Extract common Mask/Dart_Port settings of linux event handler implementation to eventhandler.h

dart/runtime/bin/eventhandler_linux.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_LINUX_H_
 #define BIN_EVENTHANDLER_LINUX_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_linux.h directly; use eventhandler.h instead.
 #endif
 
 #include <errno.h>
 #include <sys/epoll.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
 #include "platform/hashmap.h"
 #include "platform/signal_blocker.h"
 
 
 namespace dart {
 namespace bin {
 
-class ListeningSocketData;
-class SocketData {
+class DescriptorInfo : public DescriptorInfoBase {
  public:
-  explicit SocketData(intptr_t fd)
-      : fd_(fd), port_(0), mask_(0), tokens_(16) {
-    ASSERT(fd_ != -1);
-  }
+  explicit DescriptorInfo(intptr_t fd) : DescriptorInfoBase(fd) { }
 
-  virtual ~SocketData() {
-  }
+  virtual ~DescriptorInfo() { }
 
   intptr_t GetPollEvents();
 
-  void Close() {
-    port_ = 0;
-    mask_ = 0;
+  virtual void Close() {
     VOID_TEMP_FAILURE_RETRY(close(fd_));
     fd_ = -1;
   }
-
-  void SetMask(intptr_t mask) {
-    ASSERT(fd_ != -1);
-    mask_ = mask;
-  }
-
-  intptr_t fd() { return fd_; }
-  virtual Dart_Port port() { return port_; }
-
-  virtual bool IsListeningSocket() const { return false; }
-
-  virtual bool AddPort(Dart_Port port) {
-    ASSERT(port_ == 0);
-    port_ = port;
-    return true;
-  }
-
-  virtual bool RemovePort(Dart_Port port) {
-    ASSERT(port_ == 0 || port_ == port);
-    return true;
-  }
-
-  // Returns true if the last token was taken.
-  virtual bool TakeToken() {
-    ASSERT(tokens_ > 0);
-    tokens_--;
-    return tokens_ == 0;
-  }
-
-  // Returns true if the tokens was 0 before adding.
-  virtual bool ReturnToken(Dart_Port port, int count) {
-    ASSERT(port_ == port);
-    ASSERT(tokens_ >= 0);
-    bool was_empty = tokens_ == 0;
-    tokens_ += count;
-    return was_empty;
-  }
-
-  bool HasTokens() const { return tokens_ > 0; }
-
- protected:
-  intptr_t fd_;
-  Dart_Port port_;
-  intptr_t mask_;
-  int tokens_;
 };
 
