X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fio%2Fio.c;h=ddcd502f367d3afdbbb3562b91f883be13072ece;hb=c321a1d02755a77ae790d6e8976b2ff15edba89d;hp=c19b25efe8d12acbe6c5ecc669d01ff54c4801c2;hpb=cef578da77d657701616161f3c3bf826186a024e;p=ccan

diff --git a/ccan/io/io.c b/ccan/io/io.c
index c19b25ef..ddcd502f 100644
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -12,6 +12,113 @@
 
 void *io_loop_return;
 
+#ifdef DEBUG
+/* Set to skip the next plan. */
+bool io_plan_nodebug;
+/* The current connection to apply plan to. */
+struct io_conn *current;
+/* User-defined function to select which connection(s) to debug. */
+bool (*io_debug_conn)(struct io_conn *conn);
+/* Set when we wake up an connection we are debugging. */
+bool io_debug_wakeup;
+
+struct io_plan io_debug(struct io_plan plan)
+{
+	struct io_conn *ready = NULL;
+
+	if (io_plan_nodebug) {
+		io_plan_nodebug = false;
+		return plan;
+	}
+
+	if (!current || !doing_debug_on(current)) {
+		if (!io_debug_wakeup)
+			return plan;
+	}
+
+	io_debug_wakeup = false;
+	current->plan = plan;
+	backend_plan_changed(current);
+
+	/* Call back into the loop immediately. */
+	io_loop_return = do_io_loop(&ready);
+
+	if (ready) {
+		set_current(ready);
+		if (!ready->plan.next) {
+			/* Call finish function immediately. */
+			if (ready->finish) {
+				errno = ready->plan.u.close.saved_errno;
+				ready->finish(ready, ready->finish_arg);
+				ready->finish = NULL;
+			}
+			backend_del_conn(ready);
+		} else {
+			/* Calls back in itself, via io_debug_io(). */
+			if (ready->plan.io(ready->fd.fd, &ready->plan) != 2)
+				abort();
+		}
+		set_current(NULL);
+	}
+
+	/* Return a do-nothing plan, so backend_plan_changed in
+	 * io_ready doesn't do anything (it's already been called). */
+	return io_idle_();
+}
+
+int io_debug_io(int ret)
+{
+	/* Cache it for debugging; current changes. */
+	struct io_conn *conn = current;
+	int saved_errno = errno;
+
+	if (!doing_debug_on(conn))
+		return ret;
+
+	/* These will all go linearly through the io_debug() path above. */
+	switch (ret) {
+	case -1:
+		/* This will call io_debug above. */
+		errno = saved_errno;
+		io_close();
+		break;
+	case 0: /* Keep going with plan. */
+		io_debug(conn->plan);
+		break;
+	case 1: /* Done: get next plan. */
+		if (timeout_active(conn))
+			backend_del_timeout(conn);
+		conn->plan.next(conn, conn->plan.next_arg);
+		break;
+	default:
+		abort();
+	}
+
+	/* Normally-invalid value, used for sanity check. */
+	return 2;
+}
+
+static void debug_io_wake(struct io_conn *conn)
+{
+	/* We want linear if we wake a debugged connection, too. */
+	if (io_debug_conn && io_debug_conn(conn))
+		io_debug_wakeup = true;
+}
+
+/* Counterpart to io_plan_no_debug(), called in macros in io.h */
+static void io_plan_debug_again(void)
+{
+	io_plan_nodebug = false;
+}
+#else
+static void debug_io_wake(struct io_conn *conn)
+{
+}
+static void io_plan_debug_again(void)
+{
+}
+#endif
+
 struct io_listener *io_new_listener_(int fd,
 				     void (*init)(int fd, void *arg),
 				     void *arg)
@@ -39,21 +146,20 @@ void io_close_listener(struct io_listener *l)
 	free(l);
 }
 
