将结构数组的指针添加到std :: map

Question

我希望用字符串保存一个数据索引数组，我认为我最好将std::map用于此目的。我有以下示例代码：

 typedef struct MyType_s {
     long long timestamp;
     int cnt;
     bool parked;
 }MyType;

 static MyType *list = {0};
 static int listcnt  = 0;

 //-------------------------------------------------------------------------------------------------

 int map_add_item(std::map<std::string, MyType*> *pmap, std::string str, long long tmestmp)
 {
     if (listcnt == 0){
         list =(MyType*)malloc(sizeof(MyType));
         if (list)
             listcnt++;
         else
             return ENOMEM;
     }
     if (realloc(list,sizeof(MyType)*(++listcnt))==0)
         return ENOMEM;
     list->timestamp = tmestmp;
     if (!(str.length()&&tmestmp&&pmap))
         return EINVAL*-1;
     if (pmap->insert(std::make_pair(str, &list[listcnt-1])).second == false){
         pmap->find(str)->second->timestamp = tmestmp;
         return EEXIST*-1;
     }

     return OK;
 }

编译得很好，但是当我运行它时，我得到一个这样的mem转储：

*** Error in `./std_map': double free or corruption (fasttop): 0x000000000226ec20 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7f19fb6267e5]
/lib/x86_64-linux-gnu/libc.so.6(+0x8037a)[0x7f19fb62f37a]
/lib/x86_64-linux-gnu/libc.so.6(+0x83350)[0x7f19fb632350]
/lib/x86_64-linux-gnu/libc.so.6(realloc+0x179)[0x7f19fb633839]
./std_map[0x4013c8]
./std_map[0x40198d]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f19fb5cf830]
./std_map[0x401259]
======= Memory map: ========
00400000-00404000 r-xp 00000000 08:02 6054199                            /path/to/src/tmp/std_map
00604000-00605000 r--p 00004000 08:02 6054199                          /path/to/src/tmp/std_map
00605000-00606000 rw-p 00005000 08:02 6054199                            /path/to/src/tmp/std_map
0225d000-0228f000 rw-p 00000000 00:00 0                                  [heap]
7f19f4000000-7f19f4021000 rw-p 00000000 00:00 0 
7f19f4021000-7f19f8000000 ---p 00000000 00:00 0 
7f19fb2a6000-7f19fb3ae000 r-xp 00000000 08:02 28971840                   /lib/x86_64-linux-gnu/libm-2.23.so
7f19fb3ae000-7f19fb5ad000 ---p 00108000 08:02 28971840                   /lib/x86_64-linux-gnu/libm-2.23.so
7f19fb5ad000-7f19fb5ae000 r--p 00107000 08:02 28971840                   /lib/x86_64-linux-gnu/libm-2.23.so
7f19fb5ae000-7f19fb5af000 rw-p 00108000 08:02 28971840                   /lib/x86_64-linux-gnu/libm-2.23.so
7f19fb5af000-7f19fb76f000 r-xp 00000000 08:02 28971844                   /lib/x86_64-linux-gnu/libc-2.23.so
7f19fb76f000-7f19fb96f000 ---p 001c0000 08:02 28971844                   /lib/x86_64-linux-gnu/libc-2.23.so
7f19fb96f000-7f19fb973000 r--p 001c0000 08:02 28971844                   /lib/x86_64-linux-gnu/libc-2.23.so
7f19fb973000-7f19fb975000 rw-p 001c4000 08:02 28971844                   /lib/x86_64-linux-gnu/libc-2.23.so
7f19fb975000-7f19fb979000 rw-p 00000000 00:00 0 
7f19fb979000-7f19fb98f000 r-xp 00000000 08:02 28971397                   /lib/x86_64-linux-gnu/libgcc_s.so.1
7f19fb98f000-7f19fbb8e000 ---p 00016000 08:02 28971397                   /lib/x86_64-linux-gnu/libgcc_s.so.1
7f19fbb8e000-7f19fbb8f000 rw-p 00015000 08:02 28971397                   /lib/x86_64-linux-gnu/libgcc_s.so.1
7f19fbb8f000-7f19fbd01000 r-xp 00000000 08:02 23072621                   /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21
7f19fbd01000-7f19fbf01000 ---p 00172000 08:02 23072621                   /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21
7f19fbf01000-7f19fbf0b000 r--p 00172000 08:02 23072621                   /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21
7f19fbf0b000-7f19fbf0d000 rw-p 0017c000 08:02 23072621                   /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21
7f19fbf0d000-7f19fbf11000 rw-p 00000000 00:00 0
7f19fbf11000-7f19fbf37000 r-xp 00000000 08:02 28971842                   /lib/x86_64-linux-gnu/ld-2.23.so
7f19fc0fc000-7f19fc102000 rw-p 00000000 00:00 0
7f19fc135000-7f19fc136000 rw-p 00000000 00:00 0
7f19fc136000-7f19fc137000 r--p 00025000 08:02 28971842                   /lib/x86_64-linux-gnu/ld-2.23.so
7f19fc137000-7f19fc138000 rw-p 00026000 08:02 28971842                   /lib/x86_64-linux-gnu/ld-2.23.so
7f19fc138000-7f19fc139000 rw-p 00000000 00:00 0
7ffd68bf4000-7ffd68c16000 rw-p 00000000 00:00 0                          [stack]
7ffd68d88000-7ffd68d8b000 r--p 00000000 00:00 0                          [vvar]
7ffd68d8b000-7ffd68d8d000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]

Command terminated

gdb也没有给我更多的信息。这是在我从main()调用这样的函数之后：

 int main()
 {
     int ret = 0;
     std::map<std::string, MyType*> mapOfWords;
     std::cout << map_add_item(&mapOfWords,"earth",time(NULL)+1) << std::endl;
     return 0;
 }

我想知道我做错了什么，双重免费或腐败显然是一个暗示，但我不知道如何解释这个，我无法确定问题....

Answer 1

对于一个有效的解决方案，我用全局静态变量和地图中的指针替换了直接位于地图中的数据。另外，我从结构中删除了typedef，并将其声明为C ++方式，如：

std::map<std::string, MyType> *pmap

struct MyType {
     long long timestamp;
     int cnt;
     bool parked;
 };