/*
* If "expired" is true, a sleeper has timed out
*/
void _st_del_sleep_q(st_thread_t *thread, int expired)
{
st_clist_t *q;
st_thread_t *t;
/* Remove from sleep queue */
ST_ASSERT(thread->flags & _ST_FL_ON_SLEEPQ);
q = thread->links.next;
if (q != &_ST_SLEEPQ) {
if (expired) {
_ST_SLEEPQMAX -= thread->sleep;
}
else {
t = _ST_THREAD_PTR(q);
t->sleep += thread->sleep;
}
}
else {
/*
* Check if prev is the beginning of the list; if so,
* we are the only element on the list.
*/
if (thread->links.prev != &_ST_SLEEPQ)
_ST_SLEEPQMAX -= thread->sleep;
else
_ST_SLEEPQMAX = 0;
}
thread->flags &= ~_ST_FL_ON_SLEEPQ;
ST_REMOVE_LINK(&thread->links);
}
_st_stack_t *_st_stack_new(int stack_size)
{
_st_clist_t *qp;
_st_stack_t *ts;
int extra;
for (qp = _st_free_stacks.next; qp != &_st_free_stacks; qp = qp->next) {
ts = _ST_THREAD_STACK_PTR(qp);
//下面这个不执行
if (ts->stk_size >= stack_size) {
/* Found a stack that is big enough */
ST_REMOVE_LINK(&ts->links);
_st_num_free_stacks--;
ts->links.next = NULL;
ts->links.prev = NULL;
return ts;
}
}
/* Make a new thread stack object.创建一个新的线程stack对象 */
if ((ts = (_st_stack_t *)calloc(1, sizeof(_st_stack_t))) == NULL)
{
//内存分配失败，会退出
LOGE("calloc error");
return NULL;
}
extra = _st_randomize_stacks ? _ST_PAGE_SIZE : 0;
ts->vaddr_size = stack_size + 2*REDZONE + extra;
ts->vaddr = _st_new_stk_segment(ts->vaddr_size);
if (!ts->vaddr) {
free(ts);
return NULL;
}
ts->stk_size = stack_size;
ts->stk_bottom = ts->vaddr + REDZONE;
ts->stk_top = ts->stk_bottom + stack_size;
#ifdef DEBUG
mprotect(ts->vaddr, REDZONE, PROT_NONE);
mprotect(ts->stk_top + extra, REDZONE, PROT_NONE);
#endif
if (extra) {
long offset = (random() % extra) & ~0xf;
ts->stk_bottom += offset;
ts->stk_top += offset;
}
return ts;
}
int st_mutex_lock(_st_mutex_t *lock)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
if (lock->owner == NULL) {
/* Got the mutex */
lock->owner = me;
return 0;
}
if (lock->owner == me) {
errno = EDEADLK;
return -1;
}
/* Put caller thread on the mutex's wait queue */
me->state = _ST_ST_LOCK_WAIT;
ST_APPEND_LINK(&me->wait_links, &lock->wait_q);
_ST_SWITCH_CONTEXT(me);
ST_REMOVE_LINK(&me->wait_links);
if ((me->flags & _ST_FL_INTERRUPT) && lock->owner != me) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
return 0;
}
int st_cond_timedwait(_st_cond_t *cvar, st_utime_t timeout)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
int rv;
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
/* Put caller thread on the condition variable's wait queue */
me->state = _ST_ST_COND_WAIT;
ST_APPEND_LINK(&me->wait_links, &cvar->wait_q);
if (timeout != ST_UTIME_NO_TIMEOUT)
_ST_ADD_SLEEPQ(me, timeout);
_ST_SWITCH_CONTEXT(me);
ST_REMOVE_LINK(&me->wait_links);
rv = 0;
if (me->flags & _ST_FL_TIMEDOUT) {
me->flags &= ~_ST_FL_TIMEDOUT;
errno = ETIME;
rv = -1;
}
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
rv = -1;
}
return rv;
}
ST_HIDDEN void _st_select_find_bad_fd(void)
{
_st_clist_t *q;
_st_pollq_t *pq;
int notify;
struct pollfd *pds, *epds;
int pq_max_osfd, osfd;
short events;
unsigned long noBlock = 0;
_ST_SELECT_MAX_OSFD = -1;
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
notify = 0;
epds = pq->pds + pq->npds;
pq_max_osfd = -1;
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