-struct io_conn *io_new_conn_(int fd,
-			     struct io_plan plan,
-			     void (*finish)(struct io_conn *, void *),
-			     void *arg)
+struct io_conn *io_new_conn_(int fd, struct io_plan plan)
 {
 	struct io_conn *conn = malloc(sizeof(*conn));
 
+	io_plan_debug_again();
+
 	if (!conn)
 		return NULL;
 
 	conn->fd.listener = false;
 	conn->fd.fd = fd;
 	conn->plan = plan;
-	conn->finish = finish;
-	conn->finish_arg = arg;
+	conn->finish = NULL;
+	conn->finish_arg = NULL;
 	conn->duplex = NULL;
 	conn->timeout = NULL;
 	if (!add_conn(conn)) {
@@ -63,13 +169,20 @@ struct io_conn *io_new_conn_(int fd,
 	return conn;
 }
 
-struct io_conn *io_duplex_(struct io_conn *old,
-			   struct io_plan plan,
-			   void (*finish)(struct io_conn *, void *),
-			   void *arg)
+void io_set_finish_(struct io_conn *conn,
+		    void (*finish)(struct io_conn *, void *),
+		    void *arg)
+{
+	conn->finish = finish;
+	conn->finish_arg = arg;
+}
+
+struct io_conn *io_duplex_(struct io_conn *old, struct io_plan plan)
 {
 	struct io_conn *conn;
 
+	io_plan_debug_again();
+
 	assert(!old->duplex);
 
 	conn = malloc(sizeof(*conn));
@@ -80,8 +193,8 @@ struct io_conn *io_duplex_(struct io_conn *old,
 	conn->fd.fd = old->fd.fd;
 	conn->plan = plan;
 	conn->duplex = old;
-	conn->finish = finish;
-	conn->finish_arg = arg;
+	conn->finish = NULL;
+	conn->finish_arg = NULL;
 	conn->timeout = NULL;
 	if (!add_duplex(conn)) {
 		free(conn);
@@ -110,18 +223,15 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
 }
 
 /* Returns true if we're finished. */
-static bool do_write(int fd, struct io_plan *plan)
+static int do_write(int fd, struct io_plan *plan)
 {
 	ssize_t ret = write(fd, plan->u.write.buf, plan->u.write.len);
-	if (ret < 0) {
-		/* Override next function to close us. */
-		plan->next = io_close;
-		return true;
-	}
+	if (ret < 0)
+		return io_debug_io(-1);
 
 	plan->u.write.buf += ret;
 	plan->u.write.len -= ret;
-	return (plan->u.write.len == 0);
+	return io_debug_io(plan->u.write.len == 0);
 }
 
 /* Queue some data to be written. */
@@ -138,21 +248,19 @@ struct io_plan io_write_(const void *data, size_t len,
 	plan.next = cb;
 	plan.next_arg = arg;
 	plan.pollflag = POLLOUT;
+
 	return plan;
 }
 
-static bool do_read(int fd, struct io_plan *plan)
+static int do_read(int fd, struct io_plan *plan)
 {
 	ssize_t ret = read(fd, plan->u.read.buf, plan->u.read.len);
-	if (ret <= 0) {
-		/* Override next function to close us. */
-		plan->next = io_close;
-		return true;
-	}
+	if (ret <= 0)
+		return io_debug_io(-1);
 
 	plan->u.read.buf += ret;
 	plan->u.read.len -= ret;
-	return (plan->u.read.len == 0);
+	return io_debug_io(plan->u.read.len == 0);
 }
 
 /* Queue a request to read into a buffer. */
@@ -169,20 +277,18 @@ struct io_plan io_read_(void *data, size_t len,
 	plan.next = cb;
 	plan.next_arg = arg;
 	plan.pollflag = POLLIN;
+
 	return plan;
 }
 
-static bool do_read_partial(int fd, struct io_plan *plan)
+static int do_read_partial(int fd, struct io_plan *plan)
 {
 	ssize_t ret = read(fd, plan->u.readpart.buf, *plan->u.readpart.lenp);
-	if (ret <= 0) {
-		/* Override next function to close us. */
-		plan->next = io_close;
-		return true;
-	}
+	if (ret <= 0)
+		return io_debug_io(-1);
 
