Use a pool of native ports for file operations

runtime/bin/file.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_FILE_H_
 #define BIN_FILE_H_
 
 #if defined(_WIN32)
 typedef signed __int64 int64_t;
 typedef unsigned __int8 uint8_t;
 #else
 #include <stdint.h>
 #endif
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <sys/types.h>
 
+#include "bin/builtin.h"
+#include "bin/dartutils.h"
+#include "platform/globals.h"
+#include "platform/thread.h"
+
 // Forward declaration.
 class FileHandle;
 
 class File {
  public:
   enum FileOpenMode {
     kRead = 0,
     kWrite = 1,
     kTruncate = 1 << 2,
     kWriteTruncate = kWrite | kTruncate
@@ skipping 86 matching lines @@
   static bool Delete(const char* name);
   static bool IsAbsolutePath(const char* pathname);
   static char* GetCanonicalPath(const char* name);
   static char* GetContainingDirectory(char* name);
   static const char* PathSeparator();
   static const char* StringEscapedPathSeparator();
   static StdioHandleType GetStdioHandleType(int fd);
 
   static FileOpenMode DartModeToFileMode(DartFileOpenMode mode);
 
+  static Dart_Port GetServicePort();
+
  private:
   File(const char* name, FileHandle* handle) : name_(name), handle_(handle) { }
   void Close();
   bool IsClosed();
 
   static const int kClosedFd = -1;
 
   const char* name_;
   // FileHandle is an OS specific class which stores data about the file.
   FileHandle* handle_;  // OS specific handle for the file.
 
   // DISALLOW_COPY_AND_ASSIGN(File).
   File(const File&);
   void operator=(const File&);
+
+  static dart::Mutex mutex_;
+  static int service_ports_size_;
+  static Dart_Port* service_ports_;
+  static int service_ports_index_;
 };
 
 #endif  // BIN_FILE_H_