Check and set thread-safe functions separately, rather than as a single

variable.

Remove thread locking for non-thread-safe functions, instead throw a
compile error.

Platforms will have to re-run tools/thread to record their thread
safety.

10 files changed, 79 insertions, 212 deletions

diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 3b7526f3796..7fbfa66086e 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -43,6 +43,12 @@
    (--enable-thread-safety) */
 #undef ENABLE_THREAD_SAFETY
 
+/* Define if gethostbyname is not thread safe */
+#undef GETHOSTBYNAME_THREADSAFE
+
+/* Define if getpwuid is not thread safe */
+#undef GETPWUID_THREADSAFE
+
 /* Define to 1 if gettimeofday() takes only 1 argument. */
 #undef GETTIMEOFDAY_1ARG
 
@@ -554,9 +560,6 @@
 /* Define as the maximum alignment requirement of any C data type. */
 #undef MAXIMUM_ALIGNOF
 
-/* Define if non *_r libc functions are not thread safe */
-#undef NEED_REENTRANT_FUNCS
-
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT
 
@@ -588,6 +591,9 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
+/* Define if strerror is not thread safe */
+#undef STRERROR_THREADSAFE
+
 /* Define to 1 if your <sys/time.h> declares `struct tm'. */
 #undef TM_IN_SYS_TIME
 
diff --git a/src/port/thread.c b/src/port/thread.c
index e164d017d4f..d6e1b269733 100644
--- a/src/port/thread.c
+++ b/src/port/thread.c
@@ -7,7 +7,7 @@
  *
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/port/thread.c,v 1.14 2003/11/29 22:41:31 pgsql Exp $
+ * $PostgreSQL: pgsql/src/port/thread.c,v 1.15 2004/02/11 21:44:06 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,7 +31,7 @@
  *	strerror().  Other operating systems use pthread_setspecific()
  *	and pthread_getspecific() internally to allow standard library
  *	functions to return static data to threaded applications. And some
- *	operating systems have neither, meaning we have to do our own locking.
+ *	operating systems have neither.
  *
  *	Additional confusion exists because many operating systems that
  *	use pthread_setspecific/pthread_getspecific() also have *_r versions
@@ -50,18 +50,13 @@
  *
  *	The current setup is to try threading in this order:
  *
- *		use non-*_r function names if they are all thread-safe
- *			(NEED_REENTRANT_FUNCS=no)
- *		use *_r functions if they exist (configure test)
- *		do our own locking and copying of non-threadsafe functions
- *
- *	The disadvantage of the last option is not the thread overhead but
- *	the fact that all function calls are serialized, and with gethostbyname()
- *	requiring a DNS lookup, that could be slow.
+ *		use *_r function names if they exit
+ *			(*_THREADSAFE=ye)
+ *		use non-*_r functions if they are thread-safe
  *
  *	One thread-safe solution for gethostbyname() might be to use getaddrinfo().
  *
- *	See src/tools/thread to see if your operating system has thread-safe
+ *	Run src/tools/thread to see if your operating system has thread-safe
  *	non-*_r functions.
  */
  
@@ -73,7 +68,7 @@
 char *
 pqStrerror(int errnum, char *strerrbuf, size_t buflen)
 {
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_STRERROR_R)
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(HAVE_STRERROR_R)
 	/* reentrant strerror_r is available */
 	/* some early standards had strerror_r returning char * */
 	strerror_r(errnum, strerrbuf, buflen);
@@ -81,18 +76,13 @@ pqStrerror(int errnum, char *strerrbuf, size_t buflen)
 
 #else
 
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_STRERROR_R)
-	static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;
-	pthread_mutex_lock(&strerror_lock);
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && !defined(STRERROR_THREADSAFE)
+#error This platform can not create a thread-safe version because strerror is not thread-safe and there is no reentrant version
 #endif
 
 	/* no strerror_r() available, just use strerror */
 	StrNCpy(strerrbuf, strerror(errnum), buflen);
 
