Document ProcessSignal::watch.

sdk/lib/io/process.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.
 
 part of dart.io;
 
 // TODO(ager): The only reason for this class is that we
 // cannot patch a top-level at this point.
 class _ProcessUtils {
   external static void _exit(int status);
@@ skipping 328 matching lines @@
   static const ProcessSignal SIGPOLL = const ProcessSignal._(29, "SIGPOLL");
   static const ProcessSignal SIGSYS = const ProcessSignal._(31, "SIGSYS");
 
   final int _signalNumber;
   final String _name;
 
   const ProcessSignal._(this._signalNumber, this._name);
 
   String toString() => _name;
 
+  /**
+   * Watch for process signals.
+   *
+   * The following [ProcessSignal]s can be listened to:
+   *
+   *   * [ProcessSignal.SIGHUP].
+   *   * [ProcessSignal.SIGINT].
+   *   * [ProcessSignal.SIGTERM]. Not available on Windows.
+   *   * [ProcessSignal.SIGUSR1]. Not available on Windows.
+   *   * [ProcessSignal.SIGUSR2]. Not available on Windows.
+   *   * [ProcessSignal.SIGWINCH]. Not available on Windows.
+   *
+   * Other signals are disallowed, as they may be used by the VM.
+   */
   Stream<ProcessSignal> watch() => _ProcessUtils._watchSignal(this);
 }
 
 
 class SignalException implements IOException {
   final String message;
   final osError;
 
   const SignalException(this.message, [this.osError = null]);
 
@@ skipping 29 matching lines @@
   final int errorCode;
 
   const ProcessException(this.executable, this.arguments, [this.message = "",
                          this.errorCode = 0]);
   String toString() {
     var msg = (message == null) ? 'OS error code: $errorCode' : message;
     var args = arguments.join(' ');
     return "ProcessException: $msg\n  Command: $executable $args";
   }
 }