static void
death_queue_kill_all(struct death_queue_t *dq)
{
while (!death_queue_empty(dq)) {
lwan_connection_t *conn = death_queue_idx_to_node(dq, dq->head.next);
destroy_coro(dq, conn);
}
}
static lwan_connection_t *
grab_and_watch_client(int epoll_fd, int pipe_fd, lwan_connection_t *conns)
{
int fd;
if (UNLIKELY(read(pipe_fd, &fd, sizeof(int)) != sizeof(int)))
return NULL;
struct epoll_event event = {
.events = events_by_write_flag[1],
.data.ptr = &conns[fd]
};
if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &event) < 0))
return NULL;
return &conns[fd];
}
static void *
thread_io_loop(void *data)
{
lwan_thread_t *t = data;
const int epoll_fd = t->epoll_fd;
const int read_pipe_fd = t->pipe_fd[0];
const int max_events = min((int)t->lwan->thread.max_fd, 1024);
const lwan_t *lwan = t->lwan;
lwan_connection_t *conns = lwan->conns;
struct epoll_event *events;
coro_switcher_t switcher;
struct death_queue_t dq;
int n_fds;
lwan_status_debug("Starting IO loop on thread #%d",
(unsigned short)(ptrdiff_t)(t - t->lwan->thread.threads) + 1);
events = calloc((size_t)max_events, sizeof(*events));
if (UNLIKELY(!events))
lwan_status_critical("Could not allocate memory for events");
death_queue_init(&dq, lwan);
for (;;) {
switch (n_fds = epoll_wait(epoll_fd, events, max_events,
death_queue_epoll_timeout(&dq))) {
case -1:
switch (errno) {
case EBADF:
case EINVAL:
goto epoll_fd_closed;
}
continue;
case 0: /* timeout: shutdown waiting sockets */
death_queue_kill_waiting(&dq);
break;
default: /* activity in some of this poller's file descriptor */
update_date_cache(t);
for (struct epoll_event *ep_event = events; n_fds--; ep_event++) {
lwan_connection_t *conn;
if (!ep_event->data.ptr) {
conn = grab_and_watch_client(epoll_fd, read_pipe_fd, conns);
if (UNLIKELY(!conn))
continue;
spawn_coro(conn, &switcher, &dq);
} else {
conn = ep_event->data.ptr;
if (UNLIKELY(ep_event->events & (EPOLLRDHUP | EPOLLHUP))) {
destroy_coro(&dq, conn);
continue;
}
resume_coro_if_needed(&dq, conn, epoll_fd);
}
death_queue_move_to_last(&dq, conn);
}
}
}
epoll_fd_closed:
death_queue_kill_all(&dq);
free(events);
return NULL;
}
static int
process_request_coro(coro_t *coro)
{
strbuf_t *strbuf = coro_malloc_full(coro, sizeof(*strbuf), strbuf_free);
lwan_connection_t *conn = coro_get_data(coro);
lwan_t *lwan = conn->thread->lwan;
int fd = lwan_connection_get_fd(conn);
char request_buffer[DEFAULT_BUFFER_SIZE];
lwan_value_t buffer = {
.value = request_buffer,
.len = 0
};
char *next_request = NULL;
strbuf_init(strbuf);
while (true) {
lwan_request_t request = {
.conn = conn,
.fd = fd,
.response = {
.buffer = strbuf
},
};
assert(conn->flags & CONN_IS_ALIVE);
next_request = lwan_process_request(lwan, &request, &buffer, next_request);
if (!next_request)
break;
coro_yield(coro, CONN_CORO_MAY_RESUME);
if (UNLIKELY(!strbuf_reset_length(strbuf)))
return CONN_CORO_ABORT;
}
return CONN_CORO_FINISHED;
}
static ALWAYS_INLINE void
resume_coro_if_needed(struct death_queue_t *dq, lwan_connection_t *conn,
int epoll_fd)
{
assert(conn->coro);
if (!(conn->flags & CONN_SHOULD_RESUME_CORO))
return;
lwan_connection_coro_yield_t yield_result = coro_resume(conn->coro);
/* CONN_CORO_ABORT is -1, but comparing with 0 is cheaper */
if (yield_result < CONN_CORO_MAY_RESUME) {
destroy_coro(dq, conn);
return;
}
bool write_events;
if (conn->flags & CONN_MUST_READ) {
write_events = true;
} else {
bool should_resume_coro = (yield_result == CONN_CORO_MAY_RESUME);
if (should_resume_coro)
conn->flags |= CONN_SHOULD_RESUME_CORO;
else
conn->flags &= ~CONN_SHOULD_RESUME_CORO;
write_events = (conn->flags & CONN_WRITE_EVENTS);
if (should_resume_coro == write_events)
return;
}
struct epoll_event event = {
.events = events_by_write_flag[write_events],
.data.ptr = conn
};
int fd = lwan_connection_get_fd(conn);
if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &event) < 0))
lwan_status_perror("epoll_ctl");
conn->flags ^= CONN_WRITE_EVENTS;
}
static void
death_queue_kill_waiting(struct death_queue_t *dq)
{
dq->time++;
while (!death_queue_empty(dq)) {
lwan_connection_t *conn = death_queue_idx_to_node(dq, dq->head.next);
if (conn->time_to_die > dq->time)
return;
destroy_coro(dq, conn);
}
/* Death queue exhausted: reset epoch */
dq->time = 0;
}
static ALWAYS_INLINE void
resume_coro_if_needed(struct death_queue_t *dq, lwan_connection_t *conn,
int epoll_fd)
{
assert(conn->coro);
if (!(conn->flags & CONN_SHOULD_RESUME_CORO))
return;
lwan_connection_coro_yield_t yield_result = coro_resume(conn->coro);
/* CONN_CORO_ABORT is -1, but comparing with 0 is cheaper */
if (yield_result < CONN_CORO_MAY_RESUME) {
destroy_coro(dq, conn);
return;
}
bool write_events;
if (conn->flags & CONN_MUST_READ) {
write_events = true;
} else {
bool should_resume_coro = (yield_result == CONN_CORO_MAY_RESUME);
if (should_resume_coro)
conn->flags |= CONN_SHOULD_RESUME_CORO;
else
conn->flags &= ~CONN_SHOULD_RESUME_CORO;
write_events = (conn->flags & CONN_WRITE_EVENTS);
if (should_resume_coro == write_events)
return;
}
struct epoll_event event = {
.events = events_by_write_flag[write_events],
.data.ptr = conn
};
int fd = lwan_connection_get_fd(dq->lwan, conn);
if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &event) < 0))
lwan_status_perror("epoll_ctl");
conn->flags ^= CONN_WRITE_EVENTS;
}
static void
death_queue_kill_waiting(struct death_queue_t *dq)
{
dq->time++;
while (!death_queue_empty(dq)) {
lwan_connection_t *conn = death_queue_idx_to_node(dq, dq->head.next);
if (conn->time_to_die > dq->time)
return;
destroy_coro(dq, conn);
}
/* Death queue exhausted: reset epoch */
dq->time = 0;
}
void destroy_thread(Worker * thr) {
destroy_coro(thr);
free (thr);
}