 
-class ListeningSocketData : public SocketData {
- private:
-  static const int kTokenCount = 4;
-
-  static bool SamePortValue(void* key1, void* key2) {
-    return reinterpret_cast<Dart_Port>(key1) ==
-        reinterpret_cast<Dart_Port>(key2);
-  }
-
-  static uint32_t GetHashmapHashFromPort(Dart_Port port) {
-    return static_cast<uint32_t>(port & 0xFFFFFFFF);
-  }
-
-  static void* GetHashmapKeyFromPort(Dart_Port port) {
-    return reinterpret_cast<void*>(port);
-  }
-
+class DescriptorInfoSingle
+    : public DescriptorInfoSingleMixin<DescriptorInfo> {
  public:
-  explicit ListeningSocketData(intptr_t fd)
-      : SocketData(fd),
-        tokens_map_(&SamePortValue, 4) {}
-
-  bool IsListeningSocket() const { return true; }
-
-  bool AddPort(Dart_Port port) {
-    HashMap::Entry* entry = tokens_map_.Lookup(
-        GetHashmapKeyFromPort(port), GetHashmapHashFromPort(port), true);
-    entry->value = reinterpret_cast<void*>(kTokenCount);
-    return live_ports_.Add(port);
-  }
-
-  virtual bool RemovePort(Dart_Port port) {
-    HashMap::Entry* entry = tokens_map_.Lookup(
-        GetHashmapKeyFromPort(port), GetHashmapHashFromPort(port), false);
-    if (entry != NULL) {
-      intptr_t tokens = reinterpret_cast<intptr_t>(entry->value);
-      if (tokens == 0) {
-        while (idle_ports_.head() != port) {
-          idle_ports_.Rotate();
-        }
-        idle_ports_.RemoveHead();
-      } else {
-        while (live_ports_.head() != port) {
-          live_ports_.Rotate();
-        }
-        live_ports_.RemoveHead();
-      }
-      tokens_map_.Remove(
-          GetHashmapKeyFromPort(port), GetHashmapHashFromPort(port));
-    } else {
-      // NOTE: This is a listening socket which has been immediately closed.
-      //
-      // If a listening socket is not listened on, the event handler does not
-      // know about it beforehand. So the first time the event handler knows
-      // about it, is when it is supposed to be closed. We therefore do nothing
-      // here.
-      //
-      // But whether to close it, depends on whether other isolates have it open
-      // as well or not.
-    }
-    return !live_ports_.HasHead();
-  }
-
-  bool TakeToken() {
-    ASSERT(live_ports_.HasHead());
-    Dart_Port port = live_ports_.head();
-    HashMap::Entry* entry = tokens_map_.Lookup(
-        GetHashmapKeyFromPort(port), GetHashmapHashFromPort(port), false);
-    ASSERT(entry != NULL);
-    intptr_t tokens = reinterpret_cast<intptr_t>(entry->value);
-    tokens--;
-    entry->value = reinterpret_cast<void*>(tokens);
-    if (tokens == 0) {
-      live_ports_.RemoveHead();
-      idle_ports_.Add(port);
-      if (!live_ports_.HasHead()) {
-        return true;
-      }
-    } else {
-      live_ports_.Rotate();
-    }
-    return false;
-  }
-
-  Dart_Port port() { return live_ports_.head(); }
-
-  bool ReturnToken(Dart_Port port, int count) {
-    HashMap::Entry* entry = tokens_map_.Lookup(
-        GetHashmapKeyFromPort(port), GetHashmapHashFromPort(port), false);
-    ASSERT(entry != NULL);
-    intptr_t tokens = reinterpret_cast<intptr_t>(entry->value);
-    tokens += count;
-    entry->value = reinterpret_cast<void*>(tokens);
-    if (tokens == count) {
-      // Return to live_ports_.
-      while (idle_ports_.head() != port) {
-        idle_ports_.Rotate();
-      }
-      idle_ports_.RemoveHead();
-      bool was_empty = !live_ports_.HasHead();
-      live_ports_.Add(port);
-      return was_empty;
-    }
-    return false;
-  }
-
- private:
-  CircularLinkedList<Dart_Port> live_ports_;
-  CircularLinkedList<Dart_Port> idle_ports_;
-  HashMap tokens_map_;
+  explicit DescriptorInfoSingle(intptr_t fd)
+      : DescriptorInfoSingleMixin(fd) {}
+  virtual ~DescriptorInfoSingle() {}
 };
 
 
+class DescriptorInfoMultiple
+    : public DescriptorInfoMultipleMixin<DescriptorInfo> {
+ public:
+  explicit DescriptorInfoMultiple(intptr_t fd)
+      : DescriptorInfoMultipleMixin(fd) {}
+  virtual ~DescriptorInfoMultiple() {}
+};
+
+
 class EventHandlerImplementation {
  public:
   EventHandlerImplementation();
   ~EventHandlerImplementation();
 
+  void UpdateEpollInstance(intptr_t old_mask, DescriptorInfo *di);
+
   // Gets the socket data structure for a given file
   // descriptor. Creates a new one if one is not found.
-  SocketData* GetSocketData(intptr_t fd, bool is_listening);
+  DescriptorInfo* GetDescriptorInfo(intptr_t fd, bool is_listening);
   void SendData(intptr_t id, Dart_Port dart_port, int64_t data);
   void Start(EventHandler* handler);
   void Shutdown();
 
  private:
   void HandleEvents(struct epoll_event* events, int size);
   static void Poll(uword args);
   void WakeupHandler(intptr_t id, Dart_Port dart_port, int64_t data);
   void HandleInterruptFd();
   void SetPort(intptr_t fd, Dart_Port dart_port, intptr_t mask);
-  intptr_t GetPollEvents(intptr_t events, SocketData* sd);
+  intptr_t GetPollEvents(intptr_t events, DescriptorInfo* di);
   static void* GetHashmapKeyFromFd(intptr_t fd);
   static uint32_t GetHashmapHashFromFd(intptr_t fd);
 
   HashMap socket_map_;
   TimeoutQueue timeout_queue_;
   bool shutdown_;
   int interrupt_fds_[2];
   int epoll_fd_;
   int timer_fd_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_LINUX_H_