C++ C++；查找（）或插入（）上的无序映射SIGSEGV

目前，我正在尝试为我们需要为大学构建的数据库系统实现某种基本的文件访问层。为此，我被要求在内存中缓存页面。为了快速确定加载了哪些页面，我将它们全部存储在无序的_图中

现在的问题是，在对这个函数进行一些调用之后，一个SIGSEGV出现在无序映射的_M_find_之前的_节点中。我尝试使用gdb调试它，但我不知道在哪里可以找到它，因为错误发生在调用无序的_映射时：

#0  0x0000000000402ab0 in std::_Hashtable<unsigned long, std::pair<unsigned long const, BufferFrame>, std::allocator<std::pair<unsigned long const, BufferFrame> >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_find_before_node (this=0x608038, __n=2, __k=@0x7fffffffe050: 2, __code=2) at /usr/include/c++/4.9/bits/hashtable.h:1442
#1  0x0000000000402286 in std::_Hashtable<unsigned long, std::pair<unsigned long const, BufferFrame>, std::allocator<std::pair<unsigned long const, BufferFrame> >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_find_node (this=0x608038, __bkt=2, __key=@0x7fffffffe050: 2, __c=2) at /usr/include/c++/4.9/bits/hashtable.h:625
#2  0x0000000000401cd6 in std::_Hashtable<unsigned long, std::pair<unsigned long const, BufferFrame>, std::allocator<std::pair<unsigned long const, BufferFrame> >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::find (this=0x608038, __k=@0x7fffffffe050: 2) at /usr/include/c++/4.9/bits/hashtable.h:1304
#3  0x000000000040198f in std::unordered_map<unsigned long, BufferFrame, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<std::pair<unsigned long const, BufferFrame> > >::find (
this=0x608038, __x=@0x7fffffffe050: 2) at /usr/include/c++/4.9/bits/unordered_map.h:574
#4  0x00000000004013dd in BufferManager::fixPage (this=0x608030, pageId=2, exclusive=true) at BufferManager.cpp:36
#5  0x0000000000404268 in main (argc=4, argv=0x7fffffffe2c8) at buffertest.cpp:87

std:：_Hashtable:：_M_find_before_node（this=0x608038，u n=2，u k=@0x7fffffe050:2，uu code=2）at/usr/include/c++/4.9/bits/Hashtable.h:1442 #1 0x0000000000402286在std:：_Hashtable:：_M_find_节点（this=0x608038，_bkt=2，_键=@0x7fffffe050:2，__c=2）at/usr/include/c++/4.9/bits/Hashtable.h:625 #在/usr/include/c++/4.9/bits/Hashtable.h:1304中查找（this=0x608038，uu k=@0x7fffffffe050:2） #std:：无序映射：：查找中的3 0x000000000040198f( this=0x608038，uux=@0x7fffffe050:2）at/usr/include/c++/4.9/bits/unordered_map.h:574 #在BufferManager处的BufferManager:：fixPage（this=0x608030，pageId=2，exclusive=true）中的4 0x00000000004013dd。cpp:36 #在buffertest处的main（argc=4，argv=0x7fffffffe2c8）中有5个0x0000000000404268。cpp:87 我还尝试使用valgrind调试它，因为我认为在错误出现之前的某个时间点可能会出现未被注意到的内存损坏。这给了我以下输出：

