#include <ccan/tal/tal.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
#include <stdbool.h>
+#include <poll.h>
#include <unistd.h>
struct timers;
* @arg: the argument to @init.
*
* When @fd becomes readable, we accept(), create a new connection,
- * (tal'ocated off @ctx) and pass that to init().
+ * (tal'ocated off @ctx) and pass that to init(). Note that if there is
+ * an error on this file descriptor, it will be freed.
*
* Returns NULL on error (and sets errno).
*
*
* This creates a plan to read data into a buffer. Once it's all
* read, the @next function will be called: on an error, the finish
- * function is called instead.
+ * function is called instead. If read() returns 0 (EOF) errno is set
+ * to 0.
*
* Note that the I/O may actually be done immediately.
*
*
* This creates a plan to read data into a buffer. Once any data is
* read, @len is updated and the @next function will be called: on an
- * error, the finish function is called instead.
+ * error, the finish function is called instead. If read() returns 0 (EOF)
+ * errno is set to 0.
*
* Note that the I/O may actually be done immediately.
*
*/
struct io_plan *io_close_cb(struct io_conn *, void *unused);
+/**
+ * io_close_taken_fd - close a connection, but remove the filedescriptor first.
+ * @conn: the connection to take the file descriptor from and close.
+ *
+ * io_close closes the file descriptor underlying the io_conn; this version does
+ * not. Presumably you have used io_conn_fd() on it beforehand and will take
+ * care of the fd yourself.
+ *
+ * Note that this also turns off O_NONBLOCK on the fd.
+ *
+ * Example:
+ * static struct io_plan *steal_fd(struct io_conn *conn, int *fd)
+ * {
+ * *fd = io_conn_fd(conn);
+ * printf("stealing fd %i and closing\n", *fd);
+ * return io_close_taken_fd(conn);
+ * }
+ */
+struct io_plan *io_close_taken_fd(struct io_conn *conn);
+
/**
* io_loop - process fds until all closed on io_break.
* @timers - timers which are waiting to go off (or NULL for none)
* io_conn_fd - get the fd from a connection.
* @conn: the connection.
*
- * Sometimes useful, eg for getsockname().
+ * Sometimes useful, eg for getsockname(). Note that the fd is O_NONBLOCK.
+ *
+ * See Also:
+ * io_close_taken_fd
*/
int io_conn_fd(const struct io_conn *conn);
+/**
+ * io_plan_in_started - is this conn doing input I/O now?
+ * @conn: the conn.
+ *
+ * This returns true if input I/O has been performed on the conn but
+ * @next hasn't been called yet. For example, io_read() may have done
+ * a partial read.
+ *
+ * This can be useful if we want to terminate a connection only after
+ * reading a whole packet: if this returns true, we would wait until
+ * @next is called.
+ */
+bool io_plan_in_started(const struct io_conn *conn);
+
+/**
+ * io_plan_out_started - is this conn doing output I/O now?
+ * @conn: the conn.
+ *
+ * This returns true if output I/O has been performed on the conn but
+ * @next hasn't been called yet. For example, io_write() may have done
+ * a partial write.
+ *
+ * This can be useful if we want to terminate a connection only after
+ * writing a whole packet: if this returns true, we would wait until
+ * @next is called.
+ */
+bool io_plan_out_started(const struct io_conn *conn);
+
+/**
+ * io_flush_sync - (synchronously) complete any outstanding output.
+ * @conn: the connection.
+ *
+ * This is generally used as an emergency escape, for example when we
+ * want to write an error message on a socket before terminating, but it may
+ * be in the middle of existing I/O. We don't want to service any other
+ * IO, either.
+ *
+ * This returns true if all pending output is complete, false on error.
+ * The next callback is not called on the conn, but will be as soon as
+ * io_loop() is called.
+ *
+ * See Also:
+ * io_close_taken_fd
+ */
+bool io_flush_sync(struct io_conn *conn);
+
+/**
+ * io_conn_exclusive - set/unset an io_conn to exclusively serviced
+ * @conn: the connection
+ * @exclusive: whether to be exclusive or not
+ *
+ * If any io_conn is set exclusive, then no non-exclusive io_conn (or
+ * io_listener) will be serviced by io_loop(). If it's a io_duplex io_conn(),
+ * then io_conn_exclusive() makes the read-side exclusive; io_conn_out_exclusive()
+ * makes the write-side exclusive.
+ *
+ * This allows you to temporarily service only one (or several) fds.
+ * For example, you might want to flush out one io_conn and not
+ * receive any new connections or read any other input.
+ *
+ * Returns true if any exclusive io_conn remain, otherwise false.
+ * (This is useful for checking your own logic: dangling exclusive io_conn
+ * are dangerous!).
+ */
+bool io_conn_exclusive(struct io_conn *conn, bool exclusive);
+
+/**
+ * io_conn_out_exclusive - set/unset exclusive on the write-side of a duplex
+ * @conn: the connection, post io_duplex
+ * @exclusive: whether to be exclusive or not
+ *
+ * See io_conn_exclusive() above.
+ */
+bool io_conn_out_exclusive(struct io_conn *conn, bool exclusive);
+
+/**
+ * io_fd_block - helper to set an fd blocking/nonblocking.
+ * @fd: the file descriptor
+ * @block: true to set blocking, false to set non-blocking.
+ *
+ * Generally only fails is @fd isn't a valid file descriptor, otherwise
+ * returns true.
+ */
+bool io_fd_block(int fd, bool block);
+
/**
* io_time_override - override the normal call for time.
* @nowfn: the function to call.
*/
struct timemono (*io_time_override(struct timemono (*now)(void)))(void);
+/**
+ * io_poll_override - override the normal call for poll.
+ * @pollfn: the function to call.
+ *
+ * io usually uses poll() internally, but this forces it to use your
+ * function (eg. for debugging, suppressing fds, or polling on others unknown
+ * to ccan/io). Returns the old one.
+ */
+int (*io_poll_override(int (*poll)(struct pollfd *fds, nfds_t nfds, int timeout)))(struct pollfd *, nfds_t, int);
+
#endif /* CCAN_IO_H */
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