X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fio%2Fio.h;h=cbd2b9be248b803daec99586001892e6e4e716c9;hp=49b6a25e83bba172e483e6c7749056744146ef52;hb=109f8003b603675aec35e5b1fc678ee363e2f30c;hpb=0a2fd289c7bf57d9fc35ad6af36df4bcc694f361 diff --git a/ccan/io/io.h b/ccan/io/io.h index 49b6a25e..cbd2b9be 100644 --- a/ccan/io/io.h +++ b/ccan/io/io.h @@ -1,79 +1,101 @@ -/* 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 +#include #include #include -/** - * struct io_op - pointer to return from io functions. - * - * 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_conn; + +struct io_state_read { + char *buf; + size_t len; +}; + +struct io_state_write { + const char *buf; + size_t len; +}; + +struct io_state_readpart { + char *buf; + size_t *lenp; +}; + +struct io_state_writepart { + const char *buf; + size_t *lenp; +}; + +enum io_result { + RESULT_AGAIN, + RESULT_FINISHED, + RESULT_CLOSE +}; /** - * struct io_next - pointer to what we're going to do next. + * struct io_plan - returned from a setup function. * - * Bundles up callbacks, generated by io_next(). + * A plan of what IO to do, when. */ -struct io_next; +struct io_plan { + int pollflag; + /* Only NULL if idle. */ + enum io_result (*io)(struct io_conn *conn); + /* Only NULL if closing. */ + struct io_plan (*next)(struct io_conn *, void *arg); + void *next_arg; + + union { + struct io_state_read read; + struct io_state_write write; + struct io_state_readpart readpart; + struct io_state_writepart writepart; + } u; +}; /** * io_new_conn - create a new connection. * @fd: the file descriptor. - * @start: the first function to call. + * @plan: the first I/O function. * @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 + * This creates a connection which owns @fd. @plan will be called on the + * next io_loop(), and @finish will be called when an I/O operation * fails, or you call io_close() on the connection. * - * 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). */ -#define io_new_conn(fd, start, finish, arg) \ - io_new_conn_((fd), \ - typesafe_cb_preargs(struct io_op *, void *, \ - (start), (arg), struct io_conn *), \ +#define io_new_conn(fd, plan, finish, arg) \ + io_new_conn_((fd), (plan), \ 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 *), + struct io_plan plan, 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). */ -#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); /** @@ -88,121 +110,170 @@ void io_close_listener(struct io_listener *listener); * io_write - queue data to be written. * @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 will queue the data buffer for writing. 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. */ -struct io_op *io_write(const void *data, size_t len, struct io_next *next); +#define io_write(data, len, cb, arg) \ + 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. * @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 - * function is called instead. + * This will queue the data buffer for reading. 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. */ -struct io_op *io_read(void *data, size_t len, struct io_next *next); +#define io_read(data, len, cb, arg) \ + 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). * @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. + * 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. */ -struct io_op *io_read_partial(void *data, size_t *len, struct io_next *next); +#define io_read_partial(data, len, cb, arg) \ + 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). * @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. + * 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. */ -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_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. - * @conn: the current connection. * * 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. */ -struct io_op *io_idle(struct io_conn *conn); +struct io_plan io_idle(void); + +/** + * io_timeout - set timeout function if the callback doesn't fire. + * @conn: the current connection. + * @ts: how long until the timeout should be called. + * @cb to call. + * @arg: argument to @cb. + * + * 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. + */ +#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_duplex - split an fd into two connections. + * @conn: a connection. + * @plan: the first I/O function to call. + * @finish: the function to call when it's closed or fails. + * @arg: the argument to @finish. + * + * 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. + * + * You must io_close() both of them to close the fd. + */ +#define io_duplex(conn, plan, finish, arg) \ + io_duplex_((conn), (plan), \ + typesafe_cb_preargs(void, void *, (finish), (arg), \ + struct io_conn *), \ + (arg)) + +struct io_conn *io_duplex_(struct io_conn *conn, + struct io_plan plan, + void (*finish)(struct io_conn *, void *), + void *arg); /** - * io_wake - wake up and idle connection. + * 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 function for @conn. * - * This makes @conn run its @next function the next time around the - * io_loop(). + * This makes @conn do I/O the next time around the io_loop(). */ -#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); +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. */ -struct io_op *io_break(void *arg, struct io_next *next); - -/** - * 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. - * - * 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(). - * - * Note that as an optimization, the next function may be called - * immediately, which is why this should be the last statement in your - * function. - */ -#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); +struct io_plan io_break(void *ret, struct io_plan plan); /* FIXME: io_recvfrom/io_sendto */ @@ -217,7 +288,7 @@ struct io_next *io_next_(struct io_conn *conn, * It's common to 'return io_close(...)' from a @next function, but * io_close can also be used as an argument to io_next(). */ -struct io_op *io_close(struct io_conn *, void *unused); +struct io_plan io_close(struct io_conn *, void *unused); /** * io_loop - process fds until all closed on io_break.