1 /* Licensed under LGPLv2.1+ - see LICENSE file for details */
4 #include <ccan/typesafe_cb/typesafe_cb.h>
5 #include <ccan/time/time.h>
11 struct io_state_read {
16 struct io_state_write {
21 struct io_state_readpart {
26 struct io_state_writepart {
39 IO_NEXT, /* eg starting, woken from idle, return from io_break. */
45 * struct io_plan - returned from a setup function.
47 * A plan of what IO to do, when.
52 enum io_result (*io)(struct io_conn *conn);
53 struct io_plan (*next)(struct io_conn *, void *arg);
57 struct io_state_read read;
58 struct io_state_write write;
59 struct io_state_readpart readpart;
60 struct io_state_writepart writepart;
65 * io_new_conn - create a new connection.
66 * @fd: the file descriptor.
67 * @start: the first function to call.
68 * @finish: the function to call when it's closed or fails.
69 * @arg: the argument to both @start and @finish.
71 * This creates a connection which owns @fd. @start will be called on the
72 * next return to io_loop(), and @finish will be called when an I/O operation
73 * fails, or you call io_close() on the connection.
75 * The @start function must call one of the io queueing functions
76 * (eg. io_read, io_write) and return the next function to call once
77 * that is done using io_next(). The alternative is to call io_close().
79 * Returns NULL on error (and sets errno).
81 #define io_new_conn(fd, start, finish, arg) \
83 typesafe_cb_preargs(struct io_plan, void *, \
84 (start), (arg), struct io_conn *), \
85 typesafe_cb_preargs(void, void *, (finish), (arg), \
88 struct io_conn *io_new_conn_(int fd,
89 struct io_plan (*start)(struct io_conn *, void *),
90 void (*finish)(struct io_conn *, void *),
94 * io_new_listener - create a new accepting listener.
95 * @fd: the file descriptor.
96 * @init: the function to call for a new connection
97 * @arg: the argument to @init.
99 * When @fd becomes readable, we accept() and pass that fd to init().
101 * Returns NULL on error (and sets errno).
103 #define io_new_listener(fd, init, arg) \
104 io_new_listener_((fd), \
105 typesafe_cb_preargs(void, void *, \
109 struct io_listener *io_new_listener_(int fd,
110 void (*init)(int fd, void *arg),
114 * io_close_listener - delete a listener.
115 * @listener: the listener returned from io_new_listener.
117 * This closes the fd and frees @listener.
119 void io_close_listener(struct io_listener *listener);
122 * io_write - queue data to be written.
123 * @data: the data buffer.
124 * @len: the length to write.
125 * @cb: function to call once it's done.
128 * This will queue the data buffer for writing. Once it's all
129 * written, the @cb function will be called: on an error, the finish
130 * function is called instead.
132 * Note that the I/O may actually be done immediately.
134 #define io_write(data, len, cb, arg) \
135 io_write_((data), (len), \
136 typesafe_cb_preargs(struct io_plan, void *, \
137 (cb), (arg), struct io_conn *), \
139 struct io_plan io_write_(const void *data, size_t len,
140 struct io_plan (*cb)(struct io_conn *, void *),
144 * io_read - queue buffer to be read.
145 * @data: the data buffer.
146 * @len: the length to read.
147 * @cb: function to call once it's done.
150 * This will queue the data buffer for reading. Once it's all read,
151 * the @cb function will be called: on an error, the finish function
154 * Note that the I/O may actually be done immediately.
156 #define io_read(data, len, cb, arg) \
157 io_read_((data), (len), \
158 typesafe_cb_preargs(struct io_plan, void *, \
159 (cb), (arg), struct io_conn *), \
161 struct io_plan io_read_(void *data, size_t len,
162 struct io_plan (*cb)(struct io_conn *, void *),
167 * io_read_partial - queue buffer to be read (partial OK).
168 * @data: the data buffer.
169 * @len: the maximum length to read, set to the length actually read.
170 * @cb: function to call once it's done.
173 * This will queue the data buffer for reading. Once any data is
174 * read, @len is updated and the @cb function will be called: on an
175 * error, the finish function is called instead.
177 * Note that the I/O may actually be done immediately.
179 #define io_read_partial(data, len, cb, arg) \
180 io_read_partial_((data), (len), \
181 typesafe_cb_preargs(struct io_plan, void *, \
182 (cb), (arg), struct io_conn *), \
184 struct io_plan io_read_partial_(void *data, size_t *len,
185 struct io_plan (*cb)(struct io_conn *, void *),
189 * io_write_partial - queue data to be written (partial OK).
