Re: UPDATED UnixWare Threads Patch. - Mailing list pgsql-patches
From | Bruce Momjian |
---|---|
Subject | Re: UPDATED UnixWare Threads Patch. |
Date | |
Msg-id | 200308142113.h7ELDun08636@candle.pha.pa.us Whole thread Raw |
In response to | Re: UPDATED UnixWare Threads Patch. (Larry Rosenman <ler@lerctr.org>) |
List | pgsql-patches |
Sorry, patch attached and applied. I also added "SUPPORTS_THREADS=yes", which was needed. --------------------------------------------------------------------------- Larry Rosenman wrote: > what about the pieces of src/port/unixware to allow the threads stuff? > > > > --On Thursday, August 14, 2003 01:25:48 -0400 Bruce Momjian > <pgman@candle.pha.pa.us> wrote: > > > > > OK, I have applied the attached patch. > > > > Here is the comment I have added to the thread.c file: > > > > /* > > * Threading sometimes requires specially-named versions of functions > > * that return data in static buffers, like strerror_r() instead of > > * strerror(). Other operating systems use pthread_setspecific() > > * and pthread_getspecific() internally to allow standard library > > * functions to return static data to threaded applications. > > * > > * Additional confusion exists because many operating systems that > > * use pthread_setspecific/pthread_getspecific() also have *_r versions > > * of standard library functions for compatibility with operating > > systems * that require them. However, internally, these *_r > > functions merely * call the thread-safe standard library functions. > > * > > * For example, BSD/OS 4.3 uses Bind 8.2.3 for getpwuid(). Internally, > > * getpwuid() calls pthread_setspecific/pthread_getspecific() to return > > * static data to the caller in a thread-safe manner. However, BSD/OS > > * also has getpwuid_r(), which merely calls getpwuid() and shifts > > * around the arguments to match the getpwuid_r() function declaration. > > * Therefore, while BSD/OS has getpwuid_r(), it isn't required. It > > also * doesn't have strerror_r(), so we can't fall back to only using > > *_r * functions for threaded programs. > > * > > * The current setup is to assume either all standard functions are > > * thread-safe (NEED_REENTRANT_FUNC_NAMES=no), or the operating system > > * requires reentrant function names (NEED_REENTRANT_FUNC_NAMES=yes). > > */ > > > > As an additional data point, here is a README comment from Bind 8.2.3: > > > > Thread Safety: > > > > It is possible for a thread safe program to be altered to call > > the underlying interface (rather than the standard getXbyY() stubs) and > > get some reentrance capabilities. Note that the underlying libraries > > (which we call) are not all thread-safe, for example, the YP and DNS > > resolvers. A lot more work will need to be done before we have full > > thread safety. But we believe that the native API for this system does > > not impose any reentrancy problems. We don't use global or static > > variables anywhere except in the getXbyY() stubs. > > > > Here is Bind's gethostbyname_r: > > > > HOST_R_RETURN > > gethostbyname_r(const char *name, struct hostent *hptr, HOST_R_ARGS) { > > struct hostent *he = gethostbyname(name); > > > > HOST_R_ERRNO; > > > > if (he == NULL) > > return (HOST_R_BAD); > > > > return (copy_hostent(he, hptr, HOST_R_COPY)); > > } > > > > As you can see, it merely calls gethostbyname() and adjusts to return > > the proper values. > > > > I removed the pre-POSIX getpwuid_r function call and added the POSIX > > one. If we need the pre-POSIX one, we can add it with a configure > > test, but I would rather find out if someone needs it first. The > > original thread patch that was posted had only the pre-POSIX version of > > the function, and I am not sure why the didn't include the POSIX one > > too, or use that instead of the pre-POSIX one. > > > > There are also a few stylistic function declaration cleanups. > > > > The unixware optimizer changes have already been