5 Using the DECthreads Exception Package

This chapter introduces conventions for the modular use of exceptions.

Although the POSIX 1003.1c interface reports errors by returning non-zero failure codes, DECthreads uses exceptions in the following cases:

• The pthread exit function raises an exception to allow modular cleanup.

• Cancellation of a thread results in raising an exception to allow modular cleanup.

• On Digital UNIX, the synchronous signals (for example, SIGSEGV) are converted to exceptions unless a signal action is declared.

The DECthreads exception package is most useful when you are programming in the C language or for other cross-platform routines using the pthread interface. On OpenVMS systems, you can use the OpenVMS condition-handling facility to catch exceptions. On Digital UNIX systems, you can use the C language exception library to catch exceptions; you cannot use the C++ language exception library.