/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#ifndef CCAN_IO_H
#define CCAN_IO_H
+#include <ccan/tal/tal.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
-#include <ccan/time/time.h>
#include <stdbool.h>
#include <unistd.h>
+struct timers;
+struct timer;
+struct list_head;
+
/**
- * struct io_plan - pointer to return from a setup function.
+ * struct io_plan - a plan for input or output.
*
- * A plan of what IO to do, when.
+ * Each io_conn has zero to two of these active at any time.
*/
struct io_plan;
/**
- * struct io_next - pointer to what we're going to do next.
- *
- * Bundles up callbacks, generated by io_next().
+ * struct io_conn - a connection associated with an fd.
*/
-struct io_next;
+struct io_conn;
/**
* io_new_conn - create a new connection.
+ * @ctx: the context to tal from (or NULL)
* @fd: the file descriptor.
- * @start: the first function to call.
- * @finish: the function to call when it's closed or fails.
- * @arg: the argument to both @start and @finish.
- *
- * This creates a connection which owns @fd. @start will be called on the
- * next return to io_loop(), and @finish will be called when an I/O operation
- * fails, or you call io_close() on the connection.
+ * @init: the function to call for a new connection
+ * @arg: the argument to @init.
*
- * The @start function must call one of the io queueing functions
- * (eg. io_read, io_write) and return the next function to call once
- * that is done using io_next(). The alternative is to call io_close().
+ * This creates a connection which owns @fd, it then calls
+ * @init to initialize the connection, which sets up an io_plan.
*
* Returns NULL on error (and sets errno).
+ *
+ * Example:
+ * // Dumb init function to print string and tell conn to close.
+ * static struct io_plan *conn_init(struct io_conn *conn, const char *msg)
+ * {
+ * printf("Created conn %p: %s", conn, msg);
+ * return io_close(conn);
+ * }
+ *
+ * static void create_self_closing_pipe(void)
+ * {
+ * int fd[2];
+ * struct io_conn *conn;
+ *
+ * if (pipe(fd) != 0)
+ * exit(1);
+ * conn = io_new_conn(NULL, fd[0], conn_init, (const char *)"hi!");
+ * if (!conn)
+ * exit(1);
+ * }
*/
-#define io_new_conn(fd, start, finish, arg) \
- io_new_conn_((fd), \
+#define io_new_conn(ctx, fd, init, arg) \
+ io_new_conn_((ctx), (fd), \
typesafe_cb_preargs(struct io_plan *, void *, \
- (start), (arg), struct io_conn *), \
- typesafe_cb_preargs(void, void *, (finish), (arg), \
- struct io_conn *), \
- (arg))
-struct io_conn *io_new_conn_(int fd,
- struct io_plan *(*start)(struct io_conn *, void *),
- void (*finish)(struct io_conn *, void *),
+ (init), (arg), \
+ struct io_conn *conn), \
+ (void *)(arg))
+
+struct io_conn *io_new_conn_(const tal_t *ctx, int fd,
+ struct io_plan *(*init)(struct io_conn *, void *),
void *arg);
+/**
+ * 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. errno will be set to the value
+ * after the failed I/O, or at the call to io_close(). The fd
+ * will be closed before @finish is called.
+ *
+ * Example:
+ * static void finish(struct io_conn *conn, const char *msg)
+ * {
+ * // errno is not 0 after success, so this is a bit useless.
+ * printf("Conn %p closed with errno %i (%s)\n", conn, errno, msg);
+ * }
+ *
+ * // Dumb init function to print string and tell conn to close.
+ * static struct io_plan *conn_init(struct io_conn *conn, const char *msg)
+ * {
+ * io_set_finish(conn, finish, msg);
+ * return io_close(conn);
+ * }
+ */
+#define io_set_finish(conn, finish, arg) \
+ io_set_finish_((conn), \
+ typesafe_cb_preargs(void, void *, \
+ (finish), (arg), \
+ struct io_conn *), \
+ (void *)(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.
+ * @ctx: the context to tal from (or NULL)
* @fd: the file descriptor.
- * @start: the first function to call on new connections.
