| … | |
… | |
| 1634 | When C<inotify (7)> support has been compiled into libev (generally only |
1634 | When C<inotify (7)> support has been compiled into libev (generally only |
| 1635 | available on Linux) and present at runtime, it will be used to speed up |
1635 | available on Linux) and present at runtime, it will be used to speed up |
| 1636 | change detection where possible. The inotify descriptor will be created lazily |
1636 | change detection where possible. The inotify descriptor will be created lazily |
| 1637 | when the first C<ev_stat> watcher is being started. |
1637 | when the first C<ev_stat> watcher is being started. |
| 1638 | |
1638 | |
| 1639 | Inotify presense does not change the semantics of C<ev_stat> watchers |
1639 | Inotify presence does not change the semantics of C<ev_stat> watchers |
| 1640 | except that changes might be detected earlier, and in some cases, to avoid |
1640 | except that changes might be detected earlier, and in some cases, to avoid |
| 1641 | making regular C<stat> calls. Even in the presense of inotify support |
1641 | making regular C<stat> calls. Even in the presence of inotify support |
| 1642 | there are many cases where libev has to resort to regular C<stat> polling. |
1642 | there are many cases where libev has to resort to regular C<stat> polling. |
| 1643 | |
1643 | |
| 1644 | (There is no support for kqueue, as apparently it cannot be used to |
1644 | (There is no support for kqueue, as apparently it cannot be used to |
| 1645 | implement this functionality, due to the requirement of having a file |
1645 | implement this functionality, due to the requirement of having a file |
| 1646 | descriptor open on the object at all times). |
1646 | descriptor open on the object at all times). |
| … | |
… | |
| 3260 | calling select (O(n²)) will likely make this unworkable. |
3260 | calling select (O(n²)) will likely make this unworkable. |
| 3261 | |
3261 | |
| 3262 | =back |
3262 | =back |
| 3263 | |
3263 | |
| 3264 | |
3264 | |
|
|
3265 | =head1 PORTABILITY REQUIREMENTS |
|
|
3266 | |
|
|
3267 | In addition to a working ISO-C implementation, libev relies on a few |
|
|
3268 | additional extensions: |
|
|
3269 | |
|
|
3270 | =over 4 |
|
|
3271 | |
|
|
3272 | =item C<sig_atomic_t volatile> must be thread-atomic as well |
|
|
3273 | |
|
|
3274 | The type C<sig_atomic_t volatile> (or whatever is defined as |
|
|
3275 | C<EV_ATOMIC_T>) must be atomic w.r.t. accesses from different |
|
|
3276 | threads. This is not part of the specification for C<sig_atomic_t>, but is |
|
|
3277 | believed to be sufficiently portable. |
|
|
3278 | |
|
|
3279 | =item C<sigprocmask> must work in a threaded environment |
|
|
3280 | |
|
|
3281 | Libev uses C<sigprocmask> to temporarily block signals. This is not |
|
|
3282 | allowed in a threaded program (C<pthread_sigmask> has to be used). Typical |
|
|
3283 | pthread implementations will either allow C<sigprocmask> in the "main |
|
|
3284 | thread" or will block signals process-wide, both behaviours would |
|
|
3285 | be compatible with libev. Interaction between C<sigprocmask> and |
|
|
3286 | C<pthread_sigmask> could complicate things, however. |
|
|
3287 | |
|
|
3288 | The most portable way to handle signals is to block signals in all threads |
|
|
3289 | except the initial one, and run the default loop in the initial thread as |
|
|
3290 | well. |
|
|
3291 | |
|
|
3292 | =back |
|
|
3293 | |
|
|
3294 | If you know of other additional requirements drop me a note. |
|
|
3295 | |
|
|
3296 | |
| 3265 | =head1 AUTHOR |
3297 | =head1 AUTHOR |
| 3266 | |
3298 | |
| 3267 | Marc Lehmann <libev@schmorp.de>. |
3299 | Marc Lehmann <libev@schmorp.de>. |
| 3268 | |
3300 | |
