Declarative state space reduction in a transactional messaging language

• US 20040261066A1
• Filed: 06/18/2003
• Published: 12/23/2004
• Est. Priority Date: 06/18/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Maybee, Paul, Mehta, Bimal, McCrady, Donald James, Ringseth, Paul F.
• Granted Patent: US 7,343,589 B2
• Time in Patent Office: Days
• US Class Current: 717/141
• CPC Class Codes: G06F 8/43 Checking; Contextual analysis

Abstract

A XLANG/s compiler recognizes a statement in XLANG/s code to make an assumption as to the success or failure of a specified transaction. The assignment states of variables are tracked and changes to such states are recorded. While processing XLANG/s code, the compiler determines whether the assignment state of a particular correlation, operation or the like is correct for the transaction being performed. If not, the compiler may generate an error message. Moreover, by using declarative assumptions such as if(succeeded(T)) or if(!succeeded(T)), definite-assignment analysis of shared state variables may cross transactional boundaries.

Claims

1. A computer-implemented method of processing a computer language, comprising:

reading computer code comprising at least one variable and a code transaction;

detecting a statement within the code, wherein the statement specifies the code transaction and indicates that in a first logic path an exception occurred in the code transaction and in a second logic path an exception did not occur in the code transaction;

analyzing the code transaction according to each logic path and determining an assignment state of the at least one variable in the first and second logic paths;

merging the assignment state of the at least one variable as determined in the first logic path with the assignment state of the at least one variable as determined in the second logic path; and

determining whether a function is performed within the code with respect to the variable while the variable has a merged assignment state being an incorrect assignment state and, if so, declaring the function to be invalid.

2. The computer-implemented method of claim 1, wherein the method is implemented by a compiler.

3. The computer-implemented method of claim 1, wherein the method is a compilation process.

4. The computer-implemented method of claim 1, further comprising generating an error message according to the declaration.

5. The computer-implemented method of claim 2, wherein the error message comprises an error type and location of the error within the code.

6. The computer-implemented method of claim 2, wherein the error message identifies the merged assignment state of the at least one variable.

7. The computer-implemented method of claim 6, wherein the error message indicates the function that is performed within the code with respect to the variable while the variable has a merged assignment state being an incorrect assignment state

8. The computer-implemented method of claim 1, wherein the statement is an if(succeeded) statement.

9. The computer-implemented method of claim 1, wherein the determination is made based on the function being a reference to the at least one variable and the incorrect assignment state being an unassigned or indeterminate state.

10. The computer-implemented method of claim 1, wherein the at least one variable is a correlation.

11. The computer-implemented method of claim 10, wherein the determination is made based on the function being an initialization of the correlation and the incorrect assignment state being true.

12. The computer-implemented method of claim 10, wherein the determination is made based on the function being a reference to the correlation and the incorrect assignment state being false.

13. The computer-implemented method of claim 10, wherein the determination is made based on the function being either an initialization or reference to the correlation and the incorrect assignment state being indeterminate.

14. The computer-implemented method of claim 1, wherein the at least one variable is a request-response operation.

15. The computer-implemented method of claim 14, wherein the determination is made based on the function being a send and the incorrect assignment state being true.

16. The computer-implemented method of claim 14, wherein the determination is made based on the function being a receive and the incorrect assignment state being false.

17. The computer-implemented method of claim 14, wherein the determination is made based on the function being either a send or a receive and the incorrect assignment state being indeterminate.

18. The computer-implemented method of claim 14, wherein the determination is made based on the function being leaving the processing of the request-response operation and the incorrect assignment state being either true or indeterminate.

19. The computer-implemented method of claim 1, wherein the code is XLANG/s.

20. The computer-implemented method of claim 19, wherein the compiler is a XLANG/s compiler.

21. A method of compiling a XLANG/s program, comprising:

(a) reading XLANG/s code comprising at least one variable, a code transaction and at least one of an if(succeeded(n)) statement or an if(!succeeded(n)) statement;

(b) detecting, using a XLANG/s compiler, the if(succeeded(n)) or if(!succeeded(n)) statement, where n denotes the code transaction;

(c) assuming, if the if(succeeded(n)) statement was detected, that the code transaction executed without error or, if the if(!succeeded(n)) statement was detected, assuming that an error occurred with respect to the execution of the code transaction;

(d) determining an assignment state of the at least one variable according to the assumption of step (c); and

(e) determining whether a pending operation can be completed subject to the assignment state of the at least one variable determined in step (d) and, if the pending operation cannot be completed, declaring the pending operation to be invalid.

