PROBLEM: fork() & setpriority()

PROBLEM: fork() & setpriority()

[Rommer]

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Hello,

I have trouble with fork() and setpriority().
When priority of child process != priority of parent process
and used SIGCHLD handler.
See example.

kernel 2.6.12.1, no SMP

-- 
Best regards, Roman

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#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

struct sigaction sa_chld;
int i = 0;


static void chld_handler (int signum) {
    int status = 0;
    wait (&status);
    printf ("child closed: status = %i\n", status >> 8);
}


void test (void) {
    pid_t pid = fork ();

    if (pid == 0) {
	setpriority (PRIO_PROCESS, 0, 0);
	printf ("helo from child, i = %i\n", i);
	exit (i);
    }
}


int main () {
    memset (&sa_chld, 0, sizeof (sa_chld));
    sa_chld.sa_handler = &chld_handler;
    sigaction (SIGCHLD, &sa_chld, NULL);

    setpriority (PRIO_PROCESS, 0, -1);
    while (1) {
	i++;
	test ();
	sleep (3);
    }
    return 0;
}

Re: PROBLEM: fork() & setpriority()

[Arjan van de Ven]

On Mon, 2005-07-11 at 13:58 +0300, Rommer wrote:
> Hello,
> 
> I have trouble with fork() and setpriority().
> When priority of child process != priority of parent process
> and used SIGCHLD handler.
> See example.

the example is buggy in that printf() isn't allowed in signal handlers
btw...

Re: PROBLEM: fork() & setpriority()

[Rommer]

Hello,

Arjan van de Ven wrote:
> On Mon, 2005-07-11 at 13:58 +0300, Rommer wrote:
> 
>>Hello,
>>
>>I have trouble with fork() and setpriority().
>>When priority of child process != priority of parent process
>>and used SIGCHLD handler.
>>See example.
> 
> 
> the example is buggy in that printf() isn't allowed in signal handlers
> btw...
> 

ok, you can remove printf() from SIGCHLD handler.

-- 
Best regards, Roman