v3.0.0

Breaking changes

• NuGet SharedMemoryStore now creates and reads only SMS2 layout 2.0,
  resource protocol 2, required-feature mask 7, and optional-feature mask
  0.
• Removed the alternate layout selector, compatibility creator, fallback
  engine, and retired mapped-record surface. Ordinary
  SharedMemoryStoreOptions.Create(...) and CalculateRequiredBytes(...) are
  the only managed sizing and creation helpers.
• A noncurrent, unknown, or malformed mapping is rejected with
  IncompatibleLayout before key, descriptor, payload, slot, lease, or
  participant projection. There is no in-place conversion.

Added

• Completed independent native SharedMemoryStore 1.0.0 and Python
  shared-memory-store 1.0.0 distributions on the same SMS2 protocol.
• Advanced the fixed-width native boundary to C ABI 2.0, including
  participant-aware layout sizing, protocol identity, cancellation, expanded
  diagnostics, lifecycle operations, and ownership-safe opaque tokens.
• Added complete C++, Python, and nine ordered .NET/C++/Python interoperability
  coverage for publication, reservations, leases, removal/reuse, recovery,
  participant capacity, diagnostics, corruption rejection, and held-cold-lock
  progress.

Changed

