怎么使用windbg检测内存泄漏

如何使用windbg检测内存泄漏
1.设置符号路径
打开windbg,在菜单Symbol File PATH设置
"SRV*d:\symbols*http://msdl.microsoft.com/download/symbols"
d:\symbols是你本地磁盘的一个文件夹,用于下载微软的符号文件


另外,把调试的目标程序的PDB文件路径加到后面
例如:SRV*d:\symbols*http://msdl.microsoft.com/download/symbols;d:\Develop\projects\Service\bin\Release


2.启用跟踪用户模式下的栈信息
运行Gflags.exe /i xxx.exe +ust
xxx.exe是调试的目标程序名字


3.用windbg启动目标程序或附加到目标进程


4.查看堆栈信息

运行!heap -s
显示类似如下的结果
NtGlobalFlag enables following debugging aids for new heaps:
   validate parameters
   stack back traces
   Heap     Flags   Reserv  Commit  Virt   Free  List   UCR  Virt  Lock  Fast 
                     (k)     (k)    (k)     (k) length      blocks cont. heap 
   -----------------------------------------------------------------------------
    00150000 58000062    1024     12     12      1     1     1    0      0   L  
    00250000 58001062      64     24     24     15     1     1    0      0   L  
    00260000 58008060      64     12     12     10     1     1    0      0      
    00330000 58001062  261184 239484 239484     14     4     1    0      0      
   -----------------------------------------------------------------------------
从例子看到00330000的堆内存占用明显高
   
5.查看具体堆的统计信息
运行!heap -stat -h 00330000
显示这个堆的统计信息
显示类似如下结果
heap @ 00330000
group-by: TOTSIZE max-display: 20
    size     #blocks     total     ( %) (percent of total busy bytes)
    1f64 76c6 - e905f58  (99.99)
    1800 1 - 1800  (0.00)
    824 2 - 1048  (0.00)
    238 2 - 470  (0.00)
    244 1 - 244  (0.00)
    4c 5 - 17c  (0.00)
    b0 2 - 160  (0.00)
    86 2 - 10c  (0.00)
    50 3 - f0  (0.00)
    74 2 - e8  (0.00)
    38 4 - e0  (0.00)
    48 3 - d8  (0.00)
    c4 1 - c4  (0.00)
    62 2 - c4  (0.00)
    be 1 - be  (0.00)
    b8 1 - b8  (0.00)
    ae 1 - ae  (0.00)
    ac 1 - ac  (0.00)
    55 2 - aa  (0.00)
    a4 1 - a4  (0.00)
可以看到有0x76c6个1f64字节的块被分配,占比为99.99%


