FIX: Access Violation When You Use ios-Derived Type in Multithreaded Applications (814308)
The information in this article applies to:
- Microsoft Visual Studio 6.0 SP1
- Microsoft Visual Studio 6.0 SP4
- Microsoft Visual Studio 6.0 SP5
SYMPTOMSWhen you create and destroy ios-derived classes in multiple
threads, you may receive an access violation error message. This problem occurs only when you use the old
iostream library instead of the Standard C++ Library that was introduced in Visual C++
5.0. You can gain access to the old iostream library by including iostream header files
that have the .h extension, such as iostream.h or strstrea.h. The new header files do
not have an extension, such as iostream or strstream. CAUSEA static member, ios::fLockcInit, is used to hold reference
counts for a critical section that is used in the multithreaded C Run-Time Library. This critical section reference provides synchronization for the ios class. The ios::fLockcInit static member is changed without
synchronization when you create and destroy ios. This scenario permits a
race condition. The critical section reference count that ios::fLockcInit holds may
be destroyed more than one time or may be used after it is destroyed.RESOLUTIONA supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem. Note You must have a Visual Studio license agreement to obtain this hotfix. To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site: Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. Date Time Version Size File name
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05-Feb-2003 22:57 481,910 Libcimt.lib
05-Feb-2003 22:48 608,636 Libcimtd.lib
05-Feb-2003 23:46 6.0.9746.0 77,878 Msvcirt.dll
05-Feb-2003 22:51 6.0.9746.0 94,285 Msvcirtd.dll
05-Feb-2003 21:11 7,146 _ios.cpp WORKAROUNDUse the Standard C++ Library instead of the old iostream
library.STATUS
Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.
Modification Type: | Minor | Last Reviewed: | 10/21/2005 |
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Keywords: | kbfix kbBug KB814308 |
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