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_STRERROR_R)
-	pthread_mutex_unlock(&strerror_lock);
-#endif
-
 	return strerrbuf;
 #endif
 }
@@ -106,7 +96,7 @@ int
 pqGetpwuid(uid_t uid, struct passwd *resultbuf, char *buffer,
 		   size_t buflen, struct passwd **result)
 {
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_GETPWUID_R)
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(HAVE_GETPWUID_R)
 	/*
 	 * Early POSIX draft of getpwuid_r() returns 'struct passwd *'.
 	 *    getpwuid_r(uid, resultbuf, buffer, buflen)
@@ -117,53 +107,14 @@ pqGetpwuid(uid_t uid, struct passwd *resultbuf, char *buffer,
 
 #else
 
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETPWUID_R)
-	static pthread_mutex_t getpwuid_lock = PTHREAD_MUTEX_INITIALIZER;
-	pthread_mutex_lock(&getpwuid_lock);
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && !defined(GETPWUID_THREADSAFE)
+#error This platform can not create a thread-safe version because getpwuid is not thread-safe and there is no reentrant version
 #endif
 
 	/* no getpwuid_r() available, just use getpwuid() */
 	*result = getpwuid(uid);
-
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETPWUID_R)
-
-	/* Use 'buffer' memory for storage of strings used by struct passwd */
-	if (*result &&
-		strlen((*result)->pw_name) + 1 +
-		strlen((*result)->pw_passwd) + 1 +
-		strlen((*result)->pw_gecos) + 1 +
-		/* skip class if it exists */
-		strlen((*result)->pw_dir) + 1 +
-		strlen((*result)->pw_shell) + 1 <= buflen)
-	{
-		memcpy(resultbuf, *result, sizeof(struct passwd));
-		strcpy(buffer, (*result)->pw_name);
-		resultbuf->pw_name = buffer;
-		buffer += strlen(resultbuf->pw_name) + 1;
-		strcpy(buffer, (*result)->pw_passwd);
-		resultbuf->pw_passwd = buffer;
-		buffer += strlen(resultbuf->pw_passwd) + 1;
-		strcpy(buffer, (*result)->pw_gecos);
-		resultbuf->pw_gecos = buffer;
-		buffer += strlen(resultbuf->pw_gecos) + 1;
-		strcpy(buffer, (*result)->pw_dir);
-		resultbuf->pw_dir = buffer;
-		buffer += strlen(resultbuf->pw_dir) + 1;
-		strcpy(buffer, (*result)->pw_shell);
-		resultbuf->pw_shell = buffer;
-		buffer += strlen(resultbuf->pw_shell) + 1;
-
-		*result = resultbuf;
-	}
-	else
-	{
-		*result = NULL;
-		errno = ERANGE;
-	}
-
-	pthread_mutex_unlock(&getpwuid_lock);
-#endif
 #endif
+
 	return (*result == NULL) ? -1 : 0;
 }
 #endif
@@ -181,7 +132,7 @@ pqGethostbyname(const char *name,
 				struct hostent **result,
 				int *herrno)
 {
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && defined(HAVE_GETHOSTBYNAME_R)
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(HAVE_GETHOSTBYNAME_R)
 	/*
 	 * broken (well early POSIX draft) gethostbyname_r() which returns
 	 * 'struct hostent *'
@@ -191,87 +142,16 @@ pqGethostbyname(const char *name,
 
 #else
 
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
-	static pthread_mutex_t gethostbyname_lock = PTHREAD_MUTEX_INITIALIZER;
-	pthread_mutex_lock(&gethostbyname_lock);
+#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && !defined(GETHOSTBYNAME_THREADSAFE)
+#error This platform can not create a thread-safe version because getaddrinfo is not thread-safe and there is no reentrant version
 #endif
 
 	/* no gethostbyname_r(), just use gethostbyname() */
 	*result = gethostbyname(name);
 
