Abstract: A method and apparatus for allowing a first thread to “share” its remaining time quantum with a second thread when the first thread is blocked. A thread may be blocked, for example, if it is waiting for a resource such as a data file or a lock. A thread may also be blocked if it is waiting for an event, such as a user keystroke. If there is a thread on the run queue that “owns” the resource needed by the consumer thread, the blocked consumer thread transfers its right to execute for a remaining time quantum to the owner thread, and the owner thread executes next. If the threads are in a same process, this transfer means that no process context switch is required, since the consumer thread and the owner thread are threads of the same process. In addition, this transfer means that the time before the resource becomes available to the blocked consumer thread will be short.

Abstract: A method and apparatus for implementing proportional sharing in a single processor system and/or in a multi-processor system. The invention can also implement proportional sharing in a system that executes multi-threaded computer programs. The invention uses the metaphor of "tickets." Each process in the system has a number of tickets and each ticket entitles the process to use a processor for a period of a time quantum. The operating system allocates the processor(s) first to the process with the highest number of tickets. As each process (or thread) finishes being executed for a predetermined amount of time, the tickets of that process/thread are adjusted accordingly and a new process (or thread) is chosen for execution. Tickets can be allocated to each process in the system. Alternatively, tickets can be allocated to each process and shared by all threads of the process. Alternatively, tickets can be allocated to a group of processes and shared by all processes within the group.