* to have two connections for the same fd, and use one for read
* operations and one for write.
*
- * Returning io_close() on one will close both fds!
+ * You must io_close() both of them to close the fd.
*
* Example:
* static void setup_read_write(int fd,
#define io_wake(conn, plan) (io_plan_no_debug(), io_wake_((conn), (plan)))
void io_wake_(struct io_conn *conn, struct io_plan plan);
+/**
+ * io_is_idle - is a connection idle?
+ *
+ * This can be useful for complex protocols, eg. where you want a connection
+ * to send something, so you queue it and wake it if it's idle.
+ *
+ * Example:
+ * struct io_conn *sleeper;
+ * sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
+ *
+ * assert(io_is_idle(sleeper));
+ * io_wake(sleeper, io_write("junk", 4, io_close_cb, NULL));
+ */
+bool io_is_idle(const struct io_conn *conn);
+
/**
* io_break - return from io_loop()
* @ret: non-NULL value to return from io_loop().