Method and apparatus for serializing access to multithreading unsafe resources

A computer-implemented method for synchronizing multithreaded processes so that multiple threads can safely access a multithreading unsafe algorithm, said method comprising the computer-implemented steps of:

• (a) creating baton objects for each thread desiring access to a multithreading unsafe algorithm, each of the baton objects contending for a baton associated with the multithreading unsafe algorithm;
• (b) before one of the threads calls the multithreading unsafe algorithm, requiring the baton object associated with the one of the threads to grab the baton associated with the multithreading unsafe algorithm;
• (c) subsequent to said requiring step (b), permitting the thread associated with the baton object holding the baton to call the multithreading unsafe algorithm, wherein the multithreading unsafe algorithm may only be called by a particular thread when such thread's associated baton object holds the baton;
• (d) returning from the multithreading unsafe algorithm;
• and
• (e) subsequent to said returning step (d), releasing the baton from the baton object that grabbed the baton in step (b);
• and
• whereby when a particular baton object holds the baton, other baton objects are prevented from holding the baton and the threads associated with the baton object that are prevented from holding the baton are prevented from accessing the multithreading unsafe algorithm.

An apparatus for serializing access to a multithreading unsafe resource, said apparatus comprising:

• executable computer code including access requests to the multithreading unsafe resource;
• a computer system and an operating system which both support multithreading, said computer system in conjunction with said operating system being arranged to execute said executable computer code in a multithreaded manner;
• and
• a baton manager, operatively connected to said computer system and said operating system and the multithreading unsafe resource, for serializing access of the multithreading unsafe resource by said computer system and said operating system during the execution of said executable computer code so that at any given point in time only a single thread accesses the multithreading unsafe resource, wherein said baton manager uses at least one baton object to manage ownership of a mutually exclusive lock, the baton objects being associated with at most one thread and the mutually exclusive lock being arranged to insure that the accesses to the multithreading unsafe resource are serialized.

A computer program product, comprising:

• a computer usable medium having computer readable code embodied therein for serializing access to multithreading unsafe resources, and wherein said computer readable code comprises:
• first computer readable program code devices configured to cause a computer to effect creating a baton object associated with at most one thread, the baton object being configured to facilitate accessing a multithreading unsafe resource wherein the multithreading unsafe resource may only be accessed by the thread associated with the baton object when the baton object holds the baton;
• second computer readable program code devices configured to cause a computer to effect grabbing a baton by the baton object before accessing the multithreading unsafe resource;
• third computer readable program code devices configured to cause a computer to effect accessing the multithreading unsafe resource;
• and
• fourth computer readable program code devices configured to cause a computer to effect releasing the baton from the baton object after the accessing of the multithreading unsafe resource is complete;
• and
• whereby when the baton object holds the baton, threads not associated with the baton object are prevented from accessing the multithreading unsafe resource.