从向量中删除对象 [英] Delete an object from a vector

问题描述

第1步.创建一个类的实例

Step 1. Create an instance of a class

第2步.将此实例推送到矢量

Step 2. Push this instance to a vector

第3步.在实例的成员方法中调用delete this;

Step 3. Call delete this; in a member method of an instance

第4步.一切都很好

第5步.将某物推到矢量上并得到它

Step 5. Push something to the vector and get this

*** glibc detected *** ./app: double free or corruption (fasttop): 0x0000000001017930 ***
======= Backtrace: =========
/lib/libc.so.6(+0x71bd6)[0x7f607d60cbd6]
/lib/libc.so.6(cfree+0x6c)[0x7f607d61194c]
./app[0x40231c]
./app[0x402290]
./app[0x4053c0]
./app[0x4048fe]
./app[0x404246]
./app[0x403fe0]
./app[0x402400]
./app[0x4035cb]
./app[0x4034d3]
/lib/libpthread.so.0(+0x68ca)[0x7f607e2b78ca]
/lib/libc.so.6(clone+0x6d)[0x7f607d66a92d]
======= Memory map: ========
00400000-0040f000 r-xp 00000000 09:03 60427370                           /root/AHS/app
0060e000-0060f000 rw-p 0000e000 09:03 60427370                           /root/AHS/app
01017000-01038000 rw-p 00000000 00:00 0                                  [heap]
7f6074000000-7f6074021000 rw-p 00000000 00:00 0
7f6074021000-7f6078000000 ---p 00000000 00:00 0
7f607a595000-7f607a596000 ---p 00000000 00:00 0
7f607a596000-7f607ad96000 rw-p 00000000 00:00 0
7f607ad96000-7f607ad97000 ---p 00000000 00:00 0
7f607ad97000-7f607b597000 rw-p 00000000 00:00 0
7f607b597000-7f607b598000 ---p 00000000 00:00 0
7f607b598000-7f607bd98000 rw-p 00000000 00:00 0
7f607bd98000-7f607bd99000 ---p 00000000 00:00 0
7f607bd99000-7f607c599000 rw-p 00000000 00:00 0
7f607c599000-7f607c59a000 ---p 00000000 00:00 0
7f607c59a000-7f607cd9a000 rw-p 00000000 00:00 0
7f607cd9a000-7f607cd9b000 ---p 00000000 00:00 0
7f607cd9b000-7f607d59b000 rw-p 00000000 00:00 0
7f607d59b000-7f607d6f4000 r-xp 00000000 09:03 60425052                   /lib/libc-2.11.3.so
7f607d6f4000-7f607d8f3000 ---p 00159000 09:03 60425052                   /lib/libc-2.11.3.so
7f607d8f3000-7f607d8f7000 r--p 00158000 09:03 60425052                   /lib/libc-2.11.3.so
7f607d8f7000-7f607d8f8000 rw-p 0015c000 09:03 60425052                   /lib/libc-2.11.3.so
7f607d8f8000-7f607d8fd000 rw-p 00000000 00:00 0
7f607d8fd000-7f607d913000 r-xp 00000000 09:03 60425245                   /lib/libgcc_s.so.1
7f607d913000-7f607db12000 ---p 00016000 09:03 60425245                   /lib/libgcc_s.so.1
7f607db12000-7f607db13000 rw-p 00015000 09:03 60425245                   /lib/libgcc_s.so.1
7f607db13000-7f607db93000 r-xp 00000000 09:03 60425438                   /lib/libm-2.11.3.so
7f607db93000-7f607dd93000 ---p 00080000 09:03 60425438                   /lib/libm-2.11.3.so
7f607dd93000-7f607dd94000 r--p 00080000 09:03 60425438                   /lib/libm-2.11.3.so
7f607dd94000-7f607dd95000 rw-p 00081000 09:03 60425438                   /lib/libm-2.11.3.so
7f607dd95000-7f607de8b000 r-xp 00000000 09:03 60032880                   /usr/lib/libstdc++.so.6.0.13
7f607de8b000-7f607e08b000 ---p 000f6000 09:03 60032880                   /usr/lib/libstdc++.so.6.0.13
7f607e08b000-7f607e092000 r--p 000f6000 09:03 60032880                   /usr/lib/libstdc++.so.6.0.13
7f607e092000-7f607e094000 rw-p 000fd000 09:03 60032880                   /usr/lib/libstdc++.so.6.0.13
7f607e094000-7f607e0a9000 rw-p 00000000 00:00 0
7f607e0a9000-7f607e0b0000 r-xp 00000000 09:03 60425177                   /lib/librt-2.11.3.so
7f607e0b0000-7f607e2af000 ---p 00007000 09:03 60425177                   /lib/librt-2.11.3.so
7f607e2af000-7f607e2b0000 r--p 00006000 09:03 60425177                   /lib/librt-2.11.3.so
7f607e2b0000-7f607e2b1000 rw-p 00007000 09:03 60425177                   /lib/librt-2.11.3.so
7f607e2b1000-7f607e2c8000 r-xp 00000000 09:03 60425205                   /lib/libpthread-2.11.3.so
7f607e2c8000-7f607e4c7000 ---p 00017000 09:03 60425205                   /lib/libpthread-2.11.3.so
7f607e4c7000-7f607e4c8000 r--p 00016000 09:03 60425205                   /lib/libpthread-2.11.3.so
7f607e4c8000-7f607e4c9000 rw-p 00017000 09:03 60425205                   /lib/libpthread-2.11.3.so
7f607e4c9000-7f607e4cd000 rw-p 00000000 00:00 0
7f607e4cd000-7f607e4eb000 r-xp 00000000 09:03 60425293                   /lib/ld-2.11.3.so
7f607e6da000-7f607e6df000 rw-p 00000000 00:00 0
7f607e6e7000-7f607e6ea000 rw-p 00000000 00:00 0
7f607e6ea000-7f607e6eb000 r--p 0001d000 09:03 60425293                   /lib/ld-2.11.3.so
7f607e6eb000-7f607e6ec000 rw-p 0001e000 09:03 60425293                   /lib/ld-2.11.3.so
7f607e6ec000-7f607e6ed000 rw-p 00000000 00:00 0
7fff4ee3b000-7fff4ee50000 rw-p 00000000 00:00 0                          [stack]
7fff4efff000-7fff4f000000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
Aborted

