Apparatus and method for processing events in a digital versatile disc (DVD) system using system threads and separate dormant/awake counter threads and clock driven semaphores

A method of managing digital versatile disc system, having a system clock, a multi-threaded operating system having a semaphore with a semaphore queue and a playback program with a system program thread, the method comprising:

• A. using the system thread in cooperation with the operating system to create a single independent counter program thread in the playback program when at least one of the plurality of counters is to be utilized by the system, the counter thread exclusively controlling counters that are placed under its control and becoming dormant when created;
• B. sending commands from the system program thread to the counter program thread specifying each of the plurality of counters and causing the each counter to be placed under control of the counter program thread;
• C. inserting a message into the semaphore queue at predetermined intervals of time as determined by the system clock, whereupon the semaphore detects a message in the semaphore queue and wakes up the counter program thread;
• D. using the counter program thread, when awakened, to increment and decrement all counters under its control independently of the system program thread, the counter program thread then becoming dormant;
• and
• E. controlling the counter program thread at times when the counter program thread is not incrementing and decrementing counters under its control to another function on all of the counters under its control independently of the system program thread.

Apparatus for managing a plurality of counters in a digital versatile disc system, having a system clock, a multi-threaded operating system having a semaphore with a semaphore queue and a playback program with a system program thread, the apparatus comprising:

• a single independent counter program thread created in the playback program when at least one of the plurality of counters is to be utilized by the system, the counter thread exclusively controlling counters that are placed under its control and becoming dormant when created;
• a mechanism for sending commands from the system program thread to the counter program thread specifying each of the plurality of counters and causing the each counter to be placed under control of the counter program thread;
• a time event processor for inserting a message into the semaphore queue at predetermined intervals of time as determined by the system clock, whereupon the semaphore detects a message in the semaphore queue and wakes up the counter program thread the counter program thread thereupon incrementing and decrementing all counters under its control;
• and
• a function event processor which controls the counter program thread at times when the counter program thread is not incrementing and decrementing the counters under its control to execute a selected function on counters under its control.

A computer program product for managing a plurality of counters in a digital versatile disc system, having a system clock, a multi-threaded operating system having a semaphore with a semaphore queue and a playback program with a system program thread, the computer program product comprising a computer usable medium having computer readable program code thereon comprising:

• program code for using the system program thread in cooperation with the operating system to create a single independent counter program thread in the playback program when at least one of the plurality of counters is to be utilized by the system, the counter thread exclusively controlling counters that are placed under its control and becoming dormant when created;
• program code for sending commands from the system program thread to the counter program thread specifying each of the plurality of counters and causing the each counter to be placed under control of the counter program thread;
• program code for inserting a message into the semaphore queue at predetermined intervals of time as determined by the system clock, whereupon the semaphore detects a message in the semaphore queue and wakes up the counter program thread;
• program code for using the counter program thread, when awakened, to increment and decrement all counters under its control independently of the system program thread, the counter program thread then becoming dormant;
• and
• program code for controlling the counter program thread at times when the counter program thread is not incrementing and decrementing counters under its control to execute another function on the counters under its control.

A computer data signal embodied in a carrier wave for managing a plurality of counters in a digital versatile disc system, having a system clock, a multi-threaded operating system having a semaphore with a semaphore queue and a playback program with a system program thread, the computer data signal comprising:

• program code for using the system program thread in cooperation with the operating system to create a single independent counter program thread in the playback program when at least one of the plurality of counters is to be utilized by the system, the counter thread exclusively controlling counters that are placed under its control and becoming dormant when created;
• program code for sending commands from the system program thread to the counter program thread specifying each of the plurality of counters and causing the each counter to be placed under control of the counter program thread;
• program code for inserting a message into the semaphore queue at predetermined intervals of time as determined by the system clock, whereupon the semaphore detects a message in the semaphore queue and wakes up the counter program thread;
• program code for using the counter program thread, when awakened, to increment and decrement all counters under its control independently of the system program thread, the counter program thread then becoming dormant;
• and
• program code for controlling the counter program thread at times when the counter program thread is not incrementing and decrementing counters under its control to execute another function on the counters under its control.