==27031== Memcheck, a memory error detector
==27031== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==27031== Using Valgrind-3.10.0 and LibVEX; rerun with -h for copyright info
==27031== Command: ./buffer-test 11 3 1
==27031== 
==27031== Invalid write of size 8
==27031==    at 0x401642: std::__detail::_Hash_node_base::_Hash_node_base() (hashtable_policy.h:234)
==27031==    by 0x4020A0: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::__detail::_Mod_range_hashing const&, std::__detail::_Default_ranged_hash const&, std::equal_to<std::string> const&, std::__detail::_Select1st const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:799)
==27031==    by 0x401BB5: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:420)
==27031==    by 0x4018DC: std::unordered_map<std::string, int, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, int> > >::unordered_map(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (unordered_map.h:143)
==27031==    by 0x401257: BufferManager::BufferManager(unsigned int) (BufferManager.cpp:21)
==27031==    by 0x4041B6: main (buffertest.cpp:79)
==27031==  Address 0x5c1d0e0 is 16 bytes after a block of size 64 alloc'd
==27031==    at 0x4C29180: operator new(unsigned long) (vg_replace_malloc.c:324)
==27031==    by 0x4041A3: main (buffertest.cpp:79)
==27031== 
==27031== Invalid write of size 8
==27031==    at 0x4020A5: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::__detail::_Mod_range_hashing const&, std::__detail::_Default_ranged_hash const&, std::equal_to<std::string> const&, std::__detail::_Select1st const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:799)
==27031==    by 0x401BB5: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:420)
==27031==    by 0x4018DC: std::unordered_map<std::string, int, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, int> > >::unordered_map(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (unordered_map.h:143)
==27031==    by 0x401257: BufferManager::BufferManager(unsigned int) (BufferManager.cpp:21)
==27031==    by 0x4041B6: main (buffertest.cpp:79)
==27031==  Address 0x5c1d0e8 is 24 bytes after a block of size 64 in arena "client"
==27031== 

valgrind: m_mallocfree.c:304 (get_bszB_as_is): Assertion 'bszB_lo == bszB_hi' failed.
valgrind: Heap block lo/hi size mismatch: lo = 128, hi = 0.
This is probably caused by your program erroneously writing past the
end of a heap block and corrupting heap metadata.  If you fix any
invalid writes reported by Memcheck, this assertion failure will
probably go away.  Please try that before reporting this as a bug.


host stacktrace:
==27031==    at 0x380A48EF: show_sched_status_wrk (m_libcassert.c:319)
==27031==    by 0x380A49E4: report_and_quit (m_libcassert.c:390)
==27031==    by 0x380A4B66: vgPlain_assert_fail (m_libcassert.c:455)
==27031==    by 0x380B170D: get_bszB_as_is (m_mallocfree.c:302)
==27031==    by 0x380B170D: get_bszB (m_mallocfree.c:312)
==27031==    by 0x380B170D: get_pszB (m_mallocfree.c:386)
==27031==    by 0x380B170D: vgPlain_describe_arena_addr (m_mallocfree.c:1532)
==27031==    by 0x3809DC93: vgPlain_describe_addr (m_addrinfo.c:188)
==27031==    by 0x3809C73B: vgMemCheck_update_Error_extra (mc_errors.c:1133)
==27031==    by 0x380A05BA: vgPlain_maybe_record_error (m_errormgr.c:818)
==27031==    by 0x3809BCB2: vgMemCheck_record_address_error (mc_errors.c:753)
==27031==    by 0x803EDF459: ???
==27031==    by 0x802D95EEF: ???
==27031==    by 0x3807295F: vgMemCheck_malloc (mc_malloc_wrappers.c:388)
==27031==    by 0x4020A0: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::__detail::_Mod_range_hashing const&, std::__detail::_Default_ranged_hash const&, std::equal_to<std::string> const&, std::__detail::_Select1st const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:799)

sched status:
  running_tid=1

Thread 1: status = VgTs_Runnable
==27031==    at 0x401682: std::__detail::_Prime_rehash_policy::_Prime_rehash_policy(float) (hashtable_policy.h:464)
==27031==    by 0x4020C4: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::__detail::_Mod_range_hashing const&, std::__detail::_Default_ranged_hash const&, std::equal_to<std::string> const&, std::__detail::_Select1st const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:799)
==27031==    by 0x401BB5: std::_Hashtable<std::string, std::pair<std::string const, int>, std::allocator<std::pair<std::string const, int> >, std::__detail::_Select1st, std::equal_to<std::string>, std::hash<std::string>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (hashtable.h:420)
==27031==    by 0x4018DC: std::unordered_map<std::string, int, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, int> > >::unordered_map(unsigned long, std::hash<std::string> const&, std::equal_to<std::string> const&, std::allocator<std::pair<std::string const, int> > const&) (unordered_map.h:143)
==27031==    by 0x401257: BufferManager::BufferManager(unsigned int) (BufferManager.cpp:21)
==27031==    by 0x4041B6: main (buffertest.cpp:79)


Note: see also the FAQ in the source distribution.
It contains workarounds to several common problems.
In particular, if Valgrind aborted or crashed after
identifying problems in your program, there's a good chance
that fixing those problems will prevent Valgrind aborting or
crashing, especially if it happened in m_mallocfree.c.

