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| author | Kenny Root <kroot@google.com> | 2011-02-12 07:13:44 -0800 |
|---|---|---|
| committer | Kenny Root <kroot@google.com> | 2011-02-14 09:32:56 -0800 |
| commit | f582340a6a48588aa50da17e1620e8f91b146941 (patch) | |
| tree | d30c0ffb648b7a43ff469f89f05850f5008482ec /libc/stdio/ungetc.c | |
| parent | 72f9a5c374bf559e9c69a62c1d95304f913ef6b2 (diff) | |
| download | bionic-f582340a6a48588aa50da17e1620e8f91b146941.zip bionic-f582340a6a48588aa50da17e1620e8f91b146941.tar.gz bionic-f582340a6a48588aa50da17e1620e8f91b146941.tar.bz2 | |
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
Diffstat (limited to 'libc/stdio/ungetc.c')
| -rw-r--r-- | libc/stdio/ungetc.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/libc/stdio/ungetc.c b/libc/stdio/ungetc.c index fe05258..b493d21 100644 --- a/libc/stdio/ungetc.c +++ b/libc/stdio/ungetc.c @@ -82,17 +82,20 @@ ungetc(int c, FILE *fp) return (EOF); if (!__sdidinit) __sinit(); + FLOCKFILE(fp); _SET_ORIENTATION(fp, -1); if ((fp->_flags & __SRD) == 0) { /* * Not already reading: no good unless reading-and-writing. * Otherwise, flush any current write stuff. */ - if ((fp->_flags & __SRW) == 0) + if ((fp->_flags & __SRW) == 0) { +error: FUNLOCKFILE(fp); return (EOF); + } if (fp->_flags & __SWR) { if (__sflush(fp)) - return (EOF); + goto error; fp->_flags &= ~__SWR; fp->_w = 0; fp->_lbfsize = 0; @@ -107,9 +110,10 @@ ungetc(int c, FILE *fp) */ if (HASUB(fp)) { if (fp->_r >= _UB(fp)._size && __submore(fp)) - return (EOF); + goto error; *--fp->_p = c; - fp->_r++; +inc_ret: fp->_r++; + FUNLOCKFILE(fp); return (c); } fp->_flags &= ~__SEOF; @@ -122,8 +126,7 @@ ungetc(int c, FILE *fp) if (fp->_bf._base != NULL && fp->_p > fp->_bf._base && fp->_p[-1] == c) { fp->_p--; - fp->_r++; - return (c); + goto inc_ret; } /* @@ -137,5 +140,6 @@ ungetc(int c, FILE *fp) fp->_ubuf[sizeof(fp->_ubuf) - 1] = c; fp->_p = &fp->_ubuf[sizeof(fp->_ubuf) - 1]; fp->_r = 1; + FUNLOCKFILE(fp); return (c); } |