ON DEMAND TRACING OF APPLICATION CODE EXECUTION

• US 20120297254A1
• Filed: 05/19/2011
• Published: 11/22/2012
• Est. Priority Date: 05/19/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: SHAZLY, Hassan A.
• Granted Patent: US 8,799,719 B2
• Time in Patent Office: Days
• US Class Current: 714/45
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 11/348 Circuit details, i.e. tracer hardware
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 2201/865 Monitoring of software

Abstract

On demand tracing of application code execution includes: during the execution of the application code, writing trace statements to a circular trace buffer (at a selected and potentially variable detail level); determining whether a pre-defined trigger event has occurred; in response to determining that the trigger event has occurred, outputting one or more trace statements in the circular trace buffer according to pre-defined trace parameters; determining whether a trigger end event has occurred; and in response to determining that the trigger end event has occurred, terminating the outputting of the trace statements. The trigger event and the trigger end event may be defined by names of application code variables, values for the variables, and operators to be used. The trigger end event may further be defined by a time duration for which trace statements are to be outputted, or a number of trace statements to be outputted.

Claims

1. A method for tracing execution of application code, comprising:

during the execution of the application code, writing trace statements to a circular trace buffer by a computing device;

determining whether a pre-defined trigger event has occurred by the computing device;

in response to determining that the trigger event has occurred, outputting one or more trace statements in the circular trace buffer by the computing device according to pre-defined trace parameters;

determining whether a trigger end event has occurred by the computing device; and

in response to determining that the trigger end event has occurred, terminating the outputting of the trace statements by the computing device.

2. The method of claim 1, wherein the trigger event is defined by parameters comprising a name of a variable in the application code to be used as the trigger event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the determining whether the trigger event has occurred by the computing device comprises:

determining whether the variable in the application code satisfies the operator and the value by the computing device.

3. The method of claim 1, wherein the pre-defined trace parameters comprise before-trigger-event parameters, the before-trigger-event parameters comprising a traceBefore parameter defining a number of trace statements in the circular trace buffer from before the trigger event to be outputted, wherein the outputting of the plurality of trace statements in the circular trace buffer by the computing device in response to determining that the trigger event has occurred, comprises:

in response to determining that a trigger event type of the trigger event comprises a new outputting of trace statements,

outputting a current trace statement by the computing device, and

outputting the traceBefore number of trace statements in the circular trace buffer from before the trigger event by the computing device.

4. The method of claim 1, wherein the pre-defined trace parameters comprise after-trigger-event parameters, wherein the after-trigger-event parameters comprise a traceAfterFreq parameter defining a number of trace statements in the circular trace buffer from after the trigger event to be outputting at a time, wherein the outputting of the trace statements in the circular trace buffer by the computing device according to the pre-defined trace parameters comprises:

in response to determining that a trigger event type of the trigger event comprises an in-progress outputting of trace statements,

determining whether a number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter by the computing device, and

in response to determining that the number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter, outputting the trace statements currently in the circular trace buffer by the computing device.

5. The method of claim 1, wherein the trigger end event comprises a trace end event, wherein the trace end event is defined by parameters comprising a name of a variable in the application code to be used as the trace end event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the determining whether the trigger end event has occurred by the computing device and the terminating of the outputting of the trace statements by the computing device in response to determining that the trace end event has occurred comprises:

determining whether the variable in the application code satisfies the operator and the value by the computing device; and

in response to determining that the variable in the computer program satisfies the operator and the value by the computing device, terminating the outputting of the trace statements by the computing device.

6. The method of claim 1, wherein the pre-defined trace parameters comprise a traceTime parameter defining a time duration for which the outputting of the trace statements is to continue,

wherein the determining whether the trigger end event has occurred by the computing device and the terminating of the outputting of the trace statements by the computing device in response to determining that the trace end event has occurred, comprises:

determining whether the time duration defined by the traceTime parameter has elapsed by the computing device; and

in response to determining that the time duration defined by the traceTime parameter has elapsed, terminating the outputting of the trace statements by the computing device.

