Fix signals tests

lib_eio_luv/eio_luv.ml

@@ -1332,5 +1332,5 @@ let stop_signal_thread (tid, omask, outp) =
 
 let run main =
   let sigctx = start_signal_thread () in
-  Fun.protect (fun () -> run2 stdenv)
+  Fun.protect (fun () -> run2 main)
     ~finally:(fun () -> stop_signal_thread sigctx)

tests/signal.md

@@ -2,32 +2,38 @@
 
 ```ocaml
 # #require "eio_main";;
+# open Eio.Std;;
 ```
 
 # Test cases
 
 Prove we can catch sigint:
 ```ocaml
 # Eio_main.run @@ fun _stdenv ->
-  let got_sigint = ref false in
+  let interrupted = Eio.Condition.create () in
   let old = Sys.signal Sys.sigint
-      (Signal_handle (fun _num -> got_sigint := true))
+      (Signal_handle (fun num -> if num = Sys.sigint then Eio.Condition.broadcast interrupted))
   in
-  let ppid = Unix.getpid () in
-  let () = match Unix.fork () with
-    | 0 ->
-      Unix.kill ppid Sys.sigint;
-      Unix._exit 0
-    | child_pid ->
-      let wait () =
-        let pid, status = Unix.waitpid [] child_pid in
-        assert (pid = child_pid);
-        assert (status = (Unix.WEXITED 0))
-      in
-      try wait () with Unix.Unix_error (Unix.EINTR, _, _) -> wait ()
-  in
-  Eio.Std.traceln "got_sigint = %b" !got_sigint;
+  Fiber.both
+    (fun () ->
+      Eio.Condition.await_no_mutex interrupted;
+      traceln "interrupted!";
+    )
+    (fun () ->
+      let ppid = Unix.getpid () in
+      match Unix.fork () with
+      | 0 ->
+        Unix.kill ppid Sys.sigint;
+        Unix._exit 0
+      | child_pid ->
+        let wait () =
+          let pid, status = Unix.waitpid [] child_pid in
+          assert (pid = child_pid);
+          assert (status = (Unix.WEXITED 0))
+        in
+        try wait () with Unix.Unix_error (Unix.EINTR, _, _) -> wait ()
+    );
   Sys.set_signal Sys.sigint old;;
-+got_sigint = true
++interrupted!
 - : unit = ()
 ```