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map的内存分配机制分析
该程序演示了map在形成的时候对内存的操作和分配。
因为自己对平衡二叉树的创建细节理解不够，还不太明白程序所显示的日志。等我明白了，再来修改这个文档。
/* 功能说明： map的内存分配机制分析。 代码说明： map所管理的内存地址可以是不连续的。如果key是可以通过<排序的，那么，map最后的结果是有序的。它是通过一个平衡二叉树来保存数据。所以，其查找效率极高。 实现方式： 限制条件或者存在的问题： 无 */ #include <iostream> #include <string> #include <map> #include <windows.h> using namespace std; class CData { public: CData() { sequence = 0; this->remark = "default string"; cout << "CData()\t" << toString() << "\t" << this << endl; } CData(int i, string &s) { this->sequence = i; this->remark = s; cout << "CData(int i,string &s)\t" << toString() << "\t" << this << endl; } CData(const CData &data) { this->sequence = data.sequence; this->remark = data.remark; cout << "CData(const CData &data)\t" << toString() << "\t" << this << endl; } CData operator = (const CData &data) { this->sequence = data.sequence; this->remark = data.remark; cout << "CData operator = (const CData &data)\t" << toString() << "\t" << this << endl; return *this; } void setSequence(const int i) { this->sequence = i; } void setRemark(const string &s) { this->remark = s; } string toString() const { char tmp[2048] = { 0 }; sprintf(tmp, "[sequence:%d | remark:%s]", this->sequence, this->remark.c_str()); //此处应该有内存复制操作，所以不用担心返回后tmp数组所指向的内存被修改或者不存在的情况。 return tmp; } ~CData() { cout << "~CData()\t" << this << endl; } protected: private: int sequence; string remark; }; int main(int argc, char **argv) { cout << "process begin at " << (void*)&main << endl; string str = "baby_test"; CData data1(1, str); CData data2(2, str); CData data3(3, str); CData data4(4, str); CData data5(5, str); CData data6(6, str); CData data7(7, str); CData data8(8, str); CData data9(9, str); CData data10(10, str); cout << "push CData to map" << endl; map<int,CData> map_data; cout << "max size of list<CData> is " << map_data.max_size() << endl; cout << "size of list<CData> is " << map_data.size() << endl; cout << "****************map_data.push_back(data1)" << endl; map_data.insert(make_pair(1, data1)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data2)" << endl; map_data.insert(make_pair(2, data2)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data3)" << endl; map_data.insert(make_pair(3, data3)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data4)" << endl; map_data.insert(make_pair(4, data4)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data5)" << endl; map_data.insert(make_pair(5, data5)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data6)" << endl; map_data.insert(make_pair(6, data6)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data7)" << endl; map_data.insert(make_pair(7, data7)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data8)" << endl; map_data.insert(make_pair(8, data8)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data9)" << endl; map_data.insert(make_pair(9, data9)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data10)" << endl; map_data.insert(make_pair(10, data10)); Sleep(2 * map_data.size()); // 程序到此为止，可以看到在每次push的时候，对象的复制构造函数会调用2次。为什么是2次？ cout << "===============show map by iterator" << endl; for (map<int,CData>::iterator itr = map_data.begin(); itr != map_data.end(); itr++) { // 显示的地址信息，是每次push的时候所复制的对象的地址。 cout<<"key:"<< itr->first<<"\t" << "value:address of itr is " << &(itr->second) << " and msg is " << itr->second.toString() << endl; } cout << "===============clear map 1" << endl; // map中的元素不是指针，此处的清理，会调用析构函数。 map_data.clear(); cout << "****************map_data.push_back(data6)" << endl; map_data.insert(make_pair(6, data6)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data2)" << endl; map_data.insert(make_pair(2, data2)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data3)" << endl; map_data.insert(make_pair(3, data3)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data1" << endl; map_data.insert(make_pair(1, data1)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data10)" << endl; map_data.insert(make_pair(10, data10)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data4)" << endl; map_data.insert(make_pair(4, data4)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data7)" << endl; map_data.insert(make_pair(7, data7)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data8)" << endl; map_data.insert(make_pair(8, data8)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data9)" << endl; map_data.insert(make_pair(9, data9)); Sleep(2 * map_data.size()); cout << "****************map_data.push_back(data5)" << endl; map_data.insert(make_pair(5, data5)); Sleep(2 * map_data.size()); // 程序到此为止，可以看到在每次push的时候，对象的复制构造函数会调用2次。