 	*plan->u.readpart.lenp = ret;
-	return true;
+	return io_debug_io(1);
 }
 
 /* Queue a partial request to read into a buffer. */
@@ -203,17 +309,14 @@ struct io_plan io_read_partial_(void *data, size_t *len,
 	return plan;
 }
 
-static bool do_write_partial(int fd, struct io_plan *plan)
+static int do_write_partial(int fd, struct io_plan *plan)
 {
 	ssize_t ret = write(fd, plan->u.writepart.buf, *plan->u.writepart.lenp);
-	if (ret < 0) {
-		/* Override next function to close us. */
-		plan->next = io_close;
-		return true;
-	}
+	if (ret < 0)
+		return io_debug_io(-1);
 
 	*plan->u.writepart.lenp = ret;
-	return true;
+	return io_debug_io(1);
 }
 
 /* Queue a partial write request. */
@@ -234,61 +337,76 @@ struct io_plan io_write_partial_(const void *data, size_t *len,
 	return plan;
 }
 
-struct io_plan io_idle(void)
+struct io_plan io_idle_(void)
 {
 	struct io_plan plan;
 
 	plan.pollflag = 0;
 	plan.io = NULL;
-	/* Never called (overridded by io_wake), but NULL means closing */
-	plan.next = io_close;
+	/* Never called (overridden by io_wake), but NULL means closing */
+	plan.next = (void *)io_idle_;
 
 	return plan;
 }
 
-void io_wake(struct io_conn *conn, struct io_plan plan)
+void io_wake_(struct io_conn *conn, struct io_plan plan)
 
 {
+	io_plan_debug_again();
+
 	/* It might be closing, but we haven't called its finish() yet. */
 	if (!conn->plan.next)
 		return;
 	/* It was idle, right? */
 	assert(!conn->plan.io);
 	conn->plan = plan;
-	backend_wakeup(conn);
-}
+	backend_plan_changed(conn);
 
-static struct io_plan do_next(struct io_conn *conn)
-{
-	if (timeout_active(conn))
-		backend_del_timeout(conn);
-	return conn->plan.next(conn, conn->plan.next_arg);
+	debug_io_wake(conn);
 }
 
-struct io_plan do_ready(struct io_conn *conn)
+void io_ready(struct io_conn *conn)
 {
-	if (conn->plan.io(conn->fd.fd, &conn->plan))
-		return do_next(conn);
-
-	return conn->plan;
+	set_current(conn);
+	switch (conn->plan.io(conn->fd.fd, &conn->plan)) {
+	case -1: /* Failure means a new plan: close up. */
+		conn->plan = io_close();
+		backend_plan_changed(conn);
+		break;
+	case 0: /* Keep going with plan. */
+		break;
+	case 1: /* Done: get next plan. */
+		if (timeout_active(conn))
+			backend_del_timeout(conn);
+		conn->plan = conn->plan.next(conn, conn->plan.next_arg);
+		backend_plan_changed(conn);
+	}
+	set_current(NULL);
 }
 
-/* Useful next functions. */
 /* Close the connection, we're done. */
-struct io_plan io_close(struct io_conn *conn, void *arg)
+struct io_plan io_close_(void)
 {
 	struct io_plan plan;
 
 	plan.pollflag = 0;
 	/* This means we're closing. */
 	plan.next = NULL;
+	plan.u.close.saved_errno = errno;
 
 	return plan;
 }
 
+struct io_plan io_close_cb(struct io_conn *conn, void *arg)
+{
+	return io_close();
+}
+
 /* Exit the loop, returning this (non-NULL) arg. */
-struct io_plan io_break(void *ret, struct io_plan plan)
+struct io_plan io_break_(void *ret, struct io_plan plan)
 {
+	io_plan_debug_again();
+
 	assert(ret);
 	io_loop_return = ret;