fixed_mem_pool.h File Reference

#include <new>
#include <assert.h>
#include <stdlib.h>
#include "class_level_lock.h"
#include "mem_pool_base.h"

Go to the source code of this file.

Classes
class	qx::memory::fixed_mem_pool< _Tp >
Namespaces
namespace	qx
	Root namespace for all QxOrm library features.
namespace	qx::memory
	QxOrm library memory leak detection (by Wu Yongwei)
Defines
#define	MEM_POOL_ALIGNMENT   4
#define	DECLARE_FIXED_MEM_POOL(_Cls)
#define	DECLARE_FIXED_MEM_POOL__NOTHROW(_Cls)
#define	DECLARE_FIXED_MEM_POOL__THROW_NOCHECK(_Cls)

---

Detailed Description

Definition of a fixed-size memory pool template for structs/classes. This is a easy-to-use class template for pre-allocated memory pools. The client side needs to do the following things:

• Use one of the macros DECLARE_FIXED_MEM_POOL, DECLARE_FIXED_MEM_POOL__NOTHROW, and DECLARE_FIXED_MEM_POOL__THROW_NOCHECK at the end of the class (say, class _Cls) definitions
• Call fixed_mem_pool<_Cls>::initialize at the beginning of the program
• Optionally, specialize fixed_mem_pool<_Cls>::bad_alloc_handler to change the behaviour when all memory blocks are allocated
• Optionally, call fixed_mem_pool<_Cls>::deinitialize at exit of the program to check for memory leaks
• Optionally, call fixed_mem_pool<_Cls>::get_alloc_count to check memory usage when the program is running

Version:

1.14, 2005/09/19

Author:

Wu Yongwei

Definition in file fixed_mem_pool.h.

---

Define Documentation

#define DECLARE_FIXED_MEM_POOL

(

_Cls

)

Value:

public: \
    static void* operator new(size_t __size) \
    { \
        assert(__size == sizeof(_Cls)); \
        if (void* __ptr = fixed_mem_pool<_Cls>::allocate()) \
            return __ptr; \
        else \
            throw std::bad_alloc(); \
    } \
    static void  operator delete(void* __ptr) \
    { \
        if (__ptr != NULL) \
            fixed_mem_pool<_Cls>::deallocate(__ptr); \
    }

Declares the normal (exceptionable) overload of operator new and operator delete.

Parameters:

_Cls	class to use the fixed_mem_pool

See also:

DECLARE_FIXED_MEM_POOL__THROW_NOCHECK, which, too, defines an operator new that will never return NULL, but requires more discipline on the programmer's side.

Definition at line 267 of file fixed_mem_pool.h.

#define DECLARE_FIXED_MEM_POOL__NOTHROW

(

_Cls

)

Value:

public: \
    static void* operator new(size_t __size) throw() \
    { \
        assert(__size == sizeof(_Cls)); \
        return fixed_mem_pool<_Cls>::allocate(); \
    } \
    static void  operator delete(void* __ptr) \
    { \
        if (__ptr != NULL) \
            fixed_mem_pool<_Cls>::deallocate(__ptr); \
    }

Declares the non-exceptionable overload of operator new and operator delete.

Parameters:

_Cls	class to use the fixed_mem_pool

Definition at line 289 of file fixed_mem_pool.h.

#define DECLARE_FIXED_MEM_POOL__THROW_NOCHECK

(

_Cls

)

Value:

public: \
    static void* operator new(size_t __size) \
    { \
        assert(__size == sizeof(_Cls)); \
        return fixed_mem_pool<_Cls>::allocate(); \
    } \
    static void  operator delete(void* __ptr) \
    { \
        if (__ptr != NULL) \
            fixed_mem_pool<_Cls>::deallocate(__ptr); \
    }

Declares the exceptionable, non-checking overload of operator new and operator delete.

N.B. Using this macro requires users to explicitly specialize fixed_mem_pool::bad_alloc_handler so that it shall never return false (it may throw exceptions, say, std::bad_alloc, or simply abort). Otherwise a segmentation fault might occur (instead of returning a NULL pointer).

Parameters:

_Cls	class to use the fixed_mem_pool

Definition at line 314 of file fixed_mem_pool.h.

#define MEM_POOL_ALIGNMENT   4

Defines the alignment of memory blocks.

Definition at line 75 of file fixed_mem_pool.h.