Starting with 2.4.7, libxml2 makes provisions to ensure
thatconcurrentthreads can safely work in parallel parsing different
documents.There ishowever a couple of things to do to ensure it: - configure the library accordingly using the --with-threads options
- call xmlInitParser() in the "main" thread before using any ofthelibxml2
API (except possibly selecting a different memoryallocator)
Note that the thread safety cannot be ensured for multiple
threadssharingthe same document, the locking must be done at the application
level,libxmlexports a basic mutex and reentrant mutexes API
in<libxml/threads.h>.The parts of the library checked for thread
safetyare: - concurrent loading
- file access resolution
- catalog access
- catalog building
- entities lookup/accesses
- validation
- global variables per-thread override
- memory handling
XPath is supposed to be thread safe now, but this
wasn'ttestedseriously. Daniel Veillard | 