- * @finish: the function to call when the connection is closed or fails.
- * @arg: the argument to both @start and @finish.
+ * @init: the function to call for a new connection
+ * @arg: the argument to @init.
*
- * When @fd becomes readable, we accept() and turn that fd into a new
- * connection.
+ * When @fd becomes readable, we accept(), create a new connection,
+ * (tal'ocated off @ctx) and pass that to init().
*
* Returns NULL on error (and sets errno).
+ *
+ * Example:
+ * #include <sys/types.h>
+ * #include <sys/socket.h>
+ * #include <netdb.h>
+ *
+ * ...
+ *
+ * // Set up a listening socket, return it.
+ * static struct io_listener *do_listen(const char *port)
+ * {
+ * struct addrinfo *addrinfo, hints;
+ * int fd, on = 1;
+ *
+ * memset(&hints, 0, sizeof(hints));
+ * hints.ai_family = AF_UNSPEC;
+ * hints.ai_socktype = SOCK_STREAM;
+ * hints.ai_flags = AI_PASSIVE;
+ * hints.ai_protocol = 0;
+ *
+ * if (getaddrinfo(NULL, port, &hints, &addrinfo) != 0)
+ * return NULL;
+ *
+ * fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
+ * addrinfo->ai_protocol);
+ * if (fd < 0)
+ * return NULL;
+ *
+ * freeaddrinfo(addrinfo);
+ * setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+ * if (bind(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) != 0) {
+ * close(fd);
+ * return NULL;
+ * }
+ * if (listen(fd, 1) != 0) {
+ * close(fd);
+ * return NULL;
+ * }
+ * return io_new_listener(NULL, fd, conn_init, (const char *)"listened!");
+ * }
*/
-#define io_new_listener(fd, start, finish, arg) \
- io_new_listener_((fd), \
+#define io_new_listener(ctx, fd, init, arg) \
+ io_new_listener_((ctx), (fd), \
typesafe_cb_preargs(struct io_plan *, void *, \
- (start), (arg), \
- struct io_conn *), \
- typesafe_cb_preargs(void, void *, (finish), \
- (arg), struct io_conn *), \
- (arg))
-struct io_listener *io_new_listener_(int fd,
- struct io_plan *(*start)(struct io_conn *,
- void *arg),
- void (*finish)(struct io_conn *,
- void *arg),
+ (init), (arg), \
+ struct io_conn *conn), \
+ (void *)(arg))
+struct io_listener *io_new_listener_(const tal_t *ctx, int fd,
+ struct io_plan *(*init)(struct io_conn *,
+ void *),
void *arg);
/**
* @listener: the listener returned from io_new_listener.
*
* This closes the fd and frees @listener.
+ *
+ * Example:
+ * ...
+ * struct io_listener *l = do_listen("8111");
+ * if (l) {
+ * io_loop(NULL, NULL);
+ * io_close_listener(l);
+ * }
*/
void io_close_listener(struct io_listener *listener);
/**
- * io_write - queue data to be written.
+ * io_write - output plan to write data.
+ * @conn: the connection that plan is for.
* @data: the data buffer.
* @len: the length to write.
- * @next: what to call next.
+ * @next: function to call output is done.
+ * @arg: @next argument
*
- * This will queue the data buffer for writing. Once it's all written, the
- * function registered with io_next() will be called: on an error, the finish
+ * This updates the output plan, to write out a data buffer. Once it's all
+ * written, the @next function will be called: on an error, the finish
* function is called instead.
*
* Note that the I/O may actually be done immediately.
+ *
+ * Example:
+ * static struct io_plan *write_to_conn(struct io_conn *conn, const char *msg)
+ * {
+ * // Write message, then close.
+ * return io_write(conn, msg, strlen(msg), io_close_cb, NULL);
+ * }
*/
-struct io_plan *io_write(const void *data, size_t len, struct io_next *next);
+#define io_write(conn, data, len, next, arg) \
+ io_write_((conn), (data), (len), \
+ typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), struct io_conn *), \
+ (arg))
+struct io_plan *io_write_(struct io_conn *conn,
+ const void *data, size_t len,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *arg);
/**
- * io_read - queue buffer to be read.
