Structured Exception Handling (SEH) is a Microsoft-specific extension to C and C++ designed to handle exceptional code situations, particularly hardware faults, in Windows operating systems14. It serves as a generalized error handling mechanism supported by the Windows OS and is part of the Windows Application Binary Interface (ABI)3.

Key features of SEH include:

  1. Hardware fault handling: SEH can catch CPU exceptions such as access violations, illegal instructions, and divide-by-zero errors4.
  2. OS-level mechanism: Unlike C++ exception handling, SEH is an operating system feature not tied to any specific programming language3.
  3. Per-thread basis: SEH works on a per-thread basis, with each thread containing its own Structured Exception Handling mechanism3.
  4. Untyped exceptions: SEH exceptions are not typed but share a common data structure containing an exception code and additional information about the fault4.
  5. First-chance handling: SEH allows for logging or handling exceptions before stack unwinding destroys local variables4.
  6. Finally mechanism: SEH includes a “finally” mechanism not present in standard C++ exceptions5.

While SEH is supported by Windows and Microsoft C++, it is generally recommended to use ISO-standard C++ exception handling for better portability and flexibility1. However, SEH may still be necessary for maintaining existing code or for specific types of programs that require low-level exception handling capabilities14.