compat_epoll_pwait.h

   1 /*
   2  * fake epoll_pwait() implemented using ppoll + epoll_wait.
   3  * This is only for Linux 2.6.18 / glibc 2.5 systems (Enterprise distros :P)
   4  *
   5  * Copyright (C) 2012-2020 all contributors <cmogstored-public@yhbt.net>
   6  * License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
   7  */
   8
   9 #if !defined(HAVE_EPOLL_PWAIT) \
  10     && defined(HAVE_PPOLL) && defined(HAVE_EPOLL_WAIT)
  11 static int my_epoll_pwait(int epfd, struct epoll_event *events,
  12                           int maxevents, int timeout, const sigset_t *sigmask)
  13 {
  14         struct pollfd pfds = { .fd = epfd, .events = POLLIN };
  15         int rc;
  16         struct timespec ts;
  17         struct timespec *tsp;
  18
  19         if (timeout < 0) {
  20                 tsp = NULL;
  21         } else {
  22                 ts.tv_sec = timeout / 1000;
  23                 ts.tv_nsec = (timeout % 1000) * 1000000;
  24                 tsp = &ts;
  25         }
  26
  27         /* wait on just the epoll descriptor itself */
  28         rc = ppoll(&pfds, 1, tsp, sigmask);
  29         if (rc < 0)
  30                 assert((errno == EINTR || errno == ENOMEM)
  31                        && "ppoll usage bug");
  32
  33         /* no sleep for the actual epoll call */
  34         return rc > 0 ? epoll_wait(epfd, events, maxevents, 0) : 0;
  35 }
  36 #define epoll_pwait(epfd,events,maxevents,timeout,sigmask) \
  37         my_epoll_pwait((epfd),(events),(maxevents),(timeout),(sigmask))
  38 #endif /* epoll_pwait */