pds->revents = 0;
if (pds->events == 0)
continue;
if (ioctlsocket(fds[osfd], FIONBIO , &noBlock ) < 0){
pds->revents = POLLNVAL;
notify = 1;
}
if (osfd > pq_max_osfd) {
pq_max_osfd = osfd;
}
}
if (notify) {
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
/*
* Decrement the count of descriptors for each descriptor/event
* because this I/O request is being removed from the ioq
*/
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
events = pds->events;
if (events & POLLIN) {
if (--_ST_SELECT_READ_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_READ_SET);
}
}
if (events & POLLOUT) {
if (--_ST_SELECT_WRITE_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_WRITE_SET);
}
}
if (events & POLLPRI) {
if (--_ST_SELECT_EXCEP_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_EXCEP_SET);
}
}
}
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
} else {
if (_ST_SELECT_MAX_OSFD < pq_max_osfd)
_ST_SELECT_MAX_OSFD = pq_max_osfd;
}
}
}
ST_HIDDEN void _st_select_dispatch(void)
{
struct timeval timeout, *tvp;
fd_set r, w, e;
fd_set *rp, *wp, *ep;
int nfd, pq_max_osfd, osfd;
_st_clist_t *q;
st_utime_t min_timeout;
_st_pollq_t *pq;
int notify;
struct pollfd *pds, *epds;
short events, revents;
/*
* Assignment of fd_sets
*/
r = _ST_SELECT_READ_SET;
w = _ST_SELECT_WRITE_SET;
e = _ST_SELECT_EXCEP_SET;
rp = &r;
wp = &w;
ep = &e;
if (_ST_SLEEPQ == NULL) {
tvp = NULL;
} else {
min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 :
(_ST_SLEEPQ->due - _ST_LAST_CLOCK);
timeout.tv_sec = (int) (min_timeout / 1000000);
timeout.tv_usec = (int) (min_timeout % 1000000);
tvp = &timeout;
}
/* Check for I/O operations */
nfd = select(_ST_SELECT_MAX_OSFD + 1, rp, wp, ep, tvp);
/* Notify threads that are associated with the selected descriptors */
if (nfd > 0) {
_ST_SELECT_MAX_OSFD = -1;
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
notify = 0;
epds = pq->pds + pq->npds;
pq_max_osfd = -1;
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
events = pds->events;
revents = 0;
if ((events & POLLIN) && FD_ISSET(fds[osfd], rp)) {
revents |= POLLIN;
}
if ((events & POLLOUT) && FD_ISSET(fds[osfd], wp)) {
revents |= POLLOUT;
}
if ((events & POLLPRI) && FD_ISSET(fds[osfd], ep)) {
revents |= POLLPRI;
}
pds->revents = revents;
if (revents) {
notify = 1;
}
if (osfd > pq_max_osfd) {
pq_max_osfd = osfd;
}
}
if (notify) {
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
/*
* Decrement the count of descriptors for each descriptor/event
* because this I/O request is being removed from the ioq
*/
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
events = pds->events;
if (events & POLLIN) {
if (--_ST_SELECT_READ_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_READ_SET);
}
}
if (events & POLLOUT) {
if (--_ST_SELECT_WRITE_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_WRITE_SET);
}
}
if (events & POLLPRI) {
if (--_ST_SELECT_EXCEP_CNT(osfd) == 0) {
FD_CLR(fds[osfd], &_ST_SELECT_EXCEP_SET);
}
}
}
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
} else {
if (_ST_SELECT_MAX_OSFD < pq_max_osfd)
_ST_SELECT_MAX_OSFD = pq_max_osfd;
}
}
} else if (nfd < 0) {
/*
* It can happen when a thread closes file descriptor
* that is being used by some other thread -- BAD!