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
-
-	/*
-	 *	Use 'buffer' memory for storage of structures used by struct hostent.
-	 *	The layout is:
-	 *
-	 *		addr pointers
-	 *		alias pointers
-	 *		addr structures
-	 *		alias structures
-	 *		name
-	 */
-	if (*result)
-	{
-		int		i, pointers = 2 /* for nulls */, len = 0;
-		char	**pbuffer;
-
-		for (i = 0; (*result)->h_addr_list[i]; i++, pointers++)
-			len += (*result)->h_length;
-		for (i = 0; (*result)->h_aliases[i]; i++, pointers++)
-			len += (*result)->h_length;
-
-		if (pointers * sizeof(char *) + MAXALIGN(len) + strlen((*result)->h_name) + 1 <= buflen)
-		{
-			memcpy(resultbuf, *result, sizeof(struct hostent));
-
-    		pbuffer = (char **)buffer;
-    		resultbuf->h_addr_list = pbuffer;
-    		buffer += pointers * sizeof(char *);
-
-			for (i = 0; (*result)->h_addr_list[i]; i++, pbuffer++)
-			{
-				memcpy(buffer, (*result)->h_addr_list[i], (*result)->h_length);
-    			resultbuf->h_addr_list[i] = buffer;
-    			buffer += (*result)->h_length;
-    		}
-			resultbuf->h_addr_list[i] = NULL;
-			pbuffer++;
-			    
-    		resultbuf->h_aliases = pbuffer;
-
-			for (i = 0; (*result)->h_aliases[i]; i++, pbuffer++)
-			{
-				memcpy(buffer, (*result)->h_aliases[i], (*result)->h_length);
-    			resultbuf->h_aliases[i] = buffer;
-    			buffer += (*result)->h_length;
-    		}
-			resultbuf->h_aliases[i] = NULL;
-			pbuffer++;
-
-			/* Place at end for cleaner alignment */			
-			buffer = MAXALIGN(buffer);
-			strcpy(buffer, (*result)->h_name);
-			resultbuf->h_name = buffer;
-			buffer += strlen(resultbuf->h_name) + 1;
-
-			*result = resultbuf;
-		}
-		else
-		{
-			*result = NULL;
-			errno = ERANGE;
-		}
-	}
-#endif
-
 	if (*result != NULL)
 		*herrno = h_errno;
 		
-#if defined(FRONTEND) && defined(ENABLE_THREAD_SAFETY) && defined(NEED_REENTRANT_FUNCS) && !defined(HAVE_GETHOSTBYNAME_R)
-	pthread_mutex_unlock(&gethostbyname_lock);
-#endif
-
 	if (*result != NULL)
 		return 0;
 	else
diff --git a/src/template/bsdi b/src/template/bsdi
index 4c62ce44217..dd750bdc997 100644
--- a/src/template/bsdi
+++ b/src/template/bsdi
@@ -3,4 +3,7 @@ case $host_os in
 esac
 
 THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=no		# verified 4.3 2003-09-26
+# verified 4.3.1 2004-02-11
+STRERROR_THREADSAFE=yes
+GETPWUID_THREADSAFE=yes
+GETHOSTBYNAME_THREADSAFE=yes
diff --git a/src/template/freebsd b/src/template/freebsd
index 2b155d12db9..c78b87bd761 100644
--- a/src/template/freebsd
+++ b/src/template/freebsd
@@ -2,8 +2,7 @@ case $host_cpu in
   alpha*)   CFLAGS="-O";;  # alpha has problems with -O2
 esac
 
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=yes
+# tools/thread/thread_test must be run
 THREAD_CPPFLAGS="-D_THREAD_SAFE"
 case $host_os in
 	freebsd2*|freebsd3*|freebsd4*) THREAD_LIBS="-pthread";;
diff --git a/src/template/linux b/src/template/linux
index 529da9c1694..7469b331078 100644
--- a/src/template/linux
+++ b/src/template/linux
@@ -1,7 +1,6 @@
 # Force _GNU_SOURCE on; plperl is broken with Perl 5.8.0 otherwise
 CPPFLAGS="-D_GNU_SOURCE"
 
