Mailing-List:	contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe:	<mailto:cygwin-subscribe AT sourceware DOT cygnus DOT com>
List-Archive:	<http://sourceware.cygnus.com/ml/cygwin/>
List-Post:	<mailto:cygwin AT sourceware DOT cygnus DOT com>
List-Help:	<mailto:cygwin-help AT sourceware DOT cygnus DOT com>, <http://sourceware.cygnus.com/ml/#faqs>
Sender:	cygwin-owner AT sourceware DOT cygnus DOT com
Delivered-To:	mailing list cygwin AT sourceware DOT cygnus DOT com
Date:	Tue, 25 Jan 2000 14:07:21 +0300
From:	Pakoulin Konstantin <pakko AT mail DOT ru>
X-Mailer:	The Bat! (v1.36) S/N F29DEE5D / Educational
Reply-To:	Pakoulin Konstantin <pakko AT mail DOT ru>
Organization:	dgap
X-Priority:	3 (Normal)
Message-ID:	<3588.000125@mail.ru>
To:	cygwin AT sourceware DOT cygnus DOT com
Subject:	problem with shared memory under Win9x
Mime-Version:	1.0

Hello,
I use shared memory for IPC in my programm, but it doesnt work under
Win9x. I writed test programm that works well under WinNT but doesnt
work under Win9x:

#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


#define FILENAME "test.bin"
#define FILE_MODE       (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)

int main() {

        if ( fork()!=0 ) {

                // Parent - server
                
                int fd;
                int* mem;
                int z = 0;
        
                fd  = open( FILENAME , O_RDWR | O_CREAT , FILE_MODE );
                write( fd, &z, sizeof(int) );

                mem = mmap( NULL, sizeof(int) , PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        
                close(fd);

                printf("par: Waiting!!\n");

                while(!(*mem)) ;

                // 'mem' equal 0 constantly under Win9x
                
                printf("par: !!!Works Well!!! - %d \n", *mem);

                exit(0);

        } else {

                // Child - client

                int fd;
                int* mem;

                sleep(3);

                fd  = open( FILENAME , O_RDWR | O_CREAT , FILE_MODE );

                mem = mmap( NULL, sizeof(int) , PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        
                close(fd);

                printf("ch: MEM = 3 !!\n");

                *mem = 3;

                exit(0);
        };
}

Do you have any idea ?



--
Want to unsubscribe from this list?
Send a message to cygwin-unsubscribe AT sourceware DOT cygnus DOT com

- Raw text -