-/* Licensed under BSD-MIT - see LICENSE file for details */
+/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#ifndef CCAN_IO_H
#define CCAN_IO_H
#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <ccan/time/time.h>
#include <stdbool.h>
#include <unistd.h>
+#include "io_plan.h"
/**
- * struct io_op - pointer to return from io functions.
+ * io_new_conn - create a new connection.
+ * @fd: the file descriptor.
+ * @plan: the first I/O to perform.
*
- * This undefined structure is just to help the compiler check that you
- * really do return the result of an io-queueing method.
- */
-struct io_op;
-
-/**
- * struct io_next - pointer to what we're going to do next.
+ * This creates a connection which owns @fd. @plan will be called on the
+ * next io_loop().
*
- * Bundles up callbacks, generated by io_next().
+ * Returns NULL on error (and sets errno).
+ *
+ * Example:
+ * int fd[2];
+ * struct io_conn *conn;
+ *
+ * pipe(fd);
+ * // Plan is to close the fd immediately.
+ * conn = io_new_conn(fd[0], io_close());
+ * if (!conn)
+ * exit(1);
*/
-struct io_next;
+#define io_new_conn(fd, plan) \
+ (io_plan_no_debug(), io_new_conn_((fd), (plan)))
+struct io_conn *io_new_conn_(int fd, struct io_plan plan);
/**
- * io_new_conn - create a new connection.
- * @fd: the file descriptor.
- * @start: the first function to call.
+ * 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 both @start and @finish.
+ * @arg: the argument to @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.
+ * @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 @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().
- *
- * Returns NULL on error (and sets errno).
+ * Example:
+ * static void finish(struct io_conn *conn, void *unused)
+ * {
+ * // errno is not 0 after success, so this is a bit useless.
+ * printf("Conn %p closed with errno %i\n", conn, errno);
+ * }
+ * ...
+ * io_set_finish(conn, finish, NULL);
*/
-#define io_new_conn(fd, start, finish, arg) \
- io_new_conn_((fd), \
- typesafe_cb_preargs(struct io_op *, 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_op *(*start)(struct io_conn *, void *),
- void (*finish)(struct io_conn *, void *),
- void *arg);
+#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.
* @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() and pass that fd to init().
*
* Returns NULL on error (and sets errno).
+ *
+ * Example:
+ * #include <sys/types.h>
+ * #include <sys/socket.h>
+ * #include <netdb.h>
+ *
+ * static void start_conn(int fd, char *msg)
+ * {
+ * printf("%s fd %i\n", msg, fd);
+ * close(fd);
+ * }
+ *
+ * // 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(fd, start_conn, (char *)"Got one!");
+ * }
*/
-#define io_new_listener(fd, start, finish, arg) \
+#define io_new_listener(fd, init, arg) \
io_new_listener_((fd), \
- typesafe_cb_preargs(struct io_op *, void *, \
- (start), (arg), \
- struct io_conn *), \
- typesafe_cb_preargs(void, void *, (finish), \
- (arg), struct io_conn *), \
+ typesafe_cb_preargs(void, void *, \
+ (init), (arg), \
+ int fd), \
(arg))
struct io_listener *io_new_listener_(int fd,
- struct io_op *(*start)(struct io_conn *,
- void *arg),
- void (*finish)(struct io_conn *,
- void *arg),
+ void (*init)(int fd, void *arg),
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();
+ * io_close_listener(l);
+ * }
*/
void io_close_listener(struct io_listener *listener);
/**
- * io_write - queue data to be written.
+ * io_write - plan to write data.
* @data: the data buffer.
* @len: the length to write.
- * @next: what to call next.
+ * @cb: function to call once it's done.
+ * @arg: @cb 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 creates a plan write out a data buffer. Once it's all
+ * written, the @cb 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 void start_conn_with_write(int fd, const char *msg)
+ * {
+ * // Write message, then close.
