Computer memory product with preemptive multithreading software

A computer-readable memory having stored therein a multithreaded program including a plurality of sets of instruction codes with each set executable to provide a respective thread of execution of a desktop computer having a single central microprocessor, an interrupt operation, and clock means for periodically activating said interrupt operation at predetermined time intervals to provide a plurality of series of spaced timeslices of thread execution with the timeslices of each series interleaved with the timeslices of at least one other series, said plurality of sets of program instruction codes comprising

• a first set of instruction codes executable by said central microprocessor under control of the latter to provide a first thread of execution during each timeslice of a first series of said timslices,
• said first thread of execution being periodically preempted in response to activations of said interrupt operation at a frequency in the range of about every ten to thirty milliseconds,
• a second set of instruction codes responsive to said periodic activations of said interrupt operation to acquire control of said central microprocessor and said second set of instruction codes being executable by the central microprocessor to provide a second thread of execution during the timeslices of a second series of said timeslices interleaved with said first series of timeslices,
• control of the microprocessor thereby switching back and forth among the threads at a rate so rapid that the threads execute effectively simultaneously.

A computer-readable disk means encoded with a plurality of concurrently executable threads of instructions constituting a multithreaded computer application program to control the execution of a desktop microcomputer having an interrupt operation, a clock timer for periodically activating said interrupt operation, and memory means for storing a body of data, said encoded executable instructions comprising

• a first thread of instructions executable by the microcomputer and including means to process said stored body of data,
• at least a second thread of instructions for preemptively taking control of the microcomputer in response to said periodic activations of said interrupt operation by said clock timer and including means to process said stored body of data for a brief time interval after each said preemption, and
• said first thread of instructions repeatedly regaining control of the computer after each said time interval so that said first thread of instructions resumes processing said body of data at the point where it had been previously preempted,
• whereby said threads of instructions execute concurrently in a multithreaded mode of operation.

A computer software memory element encoded with a plurality of binary patterns constituting a multithreaded program having a plurality of threads of instructions executable by a computer having a single central processor, a clock-driven periodically-activated interrupt operation providing a plurality of series of spaced timeslices with the timeslices of each series interleaved with the timeslices of at least one other series, and an interrupt service routine including a thread scheduler invoked in response to each activation of said interrupt operation to determine whether a currently non-executing thread of instructions should preempt another thread of instructions then currently having control of the central processor, said multithreaded program comprising

• a first thread of instructions executable by said central processor in successive increments during each of a first series of said timeslices, and
• at least a second thread of instructions to take control of the central processor in response to determinations by said thread scheduler at each of those activations of said interrupt operation when said scheduler has determined that said second thread should preempt said first thread, so that said second thread is executed by and controls said central processor in successive increments during those second series timeslices selected by the scheduler in accordance with the respective determination at each interrupt operation,
• whereby said program controls the single central processor to execute at least two threads of instructions concurrently with the successive execution increments of a thread interleaved with the successive execution increments of at least one other thread.

A computer-readable storage means encoded with computer-executable instructions constituting a multithreaded program to control a desktop computer system having a microprocessor with an interrupt input, a memory, and clock means to periodically activate said interrupt input and thereby periodically preempt an executing thread, said program instructions comprising

• a first thread of instructions of said program executable by said microprocessor and including means to perform a first subtask,
• a second thread of instructions of the same program executable by the same microprocessor and including means to perform a second subtask, and
• means for imparting control of the microprocessor central processing unit to said first thread of instructions and thereby initiating execution of said first thread of instructions by said microprocessor,
• said second thread of instructions preempting said first thread of instructions and acquiring control of the microprocessor in response to said periodic preemptive activations of said interrupt operation by said clock means, thereby to provide periodic execution of said second thread of instructions by said microprocessor
• after each said execution of said second thread of instructions said first thread of instructions regains control of the microprocessor and resumes execution at the point where it had been previously preempted,
• said program having an address space consisting of a range of memory address locations,
• said threads having direct access to said program address space so as to provide switching of control of the microprocessor among the threads at a rate so rapid that the threads execute effectively simultaneously thereby enabling a single microprocessor to simulate the parallel processing of a large complex mainframe computer having multiple central processing units.

A computer-readable disk store encoded with a plurality of concurrently executable sequences of program instructions constituting a multithreaded computer application program to control the execution of a computer having a central processing unit including an interrupt operation, a clock timer for periodically activating said interrupt operation, and a memory for storing a body of data code, said encoded executable program instructions comprising

• at least two sequences of instructions within the same program with each sequence executed by the central processing unit to provide a respective thread of execution for processing said body of data code,
• one of said threads including means for controlling the central processing unit to process the body of data code during a first series of spaced time intervals, and
• another of said threads including means to acquire control of the central processing unit periodically in response to said periodic activations of said interrupt operation so as to provide for execution of said another thread during a second series of spaced time intervals interleaved with said first series of spaced time intervals so as to process the same body of data cede concurrently with said processing by said one thread,
• whereby said threads execute concurrently in a multithreaded mode of operation and obtain control of the same central processing unit during respective interleaved alternate time intervals.

A computer-readable storage disk encoded with executable instructions constituting operating software for preemptive multithreaded execution of a program having a plurality of concurrently executable instruction threads for processing the same body of data by a computer including a microprocessor having an interrupt operation, memory means for storing a body of data, input means for initiating execution of one of said instruction threads to process said stored body of data, and clock means for periodically activating said interrupt operation, said operating software comprising:

• first software means responsive to periodic activation of said interrupt operation to cause the microprocessor to preemptively interrupt execution of said one thread and to execute another of said threads of said program whereby said another thread processes said body of data while the body of data is stored in said memory means, and
• second software means to cause the microprocessor to discontinue execution of said another thread and to resume execution of said one thread so as to resume processing said stored body of data at the point in the body of data where said one thread was previously interrupted,
• whereby said threads of the same program execute concurrently on the same microprocessor with said clock means periodically activating said interrupt operation to cause said microprocessor to preemptively switch execution from said one thread to said another thread periodically so that the user perceives that both threads appear to be executing simultaneously to process the same body of data.

