Add thread.c for libpq threading, and hook it into libpq/configure.

src/port/Makefile

@@ -7,7 +7,7 @@
 # with broken/missing library files.
 
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/port/Makefile,v 1.3 2002/07/27 20:10:05 petere Exp $
+#    $Header: /cvsroot/pgsql/src/port/Makefile,v 1.4 2003/06/14 14:35:42 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -22,5 +22,8 @@ endif
 libpgport.a: $(LIBOBJS)
 	$(AR) crs $@ $^
 
+thread.o: thread.c
+	$(CC) $(CFLAGS) $(THREAD_CFLAGS) -c thread.c
+
 clean distclean maintainer-clean:
 	rm -f libpgport.a $(LIBOBJS)

src/port/threads.c

@@ -0,0 +1,85 @@
+/*-------------------------------------------------------------------------
+ *
+ * threads.c
+ *
+ *		  Prototypes and macros around system calls, used to help make
+ *		  threaded libraries reentrant and safe to use from threaded applications.
+ *
+ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
+ *
+ * $Id: threads.c,v 1.1 2003/06/14 14:35:42 momjian Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+/*
+ * Wrapper around strerror and strerror_r to use the former if it is
+ * available and also return a more useful value (the error string).
+ */
+char *
+pqStrerror(int errnum, char *strerrbuf, size_t buflen)
+{
+#if defined(USE_THREADS) && defined(HAVE_STRERROR_R)
+	/* reentrant strerror_r is available */
+	/* some early standards had strerror_r returning char * */
+	strerror_r(errnum, strerrbuf, buflen);
+	return (strerrbuf);
+#else
+	/* no strerror_r() available, just use strerror */
+	return strerror(errnum);
+#endif
+}
+
+/*
+ * Wrapper around getpwuid() or getpwuid_r() to mimic POSIX getpwuid_r()
+ * behaviour, if it is not available.
+ */
+int
+pqGetpwuid(uid_t uid, struct passwd * resultbuf, char *buffer,
+		   size_t buflen, struct passwd ** result)
+{
+#if defined(USE_THREADS) && defined(HAVE_GETPWUID_R)
+	/*
+	 * broken (well early POSIX draft) getpwuid_r() which returns 'struct
+	 * passwd *'
+	 */
+	*result = getpwuid_r(uid, resultbuf, buffer, buflen);
+#else
+	/* no getpwuid_r() available, just use getpwuid() */
+	*result = getpwuid(uid);
+#endif
+	return (*result == NULL) ? -1 : 0;
+}
+
+/*
+ * Wrapper around gethostbyname() or gethostbyname_r() to mimic
+ * POSIX gethostbyname_r() behaviour, if it is not available.
+ */
+int
+pqGethostbyname(const char *name,
+				struct hostent * resbuf,
+				char *buf, size_t buflen,
+				struct hostent ** result,
+				int *herrno)
+{
+#if defined(USE_THREADS) && defined(HAVE_GETHOSTBYNAME_R)
+	/*
+	 * broken (well early POSIX draft) gethostbyname_r() which returns
+	 * 'struct hostent *'
+	 */
+	*result = gethostbyname_r(name, resbuf, buf, buflen, herrno);
+	return (*result == NULL) ? -1 : 0;
+#else
+	/* no gethostbyname_r(), just use gethostbyname() */
+	*result = gethostbyname(name);
+	if (*result != NULL)
+		return 0;
+	else
+	{
+		*herrno = h_errno;
+		return -1;
+	}
+#endif
+}