New testrunner that runs the test pipleine in an isolate.

utils/testrunner/pipeline_utils.dart

+// Copyright (c) 2012, 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.
+
+List stdout, stderr, log;
+var replyPort;
+int _procnum = 0;
+Map _procs = {};

[Siggi Cherem (dart-lang), 2012/10/02 17:45:20]

it should be perfectly valid to use the int values as keys in the map:
_procs = new Map<int, Process>();

so you shouldn't need to convert pids into strings.

[gram, 2012/10/02 23:01:59]

Done.

+
+/**
+ * Create a file path for a temporary file. The file will be in the
+ * [tmpDir] directory, with name [basis], but with any extension
+ * stripped and replaced by [suffix].
+ */
+String createTempName(String tmpDir, String basis, String suffix) {
+  var p = new Path(basis);
+  return '$tmpDir${Platform.pathSeparator}'
+      '${p.filenameWithoutExtension}${suffix}';
+}
+
+/** Create a file [fileName] and populate it with [contents]. */
+void writeFile(String fileName, String contents) {
+  var file = new File(fileName);
+  var ostream = file.openOutputStream(FileMode.WRITE);
+  ostream.writeString(contents);
+  ostream.close();
+}
+
+/*
+ * Run an external process [cmd] with command line arguments [args].
+ * [timeout] can be used to forcefully terminate the process after
+ * some number of seconds. This is used by runCommand and startProcess.
+ * If [procId] is null (runCommand) then this will return a [Future] for
+ * when the process terminates; if [procId] is instead a non-null string
+ * (startProcess) then a reference to the [Process] will be put in a
+ * map with key [procId] and [procId] will be returned; in this case
+ * the process can be terminated later by calling [stopProcess] and
+ * passing in the [procId].
+ */
+_processHelper(String command, List<String> args,
+    [int timeout = 300, String procId = null]) {
+  var completer = null;
+  if (procId == null) {
+    completer = new Completer();
+  }
+  log.add('Running $command ${Strings.join(args, " ")}');
+  var timer = null;
+  var process = Process.start(command, args);
+
+  process.onStart = () {
+    timer = new Timer(1000 * timeout, (t) {
+      timer = null;
+      process.kill();
+    });
+  };
+  process.onExit = (exitCode) {
+    if (timer != null) {
+      timer.cancel();
+    }
+    process.close();
+    if (completer != null) {
+      completer.complete(exitCode);
+    }
+  };
+  process.onError = (e) {
+    stderr.add("Error starting process:");
+    stderr.add("  Command: $command");
+    stderr.add("  Error: $e");
+    completePipeline(-1);
+  };
+
+  StringInputStream stdoutStringStream =

[Siggi Cherem (dart-lang), 2012/10/02 17:45:20]

nits (here and below): 
- remove type on the left hand side (according to our style guide)
- this var names might be over-specific, we don't need to know the type on the
variable name, how about: 'outStream' and 'errStream'?

  var outStream = new StringInputStream(process.stdout);
  var errStream = new StringInputStream(process.stdout);
  outStream.onLine = _makeReadHandler(outStream, stdout);
  errStream.onLine = _makeReadHandler(errStream, stderr);

- I just noticed that you are not even using these variables anywhere else, you
could hide this part of the logic under _makeReadHandler. E.g. rename it to
something like 'pipeStream'?

void _pipeStream(IntputStream stream, List<String> destination) {
  var source = new StringInputStream(stream);
  source.onLine = () {
    ...
  };
}

[gram, 2012/10/02 23:01:59]

Done.

+      new StringInputStream(process.stdout);
+  StringInputStream stderrStringStream =

[Siggi Cherem (dart-lang), 2012/10/02 17:45:20]

ditto

[gram, 2012/10/02 23:01:59]

Done.

+      new StringInputStream(process.stderr);
+  stdoutStringStream.onLine = _makeReadHandler(stdoutStringStream, stdout);
+  stderrStringStream.onLine = _makeReadHandler(stderrStringStream, stderr);
+  if (procId == null) {
+    return completer.future;
+  } else {
+    _procs[procId] = process;
+    return procId;
+  }
+}
+
+Function _makeReadHandler(StringInputStream source, List<String> destination) {
+  return () {
+    if (source.closed) return;
+    var line = source.readLine();
+    while (null != line) {
+      if (config["immediate"] && line.startsWith('###')) {
+        // TODO - when we dump the list later skip '###' messages if immediate.
+        print(line.substring(3));
+      }
+      destination.add(line);
+      line = source.readLine();
+    }
+  };
+}
+
+/**
+ * Run an external process [cmd] with command line arguments [args].
+ * [timeout] can be used to forcefully terminate the process after
+ * some number of seconds.
+ * Returns a [Future] for when the process terminates.
+ */
+runCommand(String command, List<String> args, [int timeout = 300]) {

[Siggi Cherem (dart-lang), 2012/10/02 17:45:20]

add return type

[gram, 2012/10/02 23:01:59]

Done.

+  return _processHelper(command, args, timeout);
+}
+
+/**
+ * Start an external process [cmd] with command line arguments [args].
+ * Returns an ID by which it can later be stopped.
+ */
+String startProcess(String command, List<String> args) {
+  return _processHelper(command, args, 3000, '${_procnum++}');
+}
+
+/**
+ * Stop a process previously started with [startProcess] or [runCommand],
+ * given the id string.
+ */
+void stopProcess(String id) {
+  Process p = _procs.remove(id);
+  p.kill();
+}
+
+/** Delete a file named [fname] if it exists. */
+bool cleanup(String fname) {
+  if (!config['keep-files']) {
+    var f = new File(fname);
+    try {
+      if (f.existsSync()) {
+        f.deleteSync();
+      }
+    } catch (e) {
+      return false;
+    }
+  }
+  return true;
+}
+
+initPipeline(port) {
+  replyPort = port;
+  stdout = new List();
+  stderr = new List();
+  log = new List();
+}
+
+void completePipeline([exitCode = 0]) {
+  replyPort.send([stdout, stderr, log, exitCode]);
+}
+
+/** Utility function to log diagnostic messages. */
+void logMessage(msg) => log.add(msg);
+