Fix the handle locking in stdio
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.
Based on OpenBSD change by guenther@openbsd.org
http://www.mail-archive.com/source-changes@cvs.openbsd.org/msg01015.html
Bug: 3446659
Change-Id: Ie82116e358c541718d6709ec45ca6796be5a007b
diff --git a/libc/stdio/vfprintf.c b/libc/stdio/vfprintf.c
index 9c36b79..dac8496 100644
--- a/libc/stdio/vfprintf.c
+++ b/libc/stdio/vfprintf.c
@@ -100,8 +100,8 @@
fake._lbfsize = 0; /* not actually used, but Just In Case */
/* do the work, then copy any error status */
- ret = vfprintf(&fake, fmt, ap);
- if (ret >= 0 && fflush(&fake))
+ ret = __vfprintf(&fake, fmt, ap);
+ if (ret >= 0 && __sflush(&fake))
ret = EOF;
if (fake._flags & __SERR)
fp->_flags |= __SERR;
@@ -158,6 +158,17 @@
int
vfprintf(FILE *fp, const char *fmt0, __va_list ap)
{
+ int ret;
+
+ FLOCKFILE(fp);
+ ret = __vfprintf(fp, fmt0, ap);
+ FUNLOCKFILE(fp);
+ return (ret);
+}
+
+int
+__vfprintf(FILE *fp, const char *fmt0, __va_list ap)
+{
char *fmt; /* format string */
int ch; /* character from fmt */
int n, m, n2; /* handy integers (short term usage) */