US 8,572,577 B2Granted

Monitoring changes to data within a critical section of a threaded program

AssigneeInternational Business Machines Corporation

InventorsCary L. Bates, Victor J. Gettler

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method, system and program product for monitoring changes to a variable within a critical section of a threaded program. The method includes establishing, using a debugging tool, a watch for monitoring changes to a variable that occur outside of the critical section and executing a portion of the threaded program with a debugger. Further, the method includes determining, using the tool, whether or not a thread has executed a start breakpoint set for the critical section, if the thread has executed the start breakpoint set, determining whether or not the thread has executed an end breakpoint set for the critical section, and if the thread has not executed the end breakpoint set, displaying any watches triggered responsive to updates to the variable that occur outside of the critical section, such that, only updates to the variable that occur outside of the critical section will trigger the displaying.

Claims17

Dependent claims

A method for monitoring changes to a value of a program variable within a threaded program which comprises different program threads configured for concurrent execution, the threaded program not changing the value of the program variable outside a predetermined section of the threaded program if the different program threads are properly synchronized with each other, the method comprising the steps of:

a debugger program setting a first break point for a start of the predetermined section, and setting a second break point for an end of the predetermined section;
the debugger program receiving a command to monitor for the changes to the value of the program variable;
the debugger program initiating execution of the threaded program, and during the execution of the threaded program a program tool coupled to the debugger program monitoring execution of the threaded program;
responsive to a change to the value of the program variable by one of the program threads in the different program threads, the program tool identifying the change to the value of the program variable, within the threaded program, resulting from the execution of the one program thread in the threaded program;
the program tool determining whether the change to the value of the program variable occurred between the start and the end of the predetermined section of the threaded program or outside the start and the end of the predetermined section based on whether the change occurs while the one program thread is executing between the first break point and the second break point;
and
if the one program thread has changed the value of the program variable between the start and the end of the predetermined section, the program tool does not indicate an error due to the change in the value of the program variable, and
if the one program thread has changed the value of the program variable outside the start and the end of the predetermined section, the program tool indicating a potential error condition.

5 more elements

A computer system for monitoring changes to a value of a program variable within a threaded program which comprises different program threads configured for concurrent execution, the threaded program not changing the value of the program variable outside a predetermined section of the threaded program if the different program threads are properly synchronized with each other, the computer system comprising:

one or more processors, one or more computer-readable memories, one or more computer-readable storage devices, and program instructions stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, the program instructions comprising:
program instructions to set a first break point for a start of the predetermined section, and set a second break point for an end of the predetermined section;
program instructions to receive a command to monitor for the changes to the value of the program variable;
program instructions to initiate execution of the threaded program in a debugging process;
program instructions, operable during the execution of the threaded program, to monitor execution of the threaded program;
program instructions, responsive to a change to the value of the program variable by one of the program threads in the different program threads, to identify the change to the value of the program variable, within the threaded program, resulting from the execution of the one program thread in the threaded program;
program instructions to determine whether the change to the value of the program variable occurred between the start and the end of the predetermined section of the threaded program or outside the start and the end of the predetermined section based on whether the change occurs while the one program thread is executing between the first break point and the second break point;
and
if the one program thread has changed the value of the program variable between the start and the end of the predetermined section, the computer system does not indicate an error due to the change in the value of the program variable, and
if the one program thread has changed the value of the program variable outside the start and the end of the predetermined section, the monitoring program instructions indicate a potential error condition.

7 more elements

A computer program product for monitoring changes to a value of a program variable within a threaded program which comprises different program threads configured for concurrent execution, the threaded program not changing the value of the program variable outside a predetermined section of the threaded program if the different program threads are properly synchronized with each other, the computer program product comprising:

one or more computer-readable storage devices and program instructions stored on at least one of the one or more storage devices, the program instructions comprising:
program instructions to set a first break point for a start of the predetermined section, and set a second break point for an end of the predetermined section;
program instructions to receive a command to monitor for the changes to the value of the program variable;
program instructions to initiate execution of the threaded program in a debugging process;
program instructions, operable during the execution of the threaded program, to monitor execution of the threaded program;
program instructions, responsive to a change to the value of the program variable by one of the program threads in the different program threads, to identify the change to the value of the program variable, within the threaded program, resulting from the execution of the one program thread in the threaded program;
program instructions to determine whether the change to the value of the program variable occurred between the start and the end of the predetermined section of the threaded program or outside the start and the end of the predetermined section based on whether the change occurs while the one program thread is executing between the first break point and the second break point;
and
if the one program thread has changed the value of the program variable between the start and the end of the predetermined section, the computer system does not indicate an error due to the change in the value of the program variable, and
if the one program thread has changed the value of the program variable outside the start and the end of the predetermined section, the monitoring program instructions indicate a potential error condition.

7 more elements

Dependencies are inferred from the claim text.