#include <ccan/tal/tal.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
#include <stdbool.h>
+#include <poll.h>
#include <unistd.h>
struct timers;
+struct timer;
struct list_head;
/**
* int fd[2];
* struct io_conn *conn;
*
- * pipe(fd);
+ * if (pipe(fd) != 0)
+ * exit(1);
* conn = io_new_conn(NULL, fd[0], conn_init, (const char *)"hi!");
* if (!conn)
* exit(1);
* @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 *(*next)(struct io_conn *, void *),
void *arg);
+/**
+ * io_out_always - output plan to immediately call next callback
+ * @conn: the connection that plan is for.
+ * @next: function to call.
+ * @arg: @next argument
+ *
+ * This is a variant of io_always() which uses the output plan; it only
+ * matters if you are using io_duplex, and thus have two plans running at
+ * once.
+ */
+#define io_out_always(conn, next, arg) \
+ io_out_always_((conn), typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), \
+ struct io_conn *), \
+ (arg))
+
+struct io_plan *io_out_always_(struct io_conn *conn,
+ struct io_plan *(*next)(struct io_conn *,
+ void *),
+ void *arg);
+
/**
* io_connect - create an asynchronous connection to a listening socket.
* @conn: the connection that plan is for.
*
* Note that if either plan closes the connection, it will be closed.
*
- * Note that if one plan is io_wait or io_always, that causes a problem:
- * they look at the input and output plan slots to figure out which to
- * use, but if the other plan hasn't been evaluated yet, that will fail.
- * In this case, you'll need to ensure the other plan is evaluated first,
- * eg. "struct io_plan *r = io_read(...); return io_duplex(r, io_always(...))"
- *
* Example:
* struct buf {
* char in[100];
* io_write(conn, b->out, sizeof(b->out), io_close_cb,b));
* }
*/
-#define io_duplex(conn, in_plan, out_plan) \
- (io_duplex_prepare(conn), io_duplex_(in_plan, out_plan))
-
-struct io_plan *io_duplex_(struct io_plan *in_plan, struct io_plan *out_plan);
-void io_duplex_prepare(struct io_conn *conn);
+struct io_plan *io_duplex(struct io_conn *conn,
+ struct io_plan *in_plan, struct io_plan *out_plan);
/**
* io_halfclose - close half of an io_duplex connection.
void *arg);
+/**
+ * io_out_wait - leave the output plan idle until something wakes us.
+ * @conn: the connection that plan is for.
+ * @waitaddr: the address to wait on.
+ * @next: function to call after waiting.
+ * @arg: @next argument
+ *
+ * io_wait() makes the input plan idle: if you're not using io_duplex it
+ * doesn't matter which plan is waiting. Otherwise, you may need to use
+ * io_out_wait() instead, to specify explicitly that the output plan is
+ * waiting.
+ */
+#define io_out_wait(conn, waitaddr, next, arg) \
+ io_out_wait_((conn), (waitaddr), \
+ typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), \
+ struct io_conn *), \
+ (arg))
+
+struct io_plan *io_out_wait_(struct io_conn *conn,
+ const void *wait,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *arg);
+
/**
* io_wake - wake up any connections waiting on @wait
* @waitaddr: the address to trigger.
/* FIXME: io_recvfrom/io_sendto */
/**
- * io_close - plan to close a connection.
+ * io_close - close a connection.
* @conn: the connection to close.
*
- * On return to io_loop, the connection will be closed. It doesn't have
- * to be the current connection and it doesn't need to be idle. No more
- * IO or callbacks will occur.
+ * The connection is immediately freed: it doesn't have to be the
+ * current connection and it doesn't need to be idle. No more IO or
+ * callbacks will occur, but if a function was added by io_set_finish()
+ * it will be called with the current errno preserved.
*
- * You can close a connection twice without harmful effects.
+ * This is equivalent to tal_free(io_conn), except it returns an io_plan
+ * for use in an io callback.
*
* Example:
* static struct io_plan *close_on_timeout(struct io_conn *conn, const char *msg)
* io_close_cb - helper callback to close a connection.
* @conn: the connection.
*
- * This schedules a connection to be closed; designed to be used as
- * a callback function.
+ * This is closes a connection; designed to be used as a callback
+ * function.
*
* Example:
* #define close_on_timeout io_close_cb
*/
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)
- * @expired - a list filled with expired timers (can be NULL if @timers is)
+ * @expired - an expired timer (can be NULL if @timers is)
*
* This is the core loop; it exits with the io_break() arg, or NULL if
- * all connections and listeners are closed, or with @expired set to a
- * list of expired timers (if @timers isn't NULL).
+ * all connections and listeners are closed, or with @expired set to an
+ * expired timer (if @timers isn't NULL).
*
* Example:
* io_loop(NULL, NULL);
*/
-void *io_loop(struct timers *timers, struct list_head *expired);
+void *io_loop(struct timers *timers, struct timer **expired);
/**
* 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_set_debug - set synchronous mode on a connection.
- * @conn: the connection.
- * @debug: whether to enable or disable debug.
+ * io_plan_in_started - is this conn doing input I/O now?
+ * @conn: the conn.
*
- * Once @debug is true on a connection, all I/O is done synchronously
- * as soon as it is set, until it is unset or @conn is closed. This
- * makes it easy to debug what's happening with a connection, but note
- * that other connections are starved while this is being done.
+ * 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.
*
- * See also: io_debug_complete()
+ * 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.
*
- * Example:
- * // Dumb init function to set debug and tell conn to close.
- * static struct io_plan *conn_init(struct io_conn *conn, const char *msg)
- * {
- * io_set_debug(conn, true);
- * return io_close(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.
*/
-void io_set_debug(struct io_conn *conn, bool debug);
+bool io_plan_out_started(const struct io_conn *conn);
/**
- * io_debug_complete - empty function called when conn is closing/waiting.
+ * io_flush_sync - (synchronously) complete any outstanding output.
* @conn: the connection.
*
- * This is for putting a breakpoint onto, when debugging. It is called
- * when a conn with io_set_debug() true can no longer be synchronous:
- * 1) It is io_close()'d
- * 2) It enters io_wait() (sychronous debug will resume after io_wake())
- * 3) io_break() is called (sychronous debug will resume after io_loop())
+ * 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_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.
+ *
+ * io usually uses time_mono() internally, but this forces it
+ * to use your function (eg. for debugging). Returns the old
+ * one.
*/
-void io_debug_complete(struct io_conn *conn);
+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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