void
evsig_process(struct event_base *base)
{
struct evsig_info *sig = &base->sig;
sig_atomic_t ncalls;
int i;
base->sig.evsig_caught = 0;
for (i = 1; i < NSIG; ++i) {
ncalls = sig->evsigcaught[i];
if (ncalls == 0)
continue;
sig->evsigcaught[i] -= ncalls;
evmap_signal_active(base, i, ncalls);
}
}
/* Callback for when the signal handler write a byte to our signaling socket */
static void
evsig_cb(evutil_socket_t fd, short what, void *arg)
{
static char signals[1024];
ev_ssize_t n;
int i;
int ncaught[NSIG];
struct event_base *base;
base = arg;
memset(&ncaught, 0, sizeof(ncaught));
while (1) {
#ifdef _WIN32
n = recv(fd, signals, sizeof(signals), 0);
#else
n = read(fd, signals, sizeof(signals));
#endif
if (n == -1) {
int err = evutil_socket_geterror(fd);
if (! EVUTIL_ERR_RW_RETRIABLE(err))
event_sock_err(1, fd, "%s: recv", __func__);
break;
} else if (n == 0) {
/* XXX warn? */
break;
}
for (i = 0; i < n; ++i) {
ev_uint8_t sig = signals[i];
if (sig < NSIG)
ncaught[sig]++;
}
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
for (i = 0; i < NSIG; ++i) {
if (ncaught[i])
evmap_signal_active(base, i, ncaught[i]);
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
}
/* Callback for when the signal handler write a byte to our signaling socket */
static void
evsig_cb(evutil_socket_t fd, short what, void *arg)
{
static char signals[1024];//用来存放信号处理函数传过来的的信号？
ev_ssize_t n;
int i;
int ncaught[NSIG];//NSIG在哪定义？
struct event_base *base;
base = arg;
memset(&ncaught, 0, sizeof(ncaught));
while (1) {
n = recv(fd, signals, sizeof(signals), 0);
if (n == -1) {
int err = evutil_socket_geterror(fd);//windows平台这是函数，而linux平台这是宏函数
if (! EVUTIL_ERR_RW_RETRIABLE(err)) //判断是否可重读写，即检查EINTR和EAGAIN
event_sock_err(1, fd, "%s: recv", __func__);
break;
} else if (n == 0) {
/* XXX warn? */
break;
}
for (i = 0; i < n; ++i) {
ev_uint8_t sig = signals[i];
if (sig < NSIG)
ncaught[sig]++;//记录传进来的信号
}
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);//base虽然是在本函数中定义的，貌似在栈上，但是他指向的地址是从外部传过来的，所以需要加锁
for (i = 0; i < NSIG; ++i) {
if (ncaught[i])
evmap_signal_active(base, i, ncaught[i]);//激活base中等待的信号
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
}
static int
kq_dispatch(struct event_base *base, struct timeval *tv)
{
struct kqop *kqop = base->evbase;
struct kevent *events = kqop->events;
struct kevent *changes;
struct timespec ts, *ts_p = NULL;
int i, n_changes, res;
if (tv != NULL) {
TIMEVAL_TO_TIMESPEC(tv, &ts);
ts_p = &ts;
}
/* Build "changes" from "base->changes" */
EVUTIL_ASSERT(kqop->changes);
n_changes = kq_build_changes_list(&base->changelist, kqop);
if (n_changes < 0)
return -1;
event_changelist_remove_all(&base->changelist, base);
/* steal the changes array in case some broken code tries to call
* dispatch twice at once. */
changes = kqop->changes;
kqop->changes = NULL;
/* Make sure that 'events' is at least as long as the list of changes:
* otherwise errors in the changes can get reported as a -1 return
* value from kevent() rather than as EV_ERROR events in the events
* array.
*
* (We could instead handle -1 return values from kevent() by
* retrying with a smaller changes array or a larger events array,
* but this approach seems less risky for now.)
*/
if (kqop->events_size < n_changes) {
int new_size = kqop->events_size;
do {
new_size *= 2;
} while (new_size < n_changes);
kq_grow_events(kqop, new_size);
events = kqop->events;
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
res = kevent(kqop->kq, changes, n_changes,
events, kqop->events_size, ts_p);
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
EVUTIL_ASSERT(kqop->changes == NULL);
kqop->changes = changes;
if (res == -1) {
if (errno != EINTR) {
event_warn("kevent");
return (-1);
}
return (0);
}
event_debug(("%s: kevent reports %d", __func__, res));
for (i = 0; i < res; i++) {
int which = 0;
if (events[i].flags & EV_ERROR) {
switch (events[i].data) {
/* Can occur on delete if we are not currently
* watching any events on this fd. That can
* happen when the fd was closed and another
* file was opened with that fd. */
case ENOENT:
/* Can occur for reasons not fully understood
* on FreeBSD. */
case EINVAL:
continue;
/* Can occur on a delete if the fd is closed. */
case EBADF:
/* XXXX On NetBSD, we can also get EBADF if we
* try to add the write side of a pipe, but
* the read side has already been closed.
