tango.net.Socket

gim Joined: 06/06/07 Posts: 8

Posted: 12/14/07 11:17:03 Modified: 03/09/08 13:37:44 Hi there, I think there's a problem with Nethost.getHostByName (and probably also, other synchronized methods) From what is written in: here if I understand correctly method with synchronized attribute is synchronized only on per-class-instance basis. I suggest changing getHostByName from current: synchronized bool getHostByName(char[] name) { char[1024] tmp; hostent* he = gethostbyname(convert2C (name, tmp)); if(!he) return false; validHostent(he); populate(he); return true; } to: bool getHostByName(char[] name) { char[1024] tmp; hostent* he; synchronized { he = gethostbyname(convert2C (name, tmp)); if(!he) return false; validHostent(he); populate(he); } return true; } The same reffers to getHostByAddr. If it's required I think, I could provide simple test-case for this issue.

Author	Message
gim Joined: 06/06/07 Posts: 8	Posted: 02/27/08 18:21:10 -- Modified: 02/27/08 18:22:02 by gim Hi again, since noone replied to this, and I see the code hasn't changed in svn, here is testcase: http://paste.dprogramming.com/dpf8jbb9 The programm on paste, should randomly crash with segmentation fault (at least on linux, I have no idea if windows has synchronous resolver), due to bad scope of synchronized as described in previous post. Please run it a few times, or add more hostnames in order to crash :]. edit Oh forgot to mention, that it doesn't crash after proposed fix.
kris Joined: 03/27/04 Posts: 581	Posted: 02/27/08 21:24:21 Hiya, Thanks, gim. You're right, and that's a bad oversight on our part. it needs to be synchronized on a single global instance of something. If I recall correctly, we can do something like synchronized(Socket.class) {}
kris Joined: 03/27/04 Posts: 581	Posted: 02/28/08 04:15:49 SVN trunk should be ok now
gim Joined: 06/06/07 Posts: 8	Posted: 02/28/08 11:54:54 thanks! I think there can be also problem with another synchronized method toAddrString in IPv4Address (also Socket.d), since inet_ntoa doesn't have to be thread safe, but I must say I haven't tested how it behaves.