Date: Fri, 14 Jun 1996 18:27:37 +1000 (EST) From: John Birrell <cimaxp1!jb@werple.net.au> To: hackers@FreeBSD.org Cc: jb@cimlogic.com.au Subject: Nonblocking writes to pipes hang Message-ID: <199606140826.SAA21378@melb.werple.net.au>
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G'day,
We're having problems with non-blocking writes to pipes under
FreeBSD 2.1R and 2.2-current (supped middle of last week). The
test program (below) gives the following results:
OSF/1 V3.1 65536 bytes written to pipe
HPUX V10.01 8192 bytes written to pipe
NetBSD 1.1A/i386 4096 bytes written to pipe
The program on either FreeBSD 2.1R or 2.2-current just hangs.
Only a kill -9 will interrupt it.
Can anyone explain what is going on?
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
int
main()
{
char *p_buff;
int desc[2];
int ierr = 0;
long num;
size_t buffsize = 100000;
if ((p_buff = (char *) malloc(buffsize)) == NULL) {
printf("Error allocating %lu bytes\n", (unsigned long) buffsize);
ierr = 1;
} else {
memset(p_buff, 'a', buffsize);
*(p_buff + buffsize - 1) = '\0';
if (pipe(desc) != 0) {
printf("Error %d from pipe()\n", errno);
ierr = 1;
} else if (fcntl(desc[1], F_SETFL, O_NONBLOCK) != 0) {
printf("Error %d from pipe()\n", errno);
ierr = 1;
} else if ((num = write(desc[1], p_buff, buffsize)) < 0) {
printf("Error %d from write()\n", errno);
ierr = 1;
} else {
printf("%ld bytes written to pipe\n", num);
}
}
return (ierr);
}
Thanks,
--
John Birrell CIMlogic Pty Ltd
jb@cimlogic.com.au 119 Cecil Street
Ph +61 3 9690 6900 South Melbourne Vic 3205
Fax +61 3 9690 6650 Australia
Mob +61 18 353 137
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