sig.c

   1 /*
   2  * Copyright (C) 2012-2020 all contributors <cmogstored-public@yhbt.net>
   3  * License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
   4  */
   5 #include "cmogstored.h"
   6
   7 /*
   8  * we block signals in pool threads, only the main thread receives signals
   9  */
  10
  11 static sigset_t fullset;
  12 sigset_t mog_emptyset;
  13
  14 __attribute__((constructor)) static void sig_init(void)
  15 {
  16         CHECK(int, 0, sigfillset(&fullset));
  17         CHECK(int, 0, sigemptyset(&mog_emptyset));
  18 }
  19
  20 void mog_intr_disable(void)
  21 {
  22         CHECK(int, 0, pthread_sigmask(SIG_SETMASK, &fullset, NULL));
  23 }
  24
  25 void mog_intr_enable(void)
  26 {
  27         CHECK(int, 0, pthread_sigmask(SIG_SETMASK, &mog_emptyset, NULL));
  28 }
  29
  30 static int sleeper(struct timespec *tsp, const sigset_t *sigmask)
  31 {
  32         int err = 0;
  33
  34         /*
  35          * pselect is a cancellation point,
  36          * ppoll is not POSIX and is only a cancellation point on glibc.
  37          */
  38         if (pselect(0, NULL, NULL, NULL, tsp, sigmask) < 0) {
  39                 err = errno;
  40                 assert((err == EINTR || err == ENOMEM) &&
  41                        "BUG in pselect usage");
  42         }
  43         return err;
  44 }
  45
  46 /* thread-safe, interruptible sleep, negative seconds -> sleep forever */
  47 int mog_sleep(long seconds)
  48 {
  49         struct timespec ts;
  50         struct timespec *tsp;
  51
  52         if (seconds < 0) {
  53                 tsp = NULL;
  54         } else {
  55                 ts.tv_sec = seconds;
  56                 ts.tv_nsec = 0;
  57                 tsp = &ts;
  58         }
  59
  60         return sleeper(tsp, &mog_emptyset);
  61 }