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/fpurge.c b/libc/stdio/fpurge.c
index fa0213a..e04c4fe 100644
--- a/libc/stdio/fpurge.c
+++ b/libc/stdio/fpurge.c
@@ -43,7 +43,9 @@
int
fpurge(FILE *fp)
{
+ FLOCKFILE(fp);
if (!fp->_flags) {
+ FUNLOCKFILE(fp);
errno = EBADF;
return(EOF);
}
@@ -54,5 +56,6 @@
fp->_p = fp->_bf._base;
fp->_r = 0;
fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
+ FUNLOCKFILE(fp);
return (0);
}