If that doesn't help, please report this bug to: www.valgrind.org

In the bug report, send all the above text, the valgrind
version, and what OS and version you are using.  Thanks.

==27031==Memcheck，内存错误检测器
==27031==Julian Seward等人2002-2013年版权（C）和GNU GPL'd。
==27031==使用Valgrind-3.10.0和LibVEX；使用-h重新运行以获取版权信息
==27031==命令：./缓冲区测试11 3 1
==27031== 
==27031==大小为8的无效写入
==27031==0x401642:std:：u详细信息：：_Hash_node_base:：_Hash_node_base（）（hashtable_policy.h:234）
==27031==by 0x4020A0:std:：\u哈希表：：\u哈希表（无符号长，std：：哈希常数和，std:：\u详细信息：：\u Mod_range_哈希常数和，std:\u详细信息：：\u默认值范围内的哈希常数和，std：：等于常数和，std:\u详细信息：：\u选择第一个常数和，std：：分配器常数和）（哈希表h:799）
==27031==by 0x401BB5:std:：_哈希表：：_哈希表（无符号长，std:：hash const&，std:：equal_to const&，std:：allocator const&）（Hashtable.h:420）
==27031==0x4018DC:std:：无序映射：：无序映射（无符号长，std:：hash const&，std:：equal_to const&，std:：allocator const&）（无序映射：h:143）
==27031==by 0x401257:BufferManager:：BufferManager（unsigned int）（BufferManager.cpp:21）
==27031==0x4041B6:main（buffertest.cpp:79）
==27031==地址0x5c1d0e0是大小为64的块分配后的16个字节
==27031==0x4C29180处：运算符新（无符号长）（vg_替换_malloc.c:324）
==27031==0x4041A3:main（buffertest.cpp:79）
==27031== 
==27031==大小为8的无效写入
==27031==at 0x4020A5:std:：：\U哈希表（无符号长，std：：哈希常数和，std:：\U详细信息：：\U Mod_range_哈希常数和，std:\U详细信息：：\U默认值范围_哈希常数和，std：：等于常数和，std:\U详细信息：\U Select1st常数和，std：：分配器常数和）（哈希表h:799）
==27031==by 0x401BB5:std:：_哈希表：：_哈希表（无符号长，std:：hash const&，std:：equal_to const&，std:：allocator const&）（Hashtable.h:420）
==27031==0x4018DC:std:：无序映射：：无序映射（无符号长，std:：hash const&，std:：equal_to const&，std:：allocator const&）（无序映射：h:143）
==27031==by 0x401257:BufferManager:：BufferManager（unsigned int）（BufferManager.cpp:21）
==27031==0x4041B6:main（buffertest.cpp:79）
==27031==地址0x5c1d0e8位于arena“客户端”中大小为64的块后24字节
==27031== 
valgrind:m_mallocfree.c:304（按原样获取）：断言'bszB_lo==bszB_hi'失败。
valgrind:堆块低/高大小不匹配：低=128，高=0。
这可能是由于您的程序错误地写入了
堆块结束并损坏堆元数据。如果你修好了
Memcheck报告的写入无效，此断言将失败
可能会走开。请在将此报告为bug之前尝试一下。
主机堆栈跟踪：
==27031==at 0x380A48EF:show_sched_status_wrk（m_libcasert.c:319）
==27031==0x380A49E4：报告并退出（m_libcasert.c:390）
==27031==0x380A4B66:vgPlain\u assert\u fail（m\u libcasert.c:455）
==27031==0x380B170D：按原样获取（m_mallocfree.c:302）
==27031==0x380B170D:get_bszB（m_mallocfree.c:312）
==27031==0x380B170D:get_pszB（m_mallocfree.c:386）
==27031==0x380B170D:vgPlain\u description\u arena\u addr（m\u mallocfree.c:1532）
==27031==0x3809DC93:vgPlain\u description\u addr（m\u addrinfo.c:188）
==27031==0x3809C73B:VGEMCHECK\U update\U Error\U extra（mc\U errors.c:1133）
==27031==by 0x380A05BA:vgPlain\u maybe\u record\u错误（m\u errormgr.c:818）
==27031==0x3809BCB2:VGEMCHECK\U记录\U地址\U错误（mc\U错误。c:753）
==27031==0x803EDF459:？？？
==27031==0x802D95EEF:？？？
==27031==0x3807295F:vgMemCheck\u malloc（mc\u malloc\u wrappers.c:388）
==27031==by 0x4020A0:std:：\u哈希表：：\u哈希表（无符号长，std：：哈希常数和，std:：\u详细信息：：\u Mod_range_哈希常数和，std:\u详细信息：：\u默认值范围内的哈希常数和，std：：等于常数和，std:\u详细信息：：\u选择第一个常数和，std：：分配器常数和）（哈希表h:799）
附表状态：
正在运行\u tid=1
线程1：状态=VgTs_可运行
==27031==0x401682:std:：_详细信息：：_Prime_rehash_policy:：_Prime_rehash_policy（float）（hashtable_policy.h:464）
==27031==by 0x4020C4:std:：：\u哈希表（无符号长，std:：hash const&，std:\u详细信息：：\u Mod_range_hash const&，std:\u详细信息：：\u默认值：\u范围：\u哈希常量&，std:：等于常量&，std:\u详细信息：：\u选择第一常量&，std:：分配器常量&）（哈希表h:799）
==27031==by 0x401BB5:std:：_哈希表：：_哈希表（无符号长，std:：hash const&，std:：equal_to const&，std:：allocator const&）（Hashtable.h:420）
==27031==0x4018DC:std:
#ifndef BUFFER_MANAGER_HPP
#include "BufferFrame.hpp"
#include <stdint.h>
#include <unordered_map>

