shameless plug
I wrote a library with the same api of :timer but with a resolution in microseconds
it’s called micro_timer
I did some investigations before writing my own module and I think the relevant snippet of the Erlang sleep implementation is this one
int
erts_milli_sleep(long ms)
{
if (ms > 0) {
#ifdef __WIN32__
Sleep((DWORD) ms);
#else
struct timeval tv;
tv.tv_sec = ms / 1000;
tv.tv_usec = (ms % 1000) * 1000;
if (select(0, NULL, NULL, NULL, &tv) < 0)
return errno == EINTR ? 1 : -1;
#endif
}
return 0;
}
Sleep for win32 is defined as
void Sleep(
DWORD dwMilliseconds
);
It only accepts milliseconds
There is a win32 implementation of the select function that take microseconds, but it’s in Winsock2 API that are supported only from Windows Vista onward.
One could try to compile ERTS using a sleep function that supports microseconds, but I guess it would break a lot of existing software.
It should also be simple enough to write a NIF that supports sleeping for microseconds, once you have the sleep function, you can build all the other functionalities around it (it’s exactly what I did in my library, except the NIF part).
EDIT:
for clarity" sleep in Erlang is implemented using the timeout for receive
-spec sleep(Time) -> 'ok' when
Time :: timeout().
sleep(T) ->
receive
after T -> ok
end.
the snippet I was referring to is what I believe is the low level C implementation.
