| … | |
… | |
| 411 | make libev check for a fork in each iteration by enabling this flag. |
411 | make libev check for a fork in each iteration by enabling this flag. |
| 412 | |
412 | |
| 413 | This works by calling C<getpid ()> on every iteration of the loop, |
413 | This works by calling C<getpid ()> on every iteration of the loop, |
| 414 | and thus this might slow down your event loop if you do a lot of loop |
414 | and thus this might slow down your event loop if you do a lot of loop |
| 415 | iterations and little real work, but is usually not noticeable (on my |
415 | iterations and little real work, but is usually not noticeable (on my |
| 416 | GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence |
416 | GNU/Linux system for example, C<getpid> is actually a simple 5-insn |
| 417 | without a system call and thus I<very> fast, but my GNU/Linux system also has |
417 | sequence without a system call and thus I<very> fast, but my GNU/Linux |
| 418 | C<pthread_atfork> which is even faster). |
418 | system also has C<pthread_atfork> which is even faster). (Update: glibc |
|
|
419 | versions 2.25 apparently removed the C<getpid> optimisation again). |
| 419 | |
420 | |
| 420 | The big advantage of this flag is that you can forget about fork (and |
421 | The big advantage of this flag is that you can forget about fork (and |
| 421 | forget about forgetting to tell libev about forking, although you still |
422 | forget about forgetting to tell libev about forking, although you still |
| 422 | have to ignore C<SIGPIPE>) when you use this flag. |
423 | have to ignore C<SIGPIPE>) when you use this flag. |
| 423 | |
424 | |
| … | |
… | |
| 2113 | |
2114 | |
| 2114 | =item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat) |
2115 | =item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat) |
| 2115 | |
2116 | |
| 2116 | =item ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat) |
2117 | =item ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat) |
| 2117 | |
2118 | |
| 2118 | Configure the timer to trigger after C<after> seconds. If C<repeat> |
2119 | Configure the timer to trigger after C<after> seconds (fractional and |
| 2119 | is C<0.>, then it will automatically be stopped once the timeout is |
2120 | negative values are supported). If C<repeat> is C<0.>, then it will |
| 2120 | reached. If it is positive, then the timer will automatically be |
2121 | automatically be stopped once the timeout is reached. If it is positive, |
| 2121 | configured to trigger again C<repeat> seconds later, again, and again, |
2122 | then the timer will automatically be configured to trigger again C<repeat> |
| 2122 | until stopped manually. |
2123 | seconds later, again, and again, until stopped manually. |
| 2123 | |
2124 | |
| 2124 | The timer itself will do a best-effort at avoiding drift, that is, if |
2125 | The timer itself will do a best-effort at avoiding drift, that is, if |
| 2125 | you configure a timer to trigger every 10 seconds, then it will normally |
2126 | you configure a timer to trigger every 10 seconds, then it will normally |
| 2126 | trigger at exactly 10 second intervals. If, however, your program cannot |
2127 | trigger at exactly 10 second intervals. If, however, your program cannot |
| 2127 | keep up with the timer (because it takes longer than those 10 seconds to |
2128 | keep up with the timer (because it takes longer than those 10 seconds to |
| … | |
… | |
| 3517 | |
3518 | |
| 3518 | There are some other functions of possible interest. Described. Here. Now. |
3519 | There are some other functions of possible interest. Described. Here. Now. |
| 3519 | |
3520 | |
| 3520 | =over 4 |
3521 | =over 4 |
| 3521 | |
3522 | |
| 3522 | =item ev_once (loop, int fd, int events, ev_tstamp timeout, callback) |
3523 | =item ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg) |
| 3523 | |
3524 | |
| 3524 | This function combines a simple timer and an I/O watcher, calls your |
3525 | This function combines a simple timer and an I/O watcher, calls your |
| 3525 | callback on whichever event happens first and automatically stops both |
3526 | callback on whichever event happens first and automatically stops both |
| 3526 | watchers. This is useful if you want to wait for a single event on an fd |
3527 | watchers. This is useful if you want to wait for a single event on an fd |
| 3527 | or timeout without having to allocate/configure/start/stop/free one or |
3528 | or timeout without having to allocate/configure/start/stop/free one or |
