]> git.ozlabs.org Git - ccan/blobdiff - ccan/io/poll.c
io: make io_close_taken_fd() unset nonblocking on the fd.
[ccan] / ccan / io / poll.c
index 8ba376a549aa47ee4be29af3345c034dfdfbf481..043feff74046226e61c367ad68644f3aba3fb54e 100644 (file)
@@ -8,71 +8,43 @@
 #include <sys/socket.h>
 #include <limits.h>
 #include <errno.h>
+#include <ccan/time/time.h>
+#include <ccan/timer/timer.h>
 
-static size_t num_fds = 0, max_fds = 0, num_closing = 0, num_waiting = 0;
-static bool some_always = false;
+static size_t num_fds = 0, max_fds = 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;
-                       io_alloc.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
-               io_alloc.free(conn);
-}
-#else
-static void io_loop_enter(void)
-{
-}
-static void io_loop_exit(void)
-{
-}
-static void free_conn(struct io_conn *conn)
+static LIST_HEAD(closing);
+static LIST_HEAD(always);
+static struct timemono (*nowfn)(void) = time_mono;
+
+struct timemono (*io_time_override(struct timemono (*now)(void)))(void)
 {
-       io_alloc.free(conn);
+       struct timemono (*old)(void) = nowfn;
+       nowfn = now;
+       return old;
 }
-#endif
 
 static bool add_fd(struct fd *fd, short events)
 {
+       if (!max_fds) {
+               assert(num_fds == 0);
+               pollfds = tal_arr(NULL, struct pollfd, 8);
+               if (!pollfds)
+                       return false;
+               fds = tal_arr(pollfds, struct fd *, 8);
+               if (!fds)
+                       return false;
+               max_fds = 8;
+       }
+
        if (num_fds + 1 > max_fds) {
-               struct pollfd *newpollfds;
-               struct fd **newfds;
-               size_t num = max_fds ? max_fds * 2 : 8;
+               size_t num = max_fds * 2;
 
-               newpollfds = io_alloc.realloc(pollfds, sizeof(*newpollfds)*num);
-               if (!newpollfds)
+               if (!tal_resize(&pollfds, num))
                        return false;
-               pollfds = newpollfds;
-               newfds = io_alloc.realloc(fds, sizeof(*newfds) * num);
-               if (!newfds)
+               if (!tal_resize(&fds, num))
                        return false;
-               fds = newfds;
                max_fds = num;
        }
 
@@ -106,145 +78,119 @@ static void del_fd(struct fd *fd)
                fds[n] = fds[num_fds-1];
                assert(fds[n]->backend_info == num_fds-1);
                fds[n]->backend_info = n;
-               /* If that happens to be a duplex, move that too. */
-               if (!fds[n]->listener) {
-                       struct io_conn *c = (void *)fds[n];
-                       if (c->duplex) {
-                               assert(c->duplex->fd.backend_info == num_fds-1);
-                               c->duplex->fd.backend_info = n;
-                       }
-               }
        } else if (num_fds == 1) {
                /* Free everything when no more fds. */
-               io_alloc.free(pollfds);
-               io_alloc.free(fds);
-               pollfds = NULL;
+               pollfds = tal_free(pollfds);
                fds = NULL;
                max_fds = 0;
        }
        num_fds--;
        fd->backend_info = -1;
-       close(fd->fd);
+}
+
+static void destroy_listener(struct io_listener *l)
+{
+       close(l->fd.fd);
+       del_fd(&l->fd);
 }
 
 bool add_listener(struct io_listener *l)
 {
        if (!add_fd(&l->fd, POLLIN))
                return false;
+       tal_add_destructor(l, destroy_listener);
        return true;
 }
 
-void backend_plan_changed(struct io_conn *conn)
+void remove_from_always(struct io_conn *conn)
 {
-       struct pollfd *pfd;
+       list_del_init(&conn->always);
+}
 