+ * io_read - input plan to read data.
+ * @conn: the connection that plan is for.
* @data: the data buffer.
* @len: the length to read.
- * @next: what to call next.
+ * @next: function to call once input is done.
+ * @arg: @next argument
*
- * This will queue the data buffer for reading. Once it's all read, the
- * function registered with io_next() will be called: on an error, the finish
+ * 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.
*
* Note that the I/O may actually be done immediately.
+ *
+ * Example:
+ * static struct io_plan *read_from_conn(struct io_conn *conn, char *buf)
+ * {
+ * // Read message, then close.
+ * return io_read(conn, buf, 12, io_close_cb, NULL);
+ * }
*/
-struct io_plan *io_read(void *data, size_t len, struct io_next *next);
+#define io_read(conn, data, len, next, arg) \
+ io_read_((conn), (data), (len), \
+ typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), struct io_conn *), \
+ (arg))
+struct io_plan *io_read_(struct io_conn *conn,
+ void *data, size_t len,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *arg);
+
/**
- * io_read_partial - queue buffer to be read (partial OK).
+ * io_read_partial - input plan to read some data.
+ * @conn: the connection that plan is for.
* @data: the data buffer.
- * @len: the maximum length to read, set to the length actually read.
- * @next: what to call next.
+ * @maxlen: the maximum length to read
+ * @lenp: set to the length actually read.
+ * @next: function to call once input is done.
+ * @arg: @next argument
*
- * This will queue the data buffer for reading. Once any data is
- * read, @len is updated and the function registered with io_next()
- * will be called: on an error, the finish function is called instead.
+ * 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.
*
* Note that the I/O may actually be done immediately.
+ *
+ * Example:
+ * struct buf {
+ * size_t len;
+ * char buf[12];
+ * };
+ *
+ * static struct io_plan *dump(struct io_conn *conn, struct buf *b)
+ * {
+ * printf("Partial read: '%*s'\n", (int)b->len, b->buf);
+ * free(b);
+ * return io_close(conn);
+ * }
+ *
+ * static struct io_plan *read_part(struct io_conn *conn, struct buf *b)
+ * {
+ * // Read message, then dump and close.
+ * return io_read_partial(conn, b->buf, sizeof(b->buf), &b->len, dump, b);
+ * }
*/
-struct io_plan *io_read_partial(void *data, size_t *len, struct io_next *next);
+#define io_read_partial(conn, data, maxlen, lenp, next, arg) \
+ io_read_partial_((conn), (data), (maxlen), (lenp), \
+ typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), \
+ struct io_conn *), \
+ (arg))
+struct io_plan *io_read_partial_(struct io_conn *conn,
+ void *data, size_t maxlen, size_t *lenp,
+ struct io_plan *(*next)(struct io_conn *,
+ void *),
+ void *arg);
/**
- * io_write_partial - queue data to be written (partial OK).
+ * io_write_partial - output plan to write some data.
+ * @conn: the connection that plan is for.
* @data: the data buffer.
- * @len: the maximum length to write, set to the length actually written.
- * @next: what to call next.
+ * @maxlen: the maximum length to write
+ * @lenp: set to the length actually written.
+ * @next: function to call once output is done.
+ * @arg: @next argument
*
- * This will queue the data buffer for writing. Once any data is
- * written, @len is updated and the function registered with io_next()
- * will be called: on an error, the finish function is called instead.
+ * This creates a plan to write data from a buffer. Once any data is
+ * written, @len is updated and the @next function will be called: on an
+ * error, the finish function is called instead.
*
* Note that the I/O may actually be done immediately.
+ *
+ * Example:
+ * struct buf {
+ * size_t len;
+ * char buf[12];
+ * };
+ *
+ * static struct io_plan *show_partial(struct io_conn *conn, struct buf *b)
+ * {
+ * printf("Only wrote: '%*s'\n", (int)b->len, b->buf);
+ * free(b);
+ * return io_close(conn);
+ * }
+ *
+ * static struct io_plan *write_part(struct io_conn *conn, struct buf *b)
+ * {
+ * // Write message, then dump and close.
