Arbortext Publishing Engine Programmer's Guide (Guide de programmeur d'Arbortext Publishing Engine) > The Arbortext Publishing Engine Request Manager > Understanding the Internal Structure of Arbortext PE Request Manager > Sous-processus Arbortext PE Pool Management > Communicating with Sous-processus Arbortext PE
  
Communicating with Sous-processus Arbortext PE
When com.arbortext.e3.E3RequestContext.allocateE3Subprocess allocates an Sous-processus Arbortext PE, it returns a reference to an object that implements the com.arbortext.e3.E3Subprocess interface. This interface has three methods.
• deallocate returns the Sous-processus Arbortext PE to its pool for allocation to another request.
• executeCommand(String cmd) method passes the ACL command cmd to the Sous-processus Arbortext PE for execution by the ACL command interpreter. This method does not return a value, but it will throw an exception if execution fails.
• evaluateFunction(String function) method passes the ACL expression function, to the Sous-processus Arbortext PE for evaluation. This method returns a string containing the result of the function. The function must include a function name (including package name, if appropriate), parentheses, and parameters, all expressed as strings.