*/
if (errno == EBADF)
_st_select_find_bad_fd();
}
}
ST_HIDDEN void _st_kq_dispatch(void)
{
struct timespec timeout, *tsp;
struct kevent kev;
st_utime_t min_timeout;
_st_clist_t *q;
_st_pollq_t *pq;
struct pollfd *pds, *epds;
int nfd, i, osfd, notify, filter;
short events, revents;
if (_ST_SLEEPQ == NULL) {
tsp = NULL;
} else {
min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 :
(_ST_SLEEPQ->due - _ST_LAST_CLOCK);
timeout.tv_sec = (time_t) (min_timeout / 1000000);
timeout.tv_nsec = (long) ((min_timeout % 1000000) * 1000);
tsp = &timeout;
}
retry_kevent:
/* Check for I/O operations */
nfd = kevent(_st_kq_data->kq,
_st_kq_data->addlist, _st_kq_data->addlist_cnt,
_st_kq_data->evtlist, _st_kq_data->evtlist_size, tsp);
_st_kq_data->addlist_cnt = 0;
if (nfd > 0) {
for (i = 0; i < nfd; i++) {
osfd = _st_kq_data->evtlist[i].ident;
filter = _st_kq_data->evtlist[i].filter;
if (filter == EVFILT_READ) {
_ST_KQ_REVENTS(osfd) |= POLLIN;
} else if (filter == EVFILT_WRITE) {
_ST_KQ_REVENTS(osfd) |= POLLOUT;
}
if (_st_kq_data->evtlist[i].flags & EV_ERROR) {
if (_st_kq_data->evtlist[i].data == EBADF) {
_ST_KQ_REVENTS(osfd) |= POLLNVAL;
} else {
_ST_KQ_REVENTS(osfd) |= POLLERR;
}
}
}
_st_kq_data->dellist_cnt = 0;
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
notify = 0;
epds = pq->pds + pq->npds;
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
events = pds->events;
revents = (short)(_ST_KQ_REVENTS(osfd) & ~(POLLIN | POLLOUT));
if ((events & POLLIN) && (_ST_KQ_REVENTS(osfd) & POLLIN)) {
revents |= POLLIN;
}
if ((events & POLLOUT) && (_ST_KQ_REVENTS(osfd) & POLLOUT)) {
revents |= POLLOUT;
}
pds->revents = revents;
if (revents) {
notify = 1;
}
}
if (notify) {
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
for (pds = pq->pds; pds < epds; pds++) {
osfd = pds->fd;
events = pds->events;
/*
* We set EV_ONESHOT flag so we only need to delete
* descriptor if it didn't fire.
*/
if ((events & POLLIN) && (--_ST_KQ_READ_CNT(osfd) == 0) &&
((_ST_KQ_REVENTS(osfd) & POLLIN) == 0)) {
memset(&kev, 0, sizeof(kev));
kev.ident = osfd;
kev.filter = EVFILT_READ;
kev.flags = EV_DELETE;
_st_kq_dellist_add(&kev);
}
if ((events & POLLOUT) && (--_ST_KQ_WRITE_CNT(osfd) == 0)
&& ((_ST_KQ_REVENTS(osfd) & POLLOUT) == 0)) {
memset(&kev, 0, sizeof(kev));
kev.ident = osfd;
kev.filter = EVFILT_WRITE;
kev.flags = EV_DELETE;
_st_kq_dellist_add(&kev);
}
}
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
}
}
if (_st_kq_data->dellist_cnt > 0) {
int rv;
do {
/* This kevent() won't block since result list size is 0 */
rv = kevent(_st_kq_data->kq, _st_kq_data->dellist,
_st_kq_data->dellist_cnt, NULL, 0, NULL);
} while (rv < 0 && errno == EINTR);
}
for (i = 0; i < nfd; i++) {
osfd = _st_kq_data->evtlist[i].ident;
_ST_KQ_REVENTS(osfd) = 0;
}
} else if (nfd < 0) {
if (errno == EBADF && _st_kq_data->pid != getpid()) {
/* We probably forked, reinitialize kqueue */
if ((_st_kq_data->kq = kqueue()) < 0) {
/* There is nothing we can do here, will retry later */
return;
}
fcntl(_st_kq_data->kq, F_SETFD, FD_CLOEXEC);
_st_kq_data->pid = getpid();
/* Re-register all descriptors on ioq with new kqueue */
memset(_st_kq_data->fd_data, 0,
_st_kq_data->fd_data_size * sizeof(_kq_fd_data_t));
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
_st_kq_pollset_add(pq->pds, pq->npds);
}
goto retry_kevent;
}
}
}
ST_HIDDEN void _st_poll_dispatch(void)
{
int timeout, nfd;
_st_clist_t *q;
st_utime_t min_timeout;
_st_pollq_t *pq;
struct pollfd *pds, *epds, *pollfds;
/*
* Build up the array of struct pollfd to wait on.
