diff options
Diffstat (limited to 'libev/ev_epoll.c')
| -rw-r--r-- | libev/ev_epoll.c | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/libev/ev_epoll.c b/libev/ev_epoll.c index d0caa93..b4e02c2 100644 --- a/libev/ev_epoll.c +++ b/libev/ev_epoll.c @@ -6,14 +6,14 @@ * * Redistribution and use in source and binary forms, with or without modifica- * tion, are permitted provided that the following conditions are met: - * + * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. - * + * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. - * + * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO @@ -144,11 +144,13 @@ epoll_poll (EV_P_ ev_tstamp timeout) int i; int eventcnt; + if (expect_false (epoll_epermcnt)) + timeout = 0.; + /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */ /* the default libev max wait time, however. */ EV_RELEASE_CB; - eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, - epoll_epermcnt ? 0 : (int)ceil (timeout * 1000.)); + eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, timeout * 1e3); EV_ACQUIRE_CB; if (expect_false (eventcnt < 0)) @@ -168,8 +170,12 @@ epoll_poll (EV_P_ ev_tstamp timeout) int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0); - /* check for spurious notification */ - /* we assume that fd is always in range, as we never shrink the anfds array */ + /* + * check for spurious notification. + * this only finds spurious notifications on egen updates + * other spurious notifications will be found by epoll_ctl, below + * we assume that fd is always in range, as we never shrink the anfds array + */ if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32))) { /* recreate kernel state */ @@ -181,8 +187,15 @@ epoll_poll (EV_P_ ev_tstamp timeout) { anfds [fd].emask = want; - /* we received an event but are not interested in it, try mod or del */ - /* I don't think we ever need MOD, but let's handle it anyways */ + /* + * we received an event but are not interested in it, try mod or del + * this often happens because we optimistically do not unregister fds + * when we are no longer interested in them, but also when we get spurious + * notifications for fds from another process. this is partially handled + * above with the gencounter check (== our fd is not the event fd), and + * partially here, when epoll_ctl returns an error (== a child has the fd + * but we closed it). + */ ev->events = (want & EV_READ ? EPOLLIN : 0) | (want & EV_WRITE ? EPOLLOUT : 0); @@ -225,7 +238,7 @@ epoll_init (EV_P_ int flags) #ifdef EPOLL_CLOEXEC backend_fd = epoll_create1 (EPOLL_CLOEXEC); - if (backend_fd <= 0) + if (backend_fd < 0) #endif backend_fd = epoll_create (256); @@ -234,9 +247,9 @@ epoll_init (EV_P_ int flags) fcntl (backend_fd, F_SETFD, FD_CLOEXEC); - backend_fudge = 0.; /* kernel sources seem to indicate this to be zero */ - backend_modify = epoll_modify; - backend_poll = epoll_poll; + backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */ + backend_modify = epoll_modify; + backend_poll = epoll_poll; epoll_eventmax = 64; /* initial number of events receivable per poll */ epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); |