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=yes	# Debian kernel 2.2 2003-09-27
+# tools/thread/thread_test must be run
 THREAD_CPPFLAGS="-D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS"
 THREAD_LIBS="-lpthread"
diff --git a/src/template/netbsd b/src/template/netbsd
index 0d119a01361..1cb953c7fb5 100644
--- a/src/template/netbsd
+++ b/src/template/netbsd
@@ -1,2 +1 @@
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=yes	# 1.6 2003-09-14
+# tools/thread/thread_test must be run
diff --git a/src/template/osf b/src/template/osf
index 9d2d6b81c1c..c331ed7f3dc 100644
--- a/src/template/osf
+++ b/src/template/osf
@@ -3,8 +3,7 @@ if test "$GCC" != yes ; then
   CFLAGS="-O -ieee"
 fi
 
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=no		# 4.0 2003-09-13
+# tools/thread/thread_test must be run
 if test "$GCC" = yes
 then	THREAD_LIBS="-pthread"
 else	THREAD_CPPFLAGS="-pthread"
diff --git a/src/template/solaris b/src/template/solaris
index 489bece9489..7534c7fe578 100644
--- a/src/template/solaris
+++ b/src/template/solaris
@@ -9,8 +9,7 @@ case $host in
   i?86-*-solaris*)   need_tas=yes; tas_file=solaris_i386.s ;;
 esac
 
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=yes	# 5.6 2003-09-13
+# tools/thread/thread_test must be run
 if test "$GCC" = yes 
 then	THREAD_LIBS="-pthread"
 else	THREAD_CPPFLAGS="-mt"
diff --git a/src/template/unixware b/src/template/unixware
index dc469873ccc..c1af94b5b4d 100644
--- a/src/template/unixware
+++ b/src/template/unixware
@@ -24,6 +24,5 @@ __EOF__
   THREAD_CPPFLAGS="-K pthread"
 fi
 
-THREAD_SUPPORT=yes
-NEED_REENTRANT_FUNCS=no		# verified 7.1.3 2003-09-03
+# tools/thread/thread_test must be run
 THREAD_CPPFLAGS="$THREAD_CPPFLAGS -D_REENTRANT"
diff --git a/src/tools/thread/thread_test.c b/src/tools/thread/thread_test.c
index 654bb155f5c..a09c8fca02d 100644
--- a/src/tools/thread/thread_test.c
+++ b/src/tools/thread/thread_test.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/tools/thread/thread_test.c,v 1.6 2003/12/19 23:29:15 momjian Exp $
+ *	$PostgreSQL: pgsql/src/tools/thread/thread_test.c,v 1.7 2004/02/11 21:44:06 momjian Exp $
  *
  *	This program tests to see if your standard libc functions use
  *	pthread_setspecific()/pthread_getspecific() to be thread-safe.
@@ -33,16 +33,14 @@
 void func_call_1(void);
 void func_call_2(void);
 
-#ifndef HAVE_GETADDRINFO
-struct hostent *hostent_p1;
-struct hostent *hostent_p2;
-#endif
+char *strerror_p1;
+char *strerror_p2;
 
 struct passwd *passwd_p1;
 struct passwd *passwd_p2;
 
-char *strerror_p1;
-char *strerror_p2;
+struct hostent *hostent_p1;
+struct hostent *hostent_p2;
 
 int main(int argc, char *argv[])
 {
@@ -64,48 +62,34 @@ defines to your template/$port file before compiling this program.\n\n"
 	pthread_join(thread1, NULL);
 	pthread_join(thread2, NULL);
 
