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| 2 | EV - perl interface to libev, a high performance full-featured event |
2 | EV - perl interface to libev, a high performance full-featured event |
| 3 | loop |
3 | loop |
| 4 | |
4 | |
| 5 | SYNOPSIS |
5 | SYNOPSIS |
| 6 | use EV; |
6 | use EV; |
| 7 | |
7 | |
| 8 | # TIMERS |
8 | # TIMERS |
| 9 | |
9 | |
| 10 | my $w = EV::timer 2, 0, sub { |
10 | my $w = EV::timer 2, 0, sub { |
| 11 | warn "is called after 2s"; |
11 | warn "is called after 2s"; |
| 12 | }; |
12 | }; |
| 13 | |
13 | |
| 14 | my $w = EV::timer 2, 2, sub { |
14 | my $w = EV::timer 2, 2, sub { |
| 15 | warn "is called roughly every 2s (repeat = 2)"; |
15 | warn "is called roughly every 2s (repeat = 2)"; |
| 16 | }; |
16 | }; |
| 17 | |
17 | |
| 18 | undef $w; # destroy event watcher again |
18 | undef $w; # destroy event watcher again |
| 19 | |
19 | |
| 20 | my $w = EV::periodic 0, 60, 0, sub { |
20 | my $w = EV::periodic 0, 60, 0, sub { |
| 21 | warn "is called every minute, on the minute, exactly"; |
21 | warn "is called every minute, on the minute, exactly"; |
| 22 | }; |
22 | }; |
| 23 | |
|
|
| 24 | # IO |
23 | |
| 25 | |
24 | # IO |
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|
25 | |
| 26 | my $w = EV::io *STDIN, EV::READ, sub { |
26 | my $w = EV::io *STDIN, EV::READ, sub { |
| 27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
| 28 | warn "stdin is readable, you entered: ", <STDIN>; |
28 | warn "stdin is readable, you entered: ", <STDIN>; |
| 29 | }; |
29 | }; |
| 30 | |
30 | |
| 31 | # SIGNALS |
31 | # SIGNALS |
| 32 | |
32 | |
| 33 | my $w = EV::signal 'QUIT', sub { |
33 | my $w = EV::signal 'QUIT', sub { |
| 34 | warn "sigquit received\n"; |
34 | warn "sigquit received\n"; |
| 35 | }; |
35 | }; |
| 36 | |
36 | |
| 37 | # CHILD/PID STATUS CHANGES |
37 | # CHILD/PID STATUS CHANGES |
| 38 | |
38 | |
| 39 | my $w = EV::child 666, sub { |
39 | my $w = EV::child 666, 0, sub { |
| 40 | my ($w, $revents) = @_; |
40 | my ($w, $revents) = @_; |
| 41 | my $status = $w->rstatus; |
41 | my $status = $w->rstatus; |
| 42 | }; |
42 | }; |
| 43 | |
43 | |
| 44 | # STAT CHANGES |
44 | # STAT CHANGES |
| 45 | my $w = EV::stat "/etc/passwd", 10, sub { |
45 | my $w = EV::stat "/etc/passwd", 10, sub { |
| 46 | my ($w, $revents) = @_; |
46 | my ($w, $revents) = @_; |
| 47 | warn $w->path, " has changed somehow.\n"; |
47 | warn $w->path, " has changed somehow.\n"; |
| 48 | }; |
48 | }; |
| 49 | |
49 | |
| 50 | # MAINLOOP |
50 | # MAINLOOP |
| 51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
| 52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
| 53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
| 54 | |
54 | |
| 55 | DESCRIPTION |
55 | DESCRIPTION |
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| 414 | changed by explicit date -s or other means such as ntpd). It is also |
414 | changed by explicit date -s or other means such as ntpd). It is also |
| 415 | the most complex watcher type in EV. |
415 | the most complex watcher type in EV. |
| 416 | |
416 | |
| 417 | It has three distinct "modes": |
417 | It has three distinct "modes": |
| 418 | |
418 | |
| 419 | * absolute timer ($interval = $reschedule_cb = 0) |
419 | * absolute timer ($interval = $reschedule_cb = 0) |
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|
420 | |
| 420 | This time simply fires at the wallclock time $at and doesn't |
421 | This time simply fires at the wallclock time $at and doesn't |
| 421 | repeat. It will not adjust when a time jump occurs, that is, if |
422 | repeat. It will not adjust when a time jump occurs, that is, if |
| 422 | it is to be run at January 1st 2011 then it will run when the |
423 | it is to be run at January 1st 2011 then it will run when the |
| 423 | system time reaches or surpasses this time. |
424 | system time reaches or surpasses this time. |
| 424 | |
425 | |
| 425 | * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
426 | * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
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|
427 | |
| 426 | In this mode the watcher will always be scheduled to time out at |
428 | In this mode the watcher will always be scheduled to time out at |
| 427 | the next "$at + N * $interval" time (for some integer N) and |
429 | the next "$at + N * $interval" time (for some integer N) and |
| 428 | then repeat, regardless of any time jumps. |
430 | then repeat, regardless of any time jumps. |
| 429 | |
431 | |
| 430 | This can be used to create timers that do not drift with respect |
432 | This can be used to create timers that do not drift with respect |
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| 439 | Another way to think about it (for the mathematically inclined) |
441 | Another way to think about it (for the mathematically inclined) |