class BufferManager {

public:
    BufferManager( const unsigned int pageCount );
    BufferFrame& fixPage( const uint64_t pageId, const bool exclusive );
    void unfixPage( BufferFrame& frame, const bool isDirty );
    ~BufferManager();

private:
    uint64_t pageCount;
    std::unordered_map<uint64_t, BufferFrame *> pages;
    std::unordered_map<std::string, int> files;
};


#define BUFFER_MANAGER_HPP
#endif

BufferManager::BufferManager( const unsigned int pageCount ) {
    this->pageCount = pageCount;
    std::cout << "BufferFrame constructor" << std::endl;
}

BufferFrame& BufferManager::fixPage( const uint64_t pageId, const bool exclusive ) {
    std::cout << "fixPage called with pageId: " << pageId << " requesting exclusive: " << exclusive<< std::endl;

    std::cout << "Pages.size(): " << pages.size() << std::endl;

    //Test if we got the frame in the buffer
    BufferFrame * frame;
    std::unordered_map<uint64_t, BufferFrame *>::const_iterator got = pages.find(pageId);
    if (got == pages.end()) {
        frame = new BufferFrame();
        frame->data = malloc(pageSize);
        frame->pageId = pageId;
        frame->isDirty = false;

        std::pair<uint64_t, BufferFrame *> element(pageId, frame);
        pages.insert(element);
        std::cout << "fixPage of page: " << pageId << " (empty page used. Load not implemented!)" << std::endl;
    }
    else {
        frame = got->second;
        std::cout << "fixPage of page: " << pageId << " (Page loaded from map)" << std::endl;
    }
    return *frame;
}

#ifndef BUFFER_FRAME_HPP
#include <stdint.h>

class BufferFrame {
    friend class BufferManager;

public:

    void* getData();

private:

    void * data;
    uint64_t pageId;
    bool isDirty;
};



#define BUFFER_FRAME_HPP
#endif

BufferFrame& BufferManager::fixPage(
    ....
    BufferFrame frame;
    ....   
    return frame;

std::unordered_map<uint64_t, BufferFrame *> pages;

std::unordered_map<uint64_t, std::shared_ptr<BufferFrame> > pages;