ccan/io: keep always pointers to plans, not a linked list.

[ccan] / ccan / io / poll.c

diff --git a/ccan/io/poll.c b/ccan/io/poll.c
index 229f7ce9ab4e6fb9bf69ccfd7ae5b650a4463613..a853c8705f1d5b68971327ec9c38d22ef4222e2b 100644 (file)
--- a/ccan/io/poll.c
+++ b/ccan/io/poll.c
@@ -11,12 +11,12 @@
 #include <ccan/time/time.h>
 #include <ccan/timer/timer.h>
 
-static size_t num_fds = 0, max_fds = 0, num_waiting = 0;
+static size_t num_fds = 0, max_fds = 0, num_waiting = 0, num_always = 0, max_always = 0;
 static struct pollfd *pollfds = NULL;
 static struct fd **fds = NULL;
-static LIST_HEAD(closing);
-static LIST_HEAD(always);
+static struct io_plan **always = NULL;
 static struct timemono (*nowfn)(void) = time_mono;
+static int (*pollfn)(struct pollfd *fds, nfds_t nfds, int timeout) = poll;
 
 struct timemono (*io_time_override(struct timemono (*now)(void)))(void)
 {
@@ -25,6 +25,13 @@ struct timemono (*io_time_override(struct timemono (*now)(void)))(void)
        return old;
 }
 
+int (*io_poll_override(int (*poll)(struct pollfd *fds, nfds_t nfds, int timeout)))(struct pollfd *, nfds_t, int)
+{
+       int (*old)(struct pollfd *fds, nfds_t nfds, int timeout) = pollfn;
+       pollfn = poll;
+       return old;
+}
+
 static bool add_fd(struct fd *fd, short events)
 {
        if (!max_fds) {
@@ -102,16 +109,52 @@ bool add_listener(struct io_listener *l)
        return true;
 }
 
-void remove_from_always(struct io_conn *conn)
+static int find_always(const struct io_plan *plan)
 {
-       list_del_init(&conn->always);
+       for (size_t i = 0; i < num_always; i++)
+               if (always[i] == plan)
+                       return i;
+       return -1;
 }
 
-void backend_new_always(struct io_conn *conn)
+static void remove_from_always(const struct io_plan *plan)
 {
-       /* In case it's already in always list. */
-       list_del(&conn->always);
-       list_add_tail(&always, &conn->always);
+       int pos;
+
+       if (plan->status != IO_ALWAYS)
+               return;
+
+       pos = find_always(plan);
+       assert(pos >= 0);
+
+       /* Move last one down if we made a hole */
+       if (pos != num_always-1)
+               always[pos] = always[num_always-1];
+       num_always--;
+}
+
+bool backend_new_always(struct io_plan *plan)
+{
+       assert(find_always(plan) == -1);
+
+       if (!max_always) {
+               assert(num_always == 0);
+               always = tal_arr(NULL, struct io_plan *, 8);
+               if (!always)
+                       return false;
+               max_always = 8;
+       }
+
+       if (num_always + 1 > max_always) {
+               size_t num = max_always * 2;
+
+               if (!tal_resize(&always, num))
+                       return false;
+               max_always = num;
+       }
+
+       always[num_always++] = plan;
+       return true;
 }
 
 void backend_new_plan(struct io_conn *conn)
@@ -122,9 +165,11 @@ void backend_new_plan(struct io_conn *conn)
                num_waiting--;
 
        pfd->events = 0;
-       if (conn->plan[IO_IN].status == IO_POLLING)
+       if (conn->plan[IO_IN].status == IO_POLLING_NOTSTARTED
+           || conn->plan[IO_IN].status == IO_POLLING_STARTED)
                pfd->events |= POLLIN;
-       if (conn->plan[IO_OUT].status == IO_POLLING)
+       if (conn->plan[IO_OUT].status == IO_POLLING_NOTSTARTED
+           || conn->plan[IO_OUT].status == IO_POLLING_STARTED)
                pfd->events |= POLLOUT;
 
        if (pfd->events) {
@@ -164,8 +209,9 @@ static void destroy_conn(struct io_conn *conn, bool close_fd)
        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);
+
+       remove_from_always(&conn->plan[IO_IN]);
+       remove_from_always(&conn->plan[IO_OUT]);
 
        /* errno saved/restored by tal_free itself. */
        if (conn->finish) {
@@ -187,11 +233,10 @@ bool add_conn(struct io_conn *c)
        return true;
 }
 
-struct io_plan *io_close_taken_fd(struct io_conn *conn)
+void cleanup_conn_without_close(struct io_conn *conn)
 {
        tal_del_destructor(conn, destroy_conn_close_fd);
        destroy_conn(conn, false);
-       return io_close(conn);
 }
 
 static void accept_conn(struct io_listener *l)
@@ -208,15 +253,12 @@ static void accept_conn(struct io_listener *l)
 static bool handle_always(void)
 {
        bool ret = false;
-       struct io_conn *conn;
 
-       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);
-
-               /* Re-initialize, for next time. */
-               list_node_init(&conn->always);
-               io_do_always(conn);
+       while (num_always > 0) {
+               /* Remove first: it might re-add */
+               struct io_plan *plan = always[num_always-1];
+               num_always--;
+               io_do_always(plan);
                ret = true;
        }
        return ret;
@@ -270,9 +312,14 @@ void *io_loop(struct timers *timers, struct timer **expired)
                        }
                }
 
-               r = poll(pollfds, num_fds, ms_timeout);
-               if (r < 0)
+               r = pollfn(pollfds, num_fds, ms_timeout);
+               if (r < 0) {
+                       /* Signals shouldn't break us, unless they set
+                        * io_loop_return. */
+                       if (errno == EINTR)
+                               continue;
                        break;
+               }
 
                for (i = 0; i < num_fds && !io_loop_return; i++) {
                        struct io_conn *c = (void *)fds[i];