+ * strcpy(b->buf, "Hello world");
+ * return io_write_partial(conn, b->buf, strlen(b->buf),
+ * &b->len, show_partial, b);
+ * }
*/
-struct io_plan *io_write_partial(const void *data, size_t *len,
- struct io_next *next);
+#define io_write_partial(conn, data, maxlen, lenp, next, arg) \
+ io_write_partial_((conn), (data), (maxlen), (lenp), \
+ typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), \
+ struct io_conn *), \
+ (arg))
+struct io_plan *io_write_partial_(struct io_conn *conn,
+ const void *data, size_t maxlen, size_t *lenp,
+ struct io_plan *(*next)(struct io_conn *,
+ void*),
+ void *arg);
/**
- * io_idle - explicitly note that this connection will do nothing.
- * @conn: the current connection.
+ * io_always - plan to immediately call next callback
+ * @conn: the connection that plan is for.
+ * @next: function to call.
+ * @arg: @next argument
+ *
+ * Sometimes it's neater to plan a callback rather than call it directly;
+ * for example, if you only need to read data for one path and not another.
*
- * This indicates the connection is idle: some other function will
- * later call io_read/io_write etc. (or io_close) on it, in which case
- * it will do that.
+ * Example:
+ * static struct io_plan *init_conn_with_nothing(struct io_conn *conn,
+ * void *unused)
+ * {
+ * // Silly example: close on next time around loop.
+ * return io_always(conn, io_close_cb, NULL);
+ * }
*/
-struct io_plan *io_idle(struct io_conn *conn);
+#define io_always(conn, next, arg) \
+ io_always_((conn), typesafe_cb_preargs(struct io_plan *, void *, \
+ (next), (arg), \
+ struct io_conn *), \
+ (arg))
+
+struct io_plan *io_always_(struct io_conn *conn,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *arg);
/**
- * io_timeout - set timeout function if the callback doesn't fire.
- * @conn: the current connection.
- * @ts: how long until the timeout should be called.
+ * io_out_always - output plan to immediately call next callback
+ * @conn: the connection that plan is for.
* @next: function to call.
- * @arg: argument to @next.
+ * @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.
+ * @addr: where to connect.
+ * @init: function to call once it's connected
+ * @arg: @init argument
+ *
+ * This initiates a connection, and creates a plan for
+ * (asynchronously) completing it. Once complete, the @init function
+ * will be called.
+ *
+ * Example:
+ * #include <sys/types.h>
+ * #include <sys/socket.h>
+ * #include <netdb.h>
*
- * If the usual next callback is not called for this connection before @ts,
- * this function will be called. If next callback is called, the timeout
- * is automatically removed.
+ * // Write, then close socket.
+ * static struct io_plan *init_connect(struct io_conn *conn,
+ * struct addrinfo *addrinfo)
+ * {
+ * return io_connect(conn, addrinfo, io_close_cb, NULL);
+ * }
*
- * Returns false on allocation failure. A connection can only have one
- * timeout.
+ * ...
+ *
+ * int fd;
+ * struct addrinfo *addrinfo;
+ *
+ * fd = socket(AF_INET, SOCK_STREAM, 0);
+ * getaddrinfo("localhost", "8111", NULL, &addrinfo);
+ * io_new_conn(NULL, fd, init_connect, addrinfo);
*/
-#define io_timeout(conn, ts, next, arg) \
- io_timeout_((conn), (ts), \
+struct addrinfo;
+#define io_connect(conn, addr, next, arg) \
+ io_connect_((conn), (addr), \
typesafe_cb_preargs(struct io_plan *, void *, \
(next), (arg), \
struct io_conn *), \
(arg))
-bool io_timeout_(struct io_conn *conn, struct timespec ts,
- struct io_plan *(*next)(struct io_conn *, void *), void *arg);
+struct io_plan *io_connect_(struct io_conn *conn, const struct addrinfo *addr,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *arg);
/**
- * io_duplex - split an fd into two connections.
