ccan/io: io_set_finish()

Rather than insisting on supplying them on every call to io_new_conn().
Also, this way it can be changed on a connection.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/io/_info

@@ -114,10 +114,8 @@
  *	sbuf.len = sizeof(sbuf.inbuf);
  * 	sbuf.reader = io_new_conn(STDIN_FILENO,
  *				  io_read_partial(sbuf.inbuf, &sbuf.len,
- *						  wake_writer, &sbuf),
- *				  reader_exit, &sbuf);
- * 	sbuf.writer = io_new_conn(tochild[1], io_idle(), fail_child_write,
- * 				  &sbuf);
+ *						  wake_writer, &sbuf));
+ * 	sbuf.writer = io_new_conn(tochild[1], io_idle());
  *
  *	out.max = 128;
  *	out.off = 0;
@@ -125,11 +123,13 @@
  *	out.buf = malloc(out.max);
  *	from_child = io_new_conn(fromchild[0],
  *				 io_read_partial(out.buf, &out.rlen,
- *						 read_from_child, &out),
- *				 NULL, NULL);
+ *						 read_from_child, &out));
  * 	if (!sbuf.reader || !sbuf.writer || !from_child)
  * 		err(1, "Allocating connections");
  *
+ *	io_set_finish(sbuf.reader, reader_exit, &sbuf);
+ *	io_set_finish(sbuf.writer, fail_child_write, &sbuf);
+ *
  * 	io_loop();
  * 	wait(&status);
  *

ccan/io/benchmarks/run-different-speed.c

@@ -152,12 +152,11 @@ int main(int argc, char *argv[])
 			/* For efficiency, we share client structure */
 			io_new_conn(ret,
 				    io_read(client.request_buffer, REQUEST_SIZE,
-					    write_reply, &client),
-				    NULL, NULL);
+					    write_reply, &client));
 		}
 	}
 
-	io_new_conn(timeout[0], io_read(&buf, 1, do_timeout, &buf), NULL, NULL);
+	io_new_conn(timeout[0], io_read(&buf, 1, do_timeout, &buf));
 
 	close(wake[0]);
 	for (i = 0; i < NUM_CHILDREN; i++)

ccan/io/benchmarks/run-length-prefix.c

@@ -157,11 +157,11 @@ int main(int argc, char *argv[])
 				err(1, "Accepting fd");
 			/* For efficiency, we share buffer */
 			client->request_buffer = buffer;
-			io_new_conn(ret, io_read_header(client), NULL, NULL);
+			io_new_conn(ret, io_read_header(client));
 		}
 	}
 
-	io_new_conn(timeout[0], io_read(&buf, 1, do_timeout, &buf), NULL, NULL);
+	io_new_conn(timeout[0], io_read(&buf, 1, do_timeout, &buf));
 
 	close(wake[0]);
 	for (i = 0; i < NUM_CHILDREN; i++)

ccan/io/benchmarks/run-loop.c

@@ -66,14 +66,13 @@ int main(void)
 		memset(buf[i].buf, i, sizeof(buf[i].buf));
 		sprintf(buf[i].buf, "%i-%i", i, i);
 
-		buf[i].reader = io_new_conn(last_read, io_idle(), NULL, NULL);
+		buf[i].reader = io_new_conn(last_read, io_idle());
 		if (!buf[i].reader)
 			err(1, "Creating reader %i", i);
 		buf[i].writer = io_new_conn(fds[1],
 					    io_write(&buf[i].buf,
 						     sizeof(buf[i].buf),
-						     poke_reader, &buf[i]),
-					    NULL, NULL);
+						     poke_reader, &buf[i]));
 		if (!buf[i].writer)
 			err(1, "Creating writer %i", i);
 		last_read = fds[0];
@@ -83,13 +82,12 @@ int main(void)
 	i = 0;
 	buf[i].iters = 0;
 	sprintf(buf[i].buf, "%i-%i", i, i);
-	buf[i].reader = io_new_conn(last_read, io_idle(), NULL, NULL);
+	buf[i].reader = io_new_conn(last_read, io_idle());
 	if (!buf[i].reader)
 		err(1, "Creating reader %i", i);
 	buf[i].writer = io_new_conn(last_write, io_write(&buf[i].buf,
 							 sizeof(buf[i].buf),
-							 poke_reader, &buf[i]),
-				    NULL, NULL);
+							 poke_reader, &buf[i]));
 	if (!buf[i].writer)
 		err(1, "Creating writer %i", i);
 

ccan/io/io.c

@@ -78,10 +78,7 @@ 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));
 