190 * @data: the data buffer.
191 * @len: the maximum length to write, set to the length actually written.
192 * @cb: function to call once it's done.
195 * This will queue the data buffer for writing. Once any data is
196 * written, @len is updated and the @cb function will be called: on an
197 * error, the finish function is called instead.
199 * Note that the I/O may actually be done immediately.
201 #define io_write_partial(data, len, cb, arg) \
202 io_write_partial_((data), (len), \
203 typesafe_cb_preargs(struct io_plan, void *, \
204 (cb), (arg), struct io_conn *), \
206 struct io_plan io_write_partial_(const void *data, size_t *len,
207 struct io_plan (*cb)(struct io_conn *, void*),
212 * io_idle - explicitly note that this connection will do nothing.
214 * This indicates the connection is idle: some other function will
215 * later call io_read/io_write etc. (or io_close) on it, in which case
218 struct io_plan io_idle(void);
221 * io_timeout - set timeout function if the callback doesn't fire.
222 * @conn: the current connection.
223 * @ts: how long until the timeout should be called.
225 * @arg: argument to @cb.
227 * If the usual next callback is not called for this connection before @ts,
228 * this function will be called. If next callback is called, the timeout
229 * is automatically removed.
231 * Returns false on allocation failure. A connection can only have one
234 #define io_timeout(conn, ts, fn, arg) \
235 io_timeout_((conn), (ts), \
236 typesafe_cb_preargs(struct io_plan, void *, \
240 bool io_timeout_(struct io_conn *conn, struct timespec ts,
241 struct io_plan (*fn)(struct io_conn *, void *), void *arg);
244 * io_duplex - split an fd into two connections.
245 * @conn: a connection.
246 * @start: the first function to call.
247 * @finish: the function to call when it's closed or fails.
248 * @arg: the argument to both @start and @finish.
250 * Sometimes you want to be able to simultaneously read and write on a
251 * single fd, but io forces a linear call sequence. The solition is
252 * to have two connections for the same fd, and use one for read
253 * operations and one for write.
255 * You must io_close() both of them to close the fd.
257 #define io_duplex(conn, start, finish, arg) \
259 typesafe_cb_preargs(struct io_plan, void *, \
260 (start), (arg), struct io_conn *), \
261 typesafe_cb_preargs(void, void *, (finish), (arg), \
265 struct io_conn *io_duplex_(struct io_conn *conn,
266 struct io_plan (*start)(struct io_conn *, void *),
267 void (*finish)(struct io_conn *, void *),
271 * io_wake - wake up and idle connection.
272 * @conn: an idle connection.
273 * @fn: the next function to call once queued IO is complete.
274 * @arg: the argument to @next.
276 * This makes @conn run its @next function the next time around the
279 #define io_wake(conn, fn, arg) \
281 typesafe_cb_preargs(struct io_plan, void *, \
282 (fn), (arg), struct io_conn *), \
284 void io_wake_(struct io_conn *conn,
285 struct io_plan (*fn)(struct io_conn *, void *), void *arg);
288 * io_break - return from io_loop()
289 * @ret: non-NULL value to return from io_loop().
290 * @cb: function to call once on return
293 * This breaks out of the io_loop. As soon as the current @next
294 * function returns, any io_closed()'d connections will have their
295 * finish callbacks called, then io_loop() with return with @ret.
297 * If io_loop() is called again, then @cb will be called.
299 #define io_break(ret, fn, arg) \
301 typesafe_cb_preargs(struct io_plan, void *, \
302 (fn), (arg), struct io_conn *), \
304 struct io_plan io_break_(void *ret,
305 struct io_plan (*fn)(struct io_conn *, void *),
308 /* FIXME: io_recvfrom/io_sendto */
311 * io_close - terminate a connection.
312 * @conn: any connection.
314 * The schedules a connection to be closed. It can be done on any
315 * connection, whether it has I/O queued or not (though that I/O may
316 * be performed first).
318 * It's common to 'return io_close(...)' from a @next function, but
319 * io_close can also be used as an argument to io_next().
321 struct io_plan io_close(struct io_conn *, void *unused);
324 * io_loop - process fds until all closed on io_break.
326 * This is the core loop; it exits with the io_break() arg, or NULL if
327 * all connections and listeners are closed.
330 #endif /* CCAN_IO_H */