首先这是一个链表的测试,
一个是我自己纯C写的链表,
一个是用的C++的STL的list,
节点都是一个结构体,结构体包含int,char*指针等等,
测试执行的过程是 给定节点数,然后就开始创建链表,创建节点,创建节点的过程中有内存分配,
然后在链表中加入节点,
随机查询节点,次数为链表节点总数的两倍,
随机查询并将节点从链表中删除,次数为链表节点总数的三分之一,
最后释放整个链表
我的 测试环境是虚拟机,配置低下,2核心256M的内存
执行效果如下
1000个节点的情况
[root@CentOS7 wonrowl]# ./wonrowllist_c 1000 start create list ..... create list over with failed 0 , use time 39ms random read NOT DEL 2000 with failed 0 , use time 12ms random read ADD DEL FROM LIST 333 with failed 0 , use time 1ms Left nod in list 667 has been cleared
这是纯C的链表
[root@CentOS7 cppstl]# ./stl 1000 start create stl list ..... create stl list over with failed 0 , use time 45ms random read STL NOT DEL 2000 with failed 0 , use time 15ms random read ADD DEL FROM LIST by STL 333 with failed 0 , use time 1ms left 667 in stl list has been cleared
这是stl的
感觉差别不大
然后增加 节点数到5000
[root@CentOS7 wonrowl]# ./wonrowllist_c 5000 start create list ..... create list over with failed 0 , use time 2742ms random read NOT DEL 10000 with failed 0 , use time 7013ms random read ADD DEL FROM LIST 1666 with failed 0 , use time 76ms Left nod in list 3334 has been cleared -------------------------------------------------------------------------------------------------
[root@CentOS7 cppstl]# ./stl 5000 start create stl list ..... create stl list over with failed 0 , use time 2124ms random read STL NOT DEL 10000 with failed 0 , use time 8356ms random read ADD DEL FROM LIST by STL 1666 with failed 0 , use time 313ms left 3334 in stl list has been cleared
差距明显出来了,
stl在创建的时候比较快,应该是得益于c++的new的效率高于c的malloc,反正文档是这么写的
最后尝试20K的节点数
[root@CentOS7 wonrowl]# ./wonrowllist_c 20000 start create list ..... create list over with failed 0 , use time 40366ms random read NOT DEL 40000 with failed 0 , use time 56761ms random read ADD DEL FROM LIST 6666 with failed 0 , use time 785ms Left nod in list 13334 has been cleared ------------------------------------------------------------------------------------------
[root@CentOS7 cppstl]# ./stl 20000 start create stl list ..... create stl list over with failed 0 , use time 34855ms random read STL NOT DEL 40000 with failed 0 , use time 89332ms random read ADD DEL FROM LIST by STL 6666 with failed 0 , use time 2761ms left 13334 in stl list has been cleared
果然除了创建的时候快点,其他的查询删除各方面,stl全面落败,
所以以后写服务器想要效率的骚年,还是花一两天时间自己创建一个适合的链表吧,
typedef struct general_wonrowl_node { int node_id; char *data_ptr; int data_len; int data_type; int data_from; int data_to; ///请求数据关系映射链表所用的数据结构
int requestor_of_client; int wanted_dev; int requstor_index; int requestor_data_type;
struct list_head list; }General_Wonrowl_Node;
extern Wonrowl_Root_List* Create_Wonrowl_Root_List(); extern struct list_head * Create_Head(); extern General_Wonrowl_Node *Alloc_General_Wonrowl_Node(int buffer_size); extern void Add_Node_At_Head(Wonrowl_Root_List *root,General_Wonrowl_Node *new_node); extern void Add_Node_At_Tail(Wonrowl_Root_List *root,General_Wonrowl_Node *new_node); extern General_Wonrowl_Node * Get_Node_At_Head(Wonrowl_Root_List *root); extern General_Wonrowl_Node * Get_Node_At_Tail(Wonrowl_Root_List *root); extern General_Wonrowl_Node * Get_Specific_Node(Wonrowl_Root_List *root,int wanted_id); extern General_Wonrowl_Node * Get_Specific_Node_Not_Del(Wonrowl_Root_List *root,int wanted_id); extern int Count_List(Wonrowl_Root_List * root); extern void Destroy_General_Wonrowl_Node(General_Wonrowl_Node **nd); extern int Clear_List(Wonrowl_Root_List * root);
这是数据结构
[root@CentOS7 wonrowl]# valgrind --leak-check=full --show-reachable=yes --trace-children=yes ./wonrowllist_c 500 ==2893== Memcheck, a memory error detector ==2893== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==2893== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info ==2893== Command: ./wonrowllist_c 500 ==2893== start create list ..... create list over with failed 0 , use time 70ms random read NOT DEL 1000 with failed 0 , use time 9ms random read ADD DEL FROM LIST 166 with failed 0 , use time 5ms Left nod in list 334 has been cleared ==2893== ==2893== HEAP SUMMARY: ==2893== in use at exit: 104 bytes in 2 blocks ==2893== total heap usage: 1,002 allocs, 1,000 frees, 51,232,604 bytes allocated ==2893== ==2893== 16 bytes in 1 blocks are still reachable in loss record 1 of 2 ==2893== at 0x4C29F73: malloc (vg_replace_malloc.c:309) ==2893== by 0x400B11: Create_Head (in /mnt/hgfs/linuxshare/others/wonrowllist_vs_stl/wonrowl/wonrowllist_c) ==2893== by 0x400B6E: Create_Wonrowl_Root_List (in /mnt/hgfs/linuxshare/others/wonrowllist_vs_stl/wonrowl/wonrowllist_c) ==2893== by 0x4014D5: main (in /mnt/hgfs/linuxshare/others/wonrowllist_vs_stl/wonrowl/wonrowllist_c) ==2893== ==2893== 88 bytes in 1 blocks are still reachable in loss record 2 of 2 ==2893== at 0x4C29F73: malloc (vg_replace_malloc.c:309) ==2893== by 0x400B52: Create_Wonrowl_Root_List (in /mnt/hgfs/linuxshare/others/wonrowllist_vs_stl/wonrowl/wonrowllist_c) ==2893== by 0x4014D5: main (in /mnt/hgfs/linuxshare/others/wonrowllist_vs_stl/wonrowl/wonrowllist_c) ==2893== ==2893== LEAK SUMMARY: ==2893== definitely lost: 0 bytes in 0 blocks ==2893== indirectly lost: 0 bytes in 0 blocks ==2893== possibly lost: 0 bytes in 0 blocks ==2893== still reachable: 104 bytes in 2 blocks ==2893== suppressed: 0 bytes in 0 blocks ==2893== ==2893== For lists of detected and suppressed errors, rerun with: -s ==2893== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
最后附上 valgrind的内存检查,内存很干净,所有malloc的空间也全部释放,
不管是中途取出的节点,还是最后释放链表,
still reachable: 104 bytes in 2 blocks 是我调试的时候申请的,不是链表的操作
同时接口也加入了锁机制,所以是线程安全的,至于为什么做这个测试,
主要是有个傻叉非要将让我将现在的纯C写的流媒体服务器(该服务器做音视频转发和数据接入,没有任何问题,而且效率很高)用c++写一次,理由是opencv都早用c++了,草,
然后跟我扯什么面向对象,stl的好处,我去他大爷的~