为什么是2次？ cout << "===============show map by iterator 2" << endl; for (map<int, CData>::iterator itr = map_data.begin(); itr != map_data.end(); itr++) { // 显示的地址信息，是每次push的时候所复制的对象的地址。 // 可以看到，不管插入的数据是如何的乱序，map的结果是排好序的。 cout << "key:" << itr->first << "\t" << "value:address of itr is " << &(itr->second) << " and msg is " << itr->second.toString() << endl; } cout << "===============clear map 2" << endl; // map中的元素不是指针，此处的清理，会调用析构函数。 map_data.clear(); cout << "======================end of process" << endl; return 0; }
程序的输出结果：
process begin at 00C917FD
CData(int i,string &s) [sequence:1 | remark:baby_test] 0053F6F0
CData(int i,string &s) [sequence:2 | remark:baby_test] 0053F6C8
CData(int i,string &s) [sequence:3 | remark:baby_test] 0053F6A0
CData(int i,string &s) [sequence:4 | remark:baby_test] 0053F678
CData(int i,string &s) [sequence:5 | remark:baby_test] 0053F650
CData(int i,string &s) [sequence:6 | remark:baby_test] 0053F628
CData(int i,string &s) [sequence:7 | remark:baby_test] 0053F600
CData(int i,string &s) [sequence:8 | remark:baby_test] 0053F5D8
CData(int i,string &s) [sequence:9 | remark:baby_test] 0053F5B0
CData(int i,string &s) [sequence:10 | remark:baby_test] 0053F588
push CData to map
max size of list<CData> is 82595524
size of list<CData> is 0
****************map_data.push_back(data1)
CData(const CData &data) [sequence:1 | remark:baby_test] 0053F158
CData(const CData &data) [sequence:1 | remark:baby_test] 005F6F74
~CData() 0053F158
****************map_data.push_back(data2)
CData(const CData &data) [sequence:2 | remark:baby_test] 0053F108
CData(const CData &data) [sequence:2 | remark:baby_test] 005FE2A4
~CData() 0053F108
****************map_data.push_back(data3)
CData(const CData &data) [sequence:3 | remark:baby_test] 0053F0B8
CData(const CData &data) [sequence:3 | remark:baby_test] 005FE304
~CData() 0053F0B8
****************map_data.push_back(data4)
CData(const CData &data) [sequence:4 | remark:baby_test] 0053F068
CData(const CData &data) [sequence:4 | remark:baby_test] 005FE364
~CData() 0053F068
****************map_data.push_back(data5)
CData(const CData &data) [sequence:5 | remark:baby_test] 0053F018
CData(const CData &data) [sequence:5 | remark:baby_test] 005FE3C4
~CData() 0053F018
****************map_data.push_back(data6)
CData(const CData &data) [sequence:6 | remark:baby_test] 0053EFC8
CData(const CData &data) [sequence:6 | remark:baby_test] 005FE424
~CData() 0053EFC8
****************map_data.push_back(data7)
CData(const CData &data) [sequence:7 | remark:baby_test] 0053EF78
CData(const CData &data) [sequence:7 | remark:baby_test] 005FE484
~CData() 0053EF78
****************map_data.push_back(data8)
CData(const CData &data) [sequence:8 | remark:baby_test] 0053EF28
CData(const CData &data) [sequence:8 | remark:baby_test] 005FE4E4
~CData() 0053EF28
****************map_data.push_back(data9)
CData(const CData &data) [sequence:9 | remark:baby_test] 0053EED8
CData(const CData &data) [sequence:9 | remark:baby_test] 005FED9C
~CData() 0053EED8
****************map_data.push_back(data10)
CData(const CData &data) [sequence:10 | remark:baby_test] 0053EE88
CData(const CData &data) [sequence:10 | remark:baby_test] 005FEDFC
~CData() 0053EE88
===============show map by iterator
key:1 value:address of itr is 005F6F74 and msg is [sequence:1 | remark:baby_test]
key:2 value:address of itr is 005FE2A4 and msg is [sequence:2 | remark:baby_test]
key:3 value:address of itr is 005FE304 and msg is [sequence:3 | remark:baby_test]
