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, 6 insertions, 1 deletions

diff --git a/lib/libc/stdio/freopen.c b/lib/libc/stdio/freopen.c
index cd2d833846b..b5dbc3096d4 100644
--- a/lib/libc/stdio/freopen.c
+++ b/lib/libc/stdio/freopen.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: freopen.c,v 1.10 2008/04/21 12:28:35 otto Exp $ */
+/*	$OpenBSD: freopen.c,v 1.11 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -60,6 +60,8 @@ freopen(const char *file, const char *mode, FILE *fp)
 	if (!__sdidinit)
 		__sinit();
 
+	FLOCKFILE(fp);
+
 	/*
 	 * There are actually programs that depend on being able to "freopen"
 	 * descriptors that weren't originally open.  Keep this from breaking.
@@ -121,6 +123,7 @@ freopen(const char *file, const char *mode, FILE *fp)
 
 	if (f < 0) {			/* did not get it after all */
 		fp->_flags = 0;		/* set it free */
+		FUNLOCKFILE(fp);
 		errno = sverrno;	/* restore in case _close clobbered */
 		return (NULL);
 	}
@@ -140,6 +143,7 @@ freopen(const char *file, const char *mode, FILE *fp)
 	/* _file is only a short */
 	if (f > SHRT_MAX) {
 		fp->_flags = 0;		/* set it free */
+		FUNLOCKFILE(fp);
 		errno = EMFILE;
 		return (NULL);
 	}
@@ -162,5 +166,6 @@ freopen(const char *file, const char *mode, FILE *fp)
 	 */
 	if (oflags & O_APPEND)
 		(void) __sseek((void *)fp, (fpos_t)0, SEEK_END);
+	FUNLOCKFILE(fp);
 	return (fp);
 }