X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fio%2Fpoll.c;h=36af33ef0854de3323c8f29c4dc522c976091764;hp=7ceb8a7eec8bc6fd3f3de65c0c22e27a2e20e43e;hb=8cb4a3ed3d44fa4f85e176aaeaaf1da1d6eab5b6;hpb=02388bfc242abbd33c7ba64b2c32d425f5359b67

diff --git a/ccan/io/poll.c b/ccan/io/poll.c
index 7ceb8a7e..36af33ef 100644
--- a/ccan/io/poll.c
+++ b/ccan/io/poll.c
@@ -1,4 +1,4 @@
-/* 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>
@@ -6,35 +6,61 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #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_next = 0, num_finished = 0, num_waiting = 0;
+static size_t num_fds = 0, max_fds = 0, num_waiting = 0;
 static struct pollfd *pollfds = NULL;
 static struct fd **fds = NULL;
+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)
+{
+	struct timemono (*old)(void) = nowfn;
+	nowfn = now;
+	return old;
+}
 
 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 = realloc(pollfds, sizeof(*newpollfds) * num);
-		if (!newpollfds)
+		if (!tal_resize(&pollfds, num))
 			return false;
-		pollfds = newpollfds;
-		newfds = realloc(fds, sizeof(*newfds) * num);
-		if (!newfds)
+		if (!tal_resize(&fds, num))
 			return false;
-		fds = newfds;
 		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;
 }
 
@@ -44,6 +70,8 @@ static void del_fd(struct fd *fd)
 
 	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];
@@ -52,14 +80,18 @@ static void del_fd(struct fd *fd)
 		fds[n]->backend_info = n;
 	} else if (num_fds == 1) {
 		/* Free everything when no more fds. */
-		free(pollfds);
-		free(fds);
-		pollfds = NULL;
+		pollfds = tal_free(pollfds);
 		fds = NULL;
 		max_fds = 0;
 	}
 	num_fds--;
 	fd->backend_info = -1;
+
+	/* Closing a local socket doesn't wake poll() because other end
+	 * has them open.  See 2.6.  When should I use shutdown()?
+	 * in http://www.faqs.org/faqs/unix-faq/socket/ */
+	shutdown(fd->fd, SHUT_RDWR);
+
 	close(fd->fd);
 }
 
@@ -67,157 +99,190 @@ bool add_listener(struct io_listener *l)
 {
 	if (!add_fd(&l->fd, POLLIN))
 		return false;
-	num_waiting++;
 	return true;
 }
 
-bool add_conn(struct io_conn *c)
+void remove_from_always(struct io_conn *conn)
 {
-	if (!add_fd(&c->fd, 0))
-		return false;
-	num_next++;
-	return true;
+	list_del_init(&conn->always);
 }
 
-bool add_duplex(struct io_conn *c)
+void backend_new_closing(struct io_conn *conn)
 {
-	c->fd.backend_info = c->duplex->fd.backend_info;
-	num_next++;
-	return true;
+	/* In case it's on always list, remove it. */
+	list_del_init(&conn->always);
+	list_add_tail(&closing, &conn->closing);
 }
 
-static void del_conn(struct io_conn *conn)
+void backend_new_always(struct io_conn *conn)
 {
-	if (conn->fd.finish)
-		conn->fd.finish(conn, conn->fd.finish_arg);
-	if (conn->duplex) {
-		/* In case fds[] pointed to the other one. */
-		fds[conn->fd.backend_info] = &conn->duplex->fd;
-		conn->duplex->duplex = NULL;
-	} else
-		del_fd(&conn->fd);
-	if (conn->state == FINISHED)
-		num_finished--;
-	else if (conn->state == NEXT)
-		num_next--;
+	/* In case it's already in always list. */
+	list_del(&conn->always);
+	list_add_tail(&always, &conn->always);
 }
 
-void del_listener(struct io_listener *l)
+void backend_new_plan(struct io_conn *conn)
 {
-	del_fd(&l->fd);
-}
+	struct pollfd *pfd = &pollfds[conn->fd.backend_info];
 
-static int pollmask(enum io_state state)
-{
-	switch (state) {
-	case READ:
-	case READPART:
-		return POLLIN;
-	case WRITE:
-	case WRITEPART:
-		return POLLOUT;
-	default:
-		return 0;
+	if (pfd->events)
+		num_waiting--;
+
+	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 {
+		pfd->fd = -conn->fd.fd;
 	}
 }
 
-void backend_set_state(struct io_conn *conn, struct io_op *op)
+void backend_wake(const void *wait)
 {
-	enum io_state state = from_ioop(op);
-	struct pollfd *pfd = &pollfds[conn->fd.backend_info];
+	unsigned int i;
 