- * @conn: a connection.
- * @start: the first function to call.
- * @finish: the function to call when it's closed or fails.
- * @arg: the argument to both @start and @finish.
+ * io_duplex - set plans for both input and output.
+ * @conn: the connection that plan is for.
+ * @in: the input plan
+ * @out: the output plan
+ *
+ * Most plans are either for input or output; io_duplex creates a plan
+ * which does both. This is often used in the init function to create
+ * two independent streams, though it can be used once on any connection.
*
- * 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
- * to have two connections for the same fd, and use one for read
- * operations and one for write.
+ * Note that if either plan closes the connection, it will be closed.
*
- * You must io_close() both of them to close the fd.
+ * Example:
+ * struct buf {
+ * char in[100];
+ * char out[100];
+ * };
+ *
+ * static struct io_plan *read_and_write(struct io_conn *conn, struct buf *b)
+ * {
+ * return io_duplex(conn,
+ * io_read(conn, b->in, sizeof(b->in), io_close_cb, b),
+ * io_write(conn, b->out, sizeof(b->out), io_close_cb,b));
+ * }
*/
-#define io_duplex(conn, start, finish, arg) \
- io_duplex_((conn), \
- typesafe_cb_preargs(struct io_plan *, void *, \
- (start), (arg), struct io_conn *), \
- typesafe_cb_preargs(void, void *, (finish), (arg), \
- struct io_conn *), \
- (arg))
+struct io_plan *io_duplex(struct io_conn *conn,
+ struct io_plan *in_plan, struct io_plan *out_plan);
-struct io_conn *io_duplex_(struct io_conn *conn,
- struct io_plan *(*start)(struct io_conn *, void *),
- void (*finish)(struct io_conn *, void *),
- void *arg);
+/**
+ * io_halfclose - close half of an io_duplex connection.
+ * @conn: the connection that plan is for.
+ *
+ * It's common to want to close a duplex connection after both input and
+ * output plans have completed. If either calls io_close() the connection
+ * closes immediately. Instead, io_halfclose() needs to be called twice.
+ *
+ * Example:
+ * struct buf {
+ * char in[100];
+ * char out[100];
+ * };
+ *
+ * static struct io_plan *finish(struct io_conn *conn, struct buf *b)
+ * {
+ * return io_halfclose(conn);
+ * }
+ *
+ * static struct io_plan *read_and_write(struct io_conn *conn, struct buf *b)
+ * {
+ * return io_duplex(conn,
+ * io_read(conn, b->in, sizeof(b->in), finish, b),
+ * io_write(conn, b->out, sizeof(b->out), finish, b));
+ * }
+ */
+struct io_plan *io_halfclose(struct io_conn *conn);
/**
- * io_wake - wake up and idle connection.
- * @conn: an idle connection.
- * @next: the next function to call once queued IO is complete.
- * @arg: the argument to @next.
+ * io_wait - leave a 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
+ *
+ * This leaves the input or output idle: io_wake(@waitaddr) will be
+ * called later to restart the connection.
*
- * This makes @conn run its @next function the next time around the
- * io_loop().
+ * Example:
+ * // Silly example to wait then close.
+ * static struct io_plan *wait(struct io_conn *conn, void *b)
+ * {
+ * return io_wait(conn, b, io_close_cb, NULL);
+ * }
*/
-#define io_wake(conn, next, arg) \
- io_wake_((conn), \
+#define io_wait(conn, waitaddr, next, arg) \
+ io_wait_((conn), (waitaddr), \
typesafe_cb_preargs(struct io_plan *, void *, \
- (next), (arg), struct io_conn *), \
+ (next), (arg), \
+ struct io_conn *), \
(arg))
-void io_wake_(struct io_conn *conn,
- struct io_plan *(*next)(struct io_conn *, void *), void *arg);
+
+struct io_plan *io_wait_(struct io_conn *conn,
+ const void *wait,
+ struct io_plan *(*next)(struct io_conn *, void *),
+ 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.
+ *
+ * All io_conns who have returned io_wait() on @waitaddr will move on
+ * to their next callback.
