-/* Licensed under BSD-MIT - see LICENSE file for details */
+/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#include "io.h"
#include "backend.h"
#include <assert.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
+#include <limits.h>
-static size_t num_fds = 0, max_fds = 0, num_next = 0, num_finished = 0;
+static size_t num_fds = 0, max_fds = 0, num_closing = 0, num_waiting = 0;
static struct pollfd *pollfds = NULL;
static struct fd **fds = NULL;
+static struct timers timeouts;
+#ifdef DEBUG
+static unsigned int io_loop_level;
+static struct io_conn *free_later;
+static void io_loop_enter(void)
+{
+ io_loop_level++;
+}
+static void io_loop_exit(void)
+{
+ io_loop_level--;
+ if (io_loop_level == 0) {
+ /* Delayed free. */
+ while (free_later) {
+ struct io_conn *c = free_later;
+ free_later = c->finish_arg;
+ free(c);
+ }
+ }
+}
+static void free_conn(struct io_conn *conn)
+{
+ /* Only free on final exit: chain via finish. */
+ if (io_loop_level > 1) {
+ struct io_conn *c;
+ for (c = free_later; c; c = c->finish_arg)
+ assert(c != conn);
+ conn->finish_arg = free_later;
+ free_later = conn;
+ } else
+ free(conn);
+}
+#else
+static void io_loop_enter(void)
+{
+}
+static void io_loop_exit(void)
+{
+}
+static void free_conn(struct io_conn *conn)
+{
+ free(conn);
+}
+#endif
static bool add_fd(struct fd *fd, short events)
{
max_fds = num;
}
- pollfds[num_fds].fd = fd->fd;
pollfds[num_fds].events = events;
+ /* In case it's idle. */
+ if (!events)
+ pollfds[num_fds].fd = -fd->fd;
+ else
+ pollfds[num_fds].fd = fd->fd;
pollfds[num_fds].revents = 0; /* In case we're iterating now */
fds[num_fds] = fd;
fd->backend_info = num_fds;
num_fds++;
+ if (events)
+ num_waiting++;
+
return true;
}
assert(n != -1);
assert(n < num_fds);
+ if (pollfds[n].events)
+ num_waiting--;
if (n != num_fds - 1) {
/* Move last one over us. */
pollfds[n] = pollfds[num_fds-1];
bool add_listener(struct io_listener *l)
{
- return add_fd(&l->fd, POLLIN);
+ if (!add_fd(&l->fd, POLLIN))
+ return false;
+ return true;
+}
+
+void backend_plan_changed(struct io_conn *conn)
+{
+ struct pollfd *pfd;
+
+ /* This can happen with debugging and delayed free... */
+ if (conn->fd.backend_info == -1)
+ return;
+
+ pfd = &pollfds[conn->fd.backend_info];
+
+ if (pfd->events)
+ num_waiting--;
+
+ pfd->events = conn->plan.pollflag;
+ if (conn->duplex) {
+ int mask = conn->duplex->plan.pollflag;
+ /* You can't *both* read/write. */
+ assert(!mask || pfd->events != mask);
+ pfd->events |= mask;
+ }
+ if (pfd->events) {
+ num_waiting++;
+ pfd->fd = conn->fd.fd;
+ } else
+ pfd->fd = -conn->fd.fd;
+
+ if (!conn->plan.next)
+ num_closing++;
}
bool add_conn(struct io_conn *c)
{
- if (!add_fd(&c->fd, 0))
+ if (!add_fd(&c->fd, c->plan.pollflag))
return false;
- num_next++;
+ /* Immediate close is allowed. */
+ if (!c->plan.next)
+ num_closing++;
+ return true;
+}
+
+bool add_duplex(struct io_conn *c)
+{
+ c->fd.backend_info = c->duplex->fd.backend_info;
+ backend_plan_changed(c);
return true;
}
static void del_conn(struct io_conn *conn)
{
- if (conn->fd.finish)
- conn->fd.finish(conn, conn->fd.finish_arg);
- del_fd(&conn->fd);
- if (conn->state == FINISHED)
- num_finished--;
- else if (conn->state == NEXT)
- num_next--;
+ if (conn->finish)
+ conn->finish(conn, conn->finish_arg);
+ if (timeout_active(conn))
+ backend_del_timeout(conn);
+ free(conn->timeout);
+ if (conn->duplex) {
+ /* In case fds[] pointed to the other one. */
+ fds[conn->fd.backend_info] = &conn->duplex->fd;
+ conn->duplex->duplex = NULL;
+ conn->fd.backend_info = -1;
+ } else
+ del_fd(&conn->fd);
+ num_closing--;
}
void del_listener(struct io_listener *l)
del_fd(&l->fd);
}
-void backend_set_state(struct io_conn *conn, struct io_op *op)
-{
- enum io_state state = from_ioop(op);
- struct pollfd *pfd = &pollfds[conn->fd.backend_info];
-
- switch (state) {
- case READ:
- case READPART:
- pfd->events = POLLIN;
- break;
- case WRITE:
- case WRITEPART:
- pfd->events = POLLOUT;
- break;
- case IDLE:
- pfd->events = 0;
- break;
- case NEXT:
- num_next++;
- break;
- case FINISHED:
- num_finished++;
- break;
- default:
- abort();
- }
- conn->state = state;