-	if (pfd->events)
-		num_waiting--;
+	for (i = 0; i < num_fds; i++) {
+		struct io_conn *c;
 
-	pfd->events = pollmask(state);
-	if (conn->duplex) {
-		int mask = pollmask(conn->duplex->state);
-		/* You can't *both* read/write. */
-		assert(!mask || pfd->events != mask);
-		pfd->events |= mask;
+		/* Ignore listeners */
+		if (fds[i]->listener)
+			continue;
+
+		c = (void *)fds[i];
+		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);
 	}
-	if (pfd->events)
-		num_waiting++;
+}
 
-	if (state == NEXT)
-		num_next++;
-	else if (state == FINISHED)
-		num_finished++;
+bool add_conn(struct io_conn *c)
+{
+	return add_fd(&c->fd, 0);
+}
 
-	conn->state = state;
+static void del_conn(struct io_conn *conn)
+{
+	del_fd(&conn->fd);
+	if (conn->finish) {
+		/* Saved by io_close */
+		errno = conn->plan[IO_IN].arg.u1.s;
+		conn->finish(conn, conn->finish_arg);
+	}
+	tal_free(conn);
+}
+
+void del_listener(struct io_listener *l)
+{
+	del_fd(&l->fd);
 }
 
 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;
-	}
+
+	io_new_conn(l->ctx, fd, l->init, l->arg);
 }
 
 /* It's OK to miss some, as long as we make progress. */
-static void finish_and_next(bool finished_only)
+static bool close_conns(void)
 {
-	unsigned int i;
+	bool ret = false;
+	struct io_conn *conn;
 
-	for (i = 0; !io_loop_return && i < num_fds; i++) {
-		struct io_conn *c, *duplex;
+	while ((conn = list_pop(&closing, struct io_conn, closing)) != NULL) {
+		assert(conn->plan[IO_IN].status == IO_CLOSING);
+		assert(conn->plan[IO_OUT].status == IO_CLOSING);
 
-		if (!num_finished) {
-			if (finished_only || num_next == 0)
-				break;
-		}
-		if (fds[i]->listener)
-			continue;
-		c = (void *)fds[i];
-		for (duplex = c->duplex; c; c = duplex, duplex = NULL) {
-			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--;
-			}
-		}
+		del_conn(conn);
+		ret = true;
 	}
+	return ret;
 }
 
-static void ready(struct io_conn *c)
+static bool handle_always(void)
 {
-	backend_set_state(c, do_ready(c));
+	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);
+		ret = true;
+	}
+	return ret;
 }
 
 /* This is the main loop. */
-void *io_loop(void)
+void *io_loop(struct timers *timers, struct timer **expired)
 {
 	void *ret;
 
+	/* if timers is NULL, expired must be.  If not, not. */
+	assert(!timers == !expired);
+
+	/* Make sure this is NULL if we exit for some other reason. */
+	if (expired)
+		*expired = NULL;
+
 	while (!io_loop_return) {
-		int i, r;
+		int i, r, ms_timeout = -1;
 
-		if (num_finished || num_next) {
-			finish_and_next(false);
+		if (close_conns()) {
 			/* Could have started/finished more. */
 			continue;
 		}
 
+		if (handle_always()) {
+			/* Could have started/finished more. */
+			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, -1);
+		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;
 
@@ -225,35 +290,29 @@ void *io_loop(void)
 			struct io_conn *c = (void *)fds[i];
 			int events = pollfds[i].revents;
 
+			if (r == 0)
+				break;
+
 			if (fds[i]->listener) {
-				if (events & POLLIN)
+				if (events & POLLIN) {
 					accept_conn((void *)c);
-			} else if (events & (POLLIN|POLLOUT)) {
-				if (c->duplex) {
-					int mask = pollmask(c->duplex->state);
-					if (events & mask) {
-						ready(c->duplex);
-						events &= ~mask;
-						if (!(events&(POLLIN|POLLOUT)))
-							continue;
-					}
+					r--;
 				}
-				ready(c);
-			} else if (events & POLLHUP) {
-				backend_set_state(c, io_close(c, NULL));
-				if (c->duplex)
-					backend_set_state(c->duplex,
-							  io_close(c->duplex,
-								   NULL));
+			} else if (events & (POLLIN|POLLOUT)) {
+				r--;
+				io_ready(c, events);
+			} else if (events & (POLLHUP|POLLNVAL|POLLERR)) {
+				r--;
+				errno = EBADF;
+				io_close(c);
 			}
-
 		}
 	}
 
-	while (num_finished)
-		finish_and_next(true);
+	close_conns();
 
 	ret = io_loop_return;
 	io_loop_return = NULL;
+
 	return ret;
 }