HP DCE/9000 Application Development Tools for HP-UX 11i Release Note

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HP DCE/9000 Version 1.8 Application Development Tools for HP-UX 11i Release Note
Developing DCE Applications with HP DCE/9000
Because the semop() wrapper adds the IPC_NOWAIT option before performing the semop()
system call, the value of semncnt and semzcnt should not be trusted when using semop() to
perform semaphore operations.
signal()
Use of the signal() system call is not supported by HP DCE Threads, as it can interfere with
signal handlers that are installed by Threads. In some cases, you can retain signal() calls in
legacy code as follows:
• Implement a wrapper for signal() that calls sigaction() or - sigwait().
• Use signal() itself to install a handler for a signal, provided the signal is not SIGVTALRM,
SIGCHLD, or SIGSYS, and provided no thread installs a handler for the signal with
sigaction() or waits for the signal with sigwait().
system()
The HP DCE Threads system() wrapper does not block SIGCHLD. It does set the handler for
SIGQUIT and SIGINT to SIG_IGN, but only for the calling thread. This behavior differs from
the behavior of the standard HP-UX version of system().
vfork()
The HP DCE Threads vfork() wrapper cannot be circumvented. The methods used to
circumvent other wrappers (defining _CMA_NOWRAPPERS_, undefining vfork, defining
vfork to be _vfork_sys) do not work.