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/local.h b/libc/stdio/local.h
index 3db1fc5..6b2111a 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -46,6 +46,7 @@
*/
int __sflush(FILE *);
+int __sflush_locked(FILE *);
FILE *__sfp(void);
int __srefill(FILE *);
int __sread(void *, char *, int);
@@ -59,6 +60,7 @@
int _fwalk(int (*)(FILE *));
int __swsetup(FILE *);
int __sflags(const char *, int *);
+int __vfprintf(FILE *, const char *, __va_list);
extern void __atexit_register_cleanup(void (*)(void));
extern int __sdidinit;
@@ -89,3 +91,6 @@
free((char *)(fp)->_lb._base); \
(fp)->_lb._base = NULL; \
}
+
+#define FLOCKFILE(fp) do { if (__isthreaded) flockfile(fp); } while (0)
+#define FUNLOCKFILE(fp) do { if (__isthreaded) funlockfile(fp); } while (0)