Foundation Classes, Standard_ErrorHandler - use thread_local stack instead of global mutex lock

[dpasukhi]

Refactored Standard_ErrorHandler to use thread_local storage for the error handler stack instead of a global list protected by mutex. This eliminates locking overhead entirely since each thread only accesses its own error handlers.

Changes:

• Replaced global mutex-protected stack with thread_local Top pointer
• Simplified FindHandler() to directly return the thread-local Top
• Removed Catches() and LastCaughtError() methods (no longer needed)
• Added Raise() method for re-throwing caught exceptions
• Removed obsolete member variables: myStatus, myThread
• Deleted unused headers: Standard_HandlerStatus.hxx, Standard_JmpBuf.hxx, Standard_PErrorHandler.hxx
• Updated OCC_CATCH_SIGNALS macro to use new Raise() method

[Copilot]

Pull request overview

This pull request refactors the error handling mechanism in OCCT's Standard_ErrorHandler class to improve performance in multi-threaded environments. The primary change replaces a global mutex-protected error handler stack with thread-local storage, eliminating synchronization overhead since each thread now only accesses its own error handlers.

Key Changes

• Converted the global error handler stack from a mutex-protected list to a thread_local pointer, removing all locking overhead
• Simplified the FindHandler() method to directly return the thread-local top handler
• Removed obsolete code including unused methods (Catches(), LastCaughtError()), member variables (myStatus, myThread), and header files

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Standard_PErrorHandler.hxx	Deleted obsolete typedef header file
Standard_JmpBuf.hxx	Deleted obsolete jump buffer typedef header file
Standard_HandlerStatus.hxx	Deleted obsolete handler status enum header file
Standard_Failure.cxx	Removed redundant Error() call before Abort() in Jump() method
Standard_ErrorHandler.hxx	Updated class interface to remove mutex includes, simplify members, and add Raise() method
Standard_ErrorHandler.cxx	Refactored implementation to use thread-local storage and simplified handler lookup logic
FILES.cmake	Removed deleted header files from build configuration

[Copilot]

Corrected 'not exception object' to 'no exception object' for grammatical correctness.

Suggested change

	std::cerr << "*** Abort *** an exception handler was called, but not exception object is set."
	std::cerr << "*** Abort *** an exception handler was called, but no exception object is set."

[Copilot]

The recovery action in the assertion (unlinking handlers until reaching this) could lead to undefined behavior if the handler is not in the stack at all. The loop doesn't update Top correctly and may cause infinite iteration. Consider adding a safety check to break the loop if we traverse the entire stack without finding this.

[Copilot]

The if-else statement without braces violates common C++ style guidelines, particularly for multi-line else blocks. Add braces around both branches for clarity and consistency.