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