Tom Lane writes: > Lee Kindness <[EMAIL PROTECTED]> writes: > > Tom Lane writes: > >>> Okay, so it seems -D_REENTRANT is the appropriate fix. > > However, _REENTRANT is not a Solarisism... On all (recent) UNIX > > systems it toggles on correct handling for thread specific instances > > of historically global variables (eg errno). It should be considered > > for all platforms if libpq is intended to be used from threaded > > programs. > Now that I think about it, what that macro is probably really doing is > switching the code from looking at a static "errno" variable to looking > at a per-thread variable. So in fact -D_REENTRANT would be correct if > you intended to link with a thread-aware libc, and wrong if you intended > to link with a non-aware libc. (Is there such a thing as a non-threaded > implementation of libc on the platforms where -D_REENTRANT does > anything?) If this analysis is right then I think we should *not* > force _REENTRANT; it will have to be up to users to choose the mechanism > they want to use in their programs.
I think in the long-term the libraries are going to have to be looked at in detail to ensure they work as would be expected from multithreaded programs. I cannot see any harm in adding -D_REENTRANT to CFLAGS even though some platforms supersede it with -lthread or something (becaue they still define _REENTRANT behind the scenes). I remember in the past reading in detail the issues involved with making shared libraries work as expected from threads. However I no-longer has access to that book, but think it was "Multithreaded Programming with Pthreads"... Again, something i'd like to look at later this month. Workwise the threaded code we had which used embedded SQL calls in C fell into heaps when moved from Ingres to PostgreSQL. And Ingres's ESQL/C is real crap for threading and we employeed loads of mutexes... So, ... Lee. ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
