next_log, msec_to_next_event);
 245                 dprint(FD_HELPERTHREAD, "next_si: %u, next_ss: %u, next_log: %u, msec_to_next_event: %u\n",
 246                         next_si, next_ss, next_log, msec_to_next_event);
 247
 248                 if (!is_backend)
 249                         print_thread_status();
 250         }
 251
 252         fio_writeout_logs(false);
 253
 254         sk_out_drop();
 255         return NULL;
 256 }
 257
 258 /*
 259  * Connect two sockets to each other to emulate the pipe() system call on Windows.
 260  */
 261 int pipe_over_loopback(int fd[2])
 262 {
 263         struct sockaddr_in addr = { .sin_family = AF_INET };
 264         socklen_t len = sizeof(addr);
 265         int res;
 266
 267         addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 268
 269         sock_init();
 270
 271         fd[0] = socket(AF_INET, SOCK_STREAM, 0);
 272         if (fd[0] < 0)
 273                 goto err;
 274         fd[1] = socket(AF_INET, SOCK_STREAM, 0);
 275         if (fd[1] < 0)
 276                 goto close_fd_0;
 277         res = bind(fd[0], (struct sockaddr *)&addr, len);
 278         if (res < 0)
 279                 goto close_fd_1;
 280         res = getsockname(fd[0], (struct sockaddr *)&addr, &len);
 281         if (res < 0)
 282                 goto close_fd_1;
 283         res = listen(fd[0], 1);
 284         if (res < 0)
 285                 goto close_fd_1;
 286         res = connect(fd[1], (struct sockaddr *)&addr, len);
 287         if (res < 0)
 288                 goto close_fd_1;
 289         res = accept(fd[0], NULL, NULL);
 290         if (res < 0)
 291                 goto close_fd_1;
 292         close(fd[0]);
 293         fd[0] = res;
 294         return 0;
 295
 296 close_fd_1:
 297         close(fd[1]);
 298
 299 close_fd_0:
 300         close(fd[0]);
 301
 302 err:
 303         return -1;
 304 }
 305
 306 int helper_thread_create(struct fio_sem *startup_sem, struct sk_out *sk_out)
 307 {
 308         struct helper_data *hd;
 309         int ret;
 310
 311         hd = scalloc(1, sizeof(*hd));
 312
 313         setup_disk_util();
 314         steadystate_setup();
 315
 316         hd->sk_out = sk_out;
 317
 318 #if defined(CONFIG_PIPE2)
 319         ret = pipe2(hd->pipe, O_CLOEXEC);
 320 #elif defined(CONFIG_PIPE)
 321         ret = pipe(hd->pipe);
 322 #else
 323         ret = pipe_over_loopback(hd->pipe);
 324 #endif
 325         if (ret)
 326                 return 1;
 327
 328         ret = make_nonblocking(hd->pipe[0]);
 329         assert(ret >= 0);
 330
 331         hd->startup_sem = startup_sem;
 332
 333         DRD_IGNORE_VAR(helper_data);
 334
 335         ret = pthread_create(&hd->thread, NULL, helper_thread_main, hd);
 336         if (ret) {
 337                 log_err("Can't create helper thread: %s\n", strerror(ret));
 338                 return 1;
 339         }
 340
 341         helper_data = hd;
 342
 343         dprint(FD_MUTEX, "wait on startup_sem\n");
 344         fio_sem_down(startup_sem);
 345         dprint(FD_MUTEX, "done waiting on startup_sem\n");
 346         return 0;
 347 }