key:4 value:address of itr is 005FE364 and msg is [sequence:4 | remark:baby_test]
key:5 value:address of itr is 005FE3C4 and msg is [sequence:5 | remark:baby_test]
key:6 value:address of itr is 005FE424 and msg is [sequence:6 | remark:baby_test]
key:7 value:address of itr is 005FE484 and msg is [sequence:7 | remark:baby_test]
key:8 value:address of itr is 005FE4E4 and msg is [sequence:8 | remark:baby_test]
key:9 value:address of itr is 005FED9C and msg is [sequence:9 | remark:baby_test]
key:10 value:address of itr is 005FEDFC and msg is [sequence:10 | remark:baby_test]
===============clear map 1
~CData() 005FEDFC
~CData() 005FED9C
~CData() 005FE4E4
~CData() 005FE484
~CData() 005FE424
~CData() 005FE3C4
~CData() 005FE364
~CData() 005FE304
~CData() 005FE2A4
~CData() 005F6F74
****************map_data.push_back(data6)
CData(const CData &data) [sequence:6 | remark:baby_test] 0053EDE0
CData(const CData &data) [sequence:6 | remark:baby_test] 005F6F74
~CData() 0053EDE0
****************map_data.push_back(data2)
CData(const CData &data) [sequence:2 | remark:baby_test] 0053ED90
CData(const CData &data) [sequence:2 | remark:baby_test] 005FED9C
~CData() 0053ED90
****************map_data.push_back(data3)
CData(const CData &data) [sequence:3 | remark:baby_test] 0053ED40
CData(const CData &data) [sequence:3 | remark:baby_test] 005FEDFC
~CData() 0053ED40
****************map_data.push_back(data1
CData(const CData &data) [sequence:1 | remark:baby_test] 0053ECF0
CData(const CData &data) [sequence:1 | remark:baby_test] 005FEE5C
~CData() 0053ECF0
****************map_data.push_back(data10)
CData(const CData &data) [sequence:10 | remark:baby_test] 0053ECA0
CData(const CData &data) [sequence:10 | remark:baby_test] 005FEEBC
~CData() 0053ECA0
****************map_data.push_back(data4)
CData(const CData &data) [sequence:4 | remark:baby_test] 0053EC50
CData(const CData &data) [sequence:4 | remark:baby_test] 005FEF1C
~CData() 0053EC50
****************map_data.push_back(data7)
CData(const CData &data) [sequence:7 | remark:baby_test] 0053EC00
CData(const CData &data) [sequence:7 | remark:baby_test] 005FEF7C
~CData() 0053EC00
****************map_data.push_back(data8)
CData(const CData &data) [sequence:8 | remark:baby_test] 0053EBB0
CData(const CData &data) [sequence:8 | remark:baby_test] 005FE2A4
~CData() 0053EBB0
****************map_data.push_back(data9)
CData(const CData &data) [sequence:9 | remark:baby_test] 0053EB60
CData(const CData &data) [sequence:9 | remark:baby_test] 005FE304
~CData() 0053EB60
****************map_data.push_back(data5)
CData(const CData &data) [sequence:5 | remark:baby_test] 0053EB10
CData(const CData &data) [sequence:5 | remark:baby_test] 005FE364
~CData() 0053EB10
===============show map by iterator 2
key:1 value:address of itr is 005FEE5C and msg is [sequence:1 | remark:baby_test]
key:2 value:address of itr is 005FED9C and msg is [sequence:2 | remark:baby_test]
key:3 value:address of itr is 005FEDFC and msg is [sequence:3 | remark:baby_test]
key:4 value:address of itr is 005FEF1C and msg is [sequence:4 | remark:baby_test]
key:5 value:address of itr is 005FE364 and msg is [sequence:5 | remark:baby_test]
key:6 value:address of itr is 005F6F74 and msg is [sequence:6 | remark:baby_test]
key:7 value:address of itr is 005FEF7C and msg is [sequence:7 | remark:baby_test]
key:8 value:address of itr is 005FE2A4 and msg is [sequence:8 | remark:baby_test]
key:9 value:address of itr is 005FE304 and msg is [sequence:9 | remark:baby_test]
key:10 value:address of itr is 005FEEBC and msg is [sequence:10 | remark:baby_test]
===============clear map 2
~CData() 005FEEBC
~CData() 005FE304
~CData() 005FE2A4
~CData() 005FEF7C
~CData() 005F6F74
~CData() 005FE364
~CData() 005FEF1C
~CData() 005FEDFC
~CData() 005FED9C
~CData() 005FEE5C
======================end of process
~CData() 0053F588
~CData() 0053F5B0
~CData() 0053F5D8
~CData() 0053F600
~CData() 0053F628
~CData() 0053F650
~CData() 0053F678
~CData() 0053F6A0
~CData() 0053F6C8
~CData() 0053F6F0
map的内存分配机制分析