Rename CefBase to CefBaseRefCounted (issue #2090)

libcef_dll/ctocpp/ctocpp_ref_counted.h

@@ -0,0 +1,176 @@
+// Copyright (c) 2009 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_DLL_CTOCPP_CTOCPP_REF_COUNTED_H_
+#define CEF_LIBCEF_DLL_CTOCPP_CTOCPP_REF_COUNTED_H_
+#pragma once
+
+#include "include/base/cef_logging.h"
+#include "include/base/cef_macros.h"
+#include "include/cef_base.h"
+#include "include/capi/cef_base_capi.h"
+#include "libcef_dll/wrapper_types.h"
+
+// Wrap a C structure with a C++ class. This is used when the implementation
+// exists on the other side of the DLL boundary but will have methods called on
+// this side of the DLL boundary.
+template <class ClassName, class BaseName, class StructName>
+class CefCToCppRefCounted : public BaseName {
+ public:
+  // Create a new wrapper instance for a structure reference received from the
+  // other side.
+  static CefRefPtr<BaseName> Wrap(StructName* s);
+
+  // Retrieve the underlying structure reference from a wrapper instance for
+  // return back to the other side.
+  static StructName* Unwrap(CefRefPtr<BaseName> c);
+
+  // CefBaseRefCounted methods increment/decrement reference counts on both this
+  // object and the underlying wrapped structure.
+  void AddRef() const {
+    UnderlyingAddRef();
+    ref_count_.AddRef();
+  }
+  bool Release() const;
+  bool HasOneRef() const { return UnderlyingHasOneRef(); }
+
+#if DCHECK_IS_ON()
+  // Simple tracking of allocated objects.
+  static base::AtomicRefCount DebugObjCt;  // NOLINT(runtime/int)
+#endif
+
+ protected:
+  CefCToCppRefCounted() {
+#if DCHECK_IS_ON()
+    base::AtomicRefCountInc(&DebugObjCt);
+#endif
+  }
+
+  virtual ~CefCToCppRefCounted() {
+#if DCHECK_IS_ON()
+    base::AtomicRefCountDec(&DebugObjCt);
+#endif
+  }
+
+  // If returning the structure across the DLL boundary use Unwrap() instead.
+  StructName* GetStruct() const {
+    WrapperStruct* wrapperStruct = GetWrapperStruct(this);
+    // Verify that the wrapper offset was calculated correctly.
+    DCHECK_EQ(kWrapperType, wrapperStruct->type_);
+    return wrapperStruct->struct_;
+  }
+
+ private:
+  // Used to associate this wrapper object and the structure reference received
+  // from the other side.
+  struct WrapperStruct;
+
+  static WrapperStruct* GetWrapperStruct(const BaseName* obj);
+
+  // Unwrap as the derived type.
+  static StructName* UnwrapDerived(CefWrapperType type, BaseName* c);
+
+  // Increment/decrement reference counts on only the underlying class.
+  void UnderlyingAddRef() const {
+    cef_base_ref_counted_t* base =
+        reinterpret_cast<cef_base_ref_counted_t*>(GetStruct());
+    if (base->add_ref)
+      base->add_ref(base);
+  }
+
+  bool UnderlyingRelease() const {
+    cef_base_ref_counted_t* base =
+        reinterpret_cast<cef_base_ref_counted_t*>(GetStruct());
+    if (!base->release)
+      return false;
+    return base->release(base) ? true : false;
+  }
+
+  bool UnderlyingHasOneRef() const {
+    cef_base_ref_counted_t* base =
+        reinterpret_cast<cef_base_ref_counted_t*>(GetStruct());
+    if (!base->has_one_ref)
+      return false;
+    return base->has_one_ref(base) ? true : false;
+  }
+
+  CefRefCount ref_count_;
+
+  static CefWrapperType kWrapperType;
+
+  DISALLOW_COPY_AND_ASSIGN(CefCToCppRefCounted);
+};
+
+template <class ClassName, class BaseName, class StructName>
+struct CefCToCppRefCounted<ClassName,BaseName,StructName>::WrapperStruct {
+  CefWrapperType type_;
+  StructName* struct_;
+  ClassName wrapper_;
+};
+
+template <class ClassName, class BaseName, class StructName>
+CefRefPtr<BaseName>
+    CefCToCppRefCounted<ClassName, BaseName, StructName>::Wrap(StructName* s) {
+  if (!s)
+    return NULL;
+
+  // Wrap their structure with the CefCToCppRefCounted object.
+  WrapperStruct* wrapperStruct = new WrapperStruct;
+  wrapperStruct->type_ = kWrapperType;
+  wrapperStruct->struct_ = s;
+
+  // Put the wrapper object in a smart pointer.
+  CefRefPtr<BaseName> wrapperPtr(&wrapperStruct->wrapper_);
+  // Release the reference that was added to the CefCppToC wrapper object on
+  // the other side before their structure was passed to us.
+  wrapperStruct->wrapper_.UnderlyingRelease();
+  // Return the smart pointer.
+  return wrapperPtr;
+}
+
+template <class ClassName, class BaseName, class StructName>
+StructName* CefCToCppRefCounted<ClassName, BaseName, StructName>::Unwrap(
+    CefRefPtr<BaseName> c) {
+  if (!c.get())
+    return NULL;
+
+  WrapperStruct* wrapperStruct = GetWrapperStruct(c.get());
+
+  // If the type does not match this object then we need to unwrap as the
+  // derived type.
+  if (wrapperStruct->type_ != kWrapperType)
+    return UnwrapDerived(wrapperStruct->type_, c.get());
+
+  // Add a reference to the CefCppToC wrapper object on the other side that
+  // will be released once the structure is received.
+  wrapperStruct->wrapper_.UnderlyingAddRef();
+  // Return their original structure.
+  return wrapperStruct->struct_;
+}
+
+template <class ClassName, class BaseName, class StructName>
+bool CefCToCppRefCounted<ClassName, BaseName, StructName>::Release() const {
+  UnderlyingRelease();
+  if (ref_count_.Release()) {
+    WrapperStruct* wrapperStruct = GetWrapperStruct(this);
+    // Verify that the wrapper offset was calculated correctly.
+    DCHECK_EQ(kWrapperType, wrapperStruct->type_);
+    delete wrapperStruct;
+    return true;
+  }
+  return false;
+}
+
+template <class ClassName, class BaseName, class StructName>
+typename CefCToCppRefCounted<ClassName, BaseName, StructName>::WrapperStruct*
+    CefCToCppRefCounted<ClassName, BaseName, StructName>::GetWrapperStruct(
+        const BaseName* obj) {
+  // Offset using the WrapperStruct size instead of individual member sizes to
+  // avoid problems due to platform/compiler differences in structure padding.
+  return reinterpret_cast<WrapperStruct*>(
+      reinterpret_cast<char*>(const_cast<BaseName*>(obj)) -
+      (sizeof(WrapperStruct) - sizeof(ClassName)));
+}
+
+#endif  // CEF_LIBCEF_DLL_CTOCPP_CTOCPP_REF_COUNTED_H_