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/fgets.c b/libc/stdio/fgets.c
index f26385d..311b7b2 100644
--- a/libc/stdio/fgets.c
+++ b/libc/stdio/fgets.c
@@ -51,6 +51,7 @@
if (n <= 0) /* sanity check */
return (NULL);
+ FLOCKFILE(fp);
_SET_ORIENTATION(fp, -1);
s = buf;
n--; /* leave space for NUL */
@@ -61,8 +62,10 @@
if (fp->_r <= 0) {
if (__srefill(fp)) {
/* EOF/error: stop with partial or no line */
- if (s == buf)
+ if (s == buf) {
+ FUNLOCKFILE(fp);
return (NULL);
+ }
break;
}
}
@@ -84,6 +87,7 @@
fp->_p = t;
(void)memcpy((void *)s, (void *)p, len);
s[len] = '\0';
+ FUNLOCKFILE(fp);
return (buf);
}
fp->_r -= len;
@@ -93,5 +97,6 @@
n -= len;
}
*s = '\0';
+ FUNLOCKFILE(fp);
return (buf);
}