有人可以告诉我，这是什么，为什么会发生以及如何解决?

Could someone please tell me, what is this, why this occurs and how do I fix it?

推荐答案

对属于vector的对象执行delete this时，您犯了两个大错误:

Doing delete this for an object belonging to a vector you are making two big mistakes:

1. 它是管理实例存储位置的内存的向量(它分配，释放，...)，因此您不应该弄乱它.换句话说，由于您不拥有该内存，因此必须将其保留.
如果使用new分配了对象，则
2. delete是正确的匹配-但是vector管理的对象不是那样分配的；取而代之的是，vector从分配器中获取一块内存(与它认为的大小一样大)，并使用放置new在那里复制被压入其中的元素；因此，不仅您要释放自己不拥有的内存，而且还使用了错误的方法来释放它.

1. it's the vector that manages the memory where that instance is stored (it allocates it, deallocates it, ...), so you shouldn't mess with it. In other words, since you don't own that memory you must leave it alone.
2. delete is a correct match if the object was allocated with new - but the object managed by the vector is not allocated like that; instead, vector grabs a chunk of memory from the allocator (as big as it thinks it's sensible) and copies there the elements that are pushed into it using placement new; so, not only you are freeing memory that you don't own, you are also using the wrong method to free it.

如果需要从vector中删除元素，只需使用vector::erase方法.

If you need to remove an element from a vector, just use the vector::erase method.

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