static void *
devpoll_init(struct event_base *base)
{
int dpfd, nfiles = NEVENT;
struct rlimit rl;
struct devpollop *devpollop;
/* Disable devpoll when this environment variable is set */
if (evutil_getenv("EVENT_NODEVPOLL"))
return (NULL);
if (!(devpollop = calloc(1, sizeof(struct devpollop))))
return (NULL);
if (getrlimit(RLIMIT_NOFILE, &rl) == 0 &&
rl.rlim_cur != RLIM_INFINITY)
nfiles = rl.rlim_cur;
/* Initialize the kernel queue */
if ((dpfd = open("/dev/poll", O_RDWR)) == -1) {
event_warn("open: /dev/poll");
free(devpollop);
return (NULL);
}
devpollop->dpfd = dpfd;
/* Initialize fields */
devpollop->events = calloc(nfiles, sizeof(struct pollfd));
if (devpollop->events == NULL) {
free(devpollop);
close(dpfd);
return (NULL);
}
devpollop->nevents = nfiles;
devpollop->fds = calloc(nfiles, sizeof(struct evdevpoll));
if (devpollop->fds == NULL) {
free(devpollop->events);
free(devpollop);
close(dpfd);
return (NULL);
}
devpollop->nfds = nfiles;
devpollop->changes = calloc(nfiles, sizeof(struct pollfd));
if (devpollop->changes == NULL) {
free(devpollop->fds);
free(devpollop->events);
free(devpollop);
close(dpfd);
return (NULL);
}
evsignal_init(base);
return (devpollop);
}
static void *
poll_init(struct event_base *base)
{
struct pollop *pollop;
/* Disable poll when this environment variable is set */
if (evutil_getenv("EVENT_NOPOLL"))
return (NULL);
if (!(pollop = calloc(1, sizeof(struct pollop))))
return (NULL);
evsignal_init(base);
return (pollop);
}
static void *
epoll_init(struct event_base *base)
{
int epfd = -1;
struct epollop *epollop;
#ifdef _EVENT_HAVE_EPOLL_CREATE1
/* First, try the shiny new epoll_create1 interface, if we have it. */
epfd = epoll_create1(EPOLL_CLOEXEC);
#endif
if (epfd == -1) {
/* Initialize the kernel queue using the old interface. (The
size field is ignored since 2.6.8.) */
if ((epfd = epoll_create(32000)) == -1) {
if (errno != ENOSYS)
event_warn("epoll_create");
return (NULL);
}
evutil_make_socket_closeonexec(epfd);
}
if (!(epollop = mm_calloc(1, sizeof(struct epollop)))) {
close(epfd);
return (NULL);
}
epollop->epfd = epfd;
/* Initialize fields */
epollop->events = mm_calloc(INITIAL_NEVENT, sizeof(struct epoll_event));
if (epollop->events == NULL) {
mm_free(epollop);
close(epfd);
return (NULL);
}
epollop->nevents = INITIAL_NEVENT;
if ((base->flags & EVENT_BASE_FLAG_EPOLL_USE_CHANGELIST) != 0 ||
((base->flags & EVENT_BASE_FLAG_IGNORE_ENV) == 0 &&
evutil_getenv("EVENT_EPOLL_USE_CHANGELIST") != NULL))
base->evsel = &epollops_changelist;
evsig_init(base);
return (epollop);
}
static void *
epoll_init(struct event_base *base)
{
int epfd;
struct epollop *epollop;
/* Disable epollueue when this environment variable is set */
if (evutil_getenv("EVENT_NOEPOLL"))
return (NULL);
/* Initalize the kernel queue */
if ((epfd = epoll_create(32000)) == -1) {
if (errno != ENOSYS)
event_warn("epoll_create");
return (NULL);
}
//fcntl(epfd,F_SETFD,1)//将1设置给epfd
FD_CLOSEONEXEC(epfd);
if (!(epollop = calloc(1, sizeof(struct epollop))))
return (NULL);
epollop->epfd = epfd;
//将nfd初始值为32大小，nevents同样如此.相应空间也会进行申请
/* Initalize fields */
epollop->events = malloc(INITIAL_NEVENTS * sizeof(struct epoll_event));
if (epollop->events == NULL) {
free(epollop);
return (NULL);
}
epollop->nevents = INITIAL_NEVENTS;
epollop->fds = calloc(INITIAL_NFILES, sizeof(struct evepoll));
if (epollop->fds == NULL) {
free(epollop->events);
free(epollop);
return (NULL);
}
epollop->nfds = INITIAL_NFILES;
//创建socket pair
evsignal_init(base);
return (epollop);
}
static void *
select_init(struct event_base *base)
{
struct selectop *sop;
/* Disable select when this environment variable is set */
if (evutil_getenv("EVENT_NOSELECT"))
return (NULL);
if (!(sop = calloc(1, sizeof(struct selectop))))
return (NULL);
select_resize(sop, howmany(32 + 1, NFDBITS)*sizeof(fd_mask));
evsignal_init(base);
return (sop);
}
static void *
epoll_init(struct event_base *base)
{
int epfd;
struct epollop *epollop;
if (evutil_getenv("EVENT_NOEPOLL"))
return (NULL);
if ((epfd = epoll_create(32000)) == -1) {
if (errno != ENOSYS)
event_warn("epoll_create");
return (NULL);
