mdw@git.distorted.org.uk Git - disorder/blob - lib/event.h

   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 typedef int ev_error_callback(ev_source *ev,
 166                               int fd,
 167                               int errno_value,
 168                               void *u);
 169 /* called when an error occurs on a writer.  Called with @errno_value@
 170  * of 0 when finished. */
 171
 172 ev_writer *ev_writer_new(ev_source *ev,
 173                          int fd,
 174                          ev_error_callback *callback,
 175                          void *u,
 176                          const char *what);
 177 /* create a new buffered writer, writing to @fd@.  Calls @error@ if an
 178  * error occurs. */
 179
 180 int ev_writer_close(ev_writer *w);
 181 /* close a writer (i.e. promise not to write to it any more) */
 182
 183 int ev_writer_cancel(ev_writer *w);
 184 /* cancel a writer */
 185
 186 int ev_writer_flush(ev_writer *w);
 187 /* attempt to flush the buffer */
 188
 189 struct sink *ev_writer_sink(ev_writer *w) attribute((const));
 190 /* return a sink for the writer - use this to actually write to it */
 191
 192 /* buffered reader ************************************************************/
 193
 194 typedef struct ev_reader ev_reader;
 195
 196 typedef int ev_reader_callback(ev_source *ev,
 197                                ev_reader *reader,
 198                                int fd,
 199                                void *ptr,
 200                                size_t bytes,
 201                                int eof,
 202                                void *u);
 203 /* Called when data is read or an error occurs.  @ptr@ and @bytes@
 204  * indicate the amount of data available. @eof@ will be 1 at eof. */
 205
 206 ev_reader *ev_reader_new(ev_source *ev,
 207                          int fd,
 208                          ev_reader_callback *callback,
 209                          ev_error_callback *error_callback,
 210                          void *u,
 211                          const char *what);
 212 /* register a new reader.  @callback@ will be called whenever data is
 213  * available. */
 214
 215 void ev_reader_buffer(ev_reader *r, size_t nbytes);
 216 /* specify a buffer size *case */
 217
 218 void ev_reader_consume(ev_reader *r, size_t nbytes);
 219 /* consume @nbytes@ bytes. */
 220
 221 int ev_reader_cancel(ev_reader *r);
 222 /* cancel a reader */
 223
 224 int ev_reader_disable(ev_reader *r);
 225 /* disable reading */
 226
 227 int ev_reader_incomplete(ev_reader *r);
 228 /* callback didn't fully process buffer, but would like another
 229  * callback (used where processing more would block too long) */
 230
 231 int ev_reader_enable(ev_reader *r);
 232 /* enable reading.  If there is unconsumed data then you get a
 233  * callback next time round the event loop even if nothing new has
 234  * been read.
 235  *
 236  * The idea is in your read callback you come across a line (or
 237  * whatever) that can't be processed immediately.  So you set up
 238  * processing and disable reading.  Later when you finish processing
 239  * you re-enable.  You'll automatically get another callback pretty
 240  * much direct from the event loop (not from inside ev_reader_enable)
 241  * so you can handle the next line (or whatever) if the whole thing
 242  * has in fact already arrived.
 243  */
 244
 245 #endif /* EVENT_H */
 246
 247 /*
 248 Local Variables:
 249 c-basic-offset:2
 250 comment-column:40
 251 fill-column:79
 252 End:
 253 */