Monitoring memory accesses for computer programs

• US 7,669,189 B1
• Filed: 06/26/2002
• Issued: 02/23/2010
• Est. Priority Date: 06/26/2002
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Umamageswaran, Kothanda
• Primary Examiner(s): DENG, ANNA CHEN
• Application Number:
  US10/184,379
• Time in Patent Office: 2,799 Days
• Field of Search: 717127-130, 714/37, 714/38, 711/100
• US Class Current: 717/127
• CPC Class Codes: G06F 11/3471 Address tracing
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 11/36 Preventing errors by testing or debugging software
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor

Abstract

Techniques for monitoring memory accesses for computer programs are provided. A user can instruct a computer program to have one of more of its processes monitor memory accesses to a memory region. As memory accesses to the memory region occur, a log can be created that includes information concerning the memory accesses. The log can be analyzed in order to debug memory access bugs. Additionally, new processes can be spawned that monitor memory accesses in a way that is similar to existing processes.

Claims

1. A computer-implemented method of monitoring memory accesses for a computer program including a plurality of processes, the computer-implemented method comprising:

receiving input to monitor memory accesses to a memory region that is shared by the plurality of processes included in the computer program;

directing each of the plurality of processes to monitor memory accesses to the memory region;

monitoring memory accesses to the memory region using each of the plurality of processes, wherein each of the plurality of processes performs the monitoring without using a process external to the computer program;

writing to a log of memory accesses to the memory region by the plurality of processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed; and

setting a configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions.

2. The method of claim 1, further comprising spawning a new process of the computer program, wherein the new process of the computer program does not monitor memory accesses to the shared memory region.

3. The method of claim 1, wherein at least one process of the computer program does not monitor memory accesses to the shared memory region.

4. The method of claim 1, wherein when the configuration parameter is four, four function names are listed in the listing of a stack of functions for each entry of the log.

5. The method of claim 4, wherein

for an entry in the log, each function name is different from the identifier of a process for that entry.

6. The method of claim 1, wherein

a first entry in the log has a first identifier of a process for that entry and a first entry in the log, immediately following the second entry, has a second identifier of a process for that entry, and the first identifier is different from the second identifier.

7. The method of claim 1, wherein

the identifier comprises an alphanumeric string.

8. The method of claim 1, wherein the configuration parameter is a positive integer.

9. The method of claim 1,

wherein each entry of the log has the same number of functions recorded for the listing of a stack of functions.

10. The method of claim 1, wherein the shared memory region is specified by a starting address and a length.

11. The method of claim 1, further comprising:

analyzing the log to identify a memory access violation when a process utilizes a stale pointer to access to the memory region.

12. The method of claim 1, wherein the computer program is a database application.

40. The method of claim 1, wherein directing each of the plurality of processes to monitor memory accesses to the memory region includes storing memory monitoring information in an area of the memory region and sending each of the plurality of processes a signal that indicates to each of the plurality of processes that each of the plurality of processes should access the area of the memory region.

42. The method of claim 1 wherein an input to monitor memory accesses comprises setting a watchpoint to monitor memory access to a memory region, where the watchpoint does not halt execution of the computer program.

43. The method of claim 1, wherein monitoring memory accesses to the memory region comprises writing a log of memory accesses to the memory region,

the log includes a location in the code of the computer program that performed the memory access, and

the location in the code of the computer program comprises a stack of functions and offsets into each function that, at least one of, called a subsequent function or performed the memory access.

13. A computer program product including a plurality of processes, the computer program product being stored on a computer readable storage medium, comprising:

computer code that generates an interface that receives input to monitor a shared memory region and directs the plurality of processes to monitor the shared memory region without using a process external to the computer program,

wherein the interface allows setting of a configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions during monitoring of the shared memory region; and

computer code that causes writing to a log of memory accesses to the memory region by the plurality of processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed.

14. A computer program product that monitors memory accesses for a computer program including a plurality of processes, comprising:

computer code that receives input to monitor memory accesses to a shared memory region;

computer code that directs each of the plurality of processes to monitor memory accesses to the shared memory region;

computer code that causes each of the plurality of processes to monitor memory accesses to the shared memory region, wherein each of the plurality of processes monitors the memory accesses without using a process external to the computer program;

computer code that causes writing to a log of memory accesses to the memory region by the plurality of processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed;

computer code that causes setting a configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions; and

a computer readable storage medium that stores the computer codes.

15. The computer program product of claim 14, wherein the computer readable storage medium is at least one of a CD-ROM, floppy disk, tape, flash memory, system memory, or hard drive.

16. A computer-implemented method of monitoring memory accesses for a database program including a plurality of processes, the computer-implemented method comprising:

receiving input that specifies that each of the plurality of processes is to monitor memory accesses to a shared memory region;

directing each of the plurality of processes to monitor memory accesses to the shared memory region, wherein each of the plurality of processes monitors memory accesses the shared memory region without using a process external to the database program;

writing to a log of memory accesses to the memory region by the plurality of processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed;

setting a configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions; and

spawning a new process, wherein the new process is also directed to monitor memory accesses to the shared memory region.

