ceph/src/common/tracked_int_ptr.hpp

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2013 Inktank Storage, Inc.
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_TRACKEDINTPTR_H
  16 #define CEPH_TRACKEDINTPTR_H
  17
  18
  19 template <class T>
  20 class TrackedIntPtr {
  21   T *ptr;
  22   uint64_t id;
  23 public:
  24   TrackedIntPtr() : ptr(NULL), id(0) {}
  25   TrackedIntPtr(T *ptr) : ptr(ptr), id(ptr ? get_with_id(ptr) : 0) {}
  26   ~TrackedIntPtr() {
  27     if (ptr)
  28       put_with_id(ptr, id);
  29     else
  30       ceph_assert(id == 0);
  31   }
  32   void swap(TrackedIntPtr &other) {
  33     T *optr = other.ptr;
  34     uint64_t oid = other.id;
  35     other.ptr = ptr;
  36     other.id = id;
  37     ptr = optr;
  38     id = oid;
  39   }
  40   TrackedIntPtr(const TrackedIntPtr &rhs) :
  41     ptr(rhs.ptr), id(ptr ? get_with_id(ptr) : 0) {}
  42
  43   TrackedIntPtr& operator=(const TrackedIntPtr &rhs) {
  44     TrackedIntPtr o(rhs.ptr);
  45     swap(o);
  46     return *this;
  47   }
  48   T &operator*() const {
  49     return *ptr;
  50   }
  51   T *operator->() const {
  52     return ptr;
  53   }
  54   T *get() const { return ptr; }
  55
  56   operator bool() const {
  57     return ptr != NULL;
  58   }
  59   bool operator<(const TrackedIntPtr &lhs) const {
  60     return ptr < lhs.ptr;
  61   }
  62   bool operator==(const TrackedIntPtr &lhs) const {
  63     return ptr == lhs.ptr;
  64   }
  65
  66   void reset() {
  67     if (ptr)
  68       put_with_id(ptr, id);
  69     ptr = nullptr;
  70     id = 0;
  71   }
  72 };
  73
  74 #endif