* next io_loop().
*
* 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);
*/
#define io_new_conn(fd, plan) \
(io_plan_no_debug(), io_new_conn_((fd), (plan)))
*
* @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().
+ * after the failed I/O, or at the call to io_close(). The fd
+ * will be closed (unless a duplex) before @finish is called.
+ *
+ * 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_set_finish(conn, finish, arg) \
io_set_finish_((conn), \
* 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, init, arg) \
io_new_listener_((fd), \
* @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);
* 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));
+ * }
*/
#define io_write(data, len, cb, arg) \
io_debug(io_write_((data), (len), \
* 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));
+ * }
*/
#define io_read(data, len, cb, arg) \
io_debug(io_read_((data), (len), \
* 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));
+ * }
*/
#define io_read_partial(data, len, cb, arg) \
io_debug(io_read_partial_((data), (len), \
* 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));
+ * }
*/
#define io_write_partial(data, len, cb, arg) \
io_debug(io_write_partial_((data), (len), \
struct io_plan (*cb)(struct io_conn *, void*),
void *arg);
+/**
+ * io_always - plan to immediately call next callback.
+ * @cb: function to call.
+ * @arg: @cb 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.
+ *
+ * Example:
+ * static void start_conn_with_nothing(int fd)
+ * {
+ * // Silly example: close on next time around loop.
+ * io_new_conn(fd, io_always(io_close_cb, NULL));
+ * }
+ */
+#define io_always(cb, arg) \
+ io_debug(io_always_(typesafe_cb_preargs(struct io_plan, void *, \
+ (cb), (arg), \
+ struct io_conn *), \
+ (arg)))
+struct io_plan io_always_(struct io_plan (*cb)(struct io_conn *, void *),
+ void *arg);
+
+/**
+ * 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);
*
* 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!");
*/
#define io_timeout(conn, ts, fn, arg) \
io_timeout_((conn), (ts), \
* 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)))
* @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());
+ *
+ * io_wake(sleeper, io_write("junk", 4, io_close_cb, NULL));
*/
#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().
* finish callbacks called, then io_loop() with return with @ret.
*
* 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());
+ * }
*/
#define io_break(ret, plan) (io_plan_no_debug(), io_break_((ret), (plan)))
struct io_plan io_break_(void *ret, struct io_plan plan);
* io_close - plan to close a connection.
*
* On return to io_loop, the connection will be closed.
+ *
+ * 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_close() io_debug(io_close_())
struct io_plan io_close_(void);
*
* This schedules a connection to be closed; 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_other - close different connection next time around the I/O loop.
+ * @conn: the connection to close.
+ *
+ * This is used to force a different connection to close: no more I/O will
+ * happen on @conn, even if it's pending.
+ *
+ * It's a bug to use this on the current connection!
+ *
+ * Example:
+ * static void stop_connection(struct io_conn *conn)
+ * {
+ * printf("forcing stop on connection\n");
+ * io_close_other(conn);
+ * }
+ */
+void io_close_other(struct io_conn *conn);
+
/**
* 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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