+ * io_new_conn(fd, io_write(msg, strlen(msg), io_close_cb, NULL));
+ * }
*/
-struct io_op *io_write(const void *data, size_t len, struct io_next *next);
+#define io_write(data, len, cb, arg) \
+ io_debug(io_write_((data), (len), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), struct io_conn *), \
+ (arg)))
+struct io_plan io_write_(const void *data, size_t len,
+ struct io_plan (*cb)(struct io_conn *, void *),
+ void *arg);
/**
- * io_read - queue buffer to be read.
+ * io_read - plan to read data.
* @data: the data buffer.
* @len: the length to read.
- * @next: what to call next.
+ * @cb: function to call once it's done.
+ * @arg: @cb 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 @cb 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 void start_conn_with_read(int fd, char msg[12])
+ * {
+ * // Read message, then close.
+ * io_new_conn(fd, io_read(msg, 12, io_close_cb, NULL));
+ * }
*/
-struct io_op *io_read(void *data, size_t len, struct io_next *next);
+#define io_read(data, len, cb, arg) \
+ io_debug(io_read_((data), (len), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), struct io_conn *), \
+ (arg)))
+struct io_plan io_read_(void *data, size_t len,
+ struct io_plan (*cb)(struct io_conn *, void *),
+ void *arg);
+
/**
- * io_read_partial - queue buffer to be read (partial OK).
+ * io_read_partial - plan to read some data.
* @data: the data buffer.
* @len: the maximum length to read, set to the length actually read.
- * @next: what to call next.
+ * @cb: function to call once it's done.
+ * @arg: @cb 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 @cb 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_and_close(struct io_conn *conn, struct buf *b)
+ * {
+ * printf("Partial read: '%*s'\n", (int)b->len, b->buf);
+ * free(b);
+ * return io_close();
+ * }
+ *
+ * static void start_conn_with_part_read(int fd, void *unused)
+ * {
+ * struct buf *b = malloc(sizeof(*b));
+ *
+ * // Read message, then dump and close.
+ * b->len = sizeof(b->buf);
+ * io_new_conn(fd, io_read_partial(b->buf, &b->len, dump_and_close, b));
+ * }
*/
-struct io_op *io_read_partial(void *data, size_t *len, struct io_next *next);
+#define io_read_partial(data, len, cb, arg) \
+ io_debug(io_read_partial_((data), (len), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), \
+ struct io_conn *), \
+ (arg)))
+struct io_plan io_read_partial_(void *data, size_t *len,
+ struct io_plan (*cb)(struct io_conn *, void *),
+ void *arg);
/**
- * io_write_partial - queue data to be written (partial OK).
+ * io_write_partial - plan to write some data.
* @data: the data buffer.
* @len: the maximum length to write, set to the length actually written.
- * @next: what to call next.
+ * @cb: function to call once it's done.
+ * @arg: @cb 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 @cb 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_remainder(struct io_conn *conn, struct buf *b)
+ * {
+ * printf("Only wrote: '%*s'\n", (int)b->len, b->buf);
+ * free(b);
+ * return io_close();
+ * }
+ *
+ * static void start_conn_with_part_read(int fd, void *unused)
+ * {
+ * struct buf *b = malloc(sizeof(*b));
+ *
+ * // Write message, then dump and close.
+ * b->len = sizeof(b->buf);
+ * strcpy(b->buf, "Hello world");
+ * io_new_conn(fd, io_write_partial(b->buf, &b->len, show_remainder, b));
+ * }
*/
-struct io_op *io_write_partial(const void *data, size_t *len,
- struct io_next *next);
+#define io_write_partial(data, len, cb, arg) \
+ io_debug(io_write_partial_((data), (len), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), \
+ struct io_conn *), \
+ (arg)))
+struct io_plan io_write_partial_(const void *data, size_t *len,
+ struct io_plan (*cb)(struct io_conn *, void*),
+ void *arg);
/**
- * io_idle - explicitly note that this connection will do nothing.
