[Unison-hackers] Unix.sleep insufficient for -repeat! Need half seconds.

[Ryan Newton]

That couldn't have been easier.  (Although it would be nice if Caml  
had a variant of "external" which would do the simple type  
conversions for you (for ints, floats, chars) -- then this wouldn't  
require C code at all!)

The below works for MacOS (intel + ppc) and linux.  If the powers  
that be are interested in this change, I can look into a solution  
that works for windows as well.

-Ryan

usleep.c:
===============================================

#include <caml/mlvalues.h>
#include <unistd.h>

value unison_usleep( value msecs ) {
   return Val_int( usleep( Int_val(msecs)));
}


uitext.ml:
===============================================

(* Defined in usleep.c *)
external usleep : int -> int  = "unison_usleep"

let rec synchronizeUntilDone () =
   let repeatinterval =
     if Prefs.read Uicommon.repeat = "" then -1.0 else
     try float_of_string (Prefs.read Uicommon.repeat)
     with Failure "float_of_string" ->
       (* If the 'repeat' pref is not a number, switch modes... *)
       synchronizePathsFromFilesystemWatcher() in

   let exitStatus = synchronizeUntilNoFailures() in
   if repeatinterval < 0.0 then
     exitStatus
   else begin
     (* Do it again *)
     Trace.status (Printf.sprintf "\nSleeping for %f seconds...\n"  
repeatinterval);

     let seconds = int_of_float repeatinterval in
     let millisec = (int_of_float (1000000. *. repeatinterval)) -  
(seconds * 1000000) in
      (* In some implementations usleep can only sleep up to 1  
second. *)
      (if seconds > 0 then Unix.sleep seconds);
      (if millisec > 0 then let _ = usleep millisec in ());

     synchronizeUntilDone ()
   end


On Apr 20, 2007, at 10:54 AM, Ryan Newton wrote:

> Hello all,
>
> I use the -repeat option *extensively* to establish a relatively  
> low-bandwidth, poor man's distributed file system.  Basically, if  
> my connection is good enough, I do development by running emacs  
> over X11 forwarding from the server.  If it's not good enough, I  
> run emacs locally, use unison -repeat, and compile/run the program  
> on the server over a simple ssh terminal.