[PATCH xorg-gtest 1/4] process: use actual time for timeouts

[Peter Hutterer]

On Tue, Oct 09, 2012 at 08:25:35AM -0700, Chase Douglas wrote:
> On Sun, Oct 7, 2012 at 6:55 PM, Peter Hutterer <peter.hutterer at who-t.net> wrote:
> > loops and usleeps are nice and simple, but have a tendency to overrun the
> > actual timeouts given. Use the actual time instead.
> >
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> >  src/process.cpp | 19 +++++++++++++++++--
> >  1 file changed, 17 insertions(+), 2 deletions(-)
> >
> > diff --git a/src/process.cpp b/src/process.cpp
> > index 4deea14..555e56b 100644
> > --- a/src/process.cpp
> > +++ b/src/process.cpp
> > @@ -30,6 +30,7 @@
> >  #include <sys/prctl.h>
> >  #include <sys/types.h>
> >  #include <sys/wait.h>
> > +#include <sys/time.h>
> >  #include <unistd.h>
> >
> >  #include <algorithm>
> > @@ -127,16 +128,30 @@ void xorg::testing::Process::Start(const std::string& program, ...) {
> >  }
> >
> >  bool xorg::testing::Process::WaitForExit(unsigned int timeout) {
> > -  for (unsigned int i = 0; i < timeout * 100; i++) {
> > +  struct timeval current;
> > +  struct timeval endtime;
> > +  struct timeval add;
> > +
> > +  if (gettimeofday(&current, NULL) != 0)
> > +    throw std::runtime_error("Failed to get the time");
> > +
> > +  add.tv_sec = timeout / 1000;
> > +  add.tv_usec = (timeout % 1000) * 1000;
> > +
> > +  timeradd(&current, &add, &endtime);
> > +
> > +  while (timercmp(&current, &endtime, <)) {
> >      int status;
> >      int pid = waitpid(Pid(), &status, WNOHANG);
> >
> > +
> >      if (pid == Pid())
> >        return true;
> >      else if (pid == -1)
> >        return errno == ECHILD;
> >
> > -      usleep(10);
> 
> Don't we still want this sleep? Without it, we'll just be busy looping
> the entire time.

oops, right. better to wait for SIGCHILD here anyway, patch for that
forthcoming.

Cheers,
   Peter

> 
> > +    if (gettimeofday(&current, NULL) != 0)
> > +      throw std::runtime_error("Failed to get the time");
> >    }
> >
> >    return false;
> > --
> > 1.7.11.4