process

Functionality for starting and stopping processes. More...

Functions
bool	ua_process_support_forking (void)
	Return true if the other functions for starting and stopping processes are implemented, false otherwise.
void	ua_process_install_sigchild_handler (void)
	Install handler for child related signals. More...
ua_pid_t	ua_process_start (const char *filename, int argc, const char *argv[])
	Forks a new child process and executes the given executable file. More...
int	ua_process_terminate (ua_pid_t pid)
	Terminates a process. More...
int	ua_process_kill (ua_pid_t pid)
	Kills a process that ignores the terminate call. More...
ua_pid_t	ua_process_own_pid (void)
	Returns the current process id.

Detailed Description

Functionality for starting and stopping processes.

ua_pid_t pid;
if (ua_process_support_forking()) {
    // install signal handler
    ua_process_install_sigchild_handler();
    // start a new process
    pid = ua_process_start("my_process");
    if (pid != UA_PROCESS_PID_INVALID) {
        // stop the new process
        ua_process_terminate(pid);
    }
}

Plaforms which don't support multiple process or forking should return false ua_process_support_forking and simply return 0 in all other functions to make these operations a NOP.

Function Documentation

void ua_process_install_sigchild_handler

(

void

)

Install handler for child related signals.

Must be be done before starting a new process with ua_process_start.

int ua_process_kill

(

ua_pid_t

pid

)

Kills a process that ignores the terminate call.

This way the process gets killed by the OS.

Parameters

pid	Process id of the process to kill.

Returns

Zero on success or errorcode on failure.

ua_pid_t ua_process_start	(	const char *	filename,
		int	argc,
		const char *	argv[]
	)

Forks a new child process and executes the given executable file.

Returns

The process id or UA_PROCESS_PID_INVALID in case of an error.

int ua_process_terminate

(

ua_pid_t

pid

)

Terminates a process.

This way the process can gracefully shut down.

Parameters

pid	Process id of the process to terminate.

Returns

Zero on success or errorcode on failure.