Non-interfering status inquiry for user threads

• US 20050198080A1
• Filed: 10/21/2003
• Published: 09/08/2005
• Est. Priority Date: 10/21/2003
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Cai, Weidong
• Granted Patent: US 7,249,348 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program

Abstract

One embodiment disclosed relates to a method of obtaining status information from user threads of a target process. A system call is performed from a querying process. The system call creates a kernel debug thread in a kernel entity of the target process. The kernel debug thread further creates a user status thread in a user entity of the target process. The method may be used to obtain the status information without stopping the target process. Another embodiment disclosed relates to an operating system with capability to obtain status information from user threads of a target process. The operating system includes at least the following first and second system calls. The first system call is configured to create a kernel debug thread in a kernel entity of the target process. The second system call is configured to awake the kernel debug thread and pass information to the kernel debug thread.

Claims

1. A method of obtaining status information from user threads of a target process, the method comprising:

performing a system call from a querying process;

creating a kernel debug thread in a kernel entity of the target process; and

creating a user status thread in a user entity of the target process.

2. The method of claim 1, wherein the method does not require stopping of the target process.

3. The method of claim 1, further comprising:

the user status thread collecting status information from other user threads of the target process.

4. The method of claim 3, further comprising:

passing the collected status information from the user status thread to the kernel debug thread.

5. The method of claim 4, wherein the user status thread goes into a sleep state after passing the collected status information to the kernel debug thread.

6. The method of claim 4, further comprising:

relaying the collected status information from the kernel debug thread to the querying process.

7. The method of claim 6, wherein the kernel debug thread goes into a sleep state after relaying the collected status information to the querying process.

8. The method of claim 1, wherein the method is performed in conjunction with an operating system having an M×

N thread model.

9. The method of claim 1, wherein the kernel debug thread is created by the system call.

10. The method of claim 1, wherein the user status thread is first created in the kernel entity as a scheduler activation and then comes up to the user entity via an upcall handler.

11. The method of claim 1, wherein the status information does not relate to registers of the user threads, and wherein none of the user threads need to be halted.

12. The method of claim 1, wherein the status information relates to at least one register of a user thread, and wherein the user thread is temporarily suspended.

13. An operating system with capability to obtain status information from user threads of a target process, the operating system:

a first system call configured to create a kernel debug thread in a kernel entity of the target process; and

a second system call configured to awake the kernel debug thread and pass information to the kernel debug thread.

14. The operating system of claim 13, further comprising:

a thread library configured to register a user status thread'"'"'s stack and data memory.

15. The operating system of claim 14, further comprising:

a body function in a thread library which is configured to sleep until awaken to act upon a user thread status inquiry.