DESCRIPTION
This module provides asynchronous notification for exiting processes in
case of normal and abnormal terminations. It must be noted that this
uses the AEM notification mechanism. The monitored (or client) processes
require NO preparation and can be already be running. Notification is
direct and asynchronous. The handler registered by the server process
receives the pid of the
dying process as well as its terminating code status in parameter.
DEFINITIONS
#include <aem.h>
This file is located in the directory {AEMSRC}/include/user in the AEM
source package. It must be installed and included with your source code.
libaem
This is the AEM library. It is located in
the directory {AEMSRC}/lib
in the AEM source package. It must be installed and linked with your
source code.
INTERFACES
The
following set of API is provided by libaem.
int aemPEXIT_init (void);
Initialize the aem-pexit functionality.
int
aemPEXIT_notify_register (int, void *)
This call register a handler specified in the second parameter to be
called when the process, pid specified in the first parameter terminates.
The handler prototype is:
void
handler (int event_id, int process_id, int exit_code)
The first
parameter is the event Id, the second parameter is the process id (pid)
of the terminating process and the last parameter is its exit code.
EXAMPLE
The following example illustrates a server that gets asynchronous
notification for process death using AEM. This example is also available
in the examples that come with the source package.
#include <aem.h>
void pexit (int ed, int pid, int exit_code)
{
printf ("pexit: process [%d] terminated with
code=%d\n", pid, exit_code);
}
/*
* Install a handler for the process given in parameter.
*
* call: pexit1 <pid>
*/
main (int argc, char **argv)
{
int pid;
if (argc != 2) {
printf ("Usage: pexit1
<pid>\n");
return;
}
aemPEXIT_init ();
pid = atoi (argv[1]);
if (pid > 0) {
int id = aemPEXIT_notify_register
(pid, pexit);
if (id < 0) {
perror ("");
exit (1);
}
if (aemCORE_event_start (id) <
0) {
perror ("");
exit (1);
}
aemCORE_pause ();
}
}
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