EASTL 的分配器是有状态的并且绑定到容器的实例上;意味着它们是在实例级别定义的:
EASTL 所做的是使用一种更熟悉的内存分配模式,即只有一个分配器类接口,它被所有容器使用。此外,EASTL 容器允许您访问它们的分配器并查询它们、命名它们、更改它们等。
EASTL 选择在容器交换和分配操作期间使分配器不会在容器之间复制。这意味着如果容器 A 与容器 B 交换其内容,则两个容器都保留其原始分配器。类似地,将容器 A 分配给容器 B 会导致容器 B 保留其原始分配器。等效的容器应通过 operator==; 报告。如果分配器相等,EASTL 将进行智能交换,否则将进行暴力交换。
来自https://github.com/questor/eastl/blob/master/doc/EASTL%20Design.html
所以我会在分配器类中添加一个成员并跟踪其中的内存计数,如下所示:
#ifndef EASTL_CUSTOM_ALLOCATOR_H_
#define EASTL_CUSTOM_ALLOCATOR_H_
#include "new_implementation.hpp"
#include <EASTL/list.h>
#include <iostream>
#define DEBUG_MACRO
class EASTL_CustomAllocator {
public:
EASTL_CustomAllocator(const char* pName = EASTL_NAME_VAL(EASTL_ALLOCATOR_DEFAULT_NAME))
: m_pName(pName), m_totalAmountOfBytesAllocated(0) {
#ifdef DEBUG_MACRO
std::cout << m_pName << ": default construct allocator" << std::endl;
#endif
}
EASTL_CustomAllocator(const EASTL_CustomAllocator& x)
: m_pName(x.m_pName),
m_totalAmountOfBytesAllocated(x.m_totalAmountOfBytesAllocated) {
#ifdef DEBUG_MACRO
std::cout << m_pName << ": copy construct allocator" << std::endl;
#endif
}
EASTL_CustomAllocator(const EASTL_CustomAllocator& x, const char* pName)
: m_pName(pName),
m_totalAmountOfBytesAllocated(x.m_totalAmountOfBytesAllocated) {
#ifdef DEBUG_MACRO
std::cout << m_pName << ": copy construct allocator" << std::endl;
#endif
}
EASTL_CustomAllocator& operator=(const EASTL_CustomAllocator& x) {
#ifdef DEBUG_MACRO
std::cout << m_pName << ": copy assignment" << std::endl;
#endif
m_pName = x.m_pName;
m_totalAmountOfBytesAllocated = x.m_totalAmountOfBytesAllocated;
return *this;
}
void* allocate(size_t num_of_bytes, int flags = 0) {
m_totalAmountOfBytesAllocated += num_of_bytes;
void* p = ::new((char*)0, flags, 0, (char*)0, 0) char[num_of_bytes];
#ifdef DEBUG_MACRO
std::cout << m_pName << ": allocate " << num_of_bytes << " bytes" << " at: " << (void*) p << std::endl;
#endif
return p;
}
void* allocate(size_t num_of_bytes, size_t alignment, size_t offset, int flags = 0) {
m_totalAmountOfBytesAllocated += num_of_bytes;
void* p = ::new(alignment, offset, (char*)0, flags, 0, (char*)0, 0) char[num_of_bytes];
#ifdef DEBUG_MACRO
std::cout << m_pName << ": allocate " << num_of_bytes << " bytes" << " at: " << (void*) p << std::endl;
#endif
return p;
}
void deallocate(void* p, size_t num_of_bytes) {
m_totalAmountOfBytesAllocated -= num_of_bytes;
#ifdef DEBUG_MACRO
std::cout << m_pName << ": deallocate " << num_of_bytes << " bytes" << " at: " << (void*) p << std::endl;
#endif
delete[](char*)p;
}
const char* get_name() const {
return m_pName;
}
void set_name(const char* pName) {
m_pName = pName;
}
size_t get_totalAmountOfBytesAllocated() const {
return m_totalAmountOfBytesAllocated;
}
protected:
const char* m_pName; // Debug name, used to track memory.
size_t m_totalAmountOfBytesAllocated; // keeps track of the memory currently allocated
};
bool operator==(const EASTL_CustomAllocator& a, const EASTL_CustomAllocator& b) {
if (&a == &b) {
return true; // allocator a and b are equal if they are the same
}
else {
return false; // otherwhise, return false, because the state m_totalAmountOfBytesAllocated needs to be increased/decreased on splice and swap
}
}
bool operator!=(const EASTL_CustomAllocator& a, const EASTL_CustomAllocator& b) {
return false;
}
#endif /* EASTL_CUSTOM_ALLOCATOR_H_ */
将该自定义分配器类型作为模板参数传递给如下所示的东部容器(您也可以在构造时设置具有用户定义名称的实例,甚至稍后通过 set_allocator() 设置):
eastl::list<int, EASTL_CustomAllocator>
list(EASTL_CustomAllocator("EASTL Some Name"));
但我不确定如何使用调试功能。