Start better error reporting for sockets

runtime/bin/socket.h

Index: runtime/bin/socket.h
diff --git a/runtime/bin/socket.h b/runtime/bin/socket.h
index 4a42d05034ecda5dc44702332c6e0cb7a6a2c85d..5650baf01e092c5e79481d22f9d68432d400374e 100644
--- a/runtime/bin/socket.h
+++ b/runtime/bin/socket.h
@@ -6,11 +6,17 @@
 #define BIN_SOCKET_H_
 
 #include "bin/builtin.h"
+#include "bin/utils.h"
 #include "platform/globals.h"
+#include "platform/thread.h"
 
 
 class Socket {
  public:
+  enum SocketRequest {
+    kLookupRequest = 0,
+  };
+
   static bool Initialize();
   static intptr_t Available(intptr_t fd);
   static int Read(intptr_t fd, void* buffer, intptr_t num_bytes);
@@ -19,6 +25,18 @@ class Socket {
   static intptr_t GetPort(intptr_t fd);
   static intptr_t GetStdioHandle(int num);
 
+  // Perform a IPv4 hostname lookup. Returns the hostname string in
+  // IPv4 dotted-decimal format.
+  static const char* LookupIPv4Address(char* host, OSError** os_error);
+
+  static Dart_Port GetServicePort();
+
+ private:
+  static dart::Mutex mutex_;
+  static int service_ports_size_;
+  static Dart_Port* service_ports_;
+  static int service_ports_index_;
+
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Socket);
 };