| 440 | is that EV::periodic will try to run the callback in this mode |
442 | is that EV::periodic will try to run the callback in this mode |
| 441 | at the next possible time where "$time = $at (mod $interval)", |
443 | at the next possible time where "$time = $at (mod $interval)", |
| 442 | regardless of any time jumps. |
444 | regardless of any time jumps. |
| 443 | |
445 | |
| 444 | * manual reschedule mode ($reschedule_cb = coderef) |
446 | * manual reschedule mode ($reschedule_cb = coderef) |
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447 | |
| 445 | In this mode $interval and $at are both being ignored. Instead, |
448 | In this mode $interval and $at are both being ignored. Instead, |
| 446 | each time the periodic watcher gets scheduled, the reschedule |
449 | each time the periodic watcher gets scheduled, the reschedule |
| 447 | callback ($reschedule_cb) will be called with the watcher as |
450 | callback ($reschedule_cb) will be called with the watcher as |
| 448 | first, and the current time as second argument. |
451 | first, and the current time as second argument. |
| 449 | |
452 | |
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| 510 | $old_signum = $w->signal ($new_signal) |
513 | $old_signum = $w->signal ($new_signal) |
| 511 | Returns the previously set signal (always as a number not name) and |
514 | Returns the previously set signal (always as a number not name) and |
| 512 | optionally set a new one. |
515 | optionally set a new one. |
| 513 | |
516 | |
| 514 | CHILD WATCHERS - watch out for process status changes |
517 | CHILD WATCHERS - watch out for process status changes |
| 515 | $w = EV::child $pid, $callback |
518 | $w = EV::child $pid, $trace, $callback |
| 516 | $w = EV::child_ns $pid, $callback |
519 | $w = EV::child_ns $pid, $trace, $callback |
| 517 | $w = $loop->child ($pid, $callback) |
520 | $w = $loop->child ($pid, $trace, $callback) |
| 518 | $w = $loop->child_ns ($pid, $callback) |
521 | $w = $loop->child_ns ($pid, $trace, $callback) |
| 519 | Call the callback when a status change for pid $pid (or any pid if |
522 | Call the callback when a status change for pid $pid (or any pid if |
| 520 | $pid is 0) has been received. More precisely: when the process |
523 | $pid is 0) has been received (a status change happens when the |
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524 | process terminates or is killed, or, when trace is true, |
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525 | additionally when it is stopped or continued). More precisely: when |
| 521 | receives a "SIGCHLD", EV will fetch the outstanding exit/wait status |
526 | the process receives a "SIGCHLD", EV will fetch the outstanding |
| 522 | for all changed/zombie children and call the callback. |
527 | exit/wait status for all changed/zombie children and call the |
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528 | callback. |
| 523 | |
529 | |
| 524 | It is valid (and fully supported) to install a child watcher after a |
530 | It is valid (and fully supported) to install a child watcher after a |
| 525 | child has exited but before the event loop has started its next |
531 | child has exited but before the event loop has started its next |
| 526 | iteration (for example, first you "fork", then the new child process |
532 | iteration (for example, first you "fork", then the new child process |
| 527 | might exit, and only then do you install a child watcher in the |
533 | might exit, and only then do you install a child watcher in the |
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| 534 | be called. |
540 | be called. |
| 535 | |
541 | |
| 536 | The "child_ns" variant doesn't start (activate) the newly created |
542 | The "child_ns" variant doesn't start (activate) the newly created |
| 537 | watcher. |
543 | watcher. |
| 538 | |
544 | |
| 539 | $w->set ($pid) |
545 | $w->set ($pid, $trace) |
| 540 | Reconfigures the watcher, see the constructor above for details. Can |
546 | Reconfigures the watcher, see the constructor above for details. Can |
| 541 | be called at any time. |
547 | be called at any time. |
| 542 | |
548 | |
| 543 | $current_pid = $w->pid |
549 | $current_pid = $w->pid |
| 544 | $old_pid = $w->pid ($new_pid) |
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| 545 | Returns the previously set process id and optionally set a new one. |
550 | Returns the previously set process id and optionally set a new one. |
| 546 | |
551 | |
| 547 | $exit_status = $w->rstatus |
552 | $exit_status = $w->rstatus |
| 548 | Return the exit/wait status (as returned by waitpid, see the waitpid |
553 | Return the exit/wait status (as returned by waitpid, see the waitpid |
| 549 | entry in perlfunc). |
554 | entry in perlfunc). |
