Profiler Won't Profile DLLs That Are Freed, Then Reloaded (72884)


The information in this article applies to:

  • Microsoft Source Profiler for OS/2
  • Microsoft Source Profiler for Windows
This article was previously published under Q72884
The information in this article is included in the documentation starting with Visual C++ 5.0. Look there for future revisions.

SUMMARY

The Microsoft Source Profiler version can profile the first instance of any and all DLLs (dynamic-link libraries) in a Windows or OS/2 application, but it cannot continue to collect statistics for a dynamically loaded DLL that is freed and then reloaded.

MORE INFORMATION

DLLs that are dynamically loaded with LoadLibrary() under Windows, or DosLoadModule() under OS/2, and that are freed and then reloaded, should not be profiled because the results will not be correct.

Under Windows, this behavior can be observed by attempting to profile code that performs the following actions:
  1. Dynamically loads a DLL with LoadLibrary().
  2. Frees the DLL with FreeLibrary().
  3. Reloads the DLL again with LoadLibrary().
Similarly, under OS/2, this behavior can be observed by attempting to profile code that performs these actions:
  1. Dynamically loads a DLL with DosLoadModule().
  2. Frees the DLL with DosFreeModule().
  3. Reloads the DLL again with DosLoadModule().
There are currently no workarounds for this limitation. The ability to handle dynamically reloaded DLLs under Windows is being considered for a future version of the Profiler. There are no current plans for an OS/2 version that can handle dynamically reloaded DLLs due to the lack of a message from the operating system when a DLL has been freed.
Modification Type:MajorLast Reviewed:10/23/2003
Keywords:kb16bitonly KB72884
©2003 Microsoft Corporation. All rights reserved.