applied. > > > > > > ------------------------------------------------------------------------- > > -- > > > > Larry Rosenman wrote: > >> > >> > >> --On Friday, August 08, 2003 18:56:45 -0500 Larry Rosenman > >> <ler@lerctr.org> wrote: > >> > >> > > >> > > >> > Here is the updated UnixWare threads patch. I need some help to set > >> > the HAVE_POSIX_GETPWUID_R define from configure, but this will suffice > >> > for now. > >> > > >> > This also includes my recommendation for the Compiler Bug issue. > >> > > >> > Please Apply, and if one of the configure guru's can help here, I'd be > >> > most appreciative. > >> Grr. I'm an idiot, the following is a CORRECTED version, basically > >> s/#elsif/#elif/ > >> > >> Index: src/port/thread.c > >> =================================================================== > >> RCS file: /projects/cvsroot/pgsql-server/src/port/thread.c,v > >> retrieving revision 1.2 > >> diff -u -r1.2 thread.c > >> --- src/port/thread.c 8 Aug 2003 03:09:56 -0000 1.2 > >> +++ src/port/thread.c 9 Aug 2003 00:47:00 -0000 > >> @@ -40,13 +40,18 @@ > >> pqGetpwuid(uid_t uid, struct passwd * resultbuf, char *buffer, > >> size_t buflen, struct passwd ** result) > >> { > >> -#if defined(USE_THREADS) && defined(HAVE_GETPWUID_R) > >> +#if defined(USE_THREADS) && defined(HAVE_GETPWUID_R) && > >> !defined(HAVE_POSIX_GETPWUID_R) > >> > >> /* > >> * broken (well early POSIX draft) getpwuid_r() which returns 'struct > >> * passwd *' > >> */ > >> *result = getpwuid_r(uid, resultbuf, buffer, buflen); > >> +#elif defined(USE_THREADS) && defined(HAVE_GETPWUID_R) && > >> defined(HAVE_POSIX_GETPWUID_R) > >> + /* > >> + * SUSv2/POSIX getpwuid_r > >> + */ > >> + return getpwuid_r(uid, resultbuf, buffer, buflen, result); > >> # else > >> /* no getpwuid_r() available, just use getpwuid() */ > >> *result = getpwuid(uid); > >> Index: src/template/unixware > >> =================================================================== > >> RCS file: /projects/cvsroot/pgsql-server/src/template/unixware,v > >> retrieving revision 1.11 > >> diff -u -r1.11 unixware > >> --- src/template/unixware 4 Sep 2002 22:54:18 -0000 1.11 > >> +++ src/template/unixware 9 Aug 2003 00:47:00 -0000 > >> @@ -1,5 +1,13 @@ > >> +SUPPORTS_THREADS=yes > >> if test "$GCC" = yes; then > >> - CFLAGS=-O2 > >> + CFLAGS="-O2 -DHAVE_POSIX_GETPWUID_R" > >> + THREAD_CFLAGS="-pthread -D_REENTRANT" > >> + NEED_REENTRANT_FUNC_NAMES=yes > >> else > >> - CFLAGS='-O -K inline' > >> +# the -Kno_host is temporary for a bug in the compiler. See -hackers > >> +# discussion on 7-8/Aug/2003. > >> +# when the 7.1.3UP3 or later compiler is out, we can do a version check. > >> + CFLAGS='-O -Kinline,no_host -DHAVE_POSIX_GETPWUID_R' > >> + THREAD_CFLAGS="-D_REENTRANT -K pthread -DHAVE_POSIX_GETPWUID_R" > >> + NEED_REENTRANT_FUNC_NAMES=yes > >> fi > >> > >> -- > >> Larry Rosenman http://www.lerctr.org/~ler > >> Phone: +1 972-414-9812 E-Mail: ler@lerctr.org > >> US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749 > > > > [ Attachment, skipping... ] > > > >> > >> ---------------------------(end of broadcast)--------------------------- > >> TIP 4: Don't 'kill -9' the postmaster > > > > -- > Larry Rosenman http://www.lerctr.org/~ler > Phone: +1 972-414-9812 E-Mail: ler@lerctr.org > US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749 > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 Index: src/template/unixware =================================================================== RCS file: /cvsroot/pgsql-server/src/template/unixware,v retrieving revision 1.12 diff -c -c -r1.12 unixware *** src/template/unixware 13 Aug 2003 23:59:49 -0000 1.12 --- src/template/unixware 14 Aug 2003 19:43:17 -0000 *************** *** 6,8 **** --- 6,13 ---- # when the 7.1.3UP3 or later compiler is out, we can do a version check. CFLAGS='-O -Kinline,no_host' fi + + SUPPORTS_THREADS=yes + THREAD_CFLAGS="-D_REENTRANT -K pthread" + NEED_REENTRANT_FUNC_NAMES=yes +
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