Patent ID: 7735082

Claim:
A task management system in an operating system for executing a plurality of tasks in parallel, comprising: a processor including, an execution standby state changer configured to generate a first verifier of a task from data stored in a task address space and to store the generated first verifier in a verifier storage area when the task is changed from an executed state to an execution standby state; an executed state changer configured to change the task from the execution standby state to the executed state without a verification by using the first verifier of the task stored in the verifier storage area; an access detector configured to detect an access to data stored in a predetermined address range of a task address space of a verification target task which is changed to the executed state by the executed state changer; and a verifying unit configured to generate a second verifier of the verification target task from the data which is accessed and to verify matching of the second verifier with the first verifier of the task stored in the verifier storage area, only when access to the data of the verification target task is detected by the access detector; and a storage unit configured to store the task address space and the verifier storage area, wherein the verifier storage area is configured to store a record to associate a predetermined address range in the task address space with the first verifier of the task, and to store a record to associate the predetermined address range, the first verifier of the task, and a valid flag with one another, and the execution standby state changer is configured to update the first verifier of the task in a record in which the first verifier of the task needs to be updated, and to store the updated first verifier in the verifier storage area, and to judge that a record having a false value set in the valid flag is a record in which the first verifier of the task needs to be updated, to update the first verifier of the task in the record, and to store the updated first verifier in the verifier storage area.