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.IX Title "RWLock 3pm"
.TH RWLock 3pm 2024-03-07 "perl v5.38.2" "User Contributed Perl Documentation"
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.SH NAME
Coro::RWLock \- reader/write locks
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\& 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) {
\&    ...;
\&    $l\->unlock;
\& }
\&
\& # try a write lock
\& if ($lck\->trywrlock) {
\&    ...;
\&    $l\->unlock;
\& }
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
This module implements reader/write locks. A read can be acquired for
read by many coroutines in parallel as long as no writer has locked it
(shared access). A single write lock can be acquired when no readers
exist. RWLocks basically allow many concurrent readers (without writers)
OR a single writer (but no readers).
.PP
You don't have to load \f(CW\*(C`Coro::RWLock\*(C'\fR manually, it will be loaded
automatically when you \f(CW\*(C`use Coro\*(C'\fR and call the \f(CW\*(C`new\*(C'\fR constructor.
.ie n .IP "$l = new Coro::RWLock;" 4
.el .IP "\f(CW$l\fR = new Coro::RWLock;" 4
.IX Item "$l = new Coro::RWLock;"
Create a new reader/writer lock.
.ie n .IP $l\->rdlock 4
.el .IP \f(CW$l\fR\->rdlock 4
.IX Item "$l->rdlock"
Acquire a read lock.
.ie n .IP $l\->tryrdlock 4
.el .IP \f(CW$l\fR\->tryrdlock 4
.IX Item "$l->tryrdlock"
Try to acquire a read lock.
.ie n .IP $l\->wrlock 4
.el .IP \f(CW$l\fR\->wrlock 4
.IX Item "$l->wrlock"
Acquire a write lock.
.ie n .IP $l\->trywrlock 4
.el .IP \f(CW$l\fR\->trywrlock 4
.IX Item "$l->trywrlock"
Try to acquire a write lock.
.ie n .IP $l\->unlock 4
.el .IP \f(CW$l\fR\->unlock 4
.IX Item "$l->unlock"
Give up a previous \f(CW\*(C`rdlock\*(C'\fR or \f(CW\*(C`wrlock\*(C'\fR.
.SH AUTHOR/SUPPORT/CONTACT
.IX Header "AUTHOR/SUPPORT/CONTACT"
.Vb 2
\&   Marc A. Lehmann <schmorp@schmorp.de>
\&   http://software.schmorp.de/pkg/Coro.html
.Ve