src/mem/AllocatorProxy.h

   1 /*
   2  * Copyright (C) 1996-2022 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 // XXX: remove AllocatorProxy.h include from mem/forward.h
  13 namespace Mem {
  14 class Allocator;
  15 class PoolStats;
  16 }
  17
  18 /**
  19  * \hideinitializer
  20  *
  21  * Pool and account the memory used for the CLASS object.
  22  * This macro is intended for use within the declaration of a class.
  23  *
  24  * The memory block allocated by operator new is not zeroed; it is the
  25  * responsibility of users to ensure that constructors correctly
  26  * initialize all data members.
  27  */
  28 #define MEMPROXY_CLASS(CLASS) \
  29     private: \
  30     static inline Mem::AllocatorProxy &Pool() { \
  31         static Mem::AllocatorProxy thePool(#CLASS, sizeof(CLASS), false); \
  32         return thePool; \
  33     } \
  34     public: \
  35     void *operator new(size_t byteCount) { \
  36         /* derived classes with different sizes must implement their own new */ \
  37         assert(byteCount == sizeof(CLASS)); \
  38         return Pool().alloc(); \
  39     } \
  40     void operator delete(void *address) { \
  41         if (address) \
  42             Pool().freeOne(address); \
  43     } \
  44     static int UseCount() { return Pool().inUseCount(); } \
  45     private:
  46
  47 namespace Mem
  48 {
  49
  50 class PoolMeter;
  51
  52 /**
  53  * Support late binding of pool type for allocator agnostic classes
  54  */
  55 class AllocatorProxy
  56 {
  57 public:
  58     AllocatorProxy(char const *aLabel, size_t const &aSize, bool doZeroBlocks = true):
  59         label(aLabel),
  60         size(aSize),
  61         theAllocator(nullptr),
  62         doZero(doZeroBlocks)
  63     {}
  64
  65     /// Allocate one element from the pool
  66     void *alloc();
  67
  68     /// Free a element allocated by Mem::AllocatorProxy::alloc()
  69     void freeOne(void *);
  70
  71     int inUseCount() const;
  72     size_t objectSize() const {return size;}
  73     char const * objectType() const {return label;}
  74
  75     PoolMeter const &getMeter() const;
  76
  77     /**
  78      * \param stats Object to be filled with statistical data about pool.
  79      * \retval      Number of objects in use, ie. allocated.
  80      */
  81     size_t getStats(PoolStats &stats);
  82
  83     void zeroBlocks(bool doIt);
  84
  85 private:
  86     Allocator *getAllocator() const;
  87
  88     const char *label;
  89     size_t size;
  90     mutable Allocator *theAllocator;
  91     bool doZero;
  92 };
  93
  94 } // namespace Mem
  95
  96 #endif /* _SQUID_SRC_MEM_ALLOCATORPROXY_H */
  97