I must wrote some code with fork() command. The thing is that i have a while statement which count till 10.
I must wrote a program that one child has only one parent. So one parent has only one child and one child has only one parent. Can you please help me with these code.
I desperately wanted one of the UNIX Gurus to help me resolve my problem asap(I have to deliver the code to the client by Monday 08-oct).
I have a file with around 5 million records (50 lakhs). Now my original process was taking around 30 hours to read the complete file, process each and every... (4 Replies)
I run this code, actually I want to both processes print the message from "data". But only one does. What happens? Anyone can help?
#include <stdio.h>
main(){
int fd, pid;
char x;
fd = open("data",0); /* open file "data" */
pid = fork();
if(pid != 0){
wait(0);
... (2 Replies)
Hi,
I am trying to attach tape drive to sun V890 running Solaris 9 on it.
I have installed HBA(qlogic) in slot 1 of 0-8 slots and booted the system. I do not see HBAin prtdiag output. The tape drive is not attached to HBA. The tape drive I am going to attach is Sony AIT3.
1.How can I make... (3 Replies)
Hi,
I wrote a simple program for understanding the fork command. The code is as below
int main(void)
{
fork(); printf("hi 1 \n");
fork(); printf("hi 2 \n");
fork(); printf("hi 3 \n");
}
I am getting a variation in the number of times the printf is called if i remove the \n from each of... (1 Reply)
Hi,
I wrote a simple program for understanding the fork command. The code is as below
int main(void)
{
fork(); printf("hi 1 \n");
fork(); printf("hi 2 \n");
fork(); printf("hi 3 \n");
}
I am getting a variation in the number of times the printf is called if i remove the \n from each... (2 Replies)
I'm trying to run a simple test on how to use fork(), i'm able to execute the child process first then the parent, but how can I execute parent then child..?
Thanks! (1 Reply)
I understand that fork create a child but I need very simple example that make child useful....
I mean how will make the program faster anyone explain with code plz
using C plz (2 Replies)
I am trying to write a shell script which takes an input file as an arguement in the terminal e.g. bash shellscriptname.sh input.txt. I would like for the file to be read line by line each time checking if the .txt file contains certain words or letters(validating the syntax). If the line being... (1 Reply)
Discussion started by: Gurdza32
1 Replies
LEARN ABOUT X11R4
pthread_atfork
PTHREAD_ATFORK(3) Library Functions Manual PTHREAD_ATFORK(3)NAME
pthread_atfork - register handlers to be called at fork(2) time
SYNOPSIS
#include <pthread.h>
int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));
DESCRIPTION
pthread_atfork registers handler functions to be called just before and just after a new process is created with fork(2). The prepare han-
dler will be called from the parent process, just before the new process is created. The parent handler will be called from the parent
process, just before fork(2) returns. The child handler will be called from the child process, just before fork(2) returns.
One or several of the three handlers prepare, parent and child can be given as NULL, meaning that no handler needs to be called at the cor-
responding point.
pthread_atfork can be called several times to install several sets of handlers. At fork(2) time, the prepare handlers are called in LIFO
order (last added with pthread_atfork, first called before fork), while the parent and child handlers are called in FIFO order (first
added, first called).
To understand the purpose of pthread_atfork, recall that fork(2) duplicates the whole memory space, including mutexes in their current
locking state, but only the calling thread: other threads are not running in the child process. The mutexes are not usable after the fork
and must be initialized with pthread_mutex_init in the child process. This is a limitation of the current implementation and might or
might not be present in future versions.
RETURN VALUE
pthread_atfork returns 0 on success and a non-zero error code on error.
ERRORS
ENOMEM insufficient memory available to register the handlers.
AUTHOR
Xavier Leroy <Xavier.Leroy@inria.fr>
SEE ALSO fork(2), pthread_mutex_lock(3), pthread_mutex_unlock(3).
LinuxThreads PTHREAD_ATFORK(3)