Signal handling, take 2.

tests/standalone/io/signals_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "dart:io";
+
+import "package:expect/expect.dart";
+import "package:async_helper/async_helper.dart";
+
+void testSignals(int usr1Expect,
+                 int usr2Expect,
+                 [int usr1Send,
+                  int usr2Send,
+                  bool shouldFail = false]) {
+  if (usr1Send == null) usr1Send = usr1Expect;
+  if (usr2Send == null) usr2Send = usr2Expect;
+  asyncStart();
+  Process.start(Platform.executable,
+      [Platform.script.resolve('signals_test_script.dart').toFilePath(),
+       usr1Expect.toString(),
+       usr2Expect.toString()])
+    .then((process) {
+      process.stdin.close();
+      process.stderr.drain();
+      int v = 0;
+      process.stdout.listen((out) {
+        // Send as many signals as 'ready\n' received on stdout
+        int count = out.where((c) => c == '\n'.codeUnitAt(0)).length;
+        for (int i = 0; i < count; i++) {
+          if (v < usr1Send) {
+            process.kill(ProcessSignal.SIGUSR1);
+          } else if (v < usr1Send + usr2Send) {
+            process.kill(ProcessSignal.SIGUSR2);
+          }
+          v++;
+        }
+      });
+      process.exitCode.then((exitCode) {
+        Expect.equals(shouldFail, exitCode != 0);
+        asyncEnd();
+      });
+    });
+}
+
+
+void testListenCancel() {
+  for (int i = 0; i < 10; i++) {
+    ProcessSignal.SIGINT.watch().listen(null).cancel();
+  }
+}
+
+void main() {
+  testListenCancel();
+  if (Platform.isWindows) return;
+  testSignals(0, 0);
+  testSignals(1, 0);
+  testSignals(0, 1);
+  testSignals(1, 1);
+  testSignals(10, 10);
+  testSignals(10, 1);
+  testSignals(1, 10);
+  testSignals(1, 0, 0, 1, true);
+  testSignals(0, 1, 1, 0, true);
+}