7. The method of claim 1, wherein the pre-defined trace parameters comprise a traceAfter parameter defining a number of trace statements from after the trigger event to be outputted,

wherein the determining whether the trigger end event has occurred by the computing device and the terminating of the outputting of the trace statements by the computing device in response to determining that the trace end event has occurred, comprises:

determining whether a number of outputted trace statements from after the trigger event equals the traceAfter parameter by the computing device; and

in response to determining that the number of outputted trace statements from after the trigger events equals the traceAfter parameter, terminating the outputting of the trace statements by the computing device.

8. The method of claim 1, wherein the terminating of the outputting of the trace statements by the computing device in response to determining that the trigger end event has occurred, comprises:

outputting the trace statements currently in the circular trace buffer and the current trace statement by the computing device.

9. A computer program product for tracing execution of application code, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to;

write trace statements to a circular trace buffer during the execution of the application code;

determine whether a pre-defined trigger event has occurred;

in response to determining that the trigger event has occurred, output one or more trace statements in the circular trace buffer according to pre-defined trace parameters;

determine whether a trigger end event has occurred; and

in response to determining that the trigger end event has occurred, terminate the outputting of the trace statements.

10. The computer program product of claim 9, wherein the trigger event is defined by parameters comprising a name of a variable in the application code to be used as the trigger event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the computer readable program code configured to determine whether the trigger event has occurred is further configured to:

determine whether the variable in the application code satisfies the operator and the value.

11. The computer program product of claim 9, wherein the pre-defined trace parameters comprises before-trigger-event parameters, the before-trigger-event parameters comprising a traceBefore parameter defining a number of trace statements in the circular trace buffer from before the trigger event to be outputted, wherein the computer readable program code configured to output the trace statements in the circular trace buffer in response to determining that the trigger event has occurred, is further configured to:

in response to determining that a trigger event type of the trigger event comprises a new outputting of trace statements,

output a current trace statement, and

output one or more trace statements in the circular trace buffer from before the trigger event according to before-trigger-event parameters.

12. The computer program product of claim 9, wherein the predefined trace parameters comprise after-trigger event parameters, wherein the after-trigger-event parameters comprises a traceAfterFreq parameter defining a number of trace statements in the circular trace buffer from after the trigger event to be outputting at a time, wherein the computer readable program code configured to output the trace statements in the circular trace buffer from after the trigger event device according to the after-trigger-event parameters is further configured to:

in response to determining that a trigger event type of the trigger event comprises an in-progress outputting of trace statements,

determine whether a number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter, and

in response to determining that the number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter, output the trace statements currently in the circular trace buffer.

13. The computer program product of claim 9, wherein the trigger end event comprises a trace end event, wherein the trace end event is defined by parameters comprising a name of a variable in the application code to be used as the trace end event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the computer readable program code configured to determine whether the trace end event has occurred and to terminate the outputting of the trace statements in response to determining that the trace end event has occurred are further configured to:

determine whether the variable in the application code satisfies the operator and the value; and

in response to determining that the variable in the application code satisfies the operator and the value, terminate the outputting of the trace statements.

14. The computer program product of claim 9, wherein the pre-defined trace parameters comprise a traceTime parameter defining a time duration for which the outputting of the trace statements is to continue,

wherein the computer readable program code configured to determine whether the trigger end event has occurred and the terminate of the output of the trace statements in response to determining that the trace end event has occurred, are further configured to:

determine whether the time duration defined by the traceTime parameter has elapsed; and

in response to determining that the time duration defined by the traceTime parameter has elapsed, terminate the outputting of the trace statements.

15. The computer program product of claim 9, wherein the pre-defined trace parameters comprise a traceAfter parameter defining a number of trace statements from after the trigger event to be outputted,

wherein the computer readable program code configured to determine whether the trigger end event has occurred and the terminate of the outputting of the trace statements in response to determining that the trace end event has occurred, are further configured to:

determine whether a number of outputted trace statements from after the trigger event equals the traceAfter parameter; and

in response to determining that the number of outputted trace statements from after the trigger events equals the traceAfter parameter, terminate the outputting of the trace statements.

16. The computer program product of claim 9, wherein the computer readable program code configured to terminate the outputting of the trace statements in response to determining that the trigger end event has occurred, is further configured to:

output the trace statements currently in the circular trace buffer and the current trace statement.

17. A system comprising:

a processor;

a circular trace buffer; and

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to;

write trace statements to a circular trace buffer during the execution of the application code;

determine whether a pre-defined trigger event has occurred;

in response to determining that the trigger event has occurred, output one or more trace statements in the circular trace buffer according to pre-defined trace parameters;

determine whether a trigger end event has occurred; and

in response to determining that the trigger end event has occurred, terminate the outputting of the trace statements.

