Add FileSystemWatcher class to dart:io.

runtime/bin/eventhandler_win.cc

 // 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.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/eventhandler.h"
 
 #include <process.h>  // NOLINT
@@ skipping 325 matching lines @@
     int fd = _open("NUL", _O_WRONLY);
     ASSERT(fd >= 0);
     _dup2(fd, _fileno(stdout));
     close(fd);
   } else {
     Handle::DoClose();
   }
 }
 
 
+void DirectoryWatchHandle::EnsureInitialized(
+    EventHandlerImplementation* event_handler) {
+  ScopedLock lock(this);
+  event_handler_ = event_handler;
+  if (completion_port_ == INVALID_HANDLE_VALUE) {
+    CreateCompletionPort(event_handler_->completion_port());
+  }
+}
+
+
+bool DirectoryWatchHandle::IsClosed() {
+  return IsClosing() && pending_read_ == NULL;
+}
+
+
+void DirectoryWatchHandle::DoClose() {
+  Handle::DoClose();
+}
+
+bool DirectoryWatchHandle::IssueRead() {
+  ScopedLock lock(this);
+  OverlappedBuffer* buffer = OverlappedBuffer::AllocateReadBuffer(kBufferSize);
+
+  ASSERT(completion_port_ != INVALID_HANDLE_VALUE);
+
+  BOOL ok = ReadDirectoryChangesW(handle_,
+                                  buffer->GetBufferStart(),
+                                  buffer->GetBufferSize(),
+                                  recursive_,
+                                  events_,
+                                  NULL,
+                                  buffer->GetCleanOverlapped(),
+                                  NULL);
+  if (ok || GetLastError() == ERROR_IO_PENDING) {
+    // Completing asynchronously.
+    pending_read_ = buffer;
+    return true;
+  }
+  OverlappedBuffer::DisposeBuffer(buffer);
+  return false;
+}
+
+
 void SocketHandle::HandleIssueError() {
   int error = WSAGetLastError();
   if (error == WSAECONNRESET) {
     event_handler_->HandleClosed(this);
   } else {
     event_handler_->HandleError(this);
   }
   WSASetLastError(error);
 }
 
@@ skipping 660 matching lines @@
 
 
 void EventHandlerImplementation::Shutdown() {
   SendData(kShutdownId, 0, 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)