+static void set_plan(struct io_conn *conn, struct io_plan plan)
+{
+ conn->plan = plan;
+ backend_plan_changed(conn);
}
static void accept_conn(struct io_listener *l)
{
- struct io_conn *c;
int fd = accept(l->fd.fd, NULL, NULL);
/* FIXME: What to do here? */
if (fd < 0)
return;
- c = io_new_conn(fd, l->fd.next, l->fd.finish, l->fd.next_arg);
- if (!c) {
- close(fd);
- return;
- }
+ l->init(fd, l->arg);
}
/* It's OK to miss some, as long as we make progress. */
-static void finish_and_next(bool finished_only)
+static void finish_conns(void)
{
unsigned int i;
for (i = 0; !io_loop_return && i < num_fds; i++) {
- struct io_conn *c;
+ struct io_conn *c, *duplex;
+
+ if (!num_closing)
+ break;
- if (!num_finished) {
- if (finished_only || num_next == 0)
- break;
- }
if (fds[i]->listener)
continue;
c = (void *)fds[i];
- if (c->state == FINISHED) {
- del_conn(c);
- free(c);
- i--;
- } else if (!finished_only && c->state == NEXT) {
- backend_set_state(c, c->fd.next(c, c->fd.next_arg));
- num_next--;
+ for (duplex = c->duplex; c; c = duplex, duplex = NULL) {
+ if (!c->plan.next) {
+ del_conn(c);
+ free_conn(c);
+ i--;
+ }
}
}
}
+void backend_add_timeout(struct io_conn *conn, struct timespec duration)
+{
+ if (!timeouts.base)
+ timers_init(&timeouts, time_now());
+ timer_add(&timeouts, &conn->timeout->timer,
+ time_add(time_now(), duration));
+ conn->timeout->conn = conn;
+}
+
+void backend_del_timeout(struct io_conn *conn)
+{
+ assert(conn->timeout->conn == conn);
+ timer_del(&timeouts, &conn->timeout->timer);
+ conn->timeout->conn = NULL;
+}
+
/* This is the main loop. */
void *io_loop(void)
{
void *ret;
+ io_loop_enter();
+
while (!io_loop_return) {
- int i, r;
+ int i, r, timeout = INT_MAX;
+ struct timespec now;
+ bool some_timeouts = false;
+
+ if (timeouts.base) {
+ struct timespec first;
+ struct list_head expired;
+ struct io_timeout *t;
+
+ now = time_now();
+
+ /* Call functions for expired timers. */
+ timers_expire(&timeouts, now, &expired);
+ while ((t = list_pop(&expired, struct io_timeout, timer.list))) {
+ struct io_conn *conn = t->conn;
+ /* Clear, in case timer re-adds */
+ t->conn = NULL;
+ set_current(conn);
+ set_plan(conn, t->next(conn, t->next_arg));
+ some_timeouts = true;
+ }
+
+ /* Now figure out how long to wait for the next one. */
+ if (timer_earliest(&timeouts, &first)) {
+ uint64_t f = time_to_msec(time_sub(first, now));
+ if (f < INT_MAX)
+ timeout = f;
+ }
+ }
- if (num_finished || num_next) {
- finish_and_next(false);
+ if (num_closing) {
+ finish_conns();
/* Could have started/finished more. */
continue;
}
+ /* debug can recurse on io_loop; anything can change. */
+ if (doing_debug() && some_timeouts)
+ continue;
+
if (num_fds == 0)
break;
- r = poll(pollfds, num_fds, -1);
+ /* You can't tell them all to go to sleep! */
+ assert(num_waiting);
+
+ r = poll(pollfds, num_fds, timeout);
if (r < 0)
break;
for (i = 0; i < num_fds && !io_loop_return; i++) {
struct io_conn *c = (void *)fds[i];
- if (pollfds[i].revents & POLLOUT)
- backend_set_state(c, do_writeable(c));
- else if (pollfds[i].revents & POLLIN) {
- if (fds[i]->listener)
+ int events = pollfds[i].revents;
+
+ if (r == 0)
+ break;
+
+ if (fds[i]->listener) {
+ if (events & POLLIN) {
accept_conn((void *)c);
- else
- backend_set_state(c, do_readable(c));
- } else if (pollfds[i].revents & POLLHUP) {
- backend_set_state(c, io_close(c, NULL));
+ r--;
+ }
+ } else if (events & (POLLIN|POLLOUT)) {
+ r--;
+ if (c->duplex) {
+ int mask = c->duplex->plan.pollflag;
+ if (events & mask) {
+ io_ready(c->duplex);
+ events &= ~mask;
+ /* debug can recurse;
+ * anything can change. */
+ if (doing_debug())
+ break;
+ if (!(events&(POLLIN|POLLOUT)))
+ continue;
+ }
+ }
+ io_ready(c);
+ /* debug can recurse; anything can change. */
+ if (doing_debug())
+ break;
+ } else if (events & (POLLHUP|POLLNVAL|POLLERR)) {
+ r--;
+ set_current(c);
+ set_plan(c, io_close());
+ if (c->duplex) {
+ set_current(c->duplex);
+ set_plan(c->duplex, io_close());
+ }
}
}
}
- while (num_finished)
- finish_and_next(true);
+ while (num_closing)
+ finish_conns();
ret = io_loop_return;
io_loop_return = NULL;
+
+ io_loop_exit();
return ret;
}
projects / ccan / blobdiff