[lttng-dev] [lttng-ust][PATCH V2] Add config time check for new gettid API

[Khem Raj]

On Fri, Jul 26, 2019 at 12:23 PM Sebastien Boisvert <sboisvert at gydle.com> wrote:
>
>
>
> On 2019-07-26 3:02 p.m., Khem Raj wrote:
> > glibc 2.30 introduced this function see [1]
> > so it's best to detect it
> > and provide fallback only if its not present
>
> nit:
>
> -if its not present
> +if it's not present
>

I sent a v3 with this fixed.

> I cloned the git repository of the glibc, but I could not find
> the definition of gettid().
>
> Do you know where it is located in glibc ?
>
see
https://sourceware.org/git/?p=glibc.git;a=commit;h=1d0fc213824eaa2a8f8c4385daaa698ee8fb7c92

> Thanks.
>
> >
> > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=6399
> >
> > Upstream-Status: Submitted [https://lists.lttng.org/pipermail/lttng-dev/2019-July/029131.html]
> >
> > Signed-off-by: Khem Raj <raj.khem at gmail.com>
> > ---
> > v2: Fix typos in commit message
> >
> >  configure.ac            | 1 +
> >  include/lttng/ust-tid.h | 7 +++++--
> >  2 files changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/configure.ac b/configure.ac
> > index 7fa059a..b1099c1 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -137,6 +137,7 @@ AC_CHECK_FUNCS([ \
> >       clock_gettime \
> >       ftruncate \
> >       getpagesize \
> > +     gettid \
> >       gettimeofday \
> >       localeconv \
> >       memchr \
> > diff --git a/include/lttng/ust-tid.h b/include/lttng/ust-tid.h
> > index e669d7e..7995c78 100644
> > --- a/include/lttng/ust-tid.h
> > +++ b/include/lttng/ust-tid.h
> > @@ -26,7 +26,10 @@
> >   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> >   * SOFTWARE.
> >   */
> > -
> > +#include <config.h>
> > +#if HAVE_GETTID
> > +#include <unistd.h>
> > +#else
> >  #ifdef __linux__
> >  #include <syscall.h>
> >  #endif
> > @@ -49,5 +52,5 @@ static inline pid_t gettid(void)
> >       return getpid();
> >  }
> >  #endif
> > -
> > +#endif /* HAVE_GETTID */
> >  #endif /* _LTTNG_UST_TID_H */
> >