Logic analyzer for software

• US 5,872,909 A
• Filed: 06/07/1995
• Issued: 02/16/1999
• Est. Priority Date: 01/24/1995
• Status: Expired due to Term

• Current Assignee: Wind River Systems Incorporated (Aptiv PLC)
• Original Assignee: Wind River Systems Incorporated (Aptiv PLC)
• Inventors: Smith, Colin, Burd, Dana, Wilner, David N., Long, Kent D., Fogelin, John C., Cohen, Robert D., Burns, Stella M., Fox, Mark A.
• Primary Examiner(s): Hua, Ly
• Application Number:
  US08/474,298
• Time in Patent Office: 1,350 Days
• Field of Search: 395/183.14, 395/183.22, 395/184.01, 395/704, 364/550
• US Class Current: 714/38.12
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/323 Visualisation of programs or trace data
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 11/3664 Environments for testing or debugging software

Abstract

The present invention logs events which occur in the target software, and stores these in a buffer for periodic uploading to a host computer. Such events include the context switching of particular software tasks, and task status at such context switch times, along with events triggering such a context switch, or other events. The host computer reconstructs the real-time status of the target software from the limited event data uploaded to it. The status information is then displayed in a user-friendly manner. This provides the ability to perform a logic analyzer function on real-time software. A display having multiple rows, with one for each task or interrupt level, is provided. Along a time line, an indicator shows the status of each program, with icons indicating events and any change in status.

Claims

1. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying a graphical pattern corresponding to execution in one of said plurality of contexts.

2. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying one of a plurality of graphical patterns, each of said plurality of graphical patterns corresponding to a different task state of a task.

3. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying an icon representing an action undertaken among said plurality of contexts.

4. The method of claim 3 wherein said step of displaying an icon comprises

displaying a first graphic representing the category of the action and

displaying a second graphic representing the event action.

5. The method of claim 4 wherein said action is creation of a semaphore and said step of displaying an icon further comprises

displaying a third graphic representing the type of said semaphore.

6. The method of claim 4 wherein said action is announcement of expiration of a time period and said step of displaying an icon further comprises

displaying a third graphic representing the type of time period which has expired.

7. The method of 3 wherein said method further comprises

highlighting an event icon;

and

displaying information associated with the highlighted event icon in a textual format.

8. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of logging comprises storing an event identifier, a time stamp and an array of parameters in a predetermined order in a buffer, and

wherein said step of logging further comprises storing event data related to the rollover of a hardware timer counter in said buffer and said step of storing a time stamp comprises storing the data count of said hardware timer counter at the time of one of said plurality of events.

9. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said steps of logging and uploading overlap, and said uploading is performed periodically.

10. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of logging comprises

repeatedly overwriting a buffer of data and afterwards terminating said logging and

said step of uploading comprises

uploading the data in said buffer only after said logging is terminated.

11. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein before said step of running is performed, the following steps are performed by the user;

modifying the source code of one of said plurality of tasks to log event data; and

compiling said modified source code to produce one of said plurality of tasks.

12. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein before said step of logging is performed, the following step is performed;

modifying the memory-resident image of one of said plurality of tasks to log event data.

13. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said event data comprises multi-level representations of multi-level events; and

wherein said step of reconstructing and storing comprises

generating single-level representations of said events from said multi-level representations, and associating each of said single-level representations with a context, said context being the context in which occurred the event represented by said each single-level representation.

14. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said event data is a time-ordered stream of representations of said events; and

wherein the information necessary to reconstruct one of said events is contained in at least two representations.