A computer-readable disk memory having a surface formed with a plurality of binary patterns constituting a multithreaded word processing program executable by a computer having a keyboard, a buffer for storing words of a language, a central processor and a clock-driven periodically-activated interrupt operation providing a plurality of series of spaced timeslices with the timeslices of each series interleaved with the timeslices of at least one other series, said multithreaded word processing program comprising

• a plurality of sets of instructions with each set executable to provide a respective thread of execution and with each thread having a respective task to perform,
• a first of said sets of instructions executable to provide a first thread of execution having control of the central processor during each successive timeslice of a first series of timeslices with successive portions of the task of said first thread performed during respective successive timeslices of said first series,
• said first set of instructions comprising lexical means for checking the spelling of words stored in said buffer,
• said first thread of execution being periodically preempted at each termination of a timeslice of said first series by said clock activation of said interrupt operation, and
• a second of said sets of instructions executable to provide a second thread of execution and responsive to said periodic preemptions to acquire control of the central processor during successive timeslices of a second series of timeslices with successive portions of the task of said second thread performed during respective succesive timeslices of said second series,
• said second set of instructions comprising editor means responsive to said keyboard for entering words into said buffer,
• whereby a preemptive multithreading mode of operation is provided for the concurrent execution of said instruction threads with said lexical means checking the spelling of said entered words in real time while concurrently therewith said editor means is entering additional words into said buffer.

A computer-readable disk memory having a surface formed with a plurality of binary patterns constituting a multithreaded application program executable by a computer having a keyboard, a buffer for storing data words, a central processor and a clock-driven periodically-activated interrupt operation providing a plurality of series of spaced timeslices with the timeslices of each series interleaved with the timeslices of at least one other series, said multithreaded application program comprising

• a plurality of sets of instructions with each set executable to provide a respective thread of execution and with each thread having a respective task to perform,
• a first of said sets of instructions executable to provide a first thread of execution having control of the central processor during each successive timeslice of a first series of timeslices with successive portions of the task of said first thread performed during respective successive timeslices of said first series,
• said first set of instructions comprising means for processing said data words stored in said buffer,
• said first thread of execution being periodically preempted at each termination of a timeslice of said first series by said clock activation of said interrupt operation, and
• a second of said sets of instructions executable to provide a second thread of execution and responsive to said periodic preemptions to acquire control of the central processor during successive timeslices of a second series of timeslices with successive portions of the task of said second thread performed during respective successive timeslices of said second series,
• said second set of instructions comprising means responsive to said keyboard for entering data words into said buffer,
• whereby a preemptive multithreading mode of operation is provided for the concurrent execution of said instruction threads with said first thread processing said entered data words in real time while concurrently therewith said second thread is entering additional data words into said buffer.

A computer-readable storage element containing an interactively multithreading application program having a plurality of threads of instructions executable to control the operation of a desktop computer including a microprocessor, a memory, a keyboard, an interrupt, a clock periodically activating the interrupt, an interrupt service routine responsive to each activation of the interrupt to preempt a currently executing thread and to take control of the microprocessor and to determine whether the keyboard has been struck, and a video monitor,

• said application program comprising:
• a first set of instructions executable by said microprocessor to provide a first thread of execution,
• at least a second set of instructions executable by said microprocessor to provide at least a second thread of execution,
• the execution of said first thread being periodically preempted at predetermined equally spaced time instants by said interrupt service routine in response to repeated activations of said interrupt by said clock,
• said second thread being responsive to invocations by said interrupt service routine to take control of the microprocessor at each of those activations of said interrupt operation when said interrupt service routine has determined that the keyboard has been struck,
• said second thread including means for entering a code into the memory in response to each keystroke of a sequence of successive keystrokes on said keyboard with a time interval between the keystrokes of each pair of successive keystrokes,
• said second thread also including means for displaying the entered code on said video monitor immediately in response to each keystroke on said keyboard,
• said first thread including means for processing said entered code,
• whereby said threads execute concurrently in an interleaved relation with said first thread repeatedly processing said entered code during said time intervals between successive keystrokes.

A computer-readable storage element containing a multithreading application program having a plurality of threads of instructions executable to control the operation of a desktop computer including a microprocessor, a memory, a user-interactive input/output device, an interrupt, a clock periodically activating the interrupt, and an interrupt service routine responsive to each activation of the interrupt to take control of the microprocessor and to determine if a user has operated said input/output device,

• said application program comprising:
• a first set of instructions executable by said microprocessor to provide a first thread of execution,
• at least a second set of instructions executable by said microprocessor to provide at least a second thread of execution,
• the execution of said first thread being periodically preempted at predetermined equally spaced time instants by said interrupt service routine in response to repeated activations of said interrupt by said clock,
• said second thread being responsive to invocations by said interrupt service routine to take control of the microprocessor at each of those activations of the interrupt when the interrupt service routine has determined that the input/output device has been operated,
• said second thread including means interactive with a user for controlling said input/output device for transmitting input/output data code in relation to said computer,
• said first thread including instructions executable to perform a subtask,
• whereby said threads execute concurrently in an interleaved relation with said first thread repeatedly performing said subtask during the time intervals between successive invocations of said second thread.