在Visual Studio C ++中,什么是内存分配表示形式?
时间:2020-03-06 14:39:51 来源:igfitidea点击:
在Visual Studio中,我们所有人都有" baadf00d",在运行时在C ++中的调试器中检查变量时看到" CC"和" CD"。
据我了解," CC"处于DEBUG模式,仅表示何时对内存进行new()或者alloc()并统一化。而" CD"代表已删除或者已释放的内存。我只在RELEASE版本中看到过" baadf00d"(但我可能错了)。
有时,我们会遇到解决内存泄漏,缓冲区溢出等问题的情况,而这类信息会派上用场。
有人会友好地指出何时以及在哪种模式下将内存设置为可识别的字节模式以进行调试吗?
解决方案
该链接具有更多信息:
http://en.wikipedia.org/wiki/Magic_number_(编程)
* 0xABABABAB : Used by Microsoft's HeapAlloc() to mark "no man's land" guard bytes after allocated heap memory * 0xABADCAFE : A startup to this value to initialize all free memory to catch errant pointers * 0xBAADF00D : Used by Microsoft's LocalAlloc(LMEM_FIXED) to mark uninitialised allocated heap memory * 0xBADCAB1E : Error Code returned to the Microsoft eVC debugger when connection is severed to the debugger * 0xBEEFCACE : Used by Microsoft .NET as a magic number in resource files * 0xCCCCCCCC : Used by Microsoft's C++ debugging runtime library to mark uninitialised stack memory * 0xCDCDCDCD : Used by Microsoft's C++ debugging runtime library to mark uninitialised heap memory * 0xDDDDDDDD : Used by Microsoft's C++ debugging heap to mark freed heap memory * 0xDEADDEAD : A Microsoft Windows STOP Error code used when the user manually initiates the crash. * 0xFDFDFDFD : Used by Microsoft's C++ debugging heap to mark "no man's land" guard bytes before and after allocated heap memory * 0xFEEEFEEE : Used by Microsoft's HeapFree() to mark freed heap memory
实际上,在调试分配中添加了很多有用的信息。该表比较完整:
http://www.nobugs.org/developer/win32/debug_crt_heap.html#table
Address Offset After HeapAlloc() After malloc() During free() After HeapFree() Comments 0x00320FD8 -40 0x01090009 0x01090009 0x01090009 0x0109005A Win32 heap info 0x00320FDC -36 0x01090009 0x00180700 0x01090009 0x00180400 Win32 heap info 0x00320FE0 -32 0xBAADF00D 0x00320798 0xDDDDDDDD 0x00320448 Ptr to next CRT heap block (allocated earlier in time) 0x00320FE4 -28 0xBAADF00D 0x00000000 0xDDDDDDDD 0x00320448 Ptr to prev CRT heap block (allocated later in time) 0x00320FE8 -24 0xBAADF00D 0x00000000 0xDDDDDDDD 0xFEEEFEEE Filename of malloc() call 0x00320FEC -20 0xBAADF00D 0x00000000 0xDDDDDDDD 0xFEEEFEEE Line number of malloc() call 0x00320FF0 -16 0xBAADF00D 0x00000008 0xDDDDDDDD 0xFEEEFEEE Number of bytes to malloc() 0x00320FF4 -12 0xBAADF00D 0x00000001 0xDDDDDDDD 0xFEEEFEEE Type (0=Freed, 1=Normal, 2=CRT use, etc) 0x00320FF8 -8 0xBAADF00D 0x00000031 0xDDDDDDDD 0xFEEEFEEE Request #, increases from 0 0x00320FFC -4 0xBAADF00D 0xFDFDFDFD 0xDDDDDDDD 0xFEEEFEEE No mans land 0x00321000 +0 0xBAADF00D 0xCDCDCDCD 0xDDDDDDDD 0xFEEEFEEE The 8 bytes you wanted 0x00321004 +4 0xBAADF00D 0xCDCDCDCD 0xDDDDDDDD 0xFEEEFEEE The 8 bytes you wanted 0x00321008 +8 0xBAADF00D 0xFDFDFDFD 0xDDDDDDDD 0xFEEEFEEE No mans land 0x0032100C +12 0xBAADF00D 0xBAADF00D 0xDDDDDDDD 0xFEEEFEEE Win32 heap allocations are rounded up to 16 bytes 0x00321010 +16 0xABABABAB 0xABABABAB 0xABABABAB 0xFEEEFEEE Win32 heap bookkeeping 0x00321014 +20 0xABABABAB 0xABABABAB 0xABABABAB 0xFEEEFEEE Win32 heap bookkeeping 0x00321018 +24 0x00000010 0x00000010 0x00000010 0xFEEEFEEE Win32 heap bookkeeping 0x0032101C +28 0x00000000 0x00000000 0x00000000 0xFEEEFEEE Win32 heap bookkeeping 0x00321020 +32 0x00090051 0x00090051 0x00090051 0xFEEEFEEE Win32 heap bookkeeping 0x00321024 +36 0xFEEE0400 0xFEEE0400 0xFEEE0400 0xFEEEFEEE Win32 heap bookkeeping 0x00321028 +40 0x00320400 0x00320400 0x00320400 0xFEEEFEEE Win32 heap bookkeeping 0x0032102C +44 0x00320400 0x00320400 0x00320400 0xFEEEFEEE Win32 heap bookkeeping