On Mon, 10 Feb 2003, Ajay Nerurkar wrote: > Is Cygwin's gethostbyname thread-safe? From a web search I got the > impression that it wasn't and also that Cygwin does not have its > reentrant version gethostbyname_r. So, what does one do? > > Ajay
Ajay, Looking at the code (src/winsup/cygwin/net.cc), 964:#ifdef _MT_SAFE 965:#define hostent_buf _reent_winsup ()->_hostent_buf 966:#else 967:static struct hostent *hostent_buf = NULL; 968:#endif 969: 970:/* exported as gethostbyname: standards? */ 971:extern "C" struct hostent * 972:cygwin_gethostbyname (const char *name) you can see that there is a provision for reentrancy. However, src/winsup/cygwin/acconfig.h #undef's _MT_SAFE. OpenGroup's specification (<http://www.opengroup.org/onlinepubs/007904975/functions/gethostbyaddr.html>) says that "The gethostbyname() function need not be reentrant." See <http://wcug.wwu.edu/lists/ipng/199710/msg00002.html> for a good discussion of gethostbyname() thread-safety issues. So, your choices for the moment are: 1) build a thread-safe cygwin1.dll for your own use 2) make sure gethostbyname() is only called (and its result used/copied) by one thread at a time (using a mutex, for example) 3) implement gethostby{name,addr}_r() yourself and submit a patch Hope this helps, Igor -- http://cs.nyu.edu/~pechtcha/ |\ _,,,---,,_ [EMAIL PROTECTED] ZZZzz /,`.-'`' -. ;-;;,_ [EMAIL PROTECTED] |,4- ) )-,_. ,\ ( `'-' Igor Pechtchanski '---''(_/--' `-'\_) fL a.k.a JaguaR-R-R-r-r-r-.-.-. Meow! Oh, boy, virtual memory! Now I'm gonna make myself a really *big* RAMdisk! -- /usr/games/fortune -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