}
FD_CLOSEONEXEC(epfd);
if (!(epollop = calloc(1, sizeof(struct epollop))))
return (NULL);
epollop->epfd = epfd;
epollop->events = malloc(INITIAL_NEVENTS * sizeof(struct epoll_event));
if (epollop->events == NULL) {
free(epollop);
return (NULL);
}
epollop->nevents = INITIAL_NEVENTS;
epollop->fds = calloc(INITIAL_NFILES, sizeof(struct evepoll));
if (epollop->fds == NULL) {
free(epollop->events);
free(epollop);
return (NULL);
}
epollop->nfds = INITIAL_NFILES;
evsignal_init(base);
return (epollop);
}
static void *
epoll_init(struct event_base *base)
{
int epfd;
struct epollop *epollop;
/* Initialize the kernel queue. (The size field is ignored since
* 2.6.8.) */
if ((epfd = epoll_create(32000)) == -1) {
if (errno != ENOSYS)
event_warn("epoll_create");
return (NULL);
}
evutil_make_socket_closeonexec(epfd);
if (!(epollop = mm_calloc(1, sizeof(struct epollop)))) {
close(epfd);
return (NULL);
}
epollop->epfd = epfd;
/* Initialize fields */
epollop->events = mm_calloc(INITIAL_NEVENT, sizeof(struct epoll_event));
if (epollop->events == NULL) {
mm_free(epollop);
close(epfd);
return (NULL);
}
epollop->nevents = INITIAL_NEVENT;
if ((base->flags & EVENT_BASE_FLAG_EPOLL_USE_CHANGELIST) != 0 ||
((base->flags & EVENT_BASE_FLAG_IGNORE_ENV) == 0 &&
evutil_getenv("EVENT_EPOLL_USE_CHANGELIST") != NULL))
base->evsel = &epollops_changelist;
evsig_init(base);
return (epollop);
}
static void *
kq_init(struct event_base *base)
{
int i, kq;
struct kqop *kqueueop;
/* Disable kqueue when this environment variable is set */
if (evutil_getenv("EVENT_NOKQUEUE"))
return (NULL);
if (!(kqueueop = calloc(1, sizeof(struct kqop))))
return (NULL);
/* Initalize the kernel queue */
if ((kq = kqueue()) == -1) {
event_warn("kqueue");
free (kqueueop);
return (NULL);
}
kqueueop->kq = kq;
kqueueop->pid = getpid();
/* Initalize fields */
kqueueop->changes = malloc(NEVENT * sizeof(struct kevent));
if (kqueueop->changes == NULL) {
free (kqueueop);
return (NULL);
}
kqueueop->events = malloc(NEVENT * sizeof(struct kevent));
if (kqueueop->events == NULL) {
free (kqueueop->changes);
free (kqueueop);
return (NULL);
}
kqueueop->nevents = NEVENT;
/* we need to keep track of multiple events per signal */
for (i = 0; i < NSIG; ++i) {
TAILQ_INIT(&kqueueop->evsigevents[i]);
}
/* Check for Mac OS X kqueue bug. */
memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]);
kqueueop->changes[0].ident = -1;
kqueueop->changes[0].filter = EVFILT_READ;
kqueueop->changes[0].flags = EV_ADD;
/*
* If kqueue works, then kevent will succeed, and it will
* stick an error in events[0]. If kqueue is broken, then
* kevent will fail.
*/
if (kevent(kq,
kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 ||
kqueueop->events[0].ident != -1 ||
kqueueop->events[0].flags != EV_ERROR) {
event_warn("%s: detected broken kqueue; not using.", __func__);
free(kqueueop->changes);
free(kqueueop->events);
free(kqueueop);
close(kq);
return (NULL);
}
return (kqueueop);
}
static void *
kq_init(struct event_base *base)
{
int i, kq;
struct kqop *kqueueop;
if (evutil_getenv("EVENT_NOKQUEUE"))
return (NULL);
if (!(kqueueop = calloc(1, sizeof(struct kqop))))
return (NULL);
if ((kq = kqueue()) == -1) {
event_warn("kqueue");
free (kqueueop);
return (NULL);
}
kqueueop->kq = kq;
kqueueop->pid = getpid();
kqueueop->changes = malloc(NEVENT * sizeof(struct kevent));
if (kqueueop->changes == NULL) {
free (kqueueop);
return (NULL);
}
kqueueop->events = malloc(NEVENT * sizeof(struct kevent));
if (kqueueop->events == NULL) {
free (kqueueop->changes);
free (kqueueop);
return (NULL);
}
kqueueop->nevents = NEVENT;
for (i = 0; i < NSIG; ++i) {
TAILQ_INIT(&kqueueop->evsigevents[i]);
}
kqueueop->changes[0].ident = -1;
kqueueop->changes[0].filter = EVFILT_READ;
kqueueop->changes[0].flags = EV_ADD;
if (kevent(kq,
kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 ||
kqueueop->events[0].ident != -1 ||
kqueueop->events[0].flags != EV_ERROR) {
event_warn("%s: detected broken kqueue; not using.", __func__);
free(kqueueop->changes);
free(kqueueop->events);
free(kqueueop);
close(kq);
return (NULL);
}
return (kqueueop);
}