+ * io_connect - plan to connect to a listening socket.
+ * @fd: file descriptor.
+ * @addr: where to connect.
+ * @cb: function to call once it's done.
+ * @arg: @cb argument
+ *
+ * This initiates a connection, and creates a plan for
+ * (asynchronously). completing it. Once complete, @len is updated
+ * and the @cb function will be called: on an error, the finish
+ * function is called instead.
+ *
+ * Note that the connect may actually be done immediately.
+ *
+ * Example:
+ * #include <sys/types.h>
+ * #include <sys/socket.h>
+ * #include <netdb.h>
+ *
+ * // Write, then close socket.
+ * static struct io_plan start_write(struct io_conn *conn, void *unused)
+ * {
+ * return io_write("hello", 5, io_close_cb, NULL);
+ * }
+ *
+ * ...
+ *
+ * int fd;
+ * struct addrinfo *addrinfo;
+ *
+ * fd = socket(AF_INET, SOCK_STREAM, 0);
+ * getaddrinfo("localhost", "8111", NULL, &addrinfo);
+ * io_new_conn(fd, io_connect(fd, addrinfo, start_write, NULL));
+ */
+struct addrinfo;
+#define io_connect(fd, addr, cb, arg) \
+ io_debug(io_connect_((fd), (addr), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), \
+ struct io_conn *), \
+ (arg)))
+struct io_plan io_connect_(int fd, const struct addrinfo *addr,
+ struct io_plan (*cb)(struct io_conn *, void*),
+ void *arg);
+
+/**
+ * io_idle - plan to do nothing.
+ *
+ * This indicates the connection is idle: io_wake() will be called later do
+ * give the connection a new plan.
+ *
+ * Example:
+ * struct io_conn *sleeper;
+ * sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
+ * if (!sleeper)
+ * exit(1);
+ */
+#define io_idle() io_debug(io_idle_())
+struct io_plan io_idle_(void);
+
+/**
+ * io_timeout - set timeout function if the callback doesn't complete.
* @conn: the current connection.
+ * @ts: how long until the timeout should be called.
+ * @cb: callback to call.
+ * @arg: argument to @cb.
*
- * 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.
+ * 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.
+ *
+ * Returns false on allocation failure. A connection can only have one
+ * timeout.
+ *
+ * Example:
+ * static struct io_plan close_on_timeout(struct io_conn *conn, char *msg)
+ * {
+ * printf("%s\n", msg);
+ * return io_close();
+ * }
+ *
+ * ...
+ * io_timeout(sleeper, time_from_msec(100),
+ * close_on_timeout, (char *)"Bye!");
*/
-struct io_op *io_idle(struct io_conn *conn);
+#define io_timeout(conn, ts, fn, arg) \
+ io_timeout_((conn), (ts), \
+ typesafe_cb_preargs(struct io_plan, void *, \
+ (fn), (arg), \
+ struct io_conn *), \
+ (arg))
+bool io_timeout_(struct io_conn *conn, struct timespec ts,
+ struct io_plan (*fn)(struct io_conn *, void *), void *arg);
/**
- * io_wake - wake up and idle connection.
+ * io_duplex - split an fd into two connections.
+ * @conn: a connection.
+ * @plan: the first I/O function to call.
+ *
+ * Sometimes you want to be able to simultaneously read and write on a
+ * single fd, but io forces a linear call sequence. The solution is
+ * to have two connections for the same fd, and use one for read
+ * operations and one for write.
+ *
+ * You must io_close() both of them to close the fd.
+ *
+ * Example:
+ * static void setup_read_write(int fd,
+ * char greet_in[5], const char greet_out[5])
+ * {
+ * struct io_conn *writer, *reader;
+ *
+ * // Read their greeting and send ours at the same time.