@@ -91,8 +88,8 @@ struct io_conn *io_new_conn_(int fd,
 	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)) {
@@ -102,10 +99,15 @@ 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;
 
@@ -119,8 +121,8 @@ 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);

ccan/io/io.h

@@ -67,25 +67,34 @@ static inline void io_plan_debug(struct io_plan *plan) { }
  * io_new_conn - create a new connection.
  * @fd: the file descriptor.
  * @plan: the first I/O function.
- * @finish: the function to call when it's closed or fails.
- * @arg: the argument to @finish.
  *
  * This creates a connection which owns @fd.  @plan will be called on the
- * next io_loop(), and @finish will be called when an I/O operation
- * fails, or you call io_close() on the connection.
+ * next io_loop().
  *
  * Returns NULL on error (and sets errno).
  */
-#define io_new_conn(fd, plan, finish, arg)				\
-	(io_plan_other(), io_new_conn_((fd), (plan),			\
-				       typesafe_cb_preargs(void, void *, \
-							   (finish), (arg), \
-							   struct io_conn *), \
-				       (arg)))
-struct io_conn *io_new_conn_(int fd,
-			     struct io_plan plan,
-			     void (*finish)(struct io_conn *, void *),
-			     void *arg);
+#define io_new_conn(fd, plan)				\
+	(io_plan_other(), io_new_conn_((fd), (plan)))
+struct io_conn *io_new_conn_(int fd, struct io_plan plan);
+
+/**
+ * io_set_finish - set finish function on a connection.
+ * @conn: the connection.
+ * @finish: the function to call when it's closed or fails.
+ * @arg: the argument to @finish.
+ *
+ * @finish will be called when an I/O operation fails, or you call
+ * io_close() on the connection.
+ */
+#define io_set_finish(conn, finish, arg)				\
+	io_set_finish_((conn),						\
+		       typesafe_cb_preargs(void, void *,		\
+					   (finish), (arg),		\
+					   struct io_conn *),		\
+		       (arg))
+void io_set_finish_(struct io_conn *conn,
+		    void (*finish)(struct io_conn *, void *),
+		    void *arg);
 
 /**
  * io_new_listener - create a new accepting listener.
@@ -241,8 +250,6 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
  * io_duplex - split an fd into two connections.
  * @conn: a connection.
  * @plan: the first I/O function to call.
- * @finish: the function to call when it's closed or fails.
- * @arg: the argument to @finish.
  *
  * Sometimes you want to be able to simultaneously read and write on a
  * single fd, but io forces a linear call sequence.  The solition is
@@ -251,17 +258,10 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
  *
  * You must io_close() both of them to close the fd.
  */
-#define io_duplex(conn, plan, finish, arg)				\
-	(io_plan_other(), io_duplex_((conn), (plan),			\
-				     typesafe_cb_preargs(void, void *,	\
-							 (finish), (arg), \
-							 struct io_conn *), \
-				     (arg)))
+#define io_duplex(conn, plan)				\
+	(io_plan_other(), io_duplex_((conn), (plan)))
 
-struct io_conn *io_duplex_(struct io_conn *conn,
-			   struct io_plan plan,
-			   void (*finish)(struct io_conn *, void *),
-			   void *arg);
+struct io_conn *io_duplex_(struct io_conn *conn, struct io_plan plan);
 
 /**
  * io_wake - wake up an idle connection.

ccan/io/test/run-01-start-finish.c

@@ -21,8 +21,8 @@ static void init_conn(int fd, int *state)
 {
 	ok1(*state == 0);
 	(*state)++;
-	if (!io_new_conn(fd, io_close(NULL, NULL), finish_ok, state))
-		abort();
+	io_set_finish(io_new_conn(fd, io_close(NULL, NULL)), finish_ok, state);
+
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-02-read.c

@@ -27,9 +27,9 @@ static void init_conn(int fd, struct data *d)
 	ok1(d->state == 0);
 	d->state++;
 
