Ensure the program runs continuously.
This library provides few utility functions which enable you to invoke a function and ensure it continues to execute.
In case the function exists due to a crash or simply because it finished, the forever library will reinvoke it.
The forever function provides control over the amount of retries and time to wait between intervals via parameters or via callback for a more
fine grained control.
The provided function is invoked as a forked process, so any crash is caught and when restarts, it will be started as a new process with a new state.
#include "forever.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
void my_program(void *context)
{
if (context != NULL)
{
// do something with the context
}
sleep(1);
exit(0);
}
int callback(void *context, const unsigned char started, int stat_loc)
{
if (context != NULL)
{
// do something with the context
}
if (stat_loc == 0 || !started)
{
return(-1); // no more retries
}
return(500); // wait 500 millies before next invocation, 0 for no wait.
}
int main()
{
void *context = NULL;
// call 'my_program' and when it ends/crashes invoke it again, up
// to 10 times and wait 250 millies between invocations.
// counter will hold the amount of times 'my_program' was invoked.
unsigned int counter = forever_with_options(
my_program, // function to invoke
context, // context that is passed to the function on every invocation
10, // max amount of retries. 0 for unlimited retries.
250 // amount of millies to wait between invocations. 0 for no wait.
);
printf("Invoked %u time/s.\n", counter);
// call 'my_program' and when it ends/crashes call the provided callback
counter = forever_with_callback(my_program, context, callback);
printf("Invoked %u time/s.\n", counter);
// run with unlimited retries and no delay between invocations
forever(my_program, context);
}See Changelog
Developed by Sagie Gur-Ari and licensed under the Apache 2 open source license.