| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2004, 2007 Richard Kettlewell |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| 18 | * USA |
| 19 | */ |
| 20 | |
| 21 | #ifndef EVENT_H |
| 22 | #define EVENT_H |
| 23 | |
| 24 | typedef struct ev_source ev_source; |
| 25 | |
| 26 | struct rusage; |
| 27 | struct sink; |
| 28 | |
| 29 | ev_source *ev_new(void); |
| 30 | /* create a new event loop */ |
| 31 | |
| 32 | int ev_run(ev_source *ev); |
| 33 | /* run an event loop. If any callback returns nonzero then that value |
| 34 | * is returned. If an error occurs then -1 is returned and @error@ is |
| 35 | * called. */ |
| 36 | |
| 37 | /* file descriptors ***********************************************************/ |
| 38 | |
| 39 | typedef enum { |
| 40 | ev_read, |
| 41 | ev_write, |
| 42 | ev_except, |
| 43 | |
| 44 | ev_nmodes |
| 45 | } ev_fdmode; |
| 46 | |
| 47 | typedef int ev_fd_callback(ev_source *ev, int fd, void *u); |
| 48 | /* signature for fd callback functions */ |
| 49 | |
| 50 | int ev_fd(ev_source *ev, |
| 51 | ev_fdmode mode, |
| 52 | int fd, |
| 53 | ev_fd_callback *callback, |
| 54 | void *u, |
| 55 | const char *what); |
| 56 | /* register a callback on a file descriptor */ |
| 57 | |
| 58 | int ev_fd_cancel(ev_source *ev, |
| 59 | ev_fdmode mode, |
| 60 | int fd); |
| 61 | /* cancel a callback on a file descriptor */ |
| 62 | |
| 63 | int ev_fd_disable(ev_source *ev, |
| 64 | ev_fdmode mode, |
| 65 | int fd); |
| 66 | /* temporarily disable callbacks on a file descriptor */ |
| 67 | |
| 68 | int ev_fd_enable(ev_source *ev, |
| 69 | ev_fdmode mode, |
| 70 | int fd); |
| 71 | /* re-enable callbacks on a file descriptor */ |
| 72 | |
| 73 | void ev_report(ev_source *ev); |
| 74 | |
| 75 | /* timeouts *******************************************************************/ |
| 76 | |
| 77 | typedef int ev_timeout_callback(ev_source *ev, |
| 78 | const struct timeval *now, |
| 79 | void *u); |
| 80 | /* signature for timeout callback functions */ |
| 81 | |
| 82 | typedef void *ev_timeout_handle; |
| 83 | |
| 84 | int ev_timeout(ev_source *ev, |
| 85 | ev_timeout_handle *handlep, |
| 86 | const struct timeval *when, |
| 87 | ev_timeout_callback *callback, |
| 88 | void *u); |
| 89 | /* register a timeout callback. If @handlep@ is not a null pointer then a |
| 90 | * handle suitable for ev_timeout_cancel() below is returned through it. */ |
| 91 | |
| 92 | int ev_timeout_cancel(ev_source *ev, |
| 93 | ev_timeout_handle handle); |
| 94 | /* cancel a timeout callback */ |
| 95 | |
| 96 | /* signals ********************************************************************/ |
| 97 | |
| 98 | typedef int ev_signal_callback(ev_source *ev, |
| 99 | int sig, |
| 100 | void *u); |
| 101 | /* signature for signal callback functions */ |
| 102 | |
| 103 | int ev_signal(ev_source *ev, |
| 104 | int sig, |
| 105 | ev_signal_callback *callback, |
| 106 | void *u); |
| 107 | /* register a signal callback */ |
| 108 | |
| 109 | int ev_signal_cancel(ev_source *ev, |
| 110 | int sig); |
| 111 | /* cancel a signal callback */ |
| 112 | |
| 113 | void ev_signal_atfork(ev_source *ev); |
| 114 | /* unhandle and unblock handled signals - call after calling fork and |
| 115 | * then setting @exitfn@ */ |
| 116 | |
| 117 | /* child processes ************************************************************/ |
| 118 | |