-	if (!io_new_conn(fd, io_read(d->buf, sizeof(d->buf), io_close, d),
-			 finish_ok, d))
-		abort();
+	io_set_finish(io_new_conn(fd,
+				  io_read(d->buf, sizeof(d->buf), io_close, d)),
+		      finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-03-readpartial.c

@@ -29,9 +29,9 @@ static void init_conn(int fd, struct data *d)
 	d->state++;
 	d->bytes = sizeof(d->buf);
 
-	if (!io_new_conn(fd, io_read_partial(d->buf, &d->bytes, io_close, d),
-			 finish_ok, d))
-		abort();
+	io_set_finish(io_new_conn(fd,
+				  io_read_partial(d->buf, &d->bytes, io_close, d)),
+		      finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-04-writepartial.c

@@ -27,9 +27,9 @@ static void init_conn(int fd, struct data *d)
 {
 	ok1(d->state == 0);
 	d->state++;
-	if (!io_new_conn(fd, io_write_partial(d->buf, &d->bytes, io_close, d),
-			 finish_ok, d))
-		abort();
+	io_set_finish(io_new_conn(fd,
+				  io_write_partial(d->buf, &d->bytes, io_close, d)),
+				  finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-05-write.c

@@ -27,9 +27,8 @@ static void init_conn(int fd, struct data *d)
 {
 	ok1(d->state == 0);
 	d->state++;
-	if (!io_new_conn(fd, io_write(d->buf, d->bytes, io_close, d),
-			 finish_ok, d))
-		abort();
+	io_set_finish(io_new_conn(fd, io_write(d->buf, d->bytes, io_close, d)),
+		      finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-06-idle.c

@@ -52,12 +52,14 @@ static void init_conn(int fd, struct data *d)
 
 	ok1(d->state == 0);
 	d->state++;
-	idler = io_new_conn(fd, io_idle(), finish_idle, d);
+	idler = io_new_conn(fd, io_idle());
+	io_set_finish(idler, finish_idle, d);
 
 	/* This will wake us up, as read will fail. */
 	fd2 = open("/dev/null", O_RDONLY);
 	ok1(fd2 >= 0);
-	ok1(io_new_conn(fd2, io_read(idler, 1, never, NULL), finish_waker, d));
+	io_set_finish(io_new_conn(fd2, io_read(idler, 1, never, NULL)),
+		      finish_waker, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)
@@ -100,7 +102,7 @@ int main(void)
 	int fd, status;
 
 	/* This is how many tests you plan to run */
-	plan_tests(14);
+	plan_tests(13);
 	d->state = 0;
 	fd = make_listen_fd(PORT, &addrinfo);
 	ok1(fd >= 0);

ccan/io/test/run-07-break.c

@@ -33,11 +33,10 @@ static void init_conn(int fd, struct data *d)
 	ok1(d->state == 0);
 	d->state++;
 
-	if (!io_new_conn(fd,
-			 io_break(d,
-				  io_read(d->buf, sizeof(d->buf), read_done, d)),
-			 finish_ok, d))
-		abort();
+	io_set_finish(io_new_conn(fd,
+				  io_break(d,
+					   io_read(d->buf, sizeof(d->buf), read_done, d))),
+		      finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-08-hangup-on-idle.c

@@ -26,13 +26,12 @@ int main(void)
 	ok1(pipe(fds) == 0);
 
 	/* Write then close. */
-	io_new_conn(fds[1], io_write("hello there world", 16, io_close, NULL),
-		    NULL, NULL);
-	conn = io_new_conn(fds[0], io_idle(), NULL, NULL);
+	io_new_conn(fds[1], io_write("hello there world", 16, io_close, NULL));
+	conn = io_new_conn(fds[0], io_idle());
 
 	/* To avoid assert(num_waiting) */
 	ok1(pipe(fds2) == 0);
-	io_new_conn(fds2[0], io_read(buf, 16, io_close, NULL), NULL, NULL);
+	io_new_conn(fds2[0], io_read(buf, 16, io_close, NULL));
 
