src/mem/AllocatorProxy.h

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef _SQUID_SRC_MEM_ALLOCATORPROXY_H
  10 #define _SQUID_SRC_MEM_ALLOCATORPROXY_H
  11
  12 class MemAllocator;
  13 class MemPoolStats;
  14 class MemPoolMeter;
  15
  16 /**
  17  * \hideinitializer
  18  *
  19  * Pool and account the memory used for the CLASS object.
  20  * This macro is intended for use within the declaration of a class.
  21  *
  22  * The memory block allocated by operator new is not zeroed; it is the
  23  * responsibility of users to ensure that constructors correctly
  24  * initialize all data members.
  25  */
  26 #define MEMPROXY_CLASS(CLASS) \
  27     private: \
  28     static inline Mem::AllocatorProxy &Pool() { \
  29         static Mem::AllocatorProxy thePool(#CLASS, sizeof(CLASS), false); \
  30         return thePool; \
  31     } \
  32     public: \
  33     void *operator new(size_t byteCount) { \
  34         /* derived classes with different sizes must implement their own new */ \
  35         assert(byteCount == sizeof(CLASS)); \
  36         return Pool().alloc(); \
  37     } \
  38     void operator delete(void *address) { \
  39         if (address) \
  40             Pool().freeOne(address); \
  41     } \
  42     static int UseCount() { return Pool().inUseCount(); } \
  43     private:
  44
  45 namespace Mem
  46 {
  47
  48 /**
  49  * Support late binding of pool type for allocator agnostic classes
  50  */
  51 class AllocatorProxy
  52 {
  53 public:
  54     AllocatorProxy(char const *aLabel, size_t const &aSize, bool doZeroBlocks = true):
  55         label(aLabel),
  56         size(aSize),
  57         theAllocator(nullptr),
  58         doZero(doZeroBlocks)
  59     {}
  60
  61     /// Allocate one element from the pool
  62     void *alloc();
  63
  64     /// Free a element allocated by Mem::AllocatorProxy::alloc()
  65     void freeOne(void *);
  66
  67     int inUseCount() const;
  68     size_t objectSize() const {return size;}
  69     char const * objectType() const {return label;}
  70
  71     MemPoolMeter const &getMeter() const;
  72
  73     /**
  74      * \param stats Object to be filled with statistical data about pool.
  75      * \retval      Number of objects in use, ie. allocated.
  76      */
  77     int getStats(MemPoolStats * stats);
  78
  79     void zeroBlocks(bool doIt);
  80
  81 private:
  82     MemAllocator *getAllocator() const;
  83
  84     const char *label;
  85     size_t size;
  86     mutable MemAllocator *theAllocator;
  87     bool doZero;
  88 };
  89
  90 } // namespace Mem
  91
  92 #endif /* _SQUID_SRC_MEM_ALLOCATORPROXY_H */
  93