+ * writer = io_new_conn(fd,
+ * io_write(greet_out, 5, io_close_cb, NULL));
+ * reader = io_duplex(writer,
+ * io_read(greet_in, 5, io_close_cb, NULL));
+ * if (!reader || !writer)
+ * exit(1);
+ * }
+ */
+#define io_duplex(conn, plan) \
+ (io_plan_no_debug(), io_duplex_((conn), (plan)))
+struct io_conn *io_duplex_(struct io_conn *conn, struct io_plan plan);
+
+/**
+ * io_wake - wake up an idle connection.
* @conn: an idle connection.
- * @next: the next function to call once queued IO is complete.
- * @arg: the argument to @next.
+ * @plan: the next I/O plan for @conn.
+ *
+ * This makes @conn ready to do I/O the next time around the io_loop().
+ *
+ * Example:
+ * struct io_conn *sleeper;
+ * sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
*
- * This makes @conn run its @next function the next time around the
- * io_loop().
+ * io_wake(sleeper, io_write("junk", 4, io_close_cb, NULL));
*/
-#define io_wake(conn, next, arg) \
- io_wake_((conn), \
- typesafe_cb_preargs(struct io_op *, void *, \
- (next), (arg), struct io_conn *), \
- (arg))
-void io_wake_(struct io_conn *conn,
- struct io_op *(*next)(struct io_conn *, void *), void *arg);
+#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_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().
+ * @plan: I/O to perform on return (if any)
*
* 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.
+ * 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)
+ * {
+ * return io_break(msg, io_close());
+ * }
*/
-struct io_op *io_break(void *arg, struct io_next *next);
+#define io_break(ret, plan) (io_plan_no_debug(), io_break_((ret), (plan)))
+struct io_plan io_break_(void *ret, struct io_plan plan);
+
+/* FIXME: io_recvfrom/io_sendto */
/**
- * 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_close - plan to close a connection.
*
- * 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().
+ * On return to io_loop, the connection will be closed.
*
- * 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 close_on_timeout(struct io_conn *conn, const char *msg)
+ * {
+ * printf("closing: %s\n", msg);
+ * return io_close();
+ * }
*/
-#define io_next(conn, next, arg) \
- io_next_((conn), \
- typesafe_cb_preargs(struct io_op *, void *, \
- (next), (arg), struct io_conn *), \
- (arg))
-struct io_next *io_next_(struct io_conn *conn,
- struct io_op *(*next)(struct io_conn *, void *arg),
- void *arg);
-
-/* FIXME: io_recvfrom/io_sendto */
+#define io_close() io_debug(io_close_())
+struct io_plan io_close_(void);
/**
- * io_close - terminate a connection.
- * @conn: any connection.
+ * io_close_cb - helper callback to close a connection.
+ * @conn: the connection.
*
- * 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 schedules a connection to be closed; designed to be used as
+ * a callback function.
*
- * 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:
+ * #define close_on_timeout io_close_cb
*/
-struct io_op *io_close(struct io_conn *, void *unused);
+struct io_plan io_close_cb(struct io_conn *, void *unused);
/**
* io_loop - process fds until all closed on io_break.
*
* This is the core loop; it exits with the io_break() arg, or NULL if
* all connections and listeners are closed.
+ *
+ * Example:
+ * io_loop();
*/
void *io_loop(void);
+
+/**
+ * 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_set_alloc - set alloc/realloc/free function for io to use.
+ * @allocfn: allocator function
+ * @reallocfn: reallocator function, ptr may be NULL, size never 0.
+ * @freefn: free function
+ *
+ * By default io uses malloc/realloc/free, and returns NULL if they fail.
+ * You can set your own variants here.
+ */
+void io_set_alloc(void *(*allocfn)(size_t size),
+ void *(*reallocfn)(void *ptr, size_t size),
+ void (*freefn)(void *ptr));
#endif /* CCAN_IO_H */
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