* Other BSDs call this situation 'EPIPE'. It
* would be good if we had a way to report
* this situation. */
continue;
/* These two can occur on an add if the fd was one side
* of a pipe, and the other side was closed. */
case EPERM:
case EPIPE:
/* Report read events, if we're listening for
* them, so that the user can learn about any
* add errors. (If the operation was a
* delete, then udata should be cleared.) */
if (events[i].udata) {
/* The operation was an add:
* report the error as a read. */
which |= EV_READ;
break;
} else {
/* The operation was a del:
* report nothing. */
continue;
}
/* Other errors shouldn't occur. */
default:
errno = events[i].data;
return (-1);
}
} else if (events[i].filter == EVFILT_READ) {
which |= EV_READ;
} else if (events[i].filter == EVFILT_WRITE) {
which |= EV_WRITE;
} else if (events[i].filter == EVFILT_SIGNAL) {
which |= EV_SIGNAL;
}
if (!which)
continue;
if (events[i].filter == EVFILT_SIGNAL) {
evmap_signal_active(base, events[i].ident, 1);
} else {
evmap_io_active(base, events[i].ident, which | EV_ET);
}
}
if (res == kqop->events_size) {
/* We used all the events space that we have. Maybe we should
make it bigger. */
kq_grow_events(kqop, kqop->events_size * 2);
}
return (0);
}
static int
kq_dispatch(struct event_base *base, struct timeval *tv)
{
struct kqop *kqop = base->evbase;
struct kevent *events = kqop->events;
struct kevent *changes;
struct timespec ts, *ts_p = NULL;
int i, n_changes, res;
if (tv != NULL) {
TIMEVAL_TO_TIMESPEC(tv, &ts);
ts_p = &ts;
}
/* Build "changes" from "base->changes" */
EVUTIL_ASSERT(kqop->changes);
n_changes = kq_build_changes_list(&base->changelist, kqop);
if (n_changes < 0)
return -1;
event_changelist_remove_all(&base->changelist, base);
/* steal the changes array in case some broken code tries to call
* dispatch twice at once. */
changes = kqop->changes;
kqop->changes = NULL;
EVBASE_RELEASE_LOCK(base, th_base_lock);
res = kevent(kqop->kq, changes, n_changes,
events, kqop->events_size, ts_p);
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
EVUTIL_ASSERT(kqop->changes == NULL);
kqop->changes = changes;
if (res == -1) {
if (errno != EINTR) {
event_warn("kevent");
return (-1);
}
return (0);
}
event_debug(("%s: kevent reports %d", __func__, res));
for (i = 0; i < res; i++) {
int which = 0;
if (events[i].flags & EV_ERROR) {
/*
* Error messages that can happen, when a delete fails.
* EBADF happens when the file descriptor has been
* closed,
* ENOENT when the file descriptor was closed and
* then reopened.
* EINVAL for some reasons not understood; EINVAL
* should not be returned ever; but FreeBSD does :-\
* An error is also indicated when a callback deletes
* an event we are still processing. In that case
* the data field is set to ENOENT.
*/
if (events[i].data == EBADF ||
events[i].data == EINVAL ||
events[i].data == ENOENT)
continue;
errno = events[i].data;
return (-1);
}
if (events[i].filter == EVFILT_READ) {
which |= EV_READ;
} else if (events[i].filter == EVFILT_WRITE) {
which |= EV_WRITE;
} else if (events[i].filter == EVFILT_SIGNAL) {
which |= EV_SIGNAL;
}
if (!which)
continue;
if (events[i].filter == EVFILT_SIGNAL) {
evmap_signal_active(base, events[i].ident, 1);
} else {
evmap_io_active(base, events[i].ident, which | EV_ET);
}
}
if (res == kqop->events_size) {
struct kevent *newresult;
int size = kqop->events_size;
/* We used all the events space that we have. Maybe we should
make it bigger. */
size *= 2;
newresult = mm_realloc(kqop->events,
size * sizeof(struct kevent));
if (newresult) {
kqop->events = newresult;
kqop->events_size = size;
}
}
return (0);
}
