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<title>Thread safety</title>
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<h1>The XML C library for Gnome</h1>
<h2>Thread safety</h2>
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<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
threads can safely work in parallel parsing different documents. There is
however a couple of things to do to ensure it:</p>
<ul>
<li>configure the library accordingly using the --with-threads options</li>
  <li>call xmlInitParser() in the &quot;main&quot; thread before using any of the
    libxml API (except possibly selecting a different memory allocator)</li>
</ul>
<p>Note that the thread safety cannot be ensured for multiple threads sharing
the same document, the locking must be done at the application level, libxml
exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
The parts of the library checked for thread safety are:</p>
<ul>
<li>concurrent loading</li>
  <li>file access resolution</li>
  <li>catalog access</li>
  <li>catalog building</li>
  <li>entities lookup/accesses</li>
  <li>validation</li>
  <li>global variables per-thread override</li>
  <li>memory handling</li>
</ul>
<p>XPath is supposed to be thread safe now, but this wasn't tested
seriously.</p>
<p><a href="bugs.html">Daniel Veillard</a></p>
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