Add gap synchronization check to stop concurrent solvers

[zengbin5966]

This commit introduces a mechanism to enhance the synchronization process of the SYNCSTORE among concurrent solvers. It checks if the latest gap in the SYNCSTORE meets the predefined limit_gap. If the condition is satisfied, the commit stops updating the shared cache and terminates all ongoing concurrent solver processes.

The changes include:

• A new function in syncstore.c that compares the current concurrent gap with the limit_gap and sets the syncstore's stopped flag accordingly.
• Integration of this check within the synchronization logic to ensure timely termination of solvers when the gap criterion is met.

This improvement aims to optimize resource utilization by preventing unnecessary computations once the desired gap threshold is achieved.

[zengbin5966]

Upon reviewing the multi-threaded version of the SCIP using TPI=TNY, it was observed that the solving process did not correctly and promptly cease when the gap reached the specified limit_gap. This could lead to unnecessary computational resources being used and longer solve times.

[ambros-gleixner]

Thank you!

• Can you please revise according to my comments and add a CHANGELOG message to the appropriate section?
• Also, I would consider this to go onto the bugfix branch v91-bugfix, can you rebase your changes?

[zengbin5966]

Thank you!

• Can you please revise according to my comments and add a CHANGELOG message to the appropriate section?
• Also, I would consider this to go onto the bugfix branch v91-bugfix, can you rebase your changes?

OK，I‘ll check it again