Remove _THREAD_SAFE and make libc thread-safe by default by

adding (weak definitions to) stubs for some of the pthread
functions.  If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
	__sys_foo - actual system call
	_foo - weak definition to __sys_foo
	foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo.  In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde).  All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes.  <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h  namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE.  We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by:	-arch

1 files changed, 16 insertions, 17 deletions

diff --git a/lib/libc/stdlib/abort.c b/lib/libc/stdlib/abort.c
index b6b4be9..0b85182 100644
--- a/lib/libc/stdlib/abort.c
+++ b/lib/libc/stdlib/abort.c
@@ -29,6 +29,8 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
+ * $FreeBSD$
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
@@ -39,17 +41,18 @@ static char sccsid[] = "@(#)abort.c	8.1 (Berkeley) 6/4/93";
 #include <stdlib.h>
 #include <stddef.h>
 #include <unistd.h>
-#ifdef _THREAD_SAFE
 #include <pthread.h>
-#include "pthread_private.h"
-#endif
 
 void (*__cleanup)();
 
+extern int	__sys_sigprocmask(int, const sigset_t *, sigset_t *);
+extern int	__sys_sigaction(int, const struct sigaction *,
+		    struct sigaction *);
+
 void
 abort()
 {
-	sigset_t mask;
+	struct sigaction act;
 
 	/*
 	 * POSIX requires we flush stdio buffers on abort
@@ -57,29 +60,25 @@ abort()
 	if (__cleanup)
 		(*__cleanup)();
 
-	sigfillset(&mask);
+	sigfillset(&act.sa_mask);
 	/*
 	 * don't block SIGABRT to give any handler a chance; we ignore
 	 * any errors -- X311J doesn't allow abort to return anyway.
 	 */
-	sigdelset(&mask, SIGABRT);
-#ifdef _THREAD_SAFE
-	(void) _thread_sys_sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
-#else
-	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
-#endif
+	sigdelset(&act.sa_mask, SIGABRT);
+	(void)__sys_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
 	(void)kill(getpid(), SIGABRT);
 
 	/*
 	 * if SIGABRT ignored, or caught and the handler returns, do
 	 * it again, only harder.
 	 */
-	(void)signal(SIGABRT, SIG_DFL);
-#ifdef _THREAD_SAFE
-	(void) _thread_sys_sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
-#else
-	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
-#endif
+	act.sa_handler = SIG_DFL;
+	act.sa_flags = 0;
+	sigfillset(&act.sa_mask);
+	(void)__sys_sigaction(SIGABRT, &act, NULL);
+	sigdelset(&act.sa_mask, SIGABRT);
+	(void)__sys_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
 	(void)kill(getpid(), SIGABRT);
 	exit(1);
 }