$Id: README,v 1.2 2001/06/29 02:11:49 af Exp $ ======================================================================== Thread::RWLock is Copyright (c) 2001 Andreas Ferber 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