[Mesa-dev] [PATCH:mesa] util: Make xmlconfig.c build on Solaris without d_type in dirent

[Roland Mainz]

On Thu, Oct 4, 2018 at 5:21 AM Alan Coopersmith
<alan.coopersmith at oracle.com> wrote:
> On 10/ 3/18 03:15 PM, Roland Mainz wrote:
> > On Wed, Oct 3, 2018 at 11:51 PM Alan Coopersmith
> > <alan.coopersmith at oracle.com> wrote:
> >> Introduced-by: commit 04bdbbcab3c4862bf3f54ce60fcc1d2007776f80
> >> Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
> >> ---
> >>   src/util/xmlconfig.c | 8 ++++++++
> >>   1 file changed, 8 insertions(+)
> >>
> >> diff --git a/src/util/xmlconfig.c b/src/util/xmlconfig.c
> >> index 5264f2598b..608972f812 100644
> >> --- a/src/util/xmlconfig.c
> >> +++ b/src/util/xmlconfig.c
> >> @@ -938,8 +938,16 @@ parseOneConfigFile(struct OptConfData *data, const char *filename)
> >>   static int
> >>   scandir_filter(const struct dirent *ent)
> >>   {
> >> +#ifndef DT_REG /* systems without d_type in dirent results */
> >> +    struct stat st;
> >> +
> >> +    lstat(ent->d_name, &st);
> >> +    if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode))
> >> +       return 0;
> >> +#else
> >
> > What about testing for the return code of |lstat()|&&|errno| before
> > looking at the value of |st| ?
>
> Oh, I suppose there is a small window in which the file could disappear after
> it's read from the directory entry, but before the lstat occurs.

The term "small" is not right here, for example:
1. The machine could be slow, overloaded, paging/swapping and/or
virtualised, which can cause many-second gaps in process/thread
execution
2. HSM (=Hierarchical Storage Management) may need some time
(=minutes) to fetch data from tape
3. You may not have the permission to |stat()| the specific file or
directory, thanks to the wonders of ACLs and/or alien filesystems like
smbfs
4. There are things like SIGSTOP, debuggers, suspend-to-@(disk|memory)
etc. which can "delay" execution for days or weeks

> Attached version checks for that.

That version looks OK for me, r=roland.mainz at nrubsig.org

----

Bye,
Roland
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