An exclusive control system provided in a system having a memory module and a plurality of processing modules sharing said memory module, each of said plurality of processing modules exclusively accessing said memory module while prohibiting other processing modules from accessing said memory module, said exclusive control system comprising:
- determination means for determining whether or not a process executed in response to an access request from a processing module, among said plurality of processing modules, is normally completed in said memory module;
- and
- retry means, responsive to a determination by said determination means that the process executed in response to the access request is not normally completed, for retrying the process while maintaining a state in which other processing modules are prohibited from accessing said memory module.