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Use a wrapper function to create the notification pipe/socketpair/eventfd

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This commit is contained in:
Nick Mathewson 2012-02-10 16:15:10 -05:00
parent 4970329a88
commit ca76cd931f
1 changed files with 10 additions and 53 deletions
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61
event.c
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@ -46,9 +46,6 @@
#ifdef _EVENT_HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef _EVENT_HAVE_SYS_EVENTFD_H
#include <sys/eventfd.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <signal.h>
@ -2948,8 +2945,8 @@ evthread_notify_drain_default(evutil_socket_t fd, short what, void *arg)
int
evthread_make_base_notifiable(struct event_base *base)
{
void (*cb)(evutil_socket_t, short, void *) = evthread_notify_drain_default;
int (*notify)(struct event_base *) = evthread_notify_base_default;
void (*cb)(evutil_socket_t, short, void *);
int (*notify)(struct event_base *);
/* XXXX grab the lock here? */
if (!base)
@ -2960,61 +2957,21 @@ evthread_make_base_notifiable(struct event_base *base)
return 0;
}
#if defined(_EVENT_HAVE_EVENTFD) && defined(_EVENT_HAVE_SYS_EVENTFD_H)
#ifndef EFD_CLOEXEC
#define EFD_CLOEXEC 0
#endif
base->th_notify_fd[0] = eventfd(0, EFD_CLOEXEC);
base->th_notify_fd[0] = evutil_eventfd(0,
EVUTIL_EFD_CLOEXEC|EVUTIL_EFD_NONBLOCK);
if (base->th_notify_fd[0] >= 0) {
evutil_make_socket_closeonexec(base->th_notify_fd[0]);
base->th_notify_fd[1] = -1;
notify = evthread_notify_base_eventfd;
cb = evthread_notify_drain_eventfd;
}
#endif
#if defined(_EVENT_HAVE_PIPE)
if (base->th_notify_fd[0] < 0) {
if ((base->evsel->features & EV_FEATURE_FDS)) {
if (pipe(base->th_notify_fd) < 0) {
event_warn("%s: pipe", __func__);
} else if (evutil_make_internal_pipe(base->th_notify_fd) == 0) {
notify = evthread_notify_base_default;
cb = evthread_notify_drain_default;
} else {
evutil_make_socket_closeonexec(base->th_notify_fd[0]);
evutil_make_socket_closeonexec(base->th_notify_fd[1]);
return -1;
}
}
}
#endif
#ifdef _WIN32
#define LOCAL_SOCKETPAIR_AF AF_INET
#else
#define LOCAL_SOCKETPAIR_AF AF_UNIX
#endif
if (base->th_notify_fd[0] < 0) {
if (evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0,
base->th_notify_fd) == -1) {
event_sock_warn(-1, "%s: socketpair", __func__);
return (-1);
} else {
evutil_make_socket_closeonexec(base->th_notify_fd[0]);
evutil_make_socket_closeonexec(base->th_notify_fd[1]);
}
}
evutil_make_socket_nonblocking(base->th_notify_fd[0]);
base->th_notify_fn = notify;
/*
Making the second socket nonblocking is a bit subtle, given that we
ignore any EAGAIN returns when writing to it, and you don't usally
do that for a nonblocking socket. But if the kernel gives us EAGAIN,
then there's no need to add any more data to the buffer, since
the main thread is already either about to wake up and drain it,
or woken up and in the process of draining it.
*/
if (base->th_notify_fd[1] > 0)
evutil_make_socket_nonblocking(base->th_notify_fd[1]);
/* prepare an event that we can use for wakeup */
event_assign(&base->th_notify, base, base->th_notify_fd[0],
EV_READ|EV_PERSIST, cb, base);