22. The method of claim 21, further comprising generating an error message according to the declaration of step (e).

23. The method of claim 22, wherein the error message comprises an error type and location of the invalid pending operation within the XLANG/s code.

24. The method of claim 22, wherein the error message identifies the at least one variable.

25. The method of claim 22, wherein the error message indicates the at least one variable as being referenced in the computer code while having the assignment state as determined in step (d) being an incorrect assignment state.

26. The method of claim 21, wherein the declaration of step (e) is made based on the pending operation being a reference to the at least one variable and the assignment state determined in step (d) being an unassigned or indeterminate state.

27. The method of claim 21, wherein the at least one variable is a correlation.

28. The method of claim 27, wherein the declaration of step (e) is made based on the pending operation being an initialization of the correlation and the assignment state determined in step (d) being true.

29. The method of claim 27, wherein the declaration of step (e) is made based on the pending operation being a reference to the correlation and the assignment state determined in step (d) being false.

30. The method of claim 27, wherein the declaration of step (e) is made based on the pending operation being either an initialization or a reference to the correlation and the assignment state determined in step (d) being indeterminate.

31. The method of claim 21, wherein the at least one variable is a request-response operation.

32. The method of claim 31, wherein the declaration of step (e) is made based on the pending operation being a send and the assignment state determined in step (d) state being true.

33. The method of claim 31, wherein the declaration of step (e) is made based on the pending operation being a receive and the assignment state determined in step (d) state being false.

34. The method of claim 31, wherein the declaration of step (e) is made based on the pending operation being either a send or a receive and the assignment state determined in step (d) being indeterminate.

35. The method of claim 31, wherein the declaration of step (e) is made based on the pending operation being leaving the processing of the request-response operation and the assignment state determined in step (d) being either true or indeterminate.

36. A computer-readable medium having computer-executable instructions for performing a method of compiling a XLANG/s program, the method comprising:

(a) reading XLANG/s code comprising at least one variable, a code transaction and at least one of an if(succeeded(n)) statement or an if(!succeeded(n)) statement;

(b) detecting, using a XLANG/s compiler, the if(succeeded(n)) or if(!succeeded(n)) statement, where n denotes the code transaction;

(c) assuming, if the if(succeeded(n)) statement was detected, that the code transaction executed without error or, if the if(!succeeded(n)) statement was detected, assuming that an error occurred with respect to the execution of the code transaction;

(d) determining an assignment state of the at least one variable according to the assumption of step (c); and

(e) determining whether a pending operation can be completed subject to the assignment state of the at least one variable determined in step (d) and, if the pending operation cannot be completed, declaring the pending operation to be invalid.

37. The computer-readable medium of claim 36, wherein the method further comprises generating an error message according to the declaration of step (e).

38. The computer-readable medium of claim 37, wherein the error message comprises an error type and location of the invalid pending operation within the XLANG/s code.

39. The computer-readable medium of claim 37, wherein the error message identifies the at least one variable.

40. The computer-readable medium of claim 37, wherein the error message indicates the at least one variable as being referenced in the computer code while having the assignment state as determined in step (d) being an incorrect assignment state.

41. The computer-readable medium of claim 36, wherein the declaration of step (e) is made based on the pending operation being a reference to the at least one variable and the assignment state determined in step (d) being an unassigned or indeterminate state.

42. The computer-readable medium of claim 36, wherein the at least one variable is a correlation.

43. The computer-readable medium of claim 42, wherein the declaration of step (e) is made based on the pending operation being an initialization of the correlation and the assignment state determined in step (d) being true.

44. The computer-readable medium of claim 42, wherein the declaration of step (e) is made based on the pending operation being a reference to the correlation and the assignment state determined in step (d) being false.

45. The computer-readable medium of claim 42, wherein the declaration of step (e) is made based on the pending operation being either an initialization or a reference to the correlation and the assignment state determined in step (d) being indeterminate.

46. The computer-readable medium of claim 36, wherein the at least one variable is a request-response operation.

47. The computer-readable medium of claim 46, wherein the declaration of step (e) is made based on the pending operation being a send and the assignment state determined in step (d) state being true.

48. The computer-readable medium of claim 36, wherein the declaration of step (e) is made based on the pending operation being a receive and the assignment state determined in step (d) state being false.

49. The computer-readable medium of claim 36, wherein the declaration of step (e) is made based on the pending operation being either a send or a receive and the assignment state determined in step (d) being indeterminate.

50. The computer-readable medium of claim 36, wherein the declaration of step (e) is made based on the pending operation being leaving the processing of the request-response operation and the assignment state determined in step (d) being either true or indeterminate.