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 <>