内存泄漏C++

Question

我有C++编写的代码，它工作正常的视觉工作室，但是当我将其转移到Linux（QT设计器）我得到一个运行时，提示以下错误显示：

*** glibc detected *** /home/hfarazi/Test/QT/Test-build-desktop/Test: malloc(): memory corruption: 0x082c2c80 *** 
======= Backtrace: ========= 
/lib/i386-linux-gnu/libc.so.6(+0x6ff22)[0x42cf22] 
/lib/i386-linux-gnu/libc.so.6(+0x718be)[0x42e8be] 
/lib/i386-linux-gnu/libc.so.6(__libc_malloc+0x68)[0x4307f8] 
/usr/lib/i386-linux-gnu/libstdc++.so.6(_Znwj+0x27)[0x2c89d7] 
/usr/lib/i386-linux-gnu/libstdc++.so.6(_Znaj+0x1b)[0x2c8afb] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x804abdc] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x8062860] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x80644b5] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x806e449] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x80604d5] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x8049205] 
/lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf3)[0x3d6113] 
/home/hfarazi/Test/QT/Test-build-desktop/Test[0x8049351] 
======= Memory map: ======== 
00219000-002f7000 r-xp 00000000 07:00 527926  /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16 
002f7000-002f8000 ---p 000de000 07:00 527926  /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16 
002f8000-002fc000 r--p 000de000 07:00 527926  /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16 
002fc000-002fd000 rw-p 000e2000 07:00 527926  /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16 
002fd000-00304000 rw-p 00000000 00:00 0 
00339000-00357000 r-xp 00000000 07:00 266017  /lib/i386-linux-gnu/ld-2.13.so 
00357000-00358000 r--p 0001d000 07:00 266017  /lib/i386-linux-gnu/ld-2.13.so 
00358000-00359000 rw-p 0001e000 07:00 266017  /lib/i386-linux-gnu/ld-2.13.so 
003a2000-003b9000 r-xp 00000000 07:00 273114  /lib/i386-linux-gnu/libpthread-2.13.so 
003b9000-003ba000 r--p 00016000 07:00 273114  /lib/i386-linux-gnu/libpthread-2.13.so 
003ba000-003bb000 rw-p 00017000 07:00 273114  /lib/i386-linux-gnu/libpthread-2.13.so 
003bb000-003bd000 rw-p 00000000 00:00 0 
003bd000-00535000 r-xp 00000000 07:00 273100  /lib/i386-linux-gnu/libc-2.13.so 
00535000-00537000 r--p 00178000 07:00 273100  /lib/i386-linux-gnu/libc-2.13.so 
00537000-00538000 rw-p 0017a000 07:00 273100  /lib/i386-linux-gnu/libc-2.13.so 
00538000-0053b000 rw-p 00000000 00:00 0 
00777000-0079f000 r-xp 00000000 07:00 273104  /lib/i386-linux-gnu/libm-2.13.so 
0079f000-007a0000 r--p 00028000 07:00 273104  /lib/i386-linux-gnu/libm-2.13.so 
007a0000-007a1000 rw-p 00029000 07:00 273104  /lib/i386-linux-gnu/libm-2.13.so 
00bf7000-00bf8000 r-xp 00000000 00:00 0   [vdso] 
00df3000-00e0f000 r-xp 00000000 07:00 262077  /lib/i386-linux-gnu/libgcc_s.so.1 
00e0f000-00e10000 r--p 0001b000 07:00 262077  /lib/i386-linux-gnu/libgcc_s.so.1 
00e10000-00e11000 rw-p 0001c000 07:00 262077  /lib/i386-linux-gnu/libgcc_s.so.1 
08048000-08075000 r-xp 00000000 07:00 401931  /home/hfarazi/Test/QT/Test-build-desktop/Test 
08075000-08076000 r--p 0002c000 07:00 401931  /home/hfarazi/Test/QT/Test-build-desktop/Test 
08076000-08077000 rw-p 0002d000 07:00 401931  /home/hfarazi/Test/QT/Test-build-desktop/Test 
082ba000-082db000 rw-p 00000000 00:00 0   [heap] 
b7600000-b7621000 rw-p 00000000 00:00 0 
b7621000-b7700000 ---p 00000000 00:00 0 
b77f4000-b77f8000 rw-p 00000000 00:00 0 
b780a000-b780d000 rw-p 00000000 00:00 0 
bff44000-bff65000 rw-p 00000000 00:00 0   [stack] 

你能帮忙我发现错误！因为这是一个公司项目，我不能轻易发送代码。 thanx提前。

---

ithink问题是在这个类，一个想法？

#define NOT_VALID NULL 
#define STACK_INITIAL_ALLOC 10 
#define STACK_CHUNK_ALLOC 10 
template<class T> 
class stack 
{ 
public: 
    stack() 
     : value(0), length(0), allocated(0) 
     { } 

    stack(const T &value) 
     : value(0), length(0), allocated(0) 
     { 
      push(value); 
     } 

    ~stack() 
     { 
      if (value) 
       delete [] value; 
     } 

    void push(const T &_value) 
     { 
      if (length == allocated) 
       allocate(); // Allocate more memory 

      value[length++] = _value; 
     } 

    T &pop() 
     { 
      if (length > 0) 
      { 
       //shrink(); 
       length--; 
       return value[length]; 
      } 
     } 

    T &peak() 
     { 
      if (length > 0) 
       return value[length - 1]; 
      //else 
       // throw runtime_error("stack empty"); 
     } 

    // Return the number of length in the stack 
    size_t count() const 
     { 
      return length; 
     } 

    size_t get_allocated() const 
     { 
      return allocated; 
     } 

private: 
    T  *value;  // The actual stack 
    size_t length; // Number of length in stack 
    size_t allocated; // Allocated length in stack 

    void copy(T *from, T *to) 
     { 
      for (size_t i = 0; i < length; i++) 
       *to++ = *from++; 
     } 

    void allocate() 
     { 
      if (value == 0) 
      { 
       allocated = STACK_INITIAL_ALLOC; 
       value = new T[allocated]; 
      } 
      else 
      { 
       // We need to allocate more memory 

       size_t new_allocated = allocated + STACK_CHUNK_ALLOC; 
       T *new_value = new T[new_allocated]; 

       // Copy from old stack to new stack 
       copy(value, new_value); 

       // Delete the old value 
       delete [] value; 

       allocated = new_allocated; 
       value = new_value; 
      } 
     } 

    // Shrink the stack, if lots of it is unused 
    void shrink() 
     { 
      // The limit which the number of length must be lower than 
      size_t shrink_limit = allocated - STACK_CHUNK_ALLOC * 2; 

      // Do not shrink if we will get lower than the initial allocation (shrink_limit > STACK_INITIAL_ALLOC) 
      if (shrink_limit > STACK_INITIAL_ALLOC && length < shrink_limit) 
      { 
       // We can shrink the allocated memory a little 
       size_t new_allocated = allocated - STACK_CHUNK_ALLOC; 

       T *new_value = new T[new_allocated]; 

       copy(value, new_value); 

       delete [] value; 

       value = new_value; 
       allocated = new_allocated; 
      } 
     } 
}; 

Answer 1

如果你不处理线程，那么如果你以某种方式读写数组边界，可能会发生这种问题。

由于此类操作的结果未定义，因此在某些特定主机/编译器中可能不会出现问题，并且只有在将代码传输到另一个主机时才会出现此问题。

有时候，如果你的程序很庞大，这种问题真的很难弄清楚。

除了使用调试器之外，还有一个建议是消除部分代码（如果可能），并尝试缩小问题出处。