X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=ccan%2Fio%2Fpoll.c;h=c1a624525e9185811ad9510eef555a4dd80bfb30;hb=cdffdf5d61f8330cfc3467e73a84876eb3928e9b;hp=fdff271c64f26e09f060b9e52e468dcf80d97696;hpb=a2dffefa5ef8d0cf71d99755c4640a8004679b1d;p=ccan

diff --git a/ccan/io/poll.c b/ccan/io/poll.c
index fdff271c..c1a62452 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 +6,50 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <limits.h>
+#include <errno.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_waiting = 0;
 static struct pollfd *pollfds = NULL;
 static struct fd **fds = NULL;
+static struct io_conn *closing = NULL, *always = NULL;
 
 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 +59,8 @@ 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];
@@ -52,9 +69,7 @@ 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;
 	}
@@ -65,128 +80,146 @@ static void del_fd(struct fd *fd)
 
 bool add_listener(struct io_listener *l)
 {
-	return add_fd(&l->fd, POLLIN);
-}
-
-bool add_conn(struct io_conn *c)
-{
-	if (!add_fd(&c->fd, 0))
+	if (!add_fd(&l->fd, POLLIN))
 		return false;
-	num_next++;
 	return true;
 }
 
-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;
+	/* Already on always list?  Remove it. */
+	if (conn->list) {
+		struct io_conn **p = &always;
+
+		while (*p != conn)
+			p = &(*p)->list;
+
+		*p = conn->list;
+	}
+
+	conn->list = closing;
+	closing = conn;
 }
 
-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--;
+	/* May already be in always list (other plan), or closing. */
+	if (!conn->list) {
+		conn->list = always;
+		always = conn;
+	}
 }
 
-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];
+
+	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;
+	}
 }
 
-static int pollmask(enum io_state state)
+void backend_wake(const void *wait)
 {
-	switch (state) {
-	case READ:
-	case READPART:
-		return POLLIN;
-	case WRITE:
-	case WRITEPART:
-		return POLLOUT;
-	default:
-		return 0;
+	unsigned int i;
+
+	for (i = 0; i < num_fds; i++) {
+		struct io_conn *c;
+
+		/* Ignore listeners */
+		if (fds[i]->listener)
+			continue;
+
+		c = (void *)fds[i];
+		if (c->plan[IO_IN].status == IO_WAITING
+		    && c->plan[IO_IN].u1.const_vp == wait)
+			io_do_wakeup(c, &c->plan[IO_IN]);
+
+		if (c->plan[IO_OUT].status == IO_WAITING
+		    && c->plan[IO_OUT].u1.const_vp == wait)
+			io_do_wakeup(c, &c->plan[IO_OUT]);
 	}
 }
 
-void backend_set_state(struct io_conn *conn, struct io_op *op)
+bool add_conn(struct io_conn *c)
 {
-	enum io_state state = from_ioop(op);
-	struct pollfd *pfd = &pollfds[conn->fd.backend_info];
+	return add_fd(&c->fd, 0);
+}
 
-	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;
+static void del_conn(struct io_conn *conn)
+{
+	del_fd(&conn->fd);
+	if (conn->finish) {
+		/* Saved by io_close */
+		errno = conn->plan[IO_IN].u1.s;
+		conn->finish(conn, conn->finish_arg);
 	}
+	tal_free(conn);
+}
 
-	if (state == NEXT)
-		num_next++;
-	else if (state == FINISHED)
-		num_finished++;
-
-	conn->state = state;
+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;
 
-	for (i = 0; !io_loop_return && i < num_fds; i++) {
-		struct io_conn *c, *duplex;
+	while (closing) {
+		struct io_conn *conn = 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--;
-			}
-		}
+		assert(conn->plan[IO_IN].status == IO_CLOSING);
+		assert(conn->plan[IO_OUT].status == IO_CLOSING);
+
+		closing = closing->list;
+		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;
+
+	while (always) {
+		struct io_conn *conn = always;
+
+		assert(conn->plan[IO_IN].status == IO_ALWAYS
+		       || conn->plan[IO_OUT].status == IO_ALWAYS);
+
+		/* Remove from list, and mark it so it knows that. */
+		always = always->list;
+		conn->list = NULL;
+		io_do_always(conn);
+		ret = true;
+	}
+	return ret;
 }
 
 /* This is the main loop. */
@@ -197,15 +230,23 @@ void *io_loop(void)
 	while (!io_loop_return) {
 		int i, r;
 
-		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 (r < 0)
 			break;
@@ -214,35 +255,29 @@ 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;
 }