First step towards support for being able to interrupt a running Dart Isolate

runtime/bin/dbg_connection_linux.cc

 // 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.
 
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/epoll.h>
 
 #include "bin/dbg_connection.h"
@@ skipping 10 matching lines @@
       FATAL("Cannot connect to more than one debugger.\n");
     }
     int fd = ServerSocket::Accept(event->data.fd);
     if (fd < 0) {
       FATAL("Accepting new debugger connection failed.\n");
     }
     FDUtils::SetBlocking(fd);
     DebuggerConnectionHandler::AcceptDbgConnection(fd);
     // TODO(hausner): add the debugger wire socket fd to the event poll queue
     // once we poll the debugger connection.
-  } else if (event->data.fd == DebuggerConnectionHandler::debugger_fd_) {
-    printf("unexpected: receiving debugger connection event.\n");
+  } else if (event->data.fd == wakeup_fds_[0]) {
+    // Sync message. Not yet implemented.
     UNIMPLEMENTED();
   } else {
-    // Sync message. Not yet implemented.
+    printf("unexpected: receiving debugger connection event.\n");
     UNIMPLEMENTED();
   }
 }
 
 
 void DebuggerConnectionImpl::Handler(uword args) {
   static const intptr_t kMaxEvents = 4;
   struct epoll_event events[kMaxEvents];
   while (1) {
     const int no_timeout = -1;
@@ skipping 49 matching lines @@
 
 
 void DebuggerConnectionImpl::StartHandler(int port_number) {
   ASSERT(DebuggerConnectionHandler::listener_fd_ != -1);
   SetupPollQueue();
   int result = dart::Thread::Start(&DebuggerConnectionImpl::Handler, 0);
   if (result != 0) {
     FATAL1("Failed to start debugger connection handler thread: %d\n", result);
   }
 }