DCE Application Programming Guide

Application Programming With NonStop DCE
Threads
HP NonStop DCE Application Programming Guide—429551-003
3-2
Threads Error Reporting
Threads Error Reporting
Like OSF DCE threads, the NonStop DCE threads API procedures can return error
indications in either of two ways:
•
Error status (using the errno variable)
With this method, the threads procedures return -1 to indicate an error condition
(instead of returning 0). The procedures set errno with the error status before
returning.
To use the error status method, a program must include the pthread.h
header file.
•
Exceptions
With this method, the threads functions report errors by raising an exception.
To use the exception method, a program must include the pthread_exc.h
header file.
All programs that use the NonStop DCE threads API must include either the
pthread.h header file or the pthread_exc.h header file, but not both. The threads
API procedure prototypes are the same in both files; the only difference is in how
failures are reported.
Signal Handling
Signal handling for NonStop DCE threads is the same as for OSF DCE threads:
•
Synchronous signals represent events that occur inside a process.
Synchronous signals occur immediately after the instruction that caused the
event—for example, attempting to divide by zero. A synchronous signal is
associated with the thread that is executing when the event occurs. A thread can
install signal handlers (using the sigaction() function) for the synchronous
signals that occur during its execution. For terminating signals, the default action is
to terminate the process.
•
Asynchronous signals represent events external to the process.
A thread can wait for a set of asynchronous signals using the sigwait() function.
If a thread is waiting for the type of signal that is received, the thread is awakened
SQL cursors Global
Environment variables Global
Signal mask Global
Table 3-1. Process Resource Types (page 2 of 2)
Resource Type Description