zircon/kernel/vm/include/vm/pinned_vm_object.h

// Copyright 2018 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#ifndef ZIRCON_KERNEL_VM_INCLUDE_VM_PINNED_VM_OBJECT_H_
#define ZIRCON_KERNEL_VM_INCLUDE_VM_PINNED_VM_OBJECT_H_

#include "vm/vm_object.h"

// An RAII wrapper around a |VmObject| that is pinned.
class PinnedVmObject {
 public:
  static zx_status_t Create(fbl::RefPtr<VmObject> vmo, size_t offset, size_t size, bool write,
                            PinnedVmObject* out_pinned_vmo);

  constexpr PinnedVmObject() = default;
  PinnedVmObject(PinnedVmObject&&) noexcept;
  PinnedVmObject& operator=(PinnedVmObject&&) noexcept;
  ~PinnedVmObject();

  const fbl::RefPtr<VmObject>& vmo() const { return vmo_; }
  size_t offset() const { return offset_; }
  size_t size() const { return size_; }

  void reset();

 private:
  fbl::RefPtr<VmObject> vmo_;
  size_t offset_ = 0;
  size_t size_ = 0;

  DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(PinnedVmObject);
};

#endif  // ZIRCON_KERNEL_VM_INCLUDE_VM_PINNED_VM_OBJECT_H_