| … | |
… | |
| 338 | |
338 | |
| 339 | These functions implement the same concept as C<dynamic-wind> in scheme |
339 | These functions implement the same concept as C<dynamic-wind> in scheme |
| 340 | does, and are useful when you want to localise some resource to a specific |
340 | does, and are useful when you want to localise some resource to a specific |
| 341 | coro. |
341 | coro. |
| 342 | |
342 | |
| 343 | They slow down coro switching considerably for coros that use |
343 | They slow down thread switching considerably for coros that use them |
| 344 | them (But coro switching is still reasonably fast if the handlers are |
344 | (about 40% for a BLOCK with a single assignment, so thread switching is |
| 345 | fast). |
345 | still reasonably fast if the handlers are fast). |
| 346 | |
346 | |
| 347 | These functions are best understood by an example: The following function |
347 | These functions are best understood by an example: The following function |
| 348 | will change the current timezone to "Antarctica/South_Pole", which |
348 | will change the current timezone to "Antarctica/South_Pole", which |
| 349 | requires a call to C<tzset>, but by using C<on_enter> and C<on_leave>, |
349 | requires a call to C<tzset>, but by using C<on_enter> and C<on_leave>, |
| 350 | which remember/change the current timezone and restore the previous |
350 | which remember/change the current timezone and restore the previous |
| … | |
… | |
| 373 | }; |
373 | }; |
| 374 | |
374 | |
| 375 | This can be used to localise about any resource (locale, uid, current |
375 | This can be used to localise about any resource (locale, uid, current |
| 376 | working directory etc.) to a block, despite the existance of other |
376 | working directory etc.) to a block, despite the existance of other |
| 377 | coros. |
377 | coros. |
|
|
378 | |
|
|
379 | Another interesting example implements time-sliced multitasking using |
|
|
380 | interval timers (this could obviously be optimised, but does the job): |
|
|
381 | |
|
|
382 | # "timeslice" the given block |
|
|
383 | sub timeslice(&) { |
|
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384 | use Time::HiRes (); |
|
|
385 | |
|
|
386 | Coro::on_enter { |
|
|
387 | # on entering the thread, we set an VTALRM handler to cede |
|
|
388 | $SIG{VTALRM} = sub { cede }; |
|
|
389 | # and then start the interval timer |
|
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390 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01; |
|
|
391 | }; |
|
|
392 | Coro::on_leave { |
|
|
393 | # on leaving the thread, we stop the interval timer again |
|
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394 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0; |
|
|
395 | }; |
|
|
396 | |
|
|
397 | &{+shift}; |
|
|
398 | } |
|
|
399 | |
|
|
400 | # use like this: |
|
|
401 | timeslice { |
|
|
402 | # The following is an endless loop that would normally |
|
|
403 | # monopolise the process. Since it runs in a timesliced |
|
|
404 | # environment, it will regularly cede to other threads. |
|
|
405 | while () { } |
|
|
406 | }; |
|
|
407 | |
| 378 | |
408 | |
| 379 | =item killall |
409 | =item killall |
| 380 | |
410 | |
| 381 | Kills/terminates/cancels all coros except the currently running one. |
411 | Kills/terminates/cancels all coros except the currently running one. |
| 382 | |
412 | |
