http://code.activestate.com/recipes/tags/locking-lock/2011-09-28T21:45:04-07:00ActiveState Code Recipes2011-09-28T21:45:04-07:00Mateusz Koboshttp://code.activestate.com/recipes/users/4178730/http://code.activestate.com/recipes/577803-reader-writer-lock-with-priority-for-writers/

<p style="color: grey"> Python recipe 577803 by <a href="/recipes/users/4178730/">Mateusz Kobos</a> (<a href="/recipes/tags/locking/">locking</a>, <a href="/recipes/tags/threads/">threads</a>). Revision 2. </p> <p>The following class implements a reader-writer lock to use in the second readers-writers problem with python threads. In this problem, many readers can simultaneously access a share, and a writer has an exclusive access to this share. Additionally, the following constraints should be met: 1) no reader should be kept waiting if the share is currently opened for reading unless a writer is also waiting for the share, 2) no writer should be kept waiting for the share longer than absolutely necessary.</p>

2009-08-22T13:00:35-07:00Max Polkhttp://code.activestate.com/recipes/users/4171523/http://code.activestate.com/recipes/576891-application-lock/

<p style="color: grey"> Python recipe 576891 by <a href="/recipes/users/4171523/">Max Polk</a> (<a href="/recipes/tags/file_lock/">file_lock</a>, <a href="/recipes/tags/locking/">locking</a>). </p> <p>Ensures application runs only once.</p>

2008-12-21T05:50:07-08:00Michael Ihdehttp://code.activestate.com/recipes/users/4168518/http://code.activestate.com/recipes/576591-simple-shelve-with-linux-file-locking/

<p style="color: grey"> Python recipe 576591 by <a href="/recipes/users/4168518/">Michael Ihde</a> (<a href="/recipes/tags/dynamic_method/">dynamic_method</a>, <a href="/recipes/tags/locking/">locking</a>, <a href="/recipes/tags/shelve/">shelve</a>). </p> <p>The shelve module is a easy way to add persistence to your application via a DBM database. However, if you have multiple reader/writer combination you need to lock the file to prevent corruption. The shelve module itself does not provide locking because it is platform specific. If you only need Linux, this simple module provide an easy way to support locking using dynamically added methods.</p>