X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fio%2Fio.c;h=c5c9bee0daf0329f433eec930058bfd20905f96c;hb=1966714494a5de39b2ee944fcc01f333c1741dbd;hp=12b2489023d94077d5562db876ab9004caae3dd4;hpb=d00c9d1be5a56fbf990882f9a6da5704b3f1ea75;p=ccan

diff --git a/ccan/io/io.c b/ccan/io/io.c
index 12b24890..c5c9bee0 100644
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -61,10 +61,7 @@ static bool next_plan(struct io_conn *conn, struct io_plan *plan)
 	if (plan == &io_conn_freed)
 		return false;
 
-	/* It should have set a plan inside this conn (or duplex) */
-	assert(plan == &conn->plan[IO_IN]
-	       || plan == &conn->plan[IO_OUT]
-	       || plan == &conn->plan[2]);
+	assert(plan == &conn->plan[plan->dir]);
 	assert(conn->plan[IO_IN].status != IO_UNSET
 	       || conn->plan[IO_OUT].status != IO_UNSET);
 
@@ -72,16 +69,19 @@ static bool next_plan(struct io_conn *conn, struct io_plan *plan)
 	return true;
 }
 
-static void set_blocking(int fd, bool block)
+bool io_fd_block(int fd, bool block)
 {
 	int flags = fcntl(fd, F_GETFL);
 
+	if (flags == -1)
+		return false;
+
 	if (block)
 		flags &= ~O_NONBLOCK;
 	else
 		flags |= O_NONBLOCK;
 
-	fcntl(fd, F_SETFL, flags);
+	return fcntl(fd, F_SETFL, flags) != -1;
 }
 
 struct io_conn *io_new_conn_(const tal_t *ctx, int fd,
@@ -103,7 +103,11 @@ struct io_conn *io_new_conn_(const tal_t *ctx, int fd,
 		return tal_free(conn);
 
 	/* Keep our I/O async. */
-	set_blocking(fd, false);
+	io_fd_block(fd, false);
+
+	/* So we can get back from plan -> conn later */
+	conn->plan[IO_OUT].dir = IO_OUT;
+	conn->plan[IO_IN].dir = IO_IN;
 
 	/* We start with out doing nothing, and in doing our init. */
 	conn->plan[IO_OUT].status = IO_UNSET;
@@ -128,7 +132,7 @@ struct io_plan_arg *io_plan_arg(struct io_conn *conn, enum io_direction dir)
 {
 	assert(conn->plan[dir].status == IO_UNSET);
 
-	conn->plan[dir].status = IO_POLLING;
+	conn->plan[dir].status = IO_POLLING_NOTSTARTED;
 	return &conn->plan[dir].arg;
 }
 
@@ -199,8 +203,12 @@ struct io_plan *io_write_(struct io_conn *conn, const void *data, size_t len,
 static int do_read(int fd, struct io_plan_arg *arg)
 {
 	ssize_t ret = read(fd, arg->u1.cp, arg->u2.s);
-	if (ret <= 0)
+	if (ret <= 0) {
+		/* Errno isn't set if we hit EOF, so set it to distinct value */
+		if (ret == 0)
+			errno = 0;
 		return -1;
+	}
 
 	arg->u1.cp += ret;
 	arg->u2.s -= ret;
@@ -227,8 +235,12 @@ struct io_plan *io_read_(struct io_conn *conn,
 static int do_read_partial(int fd, struct io_plan_arg *arg)
 {
 	ssize_t ret = read(fd, arg->u1.cp, *(size_t *)arg->u2.vp);
-	if (ret <= 0)
+	if (ret <= 0) {
+		/* Errno isn't set if we hit EOF, so set it to distinct value */
+		if (ret == 0)
+			errno = 0;
 		return -1;
+	}
 
 	*(size_t *)arg->u2.vp = ret;
 	return 1;
@@ -360,17 +372,25 @@ void io_wake(const void *wait)
 	backend_wake(wait);
 }
 
