### E.17 Thread List Format

To efficiently update the list of threads and their attributes, gdb issues the ‘`qXfer:threads:read`’ packet (see qXfer threads read) and obtains the XML document with the following structure:

         <?xml version="1.0"?>
         <threads>
             <thread id="id" core="0">
             ... description ...
             </thread>
         </threads>

Each ‘`thread`’ element must have the ‘`id`’ attribute that identifies the thread (see thread-id syntax). The ‘`core`’ attribute, if present, specifies which processor core the thread was last executing on. The content of the of ‘`thread`’ element is interpreted as human-readable auxilliary information.