+ *
+ * Example:
+ * static struct io_plan *wake_it(struct io_conn *conn, void *b)
+ * {
+ * io_wake(b);
+ * return io_close(conn);
+ * }
+ */
+void io_wake(const void *wait);
/**
* io_break - return from io_loop()
- * @arg: non-NULL value to return from io_loop().
- * @next: what to call next (can be NULL if we expect no return).
+ * @ret: non-NULL value to return from io_loop().
*
- * This breaks out of the io_loop. As soon as the current @next
- * function returns, any io_closed()'d connections will have their
- * finish callbacks called, then io_loop() with return with @arg.
+ * This breaks out of the io_loop. As soon as the current function
+ * returns, any io_close()'d connections will have their finish
+ * callbacks called, then io_loop() with return with @ret.
*
- * If io_loop() is called again, then @next will be called.
+ * If io_loop() is called again, then @plan will be carried out.
+ *
+ * Example:
+ * static struct io_plan *fail_on_timeout(struct io_conn *conn, char *msg)
+ * {
+ * io_break(msg);
+ * return io_close(conn);
+ * }
*/
-struct io_plan *io_break(void *arg, struct io_next *next);
+void io_break(const void *ret);
/**
- * io_next - indicate what callback to call next.
- * @conn: this connection.
- * @next: the next function to call once queued IO is complete.
- * @arg: the argument to @next.
+ * io_never - assert if callback is called.
+ * @conn: the connection that plan is for.
+ * @unused: an unused parameter to make this suitable for use as a callback.
*
- * Every @next (or @start) function should "return io_next(...);" once
- * they have indicated what io to perform (eg. io_write, io_idle).
- * The exception is io_close(), which can be used instead of io_next().
+ * Sometimes you want to make it clear that a callback should never happen
+ * (eg. for io_break). This will assert() if called.
*
- * Note that as an optimization, the next function may be called
- * immediately, which is why this should be the last statement in your
- * function.
+ * Example:
+ * static struct io_plan *break_out(struct io_conn *conn, void *unused)
+ * {
+ * io_break(conn);
+ * // We won't ever return from io_break
+ * return io_never(conn, NULL);
+ * }
*/
-#define io_next(conn, next, arg) \
- io_next_((conn), \
- typesafe_cb_preargs(struct io_plan *, void *, \
- (next), (arg), struct io_conn *), \
- (arg))
-struct io_next *io_next_(struct io_conn *conn,
- struct io_plan *(*next)(struct io_conn *, void *arg),
- void *arg);
+struct io_plan *io_never(struct io_conn *conn, void *unused);
/* FIXME: io_recvfrom/io_sendto */
/**
- * io_close - terminate a connection.
- * @conn: any connection.
+ * io_close - close a connection.
+ * @conn: the connection to close.
+ *
+ * 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.
*
- * The schedules a connection to be closed. It can be done on any
- * connection, whether it has I/O queued or not (though that I/O may
- * be performed first).
+ * This is equivalent to tal_free(io_conn), except it returns an io_plan
+ * for use in an io callback.
*
- * It's common to 'return io_close(...)' from a @next function, but
- * io_close can also be used as an argument to io_next().
+ * Example:
+ * static struct io_plan *close_on_timeout(struct io_conn *conn, const char *msg)
+ * {
+ * printf("closing: %s\n", msg);
+ * return io_close(conn);
+ * }
*/
-struct io_plan *io_close(struct io_conn *, void *unused);
+struct io_plan *io_close(struct io_conn *conn);
+
+/**
+ * io_close_cb - helper callback to close a connection.
+ * @conn: the connection.
+ *
+ * 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_loop - process fds until all closed on io_break.
+ * @timers - timers which are waiting to go off (or NULL for none)
+ * @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.
+ * 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(void);
+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().
+ */
+int io_conn_fd(const struct io_conn *conn);
+
+/**
+ * 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.
+ */
+struct timemono (*io_time_override(struct timemono (*now)(void)))(void);
+
#endif /* CCAN_IO_H */
projects / ccan / blobdiff