Thread: SIGCHLD handler not executing dependably

Hi, I'm trying to figure out how to use a SIGCHLD handler to execute reliably when a child worker process exits for use in larger projects, but this simple test isn't working. Since sigchld++ is executed every time the sig handler is called, and it fork()'s twice, I would expect it to print 2 every time, but it doesn't. Usually it's 2, but maybe 1/5 times it prints 1.

Code:

#include <iostream>

#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

using namespace std;

int sigchld = 0;
void sigchld_handler(int signal){
    sigchld++;
}

int main(){
    signal(SIGCHLD, sigchld_handler);
    if(fork() & fork()){
        unsigned int leftover = 1;
        while((leftover = sleep(leftover))); // The sleep is to allow both children time to exit.
        cout << sigchld << endl;
    }
    return 0;
}