-#ifndef HAVE_GETADDRINFO
-	if (hostent_p1 == hostent_p2)
-		printf("Your gethostbyname() is _not_ thread-safe\n");
-#endif
-	if (passwd_p1 == passwd_p2)
-		printf("Your getpwuid() is _not_ thread-safe\n");
-	if (strerror_p1 == strerror_p2)
-		printf("Your strerror() is _not_ thread-safe\n");
-
-	if (
-#ifndef HAVE_GETADDRINFO
-		hostent_p1 != hostent_p2 &&
-#endif
-		passwd_p1 != passwd_p2 &&
-		strerror_p1 != strerror_p2)
-	{
-		printf("All your non-*_r functions are thread-safe.\n");
-		printf("Add this to your template/$port file:\n\n");
-		printf("NEED_REENTRANT_FUNCS=no\n");
-	}
+	printf("Add this to your template/$port file:\n\n");
+
+	if (strerror_p1 != strerror_p2)
+		printf("STRERROR_THREADSAFE=yes\n");
 	else
-	{
-		printf("Not all non-*_r functions are thread-safe.\n");
-		printf("Add this to your template/$port file:\n\n");
-		printf("NEED_REENTRANT_FUNCS=yes\n");
-	}
+		printf("STRERROR_THREADSAFE=no\n");
+
+	if (passwd_p1 != passwd_p2)
+		printf("GETPWUID_THREADSAFE=yes\n");
+	else
+		printf("GETPWUID_THREADSAFE=no\n");
 
+	if (hostent_p1 != hostent_p2)
+		printf("GETHOSTBYNAME_THREADSAFE=yes\n");
+	else
+		printf("GETHOSTBYNAME_THREADSAFE=no\n");
+	
 	return 0;
 }
 
 void func_call_1(void) {
 	void *p;
 
-#ifndef HAVE_GETADDRINFO
-	hostent_p1 = gethostbyname("yahoo.com");
-	p = gethostbyname("slashdot.org");
-	if (hostent_p1 != p)
-	{
-		printf("Your gethostbyname() changes the static memory area between calls\n");
-		hostent_p1 = NULL;	/* force thread-safe failure report */
-	}
-#endif
+	strerror_p1 = strerror(EACCES);
+	/*
+	 *	If strerror() uses sys_errlist, the pointer might change for different
+	 *	errno values, so we don't check to see if it varies within the thread.
+	 */
 
 	passwd_p1 = getpwuid(0);
 	p = getpwuid(1);
@@ -115,26 +99,24 @@ void func_call_1(void) {
 		passwd_p1 = NULL;	/* force thread-safe failure report */
 	}
 
-	strerror_p1 = strerror(EACCES);
-	/*
-	 *	If strerror() uses sys_errlist, the pointer might change for different
-	 *	errno values, so we don't check to see if it varies within the thread.
-	 */
+	hostent_p1 = gethostbyname("yahoo.com");
+	p = gethostbyname("slashdot.org");
+	if (hostent_p1 != p)
+	{
+		printf("Your gethostbyname() changes the static memory area between calls\n");
+		hostent_p1 = NULL;	/* force thread-safe failure report */
+	}
 }
 
 
 void func_call_2(void) {
 	void *p;
 
-#ifndef HAVE_GETADDRINFO
-	hostent_p2 = gethostbyname("google.com");
-	p = gethostbyname("postgresql.org");
-	if (hostent_p2 != p)
-	{
-		printf("Your gethostbyname() changes the static memory area between calls\n");
-		hostent_p2 = NULL;	/* force thread-safe failure report */
-	}
-#endif
+	strerror_p2 = strerror(EINVAL);
+	/*
+	 *	If strerror() uses sys_errlist, the pointer might change for different
+	 *	errno values, so we don't check to see if it varies within the thread.
+	 */
 
 	passwd_p2 = getpwuid(2);
 	p = getpwuid(3);
@@ -144,9 +126,11 @@ void func_call_2(void) {
 		passwd_p2 = NULL;	/* force thread-safe failure report */
 	}
 
-	strerror_p2 = strerror(EINVAL);
-	/*
-	 *	If strerror() uses sys_errlist, the pointer might change for different
-	 *	errno values, so we don't check to see if it varies within the thread.
-	 */
+	hostent_p2 = gethostbyname("google.com");
+	p = gethostbyname("postgresql.org");
+	if (hostent_p2 != p)
+	{
+		printf("Your gethostbyname() changes the static memory area between calls\n");
+		hostent_p2 = NULL;	/* force thread-safe failure report */
+	}
 }