X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fio%2Fpoll.c;h=d7b9eb56b950b5a1b4772525c86bb944b3a60c6f;hp=070f6d842ae7f45bd4b0b529b6c31cd6c71d7b20;hb=12ab811533406e22b78ce8b227474f1056375ae4;hpb=0a2fd289c7bf57d9fc35ad6af36df4bcc694f361

diff --git a/ccan/io/poll.c b/ccan/io/poll.c
index 070f6d84..d7b9eb56 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>
@@ -6,10 +6,57 @@
 #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_closing = 0, num_waiting = 0;
+static bool some_always = false;
 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)
+{
+	io_alloc.free(conn);
+}
+#endif
 
 static bool add_fd(struct fd *fd, short events)
 {
@@ -18,23 +65,30 @@ static bool add_fd(struct fd *fd, short events)
 		struct fd **newfds;
 		size_t num = max_fds ? max_fds * 2 : 8;
 
-		newpollfds = realloc(pollfds, sizeof(*newpollfds) * num);
+		newpollfds = io_alloc.realloc(pollfds, sizeof(*newpollfds)*num);
 		if (!newpollfds)
 			return false;
 		pollfds = newpollfds;
-		newfds = realloc(fds, sizeof(*newfds) * num);
+		newfds = io_alloc.realloc(fds, sizeof(*newfds) * num);
 		if (!newfds)
 			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;
 }
 
@@ -44,16 +98,26 @@ 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];
 		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. */
-		free(pollfds);
-		free(fds);
+		io_alloc.free(pollfds);
+		io_alloc.free(fds);
 		pollfds = NULL;
 		fds = NULL;
 		max_fds = 0;
@@ -65,26 +129,83 @@ static void del_fd(struct fd *fd)
 
 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 & (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;
+	}
+	if (pfd->events) {
+		num_waiting++;
+		pfd->fd = conn->fd.fd;
+	} else
+		pfd->fd = -conn->fd.fd;
+
+	if (!conn->plan.next)
+		num_closing++;
+
+	if (conn->plan.pollflag == POLLALWAYS)
+		some_always = true;
 }
 
 bool add_conn(struct io_conn *c)
 {
-	if (!add_fd(&c->fd, 0))
+	if (!add_fd(&c->fd, c->plan.pollflag & (POLLIN|POLLOUT)))
 		return false;
-	num_next++;
+	/* Immediate close is allowed. */
+	if (!c->plan.next)
+		num_closing++;
+	if (c->plan.pollflag == POLLALWAYS)
+		some_always = true;
+	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)
+void backend_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) {
+		/* Saved by io_close */
+		errno = conn->plan.u1.s;
+		conn->finish(conn, conn->finish_arg);
+	}
+	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--;
+	free_conn(conn);
 }
 
 void del_listener(struct io_listener *l)
@@ -92,116 +213,221 @@ 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 bool finish_conns(struct io_conn **ready)
 {
 	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) {
+				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;
+}
+
+static void 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;
+
+		if (c->plan.pollflag == POLLALWAYS)
+			io_ready(c);
+
+		if (c->duplex && c->duplex->plan.pollflag == POLLALWAYS)
+			io_ready(c->duplex);
+	}
 }
 
 /* This is the main loop. */
-void *io_loop(void)
+void *do_io_loop(struct io_conn **ready)
 {
 	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;
 
-		if (num_finished || num_next) {
-			finish_and_next(false);
+			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_closing) {
+			/* If this finishes a debugging con, return now. */
+			if (finish_conns(ready))
+				return NULL;
 			/* 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;
+		}
+
 		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) {
+						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;
+			} 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());
+				}
 			}
 		}
 	}
 
-	while (num_finished)
-		finish_and_next(true);
+	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);
+}