* If existing array is not big enough, release it and allocate a new one.
*/
ST_ASSERT(_ST_POLL_OSFD_CNT >= 0);
if (_ST_POLL_OSFD_CNT > _ST_POLLFDS_SIZE) {
free(_ST_POLLFDS);
_ST_POLLFDS = (struct pollfd *) malloc((_ST_POLL_OSFD_CNT + 10) *
sizeof(struct pollfd));
ST_ASSERT(_ST_POLLFDS != NULL);
_ST_POLLFDS_SIZE = _ST_POLL_OSFD_CNT + 10;
}
pollfds = _ST_POLLFDS;
/* Gather all descriptors into one array */
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
memcpy(pollfds, pq->pds, sizeof(struct pollfd) * pq->npds);
pollfds += pq->npds;
}
ST_ASSERT(pollfds <= _ST_POLLFDS + _ST_POLLFDS_SIZE);
if (_ST_SLEEPQ == NULL) {
timeout = -1;
} else {
min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 :
(_ST_SLEEPQ->due - _ST_LAST_CLOCK);
timeout = (int) (min_timeout / 1000);
}
/* Check for I/O operations */
nfd = poll(_ST_POLLFDS, _ST_POLL_OSFD_CNT, timeout);
/* Notify threads that are associated with the selected descriptors */
if (nfd > 0) {
pollfds = _ST_POLLFDS;
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
epds = pollfds + pq->npds;
for (pds = pollfds; pds < epds; pds++) {
if (pds->revents)
break;
}
if (pds < epds) {
memcpy(pq->pds, pollfds, sizeof(struct pollfd) * pq->npds);
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
_ST_POLL_OSFD_CNT -= pq->npds;
ST_ASSERT(_ST_POLL_OSFD_CNT >= 0);
}
pollfds = epds;
}
}
}
ST_HIDDEN void _st_epoll_dispatch(void)
{
st_utime_t min_timeout;
_st_clist_t *q;
_st_pollq_t *pq;
struct pollfd *pds, *epds;
struct epoll_event ev;
int timeout, nfd, i, osfd, notify;
int events, op;
short revents;
if (_ST_SLEEPQ == NULL) {
timeout = -1;
} else {
min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 :
(_ST_SLEEPQ->due - _ST_LAST_CLOCK);
timeout = (int) (min_timeout / 1000);
}
if (_st_epoll_data->pid != getpid()) {
/* We probably forked, reinitialize epoll set */
close(_st_epoll_data->epfd);
_st_epoll_data->epfd = epoll_create(_st_epoll_data->fd_hint);
if (_st_epoll_data->epfd < 0) {
/* There is nothing we can do here, will retry later */
return;
}
fcntl(_st_epoll_data->epfd, F_SETFD, FD_CLOEXEC);
_st_epoll_data->pid = getpid();
/* Put all descriptors on ioq into new epoll set */
memset(_st_epoll_data->fd_data, 0,
_st_epoll_data->fd_data_size * sizeof(_epoll_fd_data_t));
_st_epoll_data->evtlist_cnt = 0;
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
_st_epoll_pollset_add(pq->pds, pq->npds);
}
}
/* Check for I/O operations */
nfd = epoll_wait(_st_epoll_data->epfd, _st_epoll_data->evtlist,
