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/ftell.c b/libc/stdio/ftell.c
index b7d449e..9f850ee 100644
--- a/libc/stdio/ftell.c
+++ b/libc/stdio/ftell.c
@@ -45,20 +45,22 @@
if (fp->_seek == NULL) {
errno = ESPIPE; /* historic practice */
- return ((off_t)-1);
+ pos = -1;
+ goto out;
}
/*
* Find offset of underlying I/O object, then
* adjust for buffered bytes.
*/
+ FLOCKFILE(fp);
__sflush(fp); /* may adjust seek offset on append stream */
if (fp->_flags & __SOFF)
pos = fp->_offset;
else {
pos = (*fp->_seek)(fp->_cookie, (fpos_t)0, SEEK_CUR);
- if (pos == -1L)
- return (pos);
+ if (pos == -1)
+ goto out;
}
if (fp->_flags & __SRD) {
/*
@@ -77,6 +79,7 @@
*/
pos += fp->_p - fp->_bf._base;
}
+out: FUNLOCKFILE(fp);
return (pos);
}