… | |
… | |
1222 | not exist" is signified by the C<st_nlink> field being zero (which is |
1222 | not exist" is signified by the C<st_nlink> field being zero (which is |
1223 | otherwise always forced to be at least one) and all the other fields of |
1223 | otherwise always forced to be at least one) and all the other fields of |
1224 | the stat buffer having unspecified contents. |
1224 | the stat buffer having unspecified contents. |
1225 | |
1225 | |
1226 | Since there is no standard to do this, the portable implementation simply |
1226 | Since there is no standard to do this, the portable implementation simply |
1227 | calls C<stat (2)> regulalry on the path to see if it changed somehow. You |
1227 | calls C<stat (2)> regularly on the path to see if it changed somehow. You |
1228 | can specify a recommended polling interval for this case. If you specify |
1228 | can specify a recommended polling interval for this case. If you specify |
1229 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
1229 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
1230 | unspecified default> value will be used (which you can expect to be around |
1230 | unspecified default> value will be used (which you can expect to be around |
1231 | five seconds, although this might change dynamically). Libev will also |
1231 | five seconds, although this might change dynamically). Libev will also |
1232 | impose a minimum interval which is currently around C<0.1>, but thats |
1232 | impose a minimum interval which is currently around C<0.1>, but thats |
… | |
… | |
1234 | |
1234 | |
1235 | This watcher type is not meant for massive numbers of stat watchers, |
1235 | This watcher type is not meant for massive numbers of stat watchers, |
1236 | as even with OS-supported change notifications, this can be |
1236 | as even with OS-supported change notifications, this can be |
1237 | resource-intensive. |
1237 | resource-intensive. |
1238 | |
1238 | |
1239 | At the time of this writing, no specific OS backends are implemented, but |
1239 | At the time of this writing, only the Linux inotify interface is |
1240 | if demand increases, at least a kqueue and inotify backend will be added. |
1240 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1241 | reader). Inotify will be used to give hints only and should not change the |
|
|
1242 | semantics of C<ev_stat> watchers, which means that libev sometimes needs |
|
|
1243 | to fall back to regular polling again even with inotify, but changes are |
|
|
1244 | usually detected immediately, and if the file exists there will be no |
|
|
1245 | polling. |
1241 | |
1246 | |
1242 | =over 4 |
1247 | =over 4 |
1243 | |
1248 | |
1244 | =item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) |
1249 | =item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) |
1245 | |
1250 | |