$Id: README,v 1.2 2001/06/29 02:11:49 af Exp $
========================================================================
Thread::RWLock is Copyright (c) 2001 Andreas Ferber <
[email protected]>
It can be redistributed or modified under the same terms as Perl itself.
========================================================================
for more information:
perldoc Thread::RWLock
NAME
Thread::RWLock - rwlock implementation for perl threads
SYNOPSIS
use Thread::RWLock;
my $rwlock = new Thread::RWLock;
# Reader
$rwlock->down_read;
$rwlock->up_read;
# Writer
$rwlock->down_write;
$rwlock->up_write;
DESCRIPTION
RWLocks provide a mechanism to regulate access to resources. Multiple
concurrent reader may hold the rwlock at the same time, while a writer
holds the lock exclusively.
New reader threads are blocked if any writer are currently waiting to
obtain the lock. The read lock gets through after all write lock
requests have completed.
This RWLock implementation also takes into account that one thread may
obtain multiple readlocks at the same time and prevents deadlocking in
this case.
FUNCTIONS AND METHODS
new `new' creates a new rwlock. The new rwlock is unlocked.
down_read
The `down_read' method obtains a read lock. If the lock is
currantly held by a writer or writer are waiting for the lock,
`down_read' blocks until the lock is available.
up_read Releases a read lock previously obtained via `down_read'.
down_write
Obtains a write lock from the rwlock. Write locks are exclusive,
so no other reader or writer are allowed until the lock is
released. `down_write' blocks until the lock is available.
up_write
Release a write lock previously obtained via `down_write'.
SEE ALSO
the Thread::Semaphore manpage
AUTHOR
Andreas Ferber <
[email protected]>
