Fix the handle locking in stdio to use flockfile/funlockfile

internally when and where required.  Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking.  A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization.  Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

ok kurt@, earlier version tested by sthen@ and jj@

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/libc/stdio/fpurge.c b/lib/libc/stdio/fpurge.c
index fa0213ac7b7..4a0988e8479 100644
--- a/lib/libc/stdio/fpurge.c
+++ b/lib/libc/stdio/fpurge.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fpurge.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fpurge.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -43,7 +43,9 @@
 int
 fpurge(FILE *fp)
 {
+	FLOCKFILE(fp);
 	if (!fp->_flags) {
+		FUNLOCKFILE(fp);
 		errno = EBADF;
 		return(EOF);
 	}
@@ -54,5 +56,6 @@ fpurge(FILE *fp)
 	fp->_p = fp->_bf._base;
 	fp->_r = 0;
 	fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
+	FUNLOCKFILE(fp);
 	return (0);
 }