On Thu, Jan 21, 1999 at 02:00:53PM -0800, Kurt D. Zeilenga wrote: > > For kernel threading you just use libc. Whether or not libc generates > > thread safe (re-entrant) calls depends on whether its also linked with > > a library that 1) sets __isthreaded to a non-zero value, 2) has a > > _spinlock() > > implementationm, and 3) implements the functions flockfile, funlockfile, > > etc. > > There are also a few macros in header files that require _THREAD_SAFE to > > be defined to be thread safe. > > > I was hoping to be able to produce one ldap library that could be safely > linked with or without threads. However, if I must define _THREAD_SAFE > to generate code to be linked with threads then I must produce two libraries > (-lfoolib compiled with -U_THREAD_SAFE and -lfoolib_r with -D_THREAD_SAFE).
_THREAD_SAFE is only used in stdio.h. Looking at what's there, it could be rewritten to eliminate _THREAD_SAFE entirely, at a (very slight) performance penalty. You'd have to check __isthreaded (could be done once, instead of twice, as in the code now) each time you call one of the functions defined within the _THREAD_SAFE switch. All _THREAD_SAFE does is let you avoid checking __isthreaded when you're not threaded. -- Richard Seamman, Jr. email: d...@tar.com 5182 N. Maple Lane phone: 414-367-5450 Chenequa WI 53058 fax: 414-367-5852 To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-current" in the body of the message
