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/include/stdio.h b/libc/include/stdio.h
index c38ed5a..4006882 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -170,6 +170,7 @@
#define __SOFF 0x1000 /* set iff _offset is in fact correct */
#define __SMOD 0x2000 /* true => fgetln modified _p text */
#define __SALC 0x4000 /* allocate string space dynamically */
+#define __SIGN 0x8000 /* ignore this file in _fwalk */
/*
* The following three definitions are for ANSI C, which took them
@@ -406,38 +407,43 @@
#define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR|__SEOF)))
#define __sfileno(p) ((p)->_file)
-#define feof(p) __sfeof(p)
-#define ferror(p) __sferror(p)
+extern int __isthreaded;
-#ifndef _POSIX_THREADS
-#define clearerr(p) __sclearerr(p)
-#endif
+#define feof(p) (!__isthreaded ? __sfeof(p) : (feof)(p))
+#define ferror(p) (!__isthreaded ? __sferror(p) : (ferror)(p))
+#define clearerr(p) (!__isthreaded ? __sclearerr(p) : (clearerr)(p))
#if __POSIX_VISIBLE
-#define fileno(p) __sfileno(p)
+#define fileno(p) (!__isthreaded ? __sfileno(p) : (fileno)(p))
#endif
+#define getc(fp) (!__isthreaded ? __sgetc(fp) : (getc)(fp))
+
+#if __BSD_VISIBLE
+/*
+ * The macro implementations of putc and putc_unlocked are not
+ * fully POSIX compliant; they do not set errno on failure
+ */
+#define putc(x, fp) (!__isthreaded ? __sputc(x, fp) : (putc)(x, fp))
+#endif /* __BSD_VISIBLE */
+
#ifndef lint
-#ifndef _POSIX_THREADS
-#define getc(fp) __sgetc(fp)
-#endif /* _POSIX_THREADS */
+#if __POSIX_VISIBLE >= 199506
#define getc_unlocked(fp) __sgetc(fp)
/*
* The macro implementations of putc and putc_unlocked are not
* fully POSIX compliant; they do not set errno on failure
*/
#if __BSD_VISIBLE
-#ifndef _POSIX_THREADS
-#define putc(x, fp) __sputc(x, fp)
-#endif /* _POSIX_THREADS */
#define putc_unlocked(x, fp) __sputc(x, fp)
#endif /* __BSD_VISIBLE */
+#endif /* __POSIX_VISIBLE >= 199506 */
#endif /* lint */
#define getchar() getc(stdin)
#define putchar(x) putc(x, stdout)
-#define getchar_unlocked() getc_unlocked(stdin)
-#define putchar_unlocked(c) putc_unlocked(c, stdout)
+#define getchar_unlocked() getc_unlocked(stdin)
+#define putchar_unlocked(c) putc_unlocked(c, stdout)
#ifdef _GNU_SOURCE
/*