[MLton] sleep vs. nanosleep
Tue, 12 Jul 2005 10:40:52 -0500
I looked some on the web and did some tests, and the results are pretty
goofy. It seems that the glibc version of sleep() returns the number of
seconds left if it is awoken by an interrupt, else 0. Also, if even a
SIGSTOP/SIGCONT arrive (i.e., process suspended, resumed) or any thing, the
sleep() returns. This certainly doesn't match what the basis library spec
says either OS.Process.sleep or Posix.Process.sleep should do. (The case for
signals being caught is not discussed. Either way it should be specified.)
Any way, the basis spec seems to require that the code loop.
I tried this in SML/NJ 110.44. They don't have any OS.Process.sleep. Their
Posix.Process.sleep yields a Time.time, returning the amount of time left in
the case of any signal. Just as the sleep() in glibc, in the case of
SIGSTOP/SIGCONT and the like, it returns immediately on restart.
I think that the loop should probably be put in since with both sleep's
returning unit it doesn't make much sense to return early. Again, this
should be spelled out in MLton docs.