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/* 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"
/**
* io_new_conn - create a new connection.
* @fd: the file descriptor.
* @plan: the first I/O to perform.
*
* This creates a connection which owns @fd. @plan will be called on the
* 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)))
struct io_conn *io_new_conn_(int fd, struct io_plan plan);
/**
* 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 (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), \
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.
* @init: the function to call for a new connection
* @arg: the argument to @init.
*
* 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), \
typesafe_cb_preargs(void, void *, \
(init), (arg), \
int fd), \
(arg))
struct io_listener *io_new_listener_(int fd,
void (*init)(int fd, void *arg),
void *arg);
/**
* io_close_listener - delete a listener.
* @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 - plan to write data.
* @data: the data buffer.
* @len: the length to write.
* @cb: function to call once it's done.
* @arg: @cb argument
*
* 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));
* }
*/
#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 - plan to read data.
* @data: the data buffer.
* @len: the length to read.
* @cb: function to call once it's done.
* @arg: @cb argument
*
* 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));
* }
*/
#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 - plan to read some data.
* @data: the data buffer.
* @len: the maximum length to read, set to the length actually read.
* @cb: function to call once it's done.
* @arg: @cb argument
*
* 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));
* }
*/
#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 - plan to write some data.
* @data: the data buffer.
* @len: the maximum length to write, set to the length actually written.
* @cb: function to call once it's done.
* @arg: @cb argument
*
* 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));
* }
*/
#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_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_wait - plan to wait for something.
* @wait: the address to wait on.
* @cb: function to call after waiting.
* @arg: @cb argument
*
* This indicates the connection is idle: io_wake() will be called later to
* restart the connection.
*
* Example:
* struct io_conn *sleeper;
* unsigned int counter = 0;
* sleeper = io_new_conn(open("/dev/null", O_RDONLY),
* io_wait(&counter, io_close_cb, NULL));
* if (!sleeper)
* exit(1);
*/
#define io_wait(wait, cb, arg) \
io_debug(io_wait_(wait, \
typesafe_cb_preargs(struct io_plan, void *, \
(cb), (arg), \
struct io_conn *), \
(arg)))
struct io_plan io_wait_(const void *wait,
struct io_plan (*cb)(struct io_conn *, void *),
void *arg);
/**
* io_timeout - set timeout function if the callback doesn't complete.
* @conn: the current connection.
* @t: how long until the timeout should be called.
* @cb: callback 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.
*
* 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), \
typesafe_cb_preargs(struct io_plan, void *, \
(fn), (arg), \
struct io_conn *), \
(arg))
bool io_timeout_(struct io_conn *conn, struct timelen t,
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.
*
* 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 any connections waiting on @wait
* @wait: the address to trigger.
*
* Example:
* unsigned int wait;
*
* io_new_conn(open("/dev/null", O_RDONLY),
* io_wait(&wait, io_close_cb, NULL));
*
* io_wake(&wait);
*/
void io_wake(const void *wait);
/**
* io_break - return from io_loop()
* @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 @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_never - assert if callback is called.
*
* Sometimes you want to make it clear that a callback should never happen
* (eg. for io_break). This will assert() if called.
*
* Example:
* static struct io_plan break_out(struct io_conn *conn, void *unused)
* {
* // We won't ever return from io_break
* return io_break(conn, io_never());
* }
*/
struct io_plan io_never(void);
/* FIXME: io_recvfrom/io_sendto */
/**
* 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);
/**
* 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.
*
* 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 */