Advancing and Rewinding a Replayed Program Execution

• US 20140380102A1
• Filed: 08/18/2014
• Published: 12/25/2014
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Inventors: Lindo, Jonathan, Jakab, Arpad, Cherukuri, Suman, Daudel, Jeffrey
• Granted Patent: US 9,122,601 B2
• Time in Patent Office: Days
• US Class Current: 714/38.11
• CPC Class Codes: G06F 11/0778 Dumping, i.e. gathering error/state information after a fault for later diagnosis
• CPC Class Codes: G06F 11/3624 by performing operations on the source code, e.g. via a compiler

Abstract

In an embodiment, a data processing system comprises a storage system coupled to a unit under test comprising a heap memory, a static memory and a stack; second logic operable to perform: detecting one or more changes in a first state of the heap memory and the static memory; storing, in the storage system, as a state point of the unit under test, the one or more changes in the first state of the heap memory and the static memory; third logic operable to perform: receiving a request to change the memory under test to a particular state point; in response to the request, loading the particular state point from the storage system and applying the particular state point to the heap memory and the static memory to result in changing the heap memory and the static memory to a second state that is substantially equivalent to the first state.

Claims

1. (canceled)

2. A method comprising:

establishing a data connection to a unit under test, the unit under test comprising unit under test memory that comprises dynamically allocated memory and static memory;

detecting a change in a first state of the unit under test memory during a record phase;

storing, in a storage system, as a first state point of the unit under test, information about the change in the first state of the under test memory;

detecting a write operation to the under test memory during a replay phase;

determining whether the storage system comprises data about the write operation of the unit under test memory; and

detecting that a replay synchronization error has occurred at a particular point in execution when the storage system does not comprise data about the write operation to the unit under test memory.

3. The method of claim 2, further comprising:

responsive to detecting that a replay synchronization error has occurred;

setting the unit under test to a second state point that is earlier in time than the particular point in execution, comprising sequentially updating the unit under test memory utilizing changes associated with a set of state points, wherein said set of state points occur between said second state point and said particular point in execution in time.

4. The method of claim 2, further comprising:

responsive to detecting that a replay synchronization error has occurred;

setting the unit under test to a second state point that is earlier in time than the particular point in execution, comprising retrieving a stored page of the unit under test memory associated with the second state point and copying the retrieved stored page of the unit under test memory associated with the second state point to the unit under test memory;

applying, to the unit under test memory, all changes associated with a next state point in time that is stored in the storage system after the second state point;

repeating the applying until reaching another state point that is closest in time before the particular point in execution.

5. The method of claim 2, wherein the detecting a write operation of the unit under test memory comprises receiving data about a write exception to a page of either the dynamically allocated memory or a page of the static memory.

6. The method of claim 2, further comprising:

detecting that a call involving operating system resources is to be executed next by the unit under test during the record phase;

responsive to the detecting, storing as a marker state point a state of the unit under test memory.

7. The method of claim 6, wherein the call is an Application Program Interface (API) call from an application program under test to a specified operation of the operating system.

8. The method of claim 6, further comprising:

receiving a request to skip to a state point that would result in skipping the marker state point during the replay phase; and

preventing skipping the marker state point during the replay phase when responding to the request.

9. The method of claim 8, wherein the preventing skipping the marker state point during the replay phase comprises:

changing the unit under test to a state represented by the marker state point;

causing the unit under test to execute the call involving operating system resources; and

changing the unit under test to the next state point in time after the marker state point.

10. A system, comprising:

a storage system; and

a processor coupled to the storage system, the processor;

establishes a data connection to a unit under test comprising unit under test memory that comprises dynamically allocated memory and static memory;

detects a change in a first state of the unit under test memory during a recording phase;

stores, in the storage system, as a first state point of the unit under test, information about the change in the first state of the under test memory;

detects a write operation to the under test memory during a replay phase;

determines whether the storage system comprises data about the write operation of the under test memory; and

detects that a replay synchronization error has occurred at a particular point in execution when the storage system does not comprise data about the write operation to the unit under test memory.

11. The system of claim 10, wherein the processor:

sets the unit under test to a second state point that is earlier in time than the particular point in execution responsive to detecting that a replay synchronization error has occurred, in which the processor sequentially updates the under test memory utilizing changes associated with a set of state points, wherein said set of state points occur between said second state point and said particular point in execution in time.

12. The system of claim 10, wherein when the processor detects a write operation to the under test memory the processor receives data about a write exception to a page of either the dynamically allocated memory or the static memory.

13. The system of claim 10, wherein the processor further:

detects that a call involving operating system resources is to be executed next by the unit under test during the record phase;

stores as a marker state point a state of the unit under test memory responsive to detecting that the call is to be executed next by the unit under test during the record phase; and

prevents skipping the marker state point during the replay phase when responding to a request to skip to a state point that would result in skipping the marker state point during the replay phase.

14. The system of claim 13, wherein the call comprises an Application Program Interface (API) call from an application under test to the operating system.

15. The system of claim 13, wherein when the processor prevents skipping the marker state point during the replay phase, the processor:

changes the unit under test to a state represented by the marker state point;

causes the unit under test to execute the call; and

changes the unit under test to the next state point in time after the marker state point.

16. A non-transitory computer-readable storage medium comprising instructions which, when executed by a processor, cause the processor to:

establish a data connection to a unit under test comprising dynamically allocated memory and static memory;

detect a change in a first state of either or both of the dynamically allocated memory and the static memory during a recording phase of an application program that executes in the unit under test;

store, in a storage system, as a first state point of the unit under test, information about the change in the first state of either or both of the dynamically allocated memory and the static memory;

detect a write operation to either the dynamically allocated memory or the static memory during a replay phase of the application program;

determine whether the storage system comprises data about the write operation of either the dynamically allocated memory or the static memory; and

detect that a replay synchronization error has occurred at a particular point in execution of the application program when the storage system does not comprise data about the write operation to either the dynamically allocated memory or the static memory.

17. The non-transitory computer-readable storage medium of claim 16, wherein the instructions which, when executed by a processor, further cause the processor to:

set the unit under test to a second state point that is earlier in time than the particular point in execution of the application program responsive to detecting that a replay synchronization error has occurred, comprising the processor being configured to sequentially update the dynamically allocated memory or the static memory utilizing changes associated with a set of state points, wherein said set of state points occur between said second state point and said particular point in execution in time.

18. The non-transitory computer-readable storage medium of claim 16, wherein the processor being caused to detect a write operation of the dynamically allocated memory or the static memory comprises the processor being caused to receive data about a write exception to a page of either the dynamically allocated memory or the static memory.

19. The non-transitory computer-readable storage medium of claim 16, wherein the instructions which, when executed by a processor, further cause the processor to:

detect that a call is to be executed from the application program to an operating system resource next by the unit under test during the record phase;

store as a marker state point a state of the unit under test memory responsive to detecting that the call is to be executed next by the unit under test during the record phase; and

prevent skipping the marker state point during the replay phase when responding to a request to skip to a state point that would result in skipping the marker state point during the replay phase.

20. The non-transitory computer-readable storage medium of claim 19, wherein the call comprises a windowing operation or a thread operation.

21. The non-transitory computer-readable storage medium of claim 19, wherein the processor being caused to prevent skipping the marker state point during the replay phase comprises the processor being caused to:

change the unit under test to a state represented by the marker state point;

cause the unit under test to execute the call; and

change the unit under test to the next state point in time after the marker state point.