 	/* After half a second, it will read. */
 	io_timeout(conn, time_from_msec(500), timeout_wakeup, buf);

ccan/io/test/run-08-read-after-hangup.c

@@ -23,9 +23,8 @@ int main(void)
 	plan_tests(3);
 
 	ok1(pipe(fds) == 0);
-	conn = io_new_conn(fds[0], io_idle(), NULL, NULL);
-	io_new_conn(fds[1], io_write("EASYTEST", 8, wake_it, conn),
-		    NULL, NULL);
+	conn = io_new_conn(fds[0], io_idle());
+	io_new_conn(fds[1], io_write("EASYTEST", 8, wake_it, conn));
 
 	ok1(io_loop() == NULL);
 	ok1(memcmp(inbuf, "EASYTEST", sizeof(inbuf)) == 0);

ccan/io/test/run-10-many.c

@@ -66,14 +66,13 @@ int main(void)
 		sprintf(buf[i].buf, "%i-%i", i, i);
 
 		/* Wait for writer to tell us to read. */
-		buf[i].reader = io_new_conn(last_read, io_idle(), NULL, &buf[i]);
+		buf[i].reader = io_new_conn(last_read, io_idle());
 		if (!buf[i].reader)
 			break;
 		buf[i].writer = io_new_conn(fds[1],
 					    io_write(&buf[i].buf,
 						     sizeof(buf[i].buf),
-						     poke_reader, &buf[i]),
-					    NULL, &buf[i]);
+						     poke_reader, &buf[i]));
 		if (!buf[i].writer)
 			break;
 		last_read = fds[0];
@@ -84,12 +83,11 @@ int main(void)
 	/* Last one completes the cirle. */
 	i = 0;
 	sprintf(buf[i].buf, "%i-%i", i, i);
-	buf[i].reader = io_new_conn(last_read, io_idle(), NULL, NULL);
+	buf[i].reader = io_new_conn(last_read, io_idle());
 	ok1(buf[i].reader);
 	buf[i].writer = io_new_conn(last_write,
 				    io_write(&buf[i].buf, sizeof(buf[i].buf),
-					     poke_reader, &buf[i]),
-				    NULL, NULL);
+					     poke_reader, &buf[i]));
 	ok1(buf[i].writer);
 
 	/* They should eventually exit */

ccan/io/test/run-12-bidir.c

@@ -39,10 +39,11 @@ static void init_conn(int fd, struct data *d)
 
 	memset(d->wbuf, 7, sizeof(d->wbuf));
 
-	conn = io_new_conn(fd, io_read(d->buf, sizeof(d->buf), io_close, d),
-			   finish_ok, d);
-	ok1(io_duplex(conn, io_write(d->wbuf, sizeof(d->wbuf), write_done, d),
-		      finish_ok, d));
+	conn = io_new_conn(fd, io_read(d->buf, sizeof(d->buf), io_close, d));
+	io_set_finish(conn, finish_ok, d);
+	conn = io_duplex(conn, io_write(d->wbuf, sizeof(d->wbuf), write_done, d));
+	ok1(conn);
+	io_set_finish(conn, finish_ok, d);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)

ccan/io/test/run-13-all-idle.c

@@ -17,7 +17,7 @@ int main(void)
 		int fds[2];
 
 		ok1(pipe(fds) == 0);
-		io_new_conn(fds[0], io_idle(), NULL, NULL);
+		io_new_conn(fds[0], io_idle());
 		io_loop();
 		exit(1);
 	}

ccan/io/test/run-15-timeout.c

@@ -48,8 +48,8 @@ static void init_conn(int fd, struct data *d)
 	ok1(d->state == 0);
 	d->state++;
 
-	conn = io_new_conn(fd, io_read(d->buf, sizeof(d->buf), no_timeout, d),
-			   finish_ok, d);
+	conn = io_new_conn(fd, io_read(d->buf, sizeof(d->buf), no_timeout, d));
+	io_set_finish(conn, finish_ok, d);
 	io_timeout(conn, time_from_usec(d->timeout_usec), timeout, d);
 }
 

ccan/io/test/run-17-homemade-io.c

@@ -92,8 +92,8 @@ static void init_conn(int fd, struct packet *pkt)
 	ok1(pkt->state == 0);
 	pkt->state++;
 
-	if (!io_new_conn(fd, io_read_packet(pkt, io_close, pkt), finish_ok, pkt))
-		abort();
+	io_set_finish(io_new_conn(fd, io_read_packet(pkt, io_close, pkt)),
+		      finish_ok, pkt);
 }
 
 static int make_listen_fd(const char *port, struct addrinfo **info)