17. The method of claim 16, wherein all of processes of the computer program monitor memory accesses to the shared memory region.

18. The method of claim 16, wherein each entry in the log includes an alphanumeric string identifier to the code of the computer program that performed the memory access.

19. The method of claim 16, wherein

each entry in the log includes alphanumeric identifiers for two or more functions leading to the memory access.

20. The method of claim 16, further comprising:

analyzing the log to identify a memory access violation when a process utilizes a stale pointer to access to the shared memory area.

21. The method of claim 16, further comprising:

setting a self configuration parameter to monitor memory accesses by the directing each of the plurality of processes.

22. The method of claim 16, further comprising:

setting an all configuration parameter to specify monitoring of all processes including processes spawned after a command initiating the directing each of the plurality of processes.

23. The method of claim 16, further comprising:

setting an exist configuration parameter to specify monitoring of all processes existing at a time of a command initiating the directing each of the plurality of processes, but not processes spawned after the time of the command.

24. The method of claim 16, wherein the shared memory region is specified by a starting address and a length.

25. The method of claim 16, wherein the shared memory region is a memory location.

41. The method of claim 16, wherein directing each of the plurality of processes to monitor memory accesses to the shared memory region includes storing memory monitoring information in an area of the shared memory region and sending each of the plurality of processes a signal that indicates to each of the plurality of processes that each of the plurality of processes should access the area of the shared memory region.

26. A computer system, comprising:

a computer program including a plurality of processes, the computer program being embodied on a computer-readable storage medium; and

an interface that receives input to monitor memory accesses to a shared memory region, directs the plurality of processes to monitor memory accesses to the shared memory region without using a process external to the computer program, and directs a new process to monitor memory accesses to the shared memory region without using a process external to the computer program, wherein the interface allows

setting of a first configuration parameter to control a number of functions that will be recorded during monitoring of the shared memory region,

setting of a second configuration parameter to monitor memory accesses by the new process,

setting of a third configuration parameter to specify monitoring of all processes including processes spawned after receiving a command to initiate monitoring memory accesses to the shared memory region, and

setting of a fourth configuration parameter to specify monitoring of all processes existing at a time when receiving the command to initiate monitoring memory accesses to the shared memory region, but not processes spawned after the time of the command.

27. A computer program product that monitors memory accesses for a computer program including a plurality of processes, comprising:

computer code that receives input to monitor memory accesses to a shared memory region;

computer code that directs each of the plurality of processes to monitor memory accesses to the shared memory region;

computer code that causes each of the plurality of processes to monitor memory accesses to the shared memory region;

computer code that causes writing to a log of memory accesses to the memory region by the plurality of processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed;

computer code that causes setting a configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions;

computer code that spawns a new process of the database program, wherein the new process of the computer program is not directed to monitor memory accesses to the shared memory region; and

a computer readable storage medium that stores the computer codes.

28. The computer program product of claim 27, wherein the computer readable storage medium is at least one of a CD-ROM, floppy disk, tape, flash memory, system memory, or hard drive.

29. A computer-implemented method of monitoring memory accesses for a computer program, comprising:

providing a function in computer code that when called during run time of the computer program will cause memory accesses to a memory region to be monitored, wherein the function specifies processes included in the computer program will monitor memory accesses to the memory region, the memory region being shared by the processes;

executing the function during run time of the computer program to monitor memory accesses to the memory region by selected processes,

wherein monitoring memory accesses to the memory region comprises writing to a log of memory accesses to the memory region by the selected processes, wherein each entry in the log comprises an address of the memory region being accessed, a value stored at the address of the memory region being accessed, an identifier of a process performing accessing of the address of the memory region being accessed, and a listing of a stack of functions leading to accessing of the address of the memory region being accessed; and

allowing setting of a first configuration parameter to control a number of functions that will be recorded for each entry of the log in the listing of the stack of functions.

30. The method of claim 29, wherein accesses to the memory region by a first process access are logged while region is accesses to the memory region by a second process access are not logged.

31. The method of claim 29, wherein each entry of the log is for single memory access and has a listing of a two or more functions leading to the memory access.

32. The method of claim 29, wherein the log includes an alphanumeric identifier for each of the two or more functions.

33. The method of claim 29, further comprising:

allowing setting of a second configuration parameter to specify monitoring of processes existing at a time when receiving a command initiating monitoring of memory accesses of the memory region, but not processes spawned after the time of the command.

34. The method of claim 33, further comprising:

allowing setting of a third configuration parameter to specify monitoring of all processes including processes spawned after receiving the command to initiate monitoring of memory accesses to the memory region.

35. The method of claim 29, wherein each entry of the log has the same number of functions recorded for the functions leading to the memory access.

36. The method of claim 29, further comprising invoking a debugger program when a process accesses the memory region, wherein memory accesses by the debugger program to the memory region are also written to the log.

37. The method of claim 29, wherein the memory region is specified by a starting address and a length as parameters to the function.

38. The method of claim 29, wherein the memory region is a memory location.

39. The method of claim 29, wherein the computer program is a database application.