Open System Services System Calls Reference Manual (G06.29+, H06.08+, J06.03+)

wait(2) OSS System Calls Reference Manual
RETURN VALUES
If the wait() function returns because the status of a child process is available, the OSS process
ID of the child is returned to the calling process. If a signal is received via pthread_kill(2) that
is not blocked,ignored, or handled, -1 is returned with an errno of EINTR.
Upon any error, the value -1 is returned and errno is set to indicate the error.
ERRORS
If any of the following conditions occurs, the wait( ) function sets errno to the corresponding
value:
[ECHILD] The calling process has no existing unwaited-for child processes.
[EFAULT] The buffer pointed to by the status_location parameter failed bounds checking.
[EINTR] The function was terminated by receipt of a signal. The information pointed to
by the status_location parameter is not meaningful when this error occurs and
should not be used in further processing.
[ENOTOSS] The calling process was not an OSS process. The wait() function cannot be
used in the Guardian environment.
RELATED INFORMATION
Functions: exec(2), _exit(2), exit(3), fork(2), spt_waitpid(2), pause(3), sigaction(2),
tdm_execve(2), tdm_execvep(2), tdm_fork(2), tdm_spawn(2), tdm_spawnp(2), waitpid(2).
STANDARDS CONFORMANCE
The POSIX standards leave some features to the implementing vendor to define. The following
features are affected in the HP implementation:
• The POSIX.1 standard states that when status information for two or more child
processes is available, the order in which the information is returned by the wait() func-
tion is unspecified. HP’s implementation also does not provide this information in a
specified sequence. The sequence should therefore not be depended upon for further
processing.
• In addition to the status information mandated by the POSIX.1 standard, the HP imple-
mentation also returns status information for processes that terminate as a result of Guar-
dian procedure calls. In addition, status is returned for processes that terminate abnor-
mally as a result of a situation that is unique to NonStop server architecture, such as
failure of the child process’s processor while the parent process continues to execute.
• The POSIX.1 standard indicates that the value in the location pointed to by the
status_location parameter is undefined when errno returns the value [EINTR]. HP’s
implementation also does not return meaningful information, and the value should not be
used for further processing.
This function does not conform to the async-signal safe requirement of the POSIX.1 standard.
10−6 Hewlett-Packard Company 527186-023