_st_epoll_data->evtlist_size, timeout);
if (nfd > 0) {
for (i = 0; i < nfd; i++) {
osfd = _st_epoll_data->evtlist[i].data.fd;
_ST_EPOLL_REVENTS(osfd) = _st_epoll_data->evtlist[i].events;
if (_ST_EPOLL_REVENTS(osfd) & (EPOLLERR | EPOLLHUP)) {
/* Also set I/O bits on error */
_ST_EPOLL_REVENTS(osfd) |= _ST_EPOLL_EVENTS(osfd);
}
}
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
notify = 0;
epds = pq->pds + pq->npds;
for (pds = pq->pds; pds < epds; pds++) {
if (_ST_EPOLL_REVENTS(pds->fd) == 0) {
pds->revents = 0;
continue;
}
osfd = pds->fd;
events = pds->events;
revents = 0;
if ((events & POLLIN) && (_ST_EPOLL_REVENTS(osfd) & EPOLLIN))
revents |= POLLIN;
if ((events & POLLOUT) && (_ST_EPOLL_REVENTS(osfd) & EPOLLOUT))
revents |= POLLOUT;
if ((events & POLLPRI) && (_ST_EPOLL_REVENTS(osfd) & EPOLLPRI))
revents |= POLLPRI;
if (_ST_EPOLL_REVENTS(osfd) & EPOLLERR)
revents |= POLLERR;
if (_ST_EPOLL_REVENTS(osfd) & EPOLLHUP)
revents |= POLLHUP;
pds->revents = revents;
if (revents) {
notify = 1;
}
}
if (notify) {
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
/*
* Here we will only delete/modify descriptors that
* didn't fire (see comments in _st_epoll_pollset_del()).
*/
_st_epoll_pollset_del(pq->pds, pq->npds);
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
}
}
for (i = 0; i < nfd; i++) {
/* Delete/modify descriptors that fired */
osfd = _st_epoll_data->evtlist[i].data.fd;
_ST_EPOLL_REVENTS(osfd) = 0;
events = _ST_EPOLL_EVENTS(osfd);
op = events ? EPOLL_CTL_MOD : EPOLL_CTL_DEL;
ev.events = events;
ev.data.fd = osfd;
if (epoll_ctl(_st_epoll_data->epfd, op, osfd, &ev) == 0 &&
op == EPOLL_CTL_DEL) {
_st_epoll_data->evtlist_cnt--;
}
}
}
}
// epoll 事件分发
ST_HIDDEN void _st_epoll_dispatch(void)
{
st_utime_t min_timeout;
_st_clist_t *q;
_st_pollq_t *pq;
struct pollfd *pds, *epds;
struct epoll_event ev;
int timeout, nfd, i, osfd, notify;
int events, op;
short revents;
if (_ST_SLEEPQ == NULL) {
timeout = -1;
} else {
// 获取最早睡眠的线程还要睡多久（用于epoll超时）
min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 :
(_ST_SLEEPQ->due - _ST_LAST_CLOCK);
timeout = (int) (min_timeout / 1000);
}
// fork 出的子进程，则重新获取 epoll fd
if (_st_epoll_data->pid != getpid()) {
/* We probably forked, reinitialize epoll set */
close(_st_epoll_data->epfd);
_st_epoll_data->epfd = epoll_create(_st_epoll_data->fd_hint);
if (_st_epoll_data->epfd < 0) {
/* There is nothing we can do here, will retry later */
return;
}
// exec 调用时关闭
fcntl(_st_epoll_data->epfd, F_SETFD, FD_CLOEXEC);
