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| author | Jeff Johnston <jjohnstn@redhat.com> | 2006-02-20 23:24:00 +0000 |
|---|---|---|
| committer | Jeff Johnston <jjohnstn@redhat.com> | 2006-02-20 23:24:00 +0000 |
| commit | 99db626d210c747e8e8da2de09afb523547329bc (patch) | |
| tree | 98ef3a36cf857e0528f6e3e4666fbc471c729919 | |
| parent | 8aaf07c7a2029da9a87e5a751b75568e129e510c (diff) | |
| download | cygnal-99db626d210c747e8e8da2de09afb523547329bc.tar.gz cygnal-99db626d210c747e8e8da2de09afb523547329bc.tar.bz2 cygnal-99db626d210c747e8e8da2de09afb523547329bc.zip | |
2006-02-20 Jeff Johnston <jjohnstn@redhat.com>
* libc/stdio/fflush.c (fflush): For an fflush on a read-only
stream, turn off fseek/rewind optimization as per POSIX/SUSv3.
* libc/stdio/fseek.c (_fseek_r): After a successful unoptimized
seek, turn off the __SNPT no-optimization flag.
| -rw-r--r-- | newlib/ChangeLog | 7 | ||||
| -rw-r--r-- | newlib/libc/stdio/fflush.c | 12 | ||||
| -rw-r--r-- | newlib/libc/stdio/fseek.c | 7 |
3 files changed, 25 insertions, 1 deletions
diff --git a/newlib/ChangeLog b/newlib/ChangeLog index 4944b8867..940ef007c 100644 --- a/newlib/ChangeLog +++ b/newlib/ChangeLog @@ -1,3 +1,10 @@ +2006-02-20 Jeff Johnston <jjohnstn@redhat.com> + + * libc/stdio/fflush.c (fflush): For an fflush on a read-only + stream, turn off fseek/rewind optimization as per POSIX/SUSv3. + * libc/stdio/fseek.c (_fseek_r): After a successful unoptimized + seek, turn off the __SNPT no-optimization flag. + 2006-02-16 Jeff Johnston <jjohnstn@redhat.com> * libc/sys/linux/aio.c: Define _GNU_SOURCE so struct aioinit diff --git a/newlib/libc/stdio/fflush.c b/newlib/libc/stdio/fflush.c index b417e5424..05084dde0 100644 --- a/newlib/libc/stdio/fflush.c +++ b/newlib/libc/stdio/fflush.c @@ -72,8 +72,18 @@ _DEFUN(fflush, (fp), _flockfile (fp); t = fp->_flags; - if ((t & __SWR) == 0 || (p = fp->_bf._base) == NULL) + if ((t & __SWR) == 0) { + /* For a read stream, an fflush causes the next seek to be + unoptimized (i.e. forces a system-level seek). This conforms + to the POSIX and SUSv3 standards. */ + fp->_flags |= __SNPT; + _funlockfile (fp); + return 0; + } + if ((p = fp->_bf._base) == NULL) + { + /* Nothing to flush. */ _funlockfile (fp); return 0; } diff --git a/newlib/libc/stdio/fseek.c b/newlib/libc/stdio/fseek.c index 2ad98551c..8b189ba17 100644 --- a/newlib/libc/stdio/fseek.c +++ b/newlib/libc/stdio/fseek.c @@ -359,6 +359,13 @@ dumb: fp->_r = 0; /* fp->_w = 0; *//* unnecessary (I think...) */ fp->_flags &= ~__SEOF; + /* Reset no-optimization flag after successful seek. The + no-optimization flag may be set in the case of a read + stream that is flushed which by POSIX/SUSv3 standards, + means that a corresponding seek must not optimize. The + optimization is then allowed if no subsequent flush + is performed. */ + fp->_flags &= ~__SNPT; _funlockfile (fp); return 0; } |