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
This commit is contained in:
Kenny Root
2011-02-12 07:13:44 -08:00
parent 72f9a5c374
commit f582340a6a
36 changed files with 239 additions and 92 deletions

View File

@@ -61,6 +61,7 @@ setvbuf(FILE *fp, char *buf, int mode, size_t size)
* malloc()ed. We also clear any eof condition, as if this were
* a seek.
*/
FLOCKFILE(fp);
ret = 0;
(void)__sflush(fp);
if (HASUB(fp))
@@ -107,6 +108,7 @@ nbf:
fp->_w = 0;
fp->_bf._base = fp->_p = fp->_nbuf;
fp->_bf._size = 1;
FUNLOCKFILE(fp);
return (ret);
}
flags |= __SMBF;
@@ -145,6 +147,7 @@ nbf:
/* begin/continue reading, or stay in intermediate state */
fp->_w = 0;
}
FUNLOCKFILE(fp);
__atexit_register_cleanup(_cleanup);
return (ret);