-       /* This can happen with debugging and delayed free... */
-       if (conn->fd.backend_info == -1)
-               return;
+void backend_new_always(struct io_conn *conn)
+{
+       /* In case it's already in always list. */
+       list_del(&conn->always);
+       list_add_tail(&always, &conn->always);
+}
 
-       pfd = &pollfds[conn->fd.backend_info];
+void backend_new_plan(struct io_conn *conn)
+{
+       struct pollfd *pfd = &pollfds[conn->fd.backend_info];
 
        if (pfd->events)
                num_waiting--;
 
-       pfd->events = conn->plan.pollflag & (POLLIN|POLLOUT);
-       if (conn->duplex) {
-               int mask = conn->duplex->plan.pollflag & (POLLIN|POLLOUT);
-               /* You can't *both* read/write. */
-               assert(!mask || pfd->events != mask);
-               pfd->events |= mask;
-       }
+       pfd->events = 0;
+       if (conn->plan[IO_IN].status == IO_POLLING)
+               pfd->events |= POLLIN;
+       if (conn->plan[IO_OUT].status == IO_POLLING)
+               pfd->events |= POLLOUT;
+
        if (pfd->events) {
                num_waiting++;
                pfd->fd = conn->fd.fd;
-       } else
+       } else {
                pfd->fd = -conn->fd.fd;
-
-       if (!conn->plan.next)
-               num_closing++;
-
-       if (conn->plan.pollflag == POLLALWAYS)
-               some_always = true;
+       }
 }
 
-void backend_wait_changed(const void *wait)
+void backend_wake(const void *wait)
 {
        unsigned int i;
 
        for (i = 0; i < num_fds; i++) {
-               struct io_conn *c, *duplex;
+               struct io_conn *c;
 
                /* Ignore listeners */
                if (fds[i]->listener)
                        continue;
+
                c = (void *)fds[i];
-               for (duplex = c->duplex; c; c = duplex, duplex = NULL) {
-                       /* Ignore closing. */
-                       if (!c->plan.next)
-                               continue;
-                       /* Not idle? */
-                       if (c->plan.io)
-                               continue;
-                       /* Waiting on something else? */
-                       if (c->plan.u1.const_vp != wait)
-                               continue;
-                       /* Make it do the next thing. */
-                       c->plan = io_always_(c->plan.next, c->plan.next_arg);
-                       backend_plan_changed(c);
-               }
+               if (c->plan[IO_IN].status == IO_WAITING
+                   && c->plan[IO_IN].arg.u1.const_vp == wait)
+                       io_do_wakeup(c, IO_IN);
+
+               if (c->plan[IO_OUT].status == IO_WAITING
+                   && c->plan[IO_OUT].arg.u1.const_vp == wait)
+                       io_do_wakeup(c, IO_OUT);
        }
 }
 
-bool add_conn(struct io_conn *c)
+static void destroy_conn(struct io_conn *conn, bool close_fd)
 {
-       if (!add_fd(&c->fd, c->plan.pollflag & (POLLIN|POLLOUT)))
-               return false;
-       /* Immediate close is allowed. */
-       if (!c->plan.next)
-               num_closing++;
-       if (c->plan.pollflag == POLLALWAYS)
-               some_always = true;
-       return true;
-}
+       int saved_errno = errno;
 
-bool add_duplex(struct io_conn *c)
-{
-       c->fd.backend_info = c->duplex->fd.backend_info;
-       backend_plan_changed(c);
-       return true;
-}
+       if (close_fd)
+               close(conn->fd.fd);
+       del_fd(&conn->fd);
+       /* In case it's on always list, remove it. */
+       list_del_init(&conn->always);
 
