Remove "Host Breakable" lock concept

[jkoritzinsky]

This seems to have only been used by SQLCLR's hosting model (in particular for SQL Server's deadlock detection mechanism). Remove it now that there is no way for the host to break a lock.

[Copilot]

Pull Request Overview

This PR removes the obsolete "Host Breakable" lock concept that was only used by SQLCLR’s hosting model for deadlock detection. The changes include renaming internal debug lock counters, removing CRST_HOST_BREAKABLE flags from lock initializations, and cleaning up associated macros and fields.

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/coreclr/vm/threads.h	Renamed debug lock counter and its associated methods to remove host breakable terminology.
src/coreclr/vm/threads.cpp	Updated constructor initialization to reflect the new lock counter naming.
src/coreclr/vm/pendingload.cpp	Removed CRST_HOST_BREAKABLE flag from lock initialization.
src/coreclr/vm/listlock.h	Eliminated m_fHostBreakable member and related methods.
src/coreclr/vm/excep.cpp	Adjusted lock count manipulations to use the new naming.
src/coreclr/vm/eventing/eventpipe/ep-rt-coreclr.h	Removed CRST_HOST_BREAKABLE flag during lock initialization.
src/coreclr/vm/dispatchinfo.cpp	Updated lock initialization by removing the host breakable flag.
src/coreclr/vm/crst.cpp	Cleaned up debug macro calls and lock count adjustments in light of the removal.
src/coreclr/vm/comcallablewrapper.cpp	Updated crst initialization to omit CRST_HOST_BREAKABLE.
src/coreclr/vm/callhelpers.cpp	Assert now verifies the updated lock state using HasLock().
src/coreclr/vm/appdomain.cpp	Changed several lock initializations, removing the host breakable flag.
src/coreclr/pal/prebuilt/inc/clrinternal.h	Removed the definition of CRST_HOST_BREAKABLE.
src/coreclr/inc/contract.h	Removed host breakable related debug macros.
src/coreclr/inc/clrinternal.idl	Commented out CRST_HOST_BREAKABLE in the IDL definitions.

Comments suppressed due to low confidence (6)

src/coreclr/vm/threads.h:3478

• Renaming m_dwUnbreakableLockCount to m_dwLockCount is consistent with the removal of host breakable locks. Please ensure that any associated comments or documentation are updated to reflect this change.

DWORD m_dwLockCount;

src/coreclr/vm/pendingload.cpp:50

• The removal of the CRST_HOST_BREAKABLE flag in lock initialization is appropriate given the updated design. Confirm that all related usages now rely solely on CRST_UNSAFE_SAMELEVEL.

CrstFlags(CRST_HOST_BREAKABLE|CRST_UNSAFE_SAMELEVEL));

src/coreclr/vm/listlock.h:241

• The removal of the m_fHostBreakable field and its usage is aligned with the removal of host breakable logic. Please verify that no dependent code expects this property.

BOOL m_fHostBreakable;        // Lock can be broken by a host for deadlock detection

src/coreclr/vm/crst.cpp:424

• The removal of the HOST_BREAKABLE_CRST_TAKEN branch and use of EE_LOCK_TAKEN is correct now. Ensure that the debug state tracking remains consistent after this change.

EE_LOCK_TAKEN(this);

src/coreclr/vm/appdomain.cpp:1682

• Replacing the CRST_HOST_BREAKABLE flag with CRST_DEFAULT for m_FileLoadLock should be reviewed to ensure that the locking semantics are maintained as expected in the new design.

m_FileLoadLock.Init(CrstAssemblyLoader, CrstFlags(CRST_HOST_BREAKABLE), TRUE);

src/coreclr/inc/clrinternal.idl:61

• Commenting out CRST_HOST_BREAKABLE in the IDL is consistent with its removal. Confirm that any external clients relying on this definition are updated accordingly.

CRST_HOST_BREAKABLE   = 0x20, // This lock is held while running managed code.  It can be terminated by a host.

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[jkotas]

Thanks

[jkoritzinsky]

/ba-g host failure looks unrelated