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RWLock(3pm) User Contributed Perl Documentation RWLock(3pm)


Coro::RWLock - reader/write locks


 use Coro;
 $lck = new Coro::RWLock;
 $lck->rdlock; # acquire read lock
 $lck->unlock; # unlock lock again
 # or:
 $lck->wrlock; # acquire write lock
 $lck->unlock; # unlock lock again
 # try a readlock
 if ($lck->tryrdlock) {
 # try a write lock
 if ($lck->trywrlock) {


This module implements reader/write locks. A read can be acquired for read by many coroutines in parallel as long as no writer has locked it (shared access). A single write lock can be acquired when no readers exist. RWLocks basically allow many concurrent readers (without writers) OR a single writer (but no readers).

You don't have to load "Coro::RWLock" manually, it will be loaded automatically when you "use Coro" and call the "new" constructor.

$l = new Coro::RWLock;
Create a new reader/writer lock.
Acquire a read lock.
Try to acquire a read lock.
Acquire a write lock.
Try to acquire a write lock.
Give up a previous "rdlock" or "wrlock".


   Marc A. Lehmann <>
2020-11-09 perl v5.32.0