The DHCP server implements multithreading, which enables it to service many clients simultaneously. Public modules are required to be MT-SAFE to support multithreading by the DHCP server.
To make your module MT-SAFE, you must synchronize calls to add_d?(), delete_d?(), and modify_d?() so that they are called serially. For example, if one thread is inside add_dn() for a given DHCP network container, no other thread may be inside add_dn(), delete_dn(), modify_dn(), or lookup_dn() for that same container. If your public module supports a local file-system-based data service, you can use the synchronization service to take care of this for you. See Synchronizing Access to File-System-Based Containers for more information.