INFO: Winsock User-Mode Dump Heap Logs and Handle-To-Pointer Translation Table Memory Usage (322980)


The information in this article applies to:

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
  • Microsoft Platform Software Development Kit (SDK) 1.0
  • Microsoft Windows XP Professional
  • Microsoft Windows XP 64-Bit Edition
  • Microsoft Windows XP Driver Development Kit (DDK)
  • Microsoft Windows XP Embedded
This article was previously published under Q322980

SUMMARY

After all socket objects are closed and while the program is still running, the user-mode dump heap (UMDH) tool may still report memory increase.

The memory allocations that are described in this article are because of creation or expansion of the Winsock Handle-To-Pointer Translation Table.

These memory allocations are not memory leaks and you can safely ignore them.

MORE INFORMATION

Winsock runtime internally maintains the Handle-To-Pointer Translation Table to manage socket objects. The table grows to handle all sockets that are being used by a program. The growth of the table is proportional to the maximum number of sockets that are open in the application at any specified time.

After the table expands, it does not shrink even when sockets are closed. The allocations can be reused for other sockets. They are freed only when either WSACleanup is called or the process is ended.

This behavior is by design.

For example, memory can be allocated in the following circumstances:

  • When the table is initially created:
    +     416 (    416 -     0)      1 allocs       BackTrace00204
+       1 (      1 -     0)     BackTrace00204  allocations

        ntdll!RtlDebugAllocateHeap+000000FD
        ntdll!RtlAllocateHeapSlowly+0000005A
        ntdll!RtlAllocateHeap+000008C2
        KERNEL32!GlobalAlloc+00000082
        WS2HELP!WahCreateHandleContextTable+00000059
        msafd!SockInitialize+000000EC
        ntdll!LdrpCallInitRoutine+00000014
        ntdll!LdrpRunInitializeRoutines+000001DF
        ntdll!LdrpLoadDll+000002DD
        ntdll!LdrLoadDll+00000017
        KERNEL32!LoadLibraryExA+0000001D
        WS2_32!DPROVIDER::Initialize+000000E6
  • When a socket is created:
    +     944 (    944 -     0)      6 allocs       BackTrace00230
+       6 (      6 -     0)     BackTrace00230  allocations

        ntdll!RtlDebugAllocateHeap+000000FD
        ntdll!RtlAllocateHeapSlowly+0000005A
        ntdll!RtlAllocateHeap+000008C2
        KERNEL32!GlobalAlloc+00000082
        WS2HELP!WahInsertHandleContext+00000160
        msafd!WSPSocket+00000500
        WS2_32!WSASocketW+000000EA
        WS2_32!socket+00000054
        client!??? @ 00401AC2
        client!??? @ 00403188
        KERNEL32!BaseThreadStart+00000052

+     912 (    912 -     0)      6 allocs       BackTrace00232
+       6 (      6 -     0)     BackTrace00232  allocations

        ntdll!RtlDebugAllocateHeap+000000FD
        ntdll!RtlAllocateHeapSlowly+0000005A

        ntdll!RtlAllocateHeap+000008C2
        KERNEL32!GlobalAlloc+00000082
        WS2HELP!WahInsertHandleContext+00000160
        WS2_32!DSOCKET::AssociateSocketHandle+00000022
        msafd!WSPSocket+00000541
        WS2_32!WSASocketW+000000EA
        WS2_32!socket+00000054
        client!??? @ 00401AC2
        client!??? @ 00403188
        KERNEL32!BaseThreadStart+00000052
  • When a socket connection is accepted:
    +     152 (    304 -   152)      2 allocs       BackTrace00178
+       1 (      2 -     1)     BackTrace00178  allocations

        ntdll!RtlDebugAllocateHeap+000000FD
        ntdll!RtlAllocateHeapSlowly+0000005A
        ntdll!RtlAllocateHeap+000008C2
        KERNEL32!GlobalAlloc+00000082
        WS2HELP!WahInsertHandleContext+00000160
        msafd!WSPSocket+00000500
        msafd!WSPAccept+000008FE
        WS2_32!WSAAccept+00000072
        WS2_32!accept+00000015
        server!mainCRTStartup+000000C5
        KERNEL32!BaseProcessStart+0000003D

+     152 (    304 -   152)      2 allocs       BackTrace00180
+       1 (      2 -     1)     BackTrace00180  allocations

        ntdll!RtlDebugAllocateHeap+000000FD
        ntdll!RtlAllocateHeapSlowly+0000005A
        ntdll!RtlAllocateHeap+000008C2
        KERNEL32!GlobalAlloc+00000082
        WS2HELP!WahInsertHandleContext+00000160
        WS2_32!DSOCKET::AssociateSocketHandle+00000022
        msafd!WSPSocket+00000541
        msafd!WSPAccept+000008FE
        WS2_32!WSAAccept+00000072
        WS2_32!accept+00000015
        server!mainCRTStartup+000000C5
        KERNEL32!BaseProcessStart+0000003D

REFERENCES

For more information about how to debug, visit the following Microsoft Web site:

Microsoft Debugging Tools
http://www.microsoft.com/whdc/devtools/ddk/default.mspx

Modification Type:MinorLast Reviewed:8/24/2005
Keywords:kbDSWNET2003Swept kbinfo KB322980 kbAudDeveloper
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