-void backend_del_conn(struct io_conn *conn)
-{
-       if (timeout_active(conn))
-               backend_del_timeout(conn);
-       io_alloc.free(conn->timeout);
-       if (conn->duplex) {
-               /* In case fds[] pointed to the other one. */
-               assert(conn->duplex->fd.backend_info == conn->fd.backend_info);
-               fds[conn->fd.backend_info] = &conn->duplex->fd;
-               conn->duplex->duplex = NULL;
-               conn->fd.backend_info = -1;
-       } else
-               del_fd(&conn->fd);
-       num_closing--;
+       /* errno saved/restored by tal_free itself. */
        if (conn->finish) {
-               /* Saved by io_close */
-               errno = conn->plan.u1.s;
+               errno = saved_errno;
                conn->finish(conn, conn->finish_arg);
        }
-       free_conn(conn);
 }
 
-void del_listener(struct io_listener *l)
+static void destroy_conn_close_fd(struct io_conn *conn)
 {
-       del_fd(&l->fd);
+       destroy_conn(conn, true);
+}
+
+bool add_conn(struct io_conn *c)
+{
+       if (!add_fd(&c->fd, 0))
+               return false;
+       tal_add_destructor(c, destroy_conn_close_fd);
+       return true;
 }
 
-static void set_plan(struct io_conn *conn, struct io_plan plan)
+void cleanup_conn_without_close(struct io_conn *conn)
 {
-       conn->plan = plan;
-       backend_plan_changed(conn);
+       tal_del_destructor(conn, destroy_conn_close_fd);
+       destroy_conn(conn, false);
 }
 
 static void accept_conn(struct io_listener *l)
@@ -254,135 +200,76 @@ static void accept_conn(struct io_listener *l)
        /* FIXME: What to do here? */
        if (fd < 0)
                return;
-       l->init(fd, l->arg);
-}
-
-/* It's OK to miss some, as long as we make progress. */
-static bool finish_conns(struct io_conn **ready)
-{
-       unsigned int i;
-
-       for (i = 0; !io_loop_return && i < num_fds; i++) {
-               struct io_conn *c, *duplex;
-
-               if (!num_closing)
-                       break;
-
-               if (fds[i]->listener)
-                       continue;
-               c = (void *)fds[i];
-               for (duplex = c->duplex; c; c = duplex, duplex = NULL) {
-                       if (!c->plan.next) {
-                               if (doing_debug_on(c) && ready) {
-                                       *ready = c;
-                                       return true;
-                               }
-                               backend_del_conn(c);
-                               i--;
-                       }
-               }
-       }
-       return false;
-}
-
-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;
+       io_new_conn(l->ctx, fd, l->init, l->arg);
 }
 
-static void handle_always(void)
+static bool handle_always(void)
 {
-       int i;
-
-       some_always = false;
-
-       for (i = 0; i < num_fds && !io_loop_return; i++) {
-               struct io_conn *c = (void *)fds[i];
-
-               if (fds[i]->listener)
-                       continue;
+       bool ret = false;
+       struct io_conn *conn;
 
-               if (c->plan.pollflag == POLLALWAYS)
-                       io_ready(c);
+       while ((conn = list_pop(&always, struct io_conn, always)) != NULL) {
+               assert(conn->plan[IO_IN].status == IO_ALWAYS
+                      || conn->plan[IO_OUT].status == IO_ALWAYS);
 
-               if (c->duplex && c->duplex->plan.pollflag == POLLALWAYS)
-                       io_ready(c->duplex);
+               /* Re-initialize, for next time. */
+               list_node_init(&conn->always);
+               io_do_always(conn);
+               ret = true;
        }
+       return ret;
 }
 
 /* This is the main loop. */
-void *do_io_loop(struct io_conn **ready)
+void *io_loop(struct timers *timers, struct timer **expired)
 {
        void *ret;
 
-       io_loop_enter();
-
-       while (!io_loop_return) {
-               int i, r, timeout = INT_MAX;
-               struct timespec now;
-               bool some_timeouts = false;
+       /* if timers is NULL, expired must be.  If not, not. */
+       assert(!timers == !expired);
 