18. The system of claim 17, wherein the trigger event is defined by parameters comprising a name of a variable in the application code to be used as the trigger event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the computer readable program code configured to determine whether the trigger event has occurred device is further configured to:

determine whether the variable in the application code satisfies the operator and the value.

19. The system of claim 17, wherein the pre-defined trace parameters comprises before-trigger-event parameters, the before-trigger-event parameters comprising a traceBefore parameter defining a number of trace statements in the circular trace buffer from before the trigger event to be outputted, wherein the computer readable program code configured to output the trace statements in the circular trace buffer in response to determining that the trigger event has occurred, is further configured to:

in response to determining that a trigger event type of the trigger event comprises a new outputting of trace statements,

output a current trace statement, and

output one or more trace statements in the circular trace buffer from before the trigger event according to before-trigger-event parameters.

20. The system of claim 17, wherein the predefined trace parameters comprise after-trigger event parameters, wherein the after-trigger-event parameters comprises a traceAfterFreq parameter defining a number of trace statements in the circular trace buffer from after the trigger event to be outputting at a time, wherein the computer readable program code configured to output the trace statements in the circular trace buffer from after the trigger event device according to the after-trigger-event parameters is further configured to:

in response to determining that a trigger event type of the trigger event comprises an in-progress outputting of trace statements,

determine whether a number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter, and

in response to determining that the number of trace statements currently in the circular trace buffer is greater than or equal to the traceAfterFreq parameter, output the trace statements currently in the circular trace buffer.

21. The system of claim 17, wherein the trigger end event comprises a trace end event, wherein the trace end event is defined by parameters comprising a name of a variable in the application code to be used as the trace end event, a value for the variable, and an operator defining a relationship between the variable and the value for the variable,

wherein the computer readable program code configured to determine whether the trigger end event has occurred and to terminate the outputting of the trace statements in response to determining that the trace end event has occurred are further configured to:

determine whether the variable in the application code satisfies the operator and the value; and

in response to determining that the variable in the application code satisfies the operator and the value, terminate the outputting of the trace statements.

23. The system claim 17, wherein the pre-defined trace parameters comprise a traceAfter parameter defining a number of trace statements from after the trigger event to be outputted,

wherein the computer readable program code configured to determine whether the trigger end event has occurred and the terminate of the outputting of the trace statements in response to determining that the trace end event has occurred, are further configured to:

determine whether a number of outputted trace statements from after the trigger event equals the traceAfter parameter; and

in response to determining that the number of outputted trace statements from after the trigger events equals the traceAfter parameter, terminate the outputting of the trace statements.

24. The system of claim 17, wherein the computer readable program code configured to terminate the outputting of the trace statements in response to determining that the trigger end event has occurred, is further configured to:

output the trace statements currently in the circular trace buffer and the current trace statement.

22. The system 17, wherein the pre-defined trace parameters comprise a traceTime parameter defining a time duration for which the outputting of the trace statements is to continue,

wherein the computer readable program code configured to determine whether the trigger end event has occurred and the terminate of the output of the trace statements in response to determining that the trace end event has occurred, are further configured to:

determine whether the time duration defined by the traceTime parameter has elapsed; and

in response to determining that the time duration defined by the traceTime parameter has elapsed, terminate the outputting of the trace statements.

25. A method for tracing execution of application code, comprising:

during the execution of the application code, writing trace statements to a circular trace buffer by a computing device;

determining whether a pre-defined trigger event has occurred by the computing device;

in response to determining that the trigger event has occurred, outputting one or more trace statements in the circular trace buffer by the computing device according to pre-defined trace parameters;

determining whether a trigger end event has occurred by the computing device, comprising;

determining whether a variable in the application code satisfies an operator and a value defined in the pre-defined trace parameters by the computing device;

determining whether a time duration defined in the pre-defined trace parameters for which the outputting of the trace statements is to continue has elapsed by the computing device;

or

determining whether the outputting of a number of outputted trace statements defined in the pre-defined trace parameters from after the trigger event has occurred by the computing device; and

in response to determining that the trigger end event has occurred, terminating the outputting of the trace statements by the computing device.