15. A method for monitoring the execution of a plurality of tasks in the memory of a target computer, said method comprising the steps of:

coupling said target computer to a host program with a communications link;

running a plurality of tasks on said target computer, producing a plurality of contexts;

logging event data representing a plurality of events in said plurality of contexts;

uploading said event data from said target computer memory to said host program;

reconstructing a status of said tasks from said event data, and storing reconstructed data in said host program; and

displaying said status from said reconstructed data for a period of time for a plurality of said tasks on a single display,

wherein said step of logging comprises

logging event data related to state transitions among said plurality of contexts for a time period,

wherein said event data is a time-ordered stream of representations of said events;

wherein each of said plurality of contexts has a status word;

wherein said host program maintains a corresponding status word for the status word of said each context; and

wherein said step of reconstructing and storing comprises modifying said corresponding status word for each event which causes a task state transition in a context, and inserting a representation of said modified corresponding status word into said stream.

16. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying a graphical pattern corresponding to execution in one of said plurality of contexts.

17. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying one of a plurality of graphical patterns, each of said plurality of graphical patterns corresponding to a different task state of a task.

18. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said step of displaying comprises

displaying a list of identifiers of said plurality of contexts along a first axis of said display,

displaying an indication of time progression along a second axis of said display; and

for a plurality of said identifiers, for a time period along said time progression, displaying an icon representing an action undertaken among said plurality of contexts.

19. The apparatus of claim 18 wherein said step of displaying an icon comprises

displaying a first graphic representing the category of the action and

displaying a second graphic representing the event action.

20. The apparatus of claim 19 wherein said action is creation of a semaphore and said step of displaying an icon further comprises

displaying a third graphic representing the type of said semaphore.

21. The apparatus of claim 19 wherein said action is announcement of expiration of a time period and said step of displaying an icon further comprises

displaying a third graphic representing the type of time period which has expired.

22. The apparatus of 18 wherein said host computer memory program further comprises

highlighting an event icon;

and

displaying information associated with the highlighted event icon in a textual format.

23. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said step of logging comprises storing an event identifier, a time stamp and an array of parameters in a predetermined order in a buffer, and

wherein said step of logging further comprises storing event data related to the rollover of a hardware timer counter in said buffer and said step of storing a time stamp comprises storing the data count of said hardware timer counter at the time of one of said plurality of events.

24. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said steps of logging and uploading overlap, and said uploading is performed periodically.

25. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said step of logging comprises

repeatedly overwriting a buffer of data and afterwards terminating said logging and

said step of uploading comprises

loading the data in said buffer only after said logging is terminated.

26. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein before said step of running is performed, the following steps are performed by the user;

modifying the source code of one of said plurality of tasks to log event data; and

compiling said modified source code to produce one of said plurality of tasks.

27. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein before said step of logging is performed, the following step is performed;

modifying the memory-resident image of one of said plurality of tasks to log event data.

28. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said event data comprises multi-level representations of multi-level events; and

wherein said step of reconstructing and storing comprises

generating single-level representations of said events from said multi-level representations, and associating each of said single-level representations with a context, said context being the context in which occurred the event represented by said each single-level representation.

29. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said event data is a time-ordered stream of representations of said events; and

wherein the information necessary to reconstruct one of said events is contained in at least two representations.

30. An apparatus for monitoring the execution of a plurality of tasks in the memory of a target computer, said apparatus comprising:

a target computer having memory, in which is located a computer program to cause said target computer to run a plurality of tasks, producing a plurality of contexts, and log event data representing a plurality of events in said plurality of contexts;

a communications link;

a display; and

a host computer, coupled to said target computer by means of said communications link, coupled to said display and having a memory, in which is located a computer program to cause said host computer to upload said event data from said target computer memory, reconstruct a status of said plurality of tasks from said event data, and storing reconstructed data in said host computer, and display said status from said reconstructed data for a period of time for a plurality of tasks by means of graphics on said display,

wherein said event data is a time-ordered stream of representations of said events;

wherein each of said plurality of contexts has a status word;

wherein said host program maintains a corresponding status word for the status word of said each context; and

wherein said step of reconstructing and storing comprises modifying said corresponding status word for each event which causes a task state transition in a context, and inserting a representation of said modified corresponding status word into said stream.