-/* Returns false if this has been freed. */
-static bool do_plan(struct io_conn *conn, struct io_plan *plan)
+/* Returns false if this should not be touched (eg. freed). */
+static bool do_plan(struct io_conn *conn, struct io_plan *plan,
+		    bool idle_on_epipe)
 {
 	/* We shouldn't have polled for this event if this wasn't true! */
-	assert(plan->status == IO_POLLING);
+	assert(plan->status == IO_POLLING_NOTSTARTED
+	       || plan->status == IO_POLLING_STARTED);
 
 	switch (plan->io(conn->fd.fd, &plan->arg)) {
 	case -1:
+		if (errno == EPIPE && idle_on_epipe) {
+			plan->status = IO_UNSET;
+			backend_new_plan(conn);
+			return false;
+		}
 		io_close(conn);
 		return false;
 	case 0:
+		plan->status = IO_POLLING_STARTED;
 		return true;
 	case 1:
 		return next_plan(conn, plan);
@@ -383,11 +403,15 @@ static bool do_plan(struct io_conn *conn, struct io_plan *plan)
 void io_ready(struct io_conn *conn, int pollflags)
 {
 	if (pollflags & POLLIN)
-		if (!do_plan(conn, &conn->plan[IO_IN]))
+		if (!do_plan(conn, &conn->plan[IO_IN], false))
 			return;
 
 	if (pollflags & POLLOUT)
-		do_plan(conn, &conn->plan[IO_OUT]);
+		/* If we're writing to a closed pipe, we need to wait for
+		 * read to fail if we're duplex: we want to drain it! */
+		do_plan(conn, &conn->plan[IO_OUT],
+			conn->plan[IO_IN].status == IO_POLLING_NOTSTARTED
+			|| conn->plan[IO_IN].status == IO_POLLING_STARTED);
 }
 
 void io_do_always(struct io_conn *conn)
@@ -436,7 +460,7 @@ struct io_plan *io_close_cb(struct io_conn *conn, void *next_arg)
 
 struct io_plan *io_close_taken_fd(struct io_conn *conn)
 {
-	set_blocking(conn->fd.fd, true);
+	io_fd_block(conn->fd.fd, true);
 
 	cleanup_conn_without_close(conn);
 	return io_close(conn);
@@ -465,7 +489,7 @@ struct io_plan *io_duplex(struct io_conn *conn,
 	assert(conn == container_of(in_plan, struct io_conn, plan[IO_IN]));
 	/* in_plan must be conn->plan[IO_IN], out_plan must be [IO_OUT] */
 	assert(out_plan == in_plan + 1);
-	return out_plan + 1;
+	return in_plan;
 }
 
 struct io_plan *io_halfclose(struct io_conn *conn)
@@ -497,17 +521,28 @@ struct io_plan *io_set_plan(struct io_conn *conn, enum io_direction dir,
 	return plan;
 }
 
+bool io_plan_in_started(const struct io_conn *conn)
+{
+	return conn->plan[IO_IN].status == IO_POLLING_STARTED;
+}
+
+bool io_plan_out_started(const struct io_conn *conn)
+{
+	return conn->plan[IO_OUT].status == IO_POLLING_STARTED;
+}
+
 bool io_flush_sync(struct io_conn *conn)
 {
 	struct io_plan *plan = &conn->plan[IO_OUT];
 	bool ok;
 
 	/* Not writing?  Nothing to do. */
-	if (plan->status != IO_POLLING)
+	if (plan->status != IO_POLLING_STARTED
+	    && plan->status != IO_POLLING_NOTSTARTED)
 		return true;
 
 	/* Synchronous please. */
-	set_blocking(io_conn_fd(conn), true);
+	io_fd_block(io_conn_fd(conn), true);
 
 again:
 	switch (plan->io(conn->fd.fd, &plan->arg)) {
@@ -516,6 +551,7 @@ again:
 		break;
 	/* Incomplete, try again. */
 	case 0:
+		plan->status = IO_POLLING_STARTED;
 		goto again;
 	case 1:
 		ok = true;
@@ -527,6 +563,6 @@ again:
 		abort();
 	}
 
-	set_blocking(io_conn_fd(conn), false);
+	io_fd_block(io_conn_fd(conn), false);
 	return ok;
 }