-               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;
-                       }
+       /* Make sure this is NULL if we exit for some other reason. */
+       if (expired)
+               *expired = NULL;
 
-                       /* 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;
-                       }
-               }
+       while (!io_loop_return) {
+               int i, r, ms_timeout = -1;
 
-               if (num_closing) {
-                       /* If this finishes a debugging con, return now. */
-                       if (finish_conns(ready))
-                               return NULL;
+               if (handle_always()) {
                        /* Could have started/finished more. */
                        continue;
                }
 
-               /* debug can recurse on io_loop; anything can change. */
-               if (doing_debug() && some_timeouts)
-                       continue;
-
-               if (some_always) {
-                       handle_always();
-                       continue;
-               }
-
+               /* Everything closed? */
                if (num_fds == 0)
                        break;
 
                /* You can't tell them all to go to sleep! */
                assert(num_waiting);
 
-               r = poll(pollfds, num_fds, timeout);
+               if (timers) {
+                       struct timemono now, first;
+
+                       now = nowfn();
+
+                       /* Call functions for expired timers. */
+                       *expired = timers_expire(timers, now);
+                       if (*expired)
+                               break;
+
+                       /* Now figure out how long to wait for the next one. */
+                       if (timer_earliest(timers, &first)) {
+                               uint64_t next;
+                               next = time_to_msec(timemono_between(first, now));
+                               if (next < INT_MAX)
+                                       ms_timeout = next;
+                               else
+                                       ms_timeout = INT_MAX;
+                       }
+               }
+
+               r = poll(pollfds, num_fds, ms_timeout);
                if (r < 0)
                        break;
 
@@ -394,68 +281,28 @@ void *do_io_loop(struct io_conn **ready)
                                break;
 
                        if (fds[i]->listener) {
+                               struct io_listener *l = (void *)fds[i];
                                if (events & POLLIN) {
-                                       accept_conn((void *)c);
+                                       accept_conn(l);
+                                       r--;
+                               } else if (events & (POLLHUP|POLLNVAL|POLLERR)) {
                                        r--;
+                                       errno = EBADF;
+                                       io_close_listener(l);
                                }
                        } else if (events & (POLLIN|POLLOUT)) {
                                r--;
-                               if (c->duplex) {
-                                       int mask = c->duplex->plan.pollflag;
-                                       if (events & mask) {
-                                               if (doing_debug_on(c->duplex)
-                                                       && ready) {
-                                                       *ready = c->duplex;
-                                                       return NULL;
-                                               }
-                                               io_ready(c->duplex);
-                                               events &= ~mask;
-                                               /* debug can recurse;
-                                                * anything can change. */
-                                               if (doing_debug())
-                                                       break;
-
-                                               /* If no events, or it closed
-                                                * the duplex, continue. */
-                                               if (!(events&(POLLIN|POLLOUT))
-                                                   || !c->plan.next)
-                                                       continue;
-                                       }
-                               }
-                               if (doing_debug_on(c) && ready) {
-                                       *ready = c;
-                                       return NULL;
-                               }
-                               io_ready(c);
-                               /* debug can recurse; anything can change. */
-                               if (doing_debug())
-                                       break;
+                               io_ready(c, events);
                        } else if (events & (POLLHUP|POLLNVAL|POLLERR)) {
                                r--;
-                               set_current(c);
                                errno = EBADF;
-                               set_plan(c, io_close());
-                               if (c->duplex) {
-                                       set_current(c->duplex);
-                                       set_plan(c->duplex, io_close());
-                               }
+                               io_close(c);
                        }
                }
        }
 
-       while (num_closing && !io_loop_return) {
-               if (finish_conns(ready))
-                       return NULL;
-       }
-
        ret = io_loop_return;
        io_loop_return = NULL;
 
-       io_loop_exit();
        return ret;
 }
-
-void *io_loop(void)
-{
-       return do_io_loop(NULL);
-}