Handle DAC DefaultCOMImpl ref-counting fix (CLRDATA_REQUEST_REVISION 10)#1401
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max-charlamb merged 2 commits intomicrosoft:mainfrom Mar 10, 2026
Merged
Handle DAC DefaultCOMImpl ref-counting fix (CLRDATA_REQUEST_REVISION 10)#1401max-charlamb merged 2 commits intomicrosoft:mainfrom
max-charlamb merged 2 commits intomicrosoft:mainfrom
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leculver
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Mar 6, 2026
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Nitpick doesn't block merge, thanks!
The DAC's DefaultCOMImpl::Release() used post-decrement (mRef--) instead of pre-decrement (--mRef), leaking all DefaultCOMImpl-derived COM objects. ClrMD compensated with an extra Release() after wrapping enumerators. With the fix in dotnet/runtime#125231 (CLRDATA_REQUEST_REVISION bumped to 10), the extra Release() would prematurely free the object. Changes: - DacRuntime: Accept DAC version 9 and 10, store version on SOSDac - SOSDac: Add DacVersion property and ReleaseLeakedDacRef() helper that only releases the leaked ref when DacVersion < 10 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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| throw new InvalidDataException("This instance of CLR either has not been initialized or does not contain any data. This may indicate the dump was taken before the CLR was fully initialized, or the dump is corrupt or truncated. Failed to request DacVersion."); | ||
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| if (version != 9) | ||
| if (version < 9) |
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Should this also reject versions higher than 10? I do not think the future versions are expected to be compatible (as this change is demonstrating).
Future DAC versions may not be compatible, so reject unknown versions rather than accepting all versions >= 9. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
leculver
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The DAC's DefaultCOMImpl::Release() used post-decrement (mRef--) instead of pre-decrement (--mRef), leaking all DefaultCOMImpl-derived COM objects. ClrMD compensated with an extra Release() after wrapping enumerators. With the fix in dotnet/runtime#125231 (CLRDATA_REQUEST_REVISION bumped to 10), the extra Release() would prematurely free the object.
Changes: