Implement windows support for having multiple Dart_Port's registered on one OS socket

dart/runtime/bin/eventhandler_win.h

 // 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.
 
 #ifndef BIN_EVENTHANDLER_WIN_H_
 #define BIN_EVENTHANDLER_WIN_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_win.h directly; use eventhandler.h instead.
 #endif
@@ skipping 136 matching lines @@
 
   // Buffer for recv/send/AcceptEx. This must be at the end of the
   // object as the object is allocated larger than it's definition
   // indicate to extend this array.
   uint8_t buffer_data_[1];
 };
 
 
 // Abstract super class for holding information on listen and connected
 // sockets.
-class Handle {
+class Handle : public DescriptorInfoBase {
  public:
   enum Type {
     kFile,
     kStd,
     kDirectoryWatch,
     kClientSocket,
     kListenSocket,
     kDatagramSocket
   };
 
@@ skipping 43 matching lines @@
   bool IsError() { return (flags_ & (1 << kError)) != 0; }
   void MarkClosing() { flags_ |= (1 << kClosing); }
   void MarkClosedRead() { flags_ |= (1 << kCloseRead); }
   void MarkClosedWrite() { flags_ |= (1 << kCloseWrite); }
   void MarkError() { flags_ |= (1 << kError); }
 
   virtual void EnsureInitialized(
     EventHandlerImplementation* event_handler) = 0;
 
   HANDLE handle() { return handle_; }
-  Dart_Port port() { return port_; }
 
   void Lock();
   void Unlock();
 
   bool CreateCompletionPort(HANDLE completion_port);
 
   void Close();
   virtual void DoClose();
   virtual bool IsClosed() = 0;
 
   bool IsHandleClosed() const { return handle_ == INVALID_HANDLE_VALUE; }
 
-  void SetPortAndMask(Dart_Port port, intptr_t mask) {
-    port_ = port;
-    mask_ = mask;
-  }
   Type type() { return type_; }
   bool is_file() { return type_ == kFile; }
   bool is_socket() { return type_ == kListenSocket ||
                             type_ == kClientSocket ||
                             type_ == kDatagramSocket; }
   bool is_listen_socket() { return type_ == kListenSocket; }
   bool is_client_socket() { return type_ == kClientSocket; }
   bool is_datagram_socket() { return type_ == kDatagramSocket; }
-  void set_mask(intptr_t mask) { mask_ = mask; }
-  intptr_t mask() { return mask_; }
 
   void MarkDoesNotSupportOverlappedIO() {
     flags_ |= (1 << kDoesNotSupportOverlappedIO);
   }
   bool SupportsOverlappedIO() {
     return (flags_ & (1 << kDoesNotSupportOverlappedIO)) == 0;
   }
 
   void ReadSyncCompleteAsync();
 
   DWORD last_error() { return last_error_; }
   void set_last_error(DWORD last_error) { last_error_ = last_error; }
 
  protected:
   enum Flags {
     kClosing = 0,
     kCloseRead = 1,
     kCloseWrite = 2,
     kDoesNotSupportOverlappedIO = 3,
     kError = 4
   };
 
-  explicit Handle(HANDLE handle);
-  Handle(HANDLE handle, Dart_Port port);
+  explicit Handle(intptr_t handle);
 
   virtual void HandleIssueError();
 
   Type type_;
   HANDLE handle_;
-  Dart_Port port_;  // Dart port to communicate events for this socket.
-  intptr_t mask_;  // Mask of events to report through the port.
   HANDLE completion_port_;
   EventHandlerImplementation* event_handler_;
 
   OverlappedBuffer* data_ready_;  // Buffer for data ready to be read.
   OverlappedBuffer* pending_read_;  // Buffer for pending read.
   OverlappedBuffer* pending_write_;  // Buffer for pending write
 
   DWORD last_error_;
 
  private:
   int flags_;
   CRITICAL_SECTION cs_;  // Critical section protecting this object.
 };
 
 
-class FileHandle : public Handle {
+class FileHandle : public DescriptorInfoSingleMixin<Handle> {
  public:
   explicit FileHandle(HANDLE handle)
-      : Handle(handle) { type_ = kFile; }
-  FileHandle(HANDLE handle, Dart_Port port)
-      : Handle(handle, port) { type_ = kFile; }
+      : DescriptorInfoSingleMixin(reinterpret_cast<intptr_t>(handle), true) {
+    type_ = kFile;
+  }
 
   virtual void EnsureInitialized(EventHandlerImplementation* event_handler);
   virtual bool IsClosed();
 };
 
 
 class StdHandle : public FileHandle {
  public:
   explicit StdHandle(HANDLE handle)
       : FileHandle(handle),
@@ skipping 15 matching lines @@
   void RunWriteLoop();
 
  private:
   intptr_t thread_wrote_;
   bool write_thread_exists_;
   bool write_thread_running_;
   Monitor* write_monitor_;
 };
 
 
-class DirectoryWatchHandle : public Handle {
+class DirectoryWatchHandle : public DescriptorInfoSingleMixin<Handle> {
  public:
   DirectoryWatchHandle(HANDLE handle, int events, bool recursive)
-      : Handle(handle),
+      : DescriptorInfoSingleMixin(reinterpret_cast<intptr_t>(handle), true),
         events_(events),
         recursive_(recursive) {
     type_ = kDirectoryWatch;
   }
 
   virtual void EnsureInitialized(EventHandlerImplementation* event_handler);
   virtual bool IsClosed();
 
   virtual bool IssueRead();
 
   void Stop();
 
  private:
   int events_;
   bool recursive_;
 };
 
 
 class SocketHandle : public Handle {
  public:
   SOCKET socket() const { return socket_; }
 
  protected:
-  explicit SocketHandle(SOCKET s)
-      : Handle(reinterpret_cast<HANDLE>(s)),
-        socket_(s) {}
-  SocketHandle(SOCKET s, Dart_Port port)
-      : Handle(reinterpret_cast<HANDLE>(s), port),
+  explicit SocketHandle(intptr_t s)
+      : Handle(s),
         socket_(s) {}
 
   virtual void HandleIssueError();
 
  private:
   const SOCKET socket_;
 };
 
 
 // Information on listen sockets.
-class ListenSocket : public SocketHandle {
+class ListenSocket : public DescriptorInfoMultipleMixin<SocketHandle> {
  public:
-  explicit ListenSocket(SOCKET s) : SocketHandle(s),
-                                    AcceptEx_(NULL),
-                                    pending_accept_count_(0),
-                                    accepted_head_(NULL),
-                                    accepted_tail_(NULL) {
+  explicit ListenSocket(intptr_t s) : DescriptorInfoMultipleMixin(s, true),
+                                      AcceptEx_(NULL),
+                                      pending_accept_count_(0),
+                                      accepted_head_(NULL),
+                                      accepted_tail_(NULL),
+                                      accepted_count_(0) {
     type_ = kListenSocket;
   }
   virtual ~ListenSocket() {
     ASSERT(!HasPendingAccept());
     ASSERT(accepted_head_ == NULL);
     ASSERT(accepted_tail_ == NULL);
   }
 
   // Socket interface exposing normal socket operations.
   ClientSocket* Accept();
   bool CanAccept();
 
   // Internal interface used by the event handler.
   bool HasPendingAccept() { return pending_accept_count_ > 0; }
   bool IssueAccept();
   void AcceptComplete(OverlappedBuffer* buffer, HANDLE completion_port);
 
   virtual void EnsureInitialized(
     EventHandlerImplementation* event_handler);
   virtual void DoClose();
   virtual bool IsClosed();
 
   int pending_accept_count() { return pending_accept_count_; }
 
+  int accepted_count() { return accepted_count_; }
+
  private:
   bool LoadAcceptEx();
 
   LPFN_ACCEPTEX AcceptEx_;
+
+  // The number of asynchronous `IssueAccept` operations which haven't completed
+  // yet.
   int pending_accept_count_;
+
   // Linked list of accepted connections provided by completion code. Ready to
   // be handed over through accept.
   ClientSocket* accepted_head_;
   ClientSocket* accepted_tail_;
+
+  // The number of accepted connections which are waiting to be removed from
+  // this queue and processed by dart isolates.
+  int accepted_count_;
 };
 
 
 // Information on connected sockets.
-class ClientSocket : public SocketHandle {
+class ClientSocket : public DescriptorInfoSingleMixin<SocketHandle> {
  public:
-  explicit ClientSocket(SOCKET s) : SocketHandle(s),
-                                    DisconnectEx_(NULL),
-                                    next_(NULL),
-                                    connected_(false),
-                                    closed_(false) {
+  explicit ClientSocket(intptr_t s) : DescriptorInfoSingleMixin(s, true),
+                                      DisconnectEx_(NULL),
+                                      next_(NULL),
+                                      connected_(false),
+                                      closed_(false) {
     LoadDisconnectEx();
     type_ = kClientSocket;
   }
-
-  ClientSocket(SOCKET s, Dart_Port port) : SocketHandle(s, port),
-                                           DisconnectEx_(NULL),
-                                           next_(NULL),
-                                           connected_(false),
-                                           closed_(false) {
-    LoadDisconnectEx();
-    type_ = kClientSocket;
-  }
 
   virtual ~ClientSocket() {
     // Don't delete this object until all pending requests have been handled.
     ASSERT(!HasPendingRead());
     ASSERT(!HasPendingWrite());
     ASSERT(next_ == NULL);
     ASSERT(closed_ == true);
   }
 
   void Shutdown(int how);
@@ skipping 22 matching lines @@
  private:
   bool LoadDisconnectEx();
 
   LPFN_DISCONNECTEX DisconnectEx_;
   ClientSocket* next_;
   bool connected_;
   bool closed_;
 };
 
 
-class DatagramSocket : public SocketHandle {
+class DatagramSocket : public DescriptorInfoSingleMixin<SocketHandle> {
  public:
-  explicit DatagramSocket(SOCKET s) : SocketHandle(s) {
+  explicit DatagramSocket(intptr_t s) : DescriptorInfoSingleMixin(s, true) {
     type_ = kDatagramSocket;
   }
 
   virtual ~DatagramSocket() {
     // Don't delete this object until all pending requests have been handled.
     ASSERT(!HasPendingRead());
     ASSERT(!HasPendingWrite());
   }
 
   // Internal interface used by the event handler.
@@ skipping 14 matching lines @@
   void SendData(intptr_t id, Dart_Port dart_port, int64_t data);
   void Start(EventHandler* handler);
   void Shutdown();
 
   static void EventHandlerEntry(uword args);
 
   int64_t GetTimeout();
   void HandleInterrupt(InterruptMessage* msg);
   void HandleTimeout();
   void HandleAccept(ListenSocket* listen_socket, OverlappedBuffer* buffer);
+  void TryDispatchingPendingAccepts(ListenSocket *listen_socket);
   void HandleRead(Handle* handle, int bytes, OverlappedBuffer* buffer);
   void HandleRecvFrom(Handle* handle, int bytes, OverlappedBuffer* buffer);
   void HandleWrite(Handle* handle, int bytes, OverlappedBuffer* buffer);
   void HandleDisconnect(ClientSocket* client_socket,
                         int bytes,
                         OverlappedBuffer* buffer);
   void HandleConnect(ClientSocket* client_socket,
                      int bytes,
                      OverlappedBuffer* buffer);
   void HandleIOCompletion(DWORD bytes, ULONG_PTR key, OVERLAPPED* overlapped);
 
   HANDLE completion_port() { return completion_port_; }
 
  private:
   ClientSocket* client_sockets_head_;
 
   TimeoutQueue timeout_queue_;  // Time for next timeout.
   bool shutdown_;
   HANDLE completion_port_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_WIN_H_