Abstract: The disclosed invention provides a system, method and computer program product for processing multithreaded application programs. The application threads are written using itineraries, which are lists of errands. The errands are small tasks that collectively constitute the entire thread's functionality. An itinerary is executed via an itinerary running service provided by the operating system, using the kernel stack as its execution stack. When an itinerary is encountered in a thread, the thread is preempted and the itinerary execution is taken over by the itinerary running service in itinerary mode. The thread remains preempted in normal mode until the complete itinerary has been executed. Within the itinerary mode, the errands are executed in the sequence specified by the itinerary, until an errand blocks. The itinerary is resumed from the same errand that previously blocked the thread.

Abstract: The disclosed invention provides a system, method and computer program product for minimizing thread-switching overheads and memory usage while processing multithreaded application programs. A new type of thread called a floating thread is provided. Floating threads do not require any reference information to be saved in the main memory when the thread is swapped out. A floating thread compiler is used for compiling the main level function of the floating thread. All preemptive functions are called through the main level of floating threads and thread swapping occurs across this main level only. The reference information of a preempted floating thread is minimal and can be stored in fast memory. Execution of a preempted thread resumes not from the point of preemption but at the start of the function that caused the thread to preempt.

Abstract: A method and system for allocating special-purpose computing resources in a multiprocessor system capable of executing a plurality of threads in a parallel manner is disclosed. A thread requesting the execution of a specific program is allocated a special-purpose processor with the requested program loaded on its local program store. The programs in the local stores of the special-purpose processors can be evicted and replaced by the requested programs, if no compatible processor is available to complete a request. The thread relinquishes the control of the allocated processor once the requested process is executed. When no free processors are available, the pending threads are blocked and added to a request-queue. As soon as a processor becomes free, it is allocated to one of the pending threads in a first-in-first-out manner, with special priority given to a thread requesting a program already loaded on the processor.