Date: Tue, 11 Apr 2000 18:26:49 -0700 (PDT) From: Ming Zhang <ming@yahoo-inc.com> To: freebsd-hackers@freebsd.org Subject: Multithread safe gethostbyname() ? Message-ID: <Pine.BSF.4.10.10004111813310.81762-100000@pious.yahoo.com>
next in thread | raw e-mail | index | archive | help
Is there a MT-safe implementation of gethostbyname() in FreeBSD (3.4/4.0)?
On Solaris there is gethostbyname_r(). Calling gethostbyname() with in
two threads cause both threads to block.
I know the "struct hostent" is static in gethostbyname(), however it seems
like the socket that is used to get the DNS info is static too.
Attached it's the code I used for testing:
-----
#include <stdio.h>
#include <netdb.h>
#include <pthread.h>
void vserv_request (void *d)
{
printf ("before byname\n");
gethostbyname ("test.exampledomain.com"); /* real host removed */
printf ("after byname\n");
}
int create_request_thread (void)
{
pthread_t t_id;
pthread_attr_t t_attr;
int i = 0;
pthread_attr_init (&t_attr);
for (i = 0; i < 2; i++) {
if (pthread_create(&t_id, &t_attr, vserv_request, (void *) NULL)
!= 0)
return (-1);
}
return (0);
}
void main (void)
{
create_request_thread();
sleep (10000); /* I know sleep() is bad, just for the test */
}
------
both threads block after print "before byname". tested on both 3.4-stable
and 4.0-stable (as of april 10th).
any hints?
Thanks
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.10.10004111813310.81762-100000>