SIGQUIT toggles VM service HTTP server

runtime/bin/main.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 <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_debugger_api.h"
@@ skipping 47 matching lines @@
 
 // Global flag that is used to indicate that we want to compile all the
 // dart functions and not run anything.
 static bool has_compile_all = false;
 
 // Global flag that is used to indicate that we want to print the source code
 // for script that is being run.
 static bool has_print_script = false;
 
 
+static const char* DEFAULT_VM_SERVICE_SERVER_IP = "127.0.0.1";
+static const int DEFAULT_VM_SERVICE_SERVER_PORT = 8181;
 // VM Service options.
-static bool start_vm_service = false;
-static const char *vm_service_server_ip = NULL;
-static int vm_service_server_port = -1;
-static const char *DEFAULT_VM_SERVICE_SERVER_IP = "127.0.0.1";
-static const int DEFAULT_VM_SERVICE_SERVER_PORT = 8181;
+static bool start_vm_service = true;
+static const char* vm_service_server_ip = DEFAULT_VM_SERVICE_SERVER_IP;
+// The 0 port is a magic value which results in the first available port
+// being allocated.
+static int vm_service_server_port = 0;
 
 // The environment provided through the command line using -D options.
 static dart::HashMap* environment = NULL;
 
 static bool IsValidFlag(const char* name,
                         const char* prefix,
                         intptr_t prefix_length) {
   intptr_t name_length = strlen(name);
   return ((name_length > prefix_length) &&
           (strncmp(name, prefix, prefix_length) == 0));
@@ skipping 892 matching lines @@
 
   // Start event handler.
   EventHandler::Start();
 
   ASSERT(Dart_CurrentIsolate() == NULL);
   // Start the VM service isolate, if necessary.
   if (start_vm_service) {
     if (!start_debugger) {
       DebuggerConnectionHandler::InitForVmService();
     }
-    ASSERT(vm_service_server_ip != NULL && vm_service_server_port >= 0);
-    bool r = VmService::Start(vm_service_server_ip , vm_service_server_port);
+    bool r = VmService::Start(vm_service_server_ip, vm_service_server_port);
     if (!r) {
       Log::PrintErr("Could not start VM Service isolate %s\n",
                     VmService::GetErrorMessage());
     }
     Dart_RegisterIsolateServiceRequestCallback(
         "io", &ServiceRequestHandler, NULL);
   }
   ASSERT(Dart_CurrentIsolate() == NULL);
 
   // Call CreateIsolateAndSetup which creates an isolate and loads up
@@ skipping 138 matching lines @@
   exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }