[PPRZ CENTER] Fixed detection of child processes exitting on Mac OS.

We are now checking if the input channel is empty when receiving the IN
callback. If that is the case we assume that the child process exitted,
ond call the close process callback that normally is treggered by the
HUP callback.

Some background: On OS X glib is using it's own implementation of poll
that does not generate the HUP signal. (It would be possible to add this
functionality modelled after the SSH implementation of bsd_poll) The
glib implementation does generate IN signal when the pipe get's closed.
So we can just check if the input channel is empty and if that is the
case infer that the pipe got closed.

sw/supervision/pc_common.ml

@@ -31,28 +31,31 @@ let conf_dir = Env.paparazzi_home // "conf"
 let my_open_process_in = fun cmd ->
   let (in_read, in_write) = Unix.pipe () in
   let inchan = Unix.in_channel_of_descr in_read in
-  let pid = Unix.create_process_env "/bin/sh" [|"/bin/sh"; "-c"; cmd|] (Array.append (Unix.environment ()) [|"GTK_SETLOCALE=0";"LANG=C"|]) Unix.stdin in_write Unix.stderr in
+  let pid = Unix.create_process_env "/bin/sh" [|"/bin/sh"; "-c"; cmd|] (Array.append (Unix.environment ()) [|"GTK_SETLOCALE=0";"LANG=C"|]) in_read in_write Unix.stderr in
   Unix.close in_write;
   pid, inchan
 
 let buf_size = 512
 
-let run_and_log = fun log com ->
+let run_and_log = fun log exit_cb com ->
   let com = com ^ " 2>&1" in
   let pid, com_stdout = my_open_process_in com in
-  let channel_out = GMain.Io.channel_of_descr (Unix.descr_of_in_channel com_stdout) in
-  let cb = fun ev ->
-    let buf = String.create buf_size in
-    (* loop until input returns zero *)
-    let rec log_input = fun out ->
-      let n = input out buf 0 buf_size in
-      (* split on beginning of new line *)
-      let s = Str.split (Str.regexp "^") (String.sub buf 0 n) in
-      List.iter (fun l -> log l) s;
-      if n = buf_size then log_input out
+  let channel_out_fd = Unix.descr_of_in_channel com_stdout in
+  let channel_out = GMain.Io.channel_of_descr channel_out_fd in
+  let cb = fun _ ->
+      let buf = String.create buf_size in
+      (* loop until input returns zero *)
+      let rec log_input = fun out ->
+        let n = input out buf 0 buf_size in
+        (* split on beginning of new line *)
+        let s = Str.split (Str.regexp "^") (String.sub buf 0 n) in
+        List.iter (fun l -> log l) s;
+        if n = buf_size then (log_input out) + n else n
+      in
+      let count = log_input com_stdout in
+      if count = 0 then exit_cb true;
+      true
     in
-    log_input com_stdout;
-    true in
   let io_watch_out = Glib.Io.add_watch [`IN] cb channel_out in
   pid, channel_out, com_stdout, io_watch_out
 
@@ -99,14 +102,16 @@ let run_and_monitor = fun ?(once = false) ?file gui log com_name com args ->
   let run = fun callback ->
     let c = p#entry_program#text in
     log (sprintf "RUN '%s'\n" c);
-    let (pi, out, unixfd, io_watch) = run_and_log log ("exec "^c) in
+
+  let (pi, out, unixfd, io_watch) = run_and_log log callback ("exec "^c) in
     pid := pi;
     outchan := unixfd;
-    let io_watch' = Glib.Io.add_watch [`HUP;`OUT] (fun _ ->
-      (* call with a delay of 200ms, not strictly needed anymore, but seems more pleasing to the eye *)
-      ignore (Glib.Timeout.add 200 (fun () -> callback true; false));
-      false) out in
-    watches := [ io_watch; io_watch'] in
+    let io_watch' = Glib.Io.add_watch ~cond:[`HUP] ~callback:
+      (fun _ ->
+         (* call with a delay of 200ms, not strictly needed anymore, but seems more pleasing to the eye *)
+         ignore (Glib.Timeout.add 200 (fun () -> callback true; false));
+         false) out in
+    watches := [ io_watch; io_watch' ] in
 
   let remove_callback = fun () ->
     gui#vbox_programs#remove p#toplevel#coerce in
@@ -153,7 +158,7 @@ let run_and_monitor = fun ?(once = false) ?file gui log com_name com args ->
 let basic_command = fun (log:string->unit) ac_name target ->
   let com = sprintf "export PATH=/usr/bin:$PATH; make -C %s -f Makefile.ac AIRCRAFT=%s %s" Env.paparazzi_src ac_name target in
   log com;
-  ignore (run_and_log log com)
+  ignore (run_and_log log (fun _ -> ()) com)
 
 
 let command = fun ?file gui (log:string->unit) ac_name target ->