VMS Help DCE_THREADS, Application Routines, exceptions *Conan The Librarian (sorry for the slow response - running on an old VAX) |
NAME exceptions - Exception handling in DCE Threads DESCRIPTION DCE Threads provides the following two ways to obtain information about the status of a threads routine: o The routine returns a status value to the thread. o The routine raises an exception. Before you write a multithreaded program, you must choose only one of the preceding two methods of receiving status. These two methods cannot be used together in the same code module. The POSIX P1003.4a (pthreads) draft standard specifies that errors be reported to the thread by setting the external variable errno to an error code and returning a function value of -1. The threads reference pages document this status value-returning interface. However, an alternative to status values is provided by DCE Threads in the exception-returning interface. Access to exceptions from the C language is defined by the macros in the exc_handling.h file. The exc_handling.h header file is included automat- ically when you include pthread_exc.h. To use the exception-returning interface, replace #include <pthread.h> with the following include statement: #include <pthread_exc.h> The following example shows the syntax for handling exceptions: TRY try_block [CATCH (exception_name) handler_block]... [CATCH_ALL handler_block] ENDTRY
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