在std::vector下，不同内存分配方式效率简单比较

#include "stdafx.h"#include <iostream>#include <vector>#include <time.h>#include <boost/pool/pool_alloc.hpp>template<typename T>class alloc {public:typedef std::size_t size_type;typedef std::ptrdiff_t difference_type;typedef T* pointer;typedef const T* const_pointer;typedef T& reference;typedef const T& const_reference;typedef T value_type;public: alloc(){} template<typename T> alloc(const alloc<T>& ){ } alloc& operator=(const alloc& rhs){ return *this; } static pointer allocate(size_type n) { return (pointer)malloc(n*sizeof(T)); }static void deallocate(pointer ptr, size_type n){free((pointer)ptr);}size_type max_size() const throw() { return size_t(-1) / sizeof(T);}template <typename U>struct rebind{ typedef alloc<U> other;};};int _tmain(int argc, _TCHAR* argv[]){ int start4 = GetTickCount();std::vector<int, alloc<int>> RR4;for (int i = 0; i < 10000000; i++){RR4.push_back(i);}int time4 = GetTickCount()- start4;std::cout<<"alloc: "<<time4<<std::endl;int start3 = GetTickCount();std::vector<int, boost::fast_pool_allocator<int>> RR3;for (int i = 0; i < 10000000; i++){RR3.push_back(i);}int time3 = GetTickCount()- start3;std::cout<<"boost::fast_pool_allocator: "<<time3<<std::endl;int start1 = GetTickCount();std::vector<int,std::allocator<int>> RR1;for (int i = 0; i < 10000000; i++){RR1.push_back(i);}int time1 = GetTickCount()- start1;std::cout<<"std::allocator: "<<time1<<std::endl;int start2 = GetTickCount();std::vector<int, boost::pool_allocator<int>> RR2;for (int i = 0; i < 10000000; i++){RR2.push_back(i);}int time2 = GetTickCount()- start2;std::cout<<"boost::pool_allocator: "<<time2<<std::endl;return 0;}

debug (VC2008):

alloc: 11438boost::fast_pool_allocator: 19437std::allocator: 11562boost::pool_allocator: 27703请按任意键继续. . .

Release(VC2008):

alloc: 375boost::fast_pool_allocator: 1032std::allocator: 343boost::pool_allocator: 1266请按任意键继续. . .