| 119 | typedef int ev_child_callback(ev_source *ev, |
| 120 | pid_t pid, |
| 121 | int status, |
| 122 | const struct rusage *rusage, |
| 123 | void *u); |
| 124 | /* signature for child wait callbacks */ |
| 125 | |
| 126 | int ev_child_setup(ev_source *ev); |
| 127 | /* must be called exactly once before @ev_child@ */ |
| 128 | |
| 129 | int ev_child(ev_source *ev, |
| 130 | pid_t pid, |
| 131 | int options, |
| 132 | ev_child_callback *callback, |
| 133 | void *u); |
| 134 | /* register a child callback. @options@ must be 0 or WUNTRACED. */ |
| 135 | |
| 136 | int ev_child_cancel(ev_source *ev, |
| 137 | pid_t pid); |
| 138 | /* cancel a child callback. */ |
| 139 | |
| 140 | /* socket listeners ***********************************************************/ |
| 141 | |
| 142 | typedef int ev_listen_callback(ev_source *ev, |
| 143 | int newfd, |
| 144 | const struct sockaddr *remote, |
| 145 | socklen_t rlen, |
| 146 | void *u); |
| 147 | /* callback when a connection arrives. */ |
| 148 | |
| 149 | int ev_listen(ev_source *ev, |
| 150 | int fd, |
| 151 | ev_listen_callback *callback, |
| 152 | void *u, |
| 153 | const char *what); |
| 154 | /* register a socket listener callback. @bind@ and @listen@ should |
| 155 | * already have been called. */ |
| 156 | |
| 157 | int ev_listen_cancel(ev_source *ev, |
| 158 | int fd); |
| 159 | /* cancel a socket listener callback */ |
| 160 | |
| 161 | /* buffered writer ************************************************************/ |
| 162 | |
| 163 | typedef struct ev_writer ev_writer; |
| 164 | |
| 165 | /** @brief Error callback for @ref ev_reader and @ref ev_writer |
| 166 | * @param ev Event loop |
| 167 | * @param errno_value Errno value (might be 0) |
| 168 | * @param u As passed to ev_writer_new() or ev_reader_new() |
| 169 | * @return 0 on success, non-0 on error |
| 170 | * |
| 171 | * This is called for a writer in the following situations: |
| 172 | * - on error, with @p errno_value != 0 |
| 173 | * - when all buffered data has been written, with @p errno_value = 0 |
| 174 | * - after called ev_writer_cancel(), with @p errno_value = 0 |
| 175 | * |
| 176 | * It is called for a reader only on error, with @p errno_value != 0. |
| 177 | */ |
| 178 | typedef int ev_error_callback(ev_source *ev, |
| 179 | int errno_value, |
| 180 | void *u); |
| 181 | |
| 182 | ev_writer *ev_writer_new(ev_source *ev, |
| 183 | int fd, |
| 184 | ev_error_callback *callback, |
| 185 | void *u, |
| 186 | const char *what); |
| 187 | /* create a new buffered writer, writing to @fd@. Calls @error@ if an |
| 188 | * error occurs. */ |
| 189 | |
| 190 | int ev_writer_time_bound(ev_writer *ev, |
| 191 | int new_time_bound); |
| 192 | int ev_writer_space_bound(ev_writer *ev, |
| 193 | int new_space_bound); |
| 194 | |
| 195 | int ev_writer_close(ev_writer *w); |
| 196 | /* close a writer (i.e. promise not to write to it any more) */ |
| 197 | |
| 198 | int ev_writer_cancel(ev_writer *w); |
| 199 | /* cancel a writer */ |
| 200 | |
| 201 | int ev_writer_flush(ev_writer *w); |
| 202 | /* attempt to flush the buffer */ |
| 203 | |
| 204 | struct sink *ev_writer_sink(ev_writer *w) attribute((const)); |
| 205 | /* return a sink for the writer - use this to actually write to it */ |
| 206 | |
| 207 | /* buffered reader ************************************************************/ |
| 208 | |
| 209 | typedef struct ev_reader ev_reader; |
