IC65849: MEMORY LEAK FROM .NET PROVIDER METHOD IBM.DATA.INFORMIX.DBCWRAPPER.ENLISTASREQUIRED

APAR status

• Closed as program error.

Error description

• The memory leak is caused by the IntPtr returned from
  Marshal.GetIUnknownForObject but never released with
  Marshal.Release().
  
  According to the documentation on Marshal.GetIUnknownForObject:
  In managed code, you seldom work directly with the IUnknown
  interface. However, GetIUnknownForObject is useful when calling
  a method that exposes a COM object parameter as an IntPtr type,
  or with custom marshaling. Calling an object with this method
  causes the reference count to increment on the interface pointer
  before the pointer is returned. Always use Marshal..::.Release
  to decrement the reference count once you have finished with the
  pointer. This method provides the opposite functionality of the
  Marshal..::.GetObjectForIUnknown method.
  
  Stack trace of the leak:
  
  Time Travel Position: 1DAA680000001.
  0012ebe0 61174d04 kernel32!InterlockedIncrement+0x9
  [d:\nt\base\win32\client\i386\critsect.asm @ 91]
  0012ebf8 61183459 msdtcprx!CITransaction::AddRef+0x17
  [d:\nt\com\complus\dtc\dtc\msdtcprx\src\dtcprxtx.cpp @ 360]
  0012ec04 79f902bf msdtcprx!CTxWrapper::AddRef+0x11
  [d:\nt\com\complus\dtc\dtc\msdtcprx\src\txwrapper.cpp @ 205]
  0012ec34 79fa9cce mscorwks!SafeAddRef+0x5c
  [f:\dd\ndp\clr\src\vm\interoputil.cpp @ 1530]
  0012ec44 79f6c386
  mscorwks!IUnkEntry::GetIUnknownForCurrContext+0x26
  [f:\dd\ndp\clr\src\vm\comcache.cpp @ 816]
  0012ec90 79f6cf8f mscorwks!GetComIPFromObjectRef+0x126
  [f:\dd\ndp\clr\src\vm\interopconverter.cpp @ 288]
  0012ed44 00e78a35
  mscorwks!MarshalNative::GetIUnknownForObjectNative+0xdb
  [f:\dd\ndp\clr\src\vm\marshalnative.cpp @ 1223]
  0012ed7c 00e77f07
  ibm_data_informix!IBM.Data.Informix.DBCWrapper.EnlistAsRequired(
  IBM.Data.Informix.IfxConnection)+0x85
  0012ee70 00e777e2
  ibm_data_informix!IBM.Data.Informix.IfxConnectionPool.Open(IBM.D
  ata.Informix.IfxConnection)+0x317
  0012ee98 00e7739a
  ibm_data_informix!IBM.Data.Informix.IfxConnPoolManager.Open(IBM.
  Data.Informix.IfxConnection)+0x42
  0012eeb4 00e735e1
  ibm_data_informix!IBM.Data.Informix.IfxConnection.Open()+0x112
  0012efc0 00e73384
  testmemoryleak!TestMemoryLeak.MemoryLeak.DistributedTxn()+0x1d9
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Windows Users                                                *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Memory leak occurs in DBCWrapper.EnlistAsRequired method.    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to CSDK 3.50.xC7.                                    *
  ****************************************************************
  

Problem conclusion

• The problem was first fixed in CSDK 3.50.xC7.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  IBM CSDK

• Fixed component ID

  5724C2381

Applicable component levels

• R350 PSY

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