csrc/node-v0.10.24/src/handle_wrap.h

// Copyright Joyent, Inc. and other Node contributors.
//
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// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef HANDLE_WRAP_H_
#define HANDLE_WRAP_H_

#include "ngx-queue.h"

namespace node {

// Rules:
//
// - Do not throw from handle methods. Set errno.
//
// - MakeCallback may only be made directly off the event loop.
//   That is there can be no JavaScript stack frames underneith it.
//   (Is there anyway to assert that?)
//
// - No use of v8::WeakReferenceCallback. The close callback signifies that
//   we're done with a handle - external resources can be freed.
//
// - Reusable?
//
// - The uv_close_cb is used to free the c++ object. The close callback
//   is not made into javascript land.
//
// - uv_ref, uv_unref counts are managed at this layer to avoid needless
//   js/c++ boundary crossing. At the javascript layer that should all be
//   taken care of.

#define UNWRAP_NO_ABORT(type)                                               \
  assert(!args.Holder().IsEmpty());                                         \
  assert(args.Holder()->InternalFieldCount() > 0);                          \
  type* wrap = static_cast<type*>(                                          \
      args.Holder()->GetPointerFromInternalField(0));

class HandleWrap {
  public:
    static void Initialize(v8::Handle<v8::Object> target);
    static v8::Handle<v8::Value> Close(const v8::Arguments& args);
    static v8::Handle<v8::Value> Ref(const v8::Arguments& args);
    static v8::Handle<v8::Value> Unref(const v8::Arguments& args);

    inline uv_handle_t* GetHandle() { return handle__; };

  protected:
    HandleWrap(v8::Handle<v8::Object> object, uv_handle_t* handle);
    virtual ~HandleWrap();

    virtual void SetHandle(uv_handle_t* h);

    v8::Persistent<v8::Object> object_;

  private:
    friend v8::Handle<v8::Value> GetActiveHandles(const v8::Arguments&);
    static void OnClose(uv_handle_t* handle);
    ngx_queue_t handle_wrap_queue_;
    // Using double underscore due to handle_ member in tcp_wrap. Probably
    // tcp_wrap should rename it's member to 'handle'.
    uv_handle_t* handle__;
    unsigned int flags_;

    static const unsigned int kUnref = 1;
    static const unsigned int kCloseCallback = 2;
};


}  // namespace node


#endif  // HANDLE_WRAP_H_