| 210 | |
| 211 | /** @brief Called when data is available to read |
| 212 | * @param ev Event loop |
| 213 | * @param reader Reader |
| 214 | * @param fd File descriptor we read from |
| 215 | * @param ptr Pointer to first byte |
| 216 | * @param bytes Number of bytes available |
| 217 | * @param eof True if EOF has been detected |
| 218 | * @param u As passed to ev_reader_new() |
| 219 | * @return 0 on succes, non-0 on error |
| 220 | * |
| 221 | * This callback should call ev_reader_consume() to indicate how many bytes you |
| 222 | * actually used. If you do not call it then it is assumed no bytes were |
| 223 | * consumed. |
| 224 | * |
| 225 | * If having consumed some number of bytes it is not possible to do any further |
| 226 | * processing until more data is available then the callback can just return. |
| 227 | * Note that this is not allowed if @p eof was set. |
| 228 | * |
| 229 | * If on the other hand it would be possible to do more processing immediately |
| 230 | * with the bytes available, but this is undesirable for some other reason, |
| 231 | * then ev_reader_incomplete() should be called. This will arrange a further |
| 232 | * callback in the very near future even if no more bytes are read. |
| 233 | */ |
| 234 | typedef int ev_reader_callback(ev_source *ev, |
| 235 | ev_reader *reader, |
| 236 | void *ptr, |
| 237 | size_t bytes, |
| 238 | int eof, |
| 239 | void *u); |
| 240 | |
| 241 | ev_reader *ev_reader_new(ev_source *ev, |
| 242 | int fd, |
| 243 | ev_reader_callback *callback, |
| 244 | ev_error_callback *error_callback, |
| 245 | void *u, |
| 246 | const char *what); |
| 247 | /* register a new reader. @callback@ will be called whenever data is |
| 248 | * available. */ |
| 249 | |
| 250 | void ev_reader_buffer(ev_reader *r, size_t nbytes); |
| 251 | /* specify a buffer size */ |
| 252 | |
| 253 | void ev_reader_consume(ev_reader *r |
| 254 | , size_t nbytes); |
| 255 | /* consume @nbytes@ bytes. */ |
| 256 | |
| 257 | int ev_reader_cancel(ev_reader *r); |
| 258 | /* cancel a reader */ |
| 259 | |
| 260 | int ev_reader_disable(ev_reader *r); |
| 261 | /* disable reading */ |
| 262 | |
| 263 | int ev_reader_incomplete(ev_reader *r); |
| 264 | /* callback didn't fully process buffer, but would like another |
| 265 | * callback (used where processing more would block too long) */ |
| 266 | |
| 267 | int ev_reader_enable(ev_reader *r); |
| 268 | /* enable reading. If there is unconsumed data then you get a |
| 269 | * callback next time round the event loop even if nothing new has |
| 270 | * been read. |
| 271 | * |
| 272 | * The idea is in your read callback you come across a line (or |
| 273 | * whatever) that can't be processed immediately. So you set up |
| 274 | * processing and disable reading. Later when you finish processing |
| 275 | * you re-enable. You'll automatically get another callback pretty |
| 276 | * much direct from the event loop (not from inside ev_reader_enable) |
| 277 | * so you can handle the next line (or whatever) if the whole thing |
| 278 | * has in fact already arrived. |
| 279 | */ |
| 280 | |
| 281 | int ev_tie(ev_reader *r, ev_writer *w); |
| 282 | |
| 283 | #endif /* EVENT_H */ |
| 284 | |
| 285 | /* |
| 286 | Local Variables: |
| 287 | c-basic-offset:2 |
| 288 | comment-column:40 |
| 289 | fill-column:79 |
| 290 | End: |
| 291 | */ |