_st_epoll_data->pid = getpid();
/* Put all descriptors on ioq into new epoll set */
memset(_st_epoll_data->fd_data, 0,
_st_epoll_data->fd_data_size * sizeof(_epoll_fd_data_t));
_st_epoll_data->evtlist_cnt = 0;
// 将 io 队列的 net fd 都加入事件系统
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
_st_epoll_pollset_add(pq->pds, pq->npds);
}
}
/* Check for I/O operations */
nfd = epoll_wait(_st_epoll_data->epfd, _st_epoll_data->evtlist,
_st_epoll_data->evtlist_size, timeout);
if (nfd > 0) {
for (i = 0; i < nfd; i++) {
osfd = _st_epoll_data->evtlist[i].data.fd;
_ST_EPOLL_REVENTS(osfd) = _st_epoll_data->evtlist[i].events;
if (_ST_EPOLL_REVENTS(osfd) & (EPOLLERR | EPOLLHUP)) {
/* Also set I/O bits on error */
_ST_EPOLL_REVENTS(osfd) |= _ST_EPOLL_EVENTS(osfd);
}
}
// ####
// 依次从 io 队列取出每个线程等待 io 的 pollfd，pq 是一个线程中加入的所有文件描述符
for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
pq = _ST_POLLQUEUE_PTR(q);
notify = 0;
epds = pq->pds + pq->npds;
// 遍历每个线程 pollfd ,获取对应的事件，然后从 io 队列中移除；如果 pollfd 上
// 有事件发生，则将其从 io 队列移除，没有事件的继续在 io 队列等待
for (pds = pq->pds; pds < epds; pds++) {
if (_ST_EPOLL_REVENTS(pds->fd) == 0) {
pds->revents = 0;
continue;
}
osfd = pds->fd;
events = pds->events;
revents = 0;
if ((events & POLLIN) && (_ST_EPOLL_REVENTS(osfd) & EPOLLIN))
revents |= POLLIN;
if ((events & POLLOUT) && (_ST_EPOLL_REVENTS(osfd) & EPOLLOUT))
revents |= POLLOUT;
if ((events & POLLPRI) && (_ST_EPOLL_REVENTS(osfd) & EPOLLPRI))
revents |= POLLPRI;
if (_ST_EPOLL_REVENTS(osfd) & EPOLLERR)
revents |= POLLERR;
if (_ST_EPOLL_REVENTS(osfd) & EPOLLHUP)
revents |= POLLHUP;
pds->revents = revents;
// 判断是不是有事件发生
if (revents) {
notify = 1;
}
}
if (notify) {
// 将有时间发生的描述符从 io 队列移除
ST_REMOVE_LINK(&pq->links);
pq->on_ioq = 0;
/*
* Here we will only delete/modify descriptors that
* didn't fire (see comments in _st_epoll_pollset_del()).
*/
// 将当前线程已处理完事件的文件描述符从事件系统中移除
_st_epoll_pollset_del(pq->pds, pq->npds);
// 如果当前线程处于睡眠则从睡眠队列移除，然后将当前线程加入运行队列
if (pq->thread->flags & _ST_FL_ON_SLEEPQ)
_ST_DEL_SLEEPQ(pq->thread);
pq->thread->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(pq->thread);
}
}
// 修改剩下还有等待事件的描述符
for (i = 0; i < nfd; i++) {
/* Delete/modify descriptors that fired */
osfd = _st_epoll_data->evtlist[i].data.fd;
_ST_EPOLL_REVENTS(osfd) = 0;
events = _ST_EPOLL_EVENTS(osfd);
op = events ? EPOLL_CTL_MOD : EPOLL_CTL_DEL;
ev.events = events;
ev.data.fd = osfd;
if (epoll_ctl(_st_epoll_data->epfd, op, osfd, &ev) == 0 &&
op == EPOLL_CTL_DEL) {
_st_epoll_data->evtlist_cnt--;
}
}
}
}
