Abstract: One embodiment of the present invention provides a system that supports recovery in the event a previous process holding a lock used for mutual exclusion purposes loses ownership of the lock. This loss of ownership may occur due to the previous process dying or the lock becoming unmapped. Under the present invention a process first attempts to acquire the lock. If the attempt to acquire the lock returns with an error indicating that the previous process holding the lock lost ownership of the lock, the process attempts to make program state protected by the lock consistent. If the attempt to make the program state consistent is successful, the system reinitializes and unlocks the lock. Otherwise, the system marks the lock as unrecoverable so that subsequent processes attempting to acquire the lock are notified that the lock is not recoverable.

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 game board comprising a playing surface having indicia thereon defining an oval race track, with toy vehicles adapted to be moved around respective lanes of the track, and additional indicia on the playing surface for advancing vehicle positions, for indicating the number of laps completed by each vehicle, and for determining any of various troubles encountered during the race. Player-actuated wheelies, and means for launching same, cooperate with the indicia on the playing board, to determine the movement forward or backward of each vehicle, generally in response to the degree of skill of the player.