6.显示块的内存地址
运行!heap -flt s 1f64
显示块大小为1f64的内存地址
    _HEAP @ 150000
    _HEAP @ 250000
    _HEAP @ 260000
    _HEAP @ 330000
      HEAP_ENTRY Size Prev Flags    UserPtr UserSize - state
        003360e0 03f0 0000  [07]   003360e8    01f64 - (busy)
        00338060 03f0 03f0  [07]   00338068    01f64 - (busy)
        00339fe0 03f0 03f0  [07]   00339fe8    01f64 - (busy)
        0033bf60 03f0 03f0  [07]   0033bf68    01f64 - (busy)
        0033dee0 03f0 03f0  [07]   0033dee8    01f64 - (busy)
        01420040 03f0 03f0  [07]   01420048    01f64 - (busy)
        01421fc0 03f0 03f0  [07]   01421fc8    01f64 - (busy)
        01423f40 03f0 03f0  [07]   01423f48    01f64 - (busy)
        01425ec0 03f0 03f0  [07]   01425ec8    01f64 - (busy)
        01427e40 03f0 03f0  [07]   01427e48    01f64 - (busy)
        01429dc0 03f0 03f0  [07]   01429dc8    01f64 - (busy)
        0142bd40 03f0 03f0  [07]   0142bd48    01f64 - (busy)
        0142dcc0 03f0 03f0  [07]   0142dcc8    01f64 - (busy)
        0142fc40 03f0 03f0  [07]   0142fc48    01f64 - (busy)
        01431bc0 03f0 03f0  [07]   01431bc8    01f64 - (busy)
        01433b40 03f0 03f0  [07]   01433b48    01f64 - (busy)
        01435ac0 03f0 03f0  [07]   01435ac8    01f64 - (busy)
        01437a40 03f0 03f0  [07]   01437a48    01f64 - (busy)
        014399c0 03f0 03f0  [07]   014399c8    01f64 - (busy)
        0143b940 03f0 03f0  [07]   0143b948    01f64 - (busy)
        0143d8c0 03f0 03f0  [07]   0143d8c8    01f64 - (busy)
        0143f840 03f0 03f0  [07]   0143f848    01f64 - (busy)
        014417c0 03f0 03f0  [07]   014417c8    01f64 - (busy)
        01443740 03f0 03f0  [07]   01443748    01f64 - (busy)
        014456c0 03f0 03f0  [07]   014456c8    01f64 - (busy)
        01447640 03f0 03f0  [07]   01447648    01f64 - (busy)
        014495c0 03f0 03f0  [07]   014495c8    01f64 - (busy)
        0144b540 03f0 03f0  [07]   0144b548    01f64 - (busy)
        0144d4c0 03f0 03f0  [07]   0144d4c8    01f64 - (busy)
        0144f440 03f0 03f0  [07]   0144f448    01f64 - (busy)
        014513c0 03f0 03f0  [07]   014513c8    01f64 - (busy)
        01453340 03f0 03f0  [07]   01453348    01f64 - (busy)
        014552c0 03f0 03f0  [07]   014552c8    01f64 - (busy)
        01457240 03f0 03f0  [07]   01457248    01f64 - (busy)
        014591c0 03f0 03f0  [07]   014591c8    01f64 - (busy)
        0145b140 03f0 03f0  [07]   0145b148    01f64 - (busy)
        0145d0c0 03f0 03f0  [07]   0145d0c8    01f64 - (busy)
        0145f040 03f0 03f0  [07]   0145f048    01f64 - (busy)
        01460fc0 03f0 03f0  [07]   01460fc8    01f64 - (busy)
        01462f40 03f0 03f0  [07]   01462f48    01f64 - (busy)
        01464ec0 03f0 03f0  [07]   01464ec8    01f64 - (busy)
        01466e40 03f0 03f0  [07]   01466e48    01f64 - (busy)
        01468dc0 03f0 03f0  [07]   01468dc8    01f64 - (busy)


7.查看调用栈信息
可使用任一个UsrPtr的值来查询
!heap -p -a 0143d8c8


    address 0143d8c8 found in
    _HEAP @ 330000
      HEAP_ENTRY Size Prev Flags    UserPtr UserSize - state
        0143d8c0 03f0 0000  [07]   0143d8c8    01f64 - (busy)
        Trace: 0025
        7c96d6dc ntdll!RtlDebugAllocateHeap+0x000000e1
        7c949d18 ntdll!RtlAllocateHeapSlowly+0x00000044
        7c91b298 ntdll!RtlAllocateHeap+0x00000e64
        102c103e MSVCR90D!_heap_alloc_base+0x0000005e
        102cfd76 MSVCR90D!_heap_alloc_dbg_impl+0x000001f6
        102cfb2f MSVCR90D!_nh_malloc_dbg_impl+0x0000001f
        102cfadc MSVCR90D!_nh_malloc_dbg+0x0000002c
        102db25b MSVCR90D!malloc+0x0000001b
        102bd691 MSVCR90D!operator new+0x00000011
        102bd71f MSVCR90D!operator new[]+0x0000000f
        4113d8 Test2!AllocateMemory+0x00000028
        41145c Test2!wmain+0x0000002c
        411a08 Test2!__tmainCRTStartup+0x000001a8
        41184f Test2!wmainCRTStartup+0x0000000f

        7c816fd7 kernel32!BaseProcessStart+0x00000023



文章翻译和节选自:http://www.codeproject.com/Articles/31382/Memory-Leak-Detection-Using-Windbg

       

windbg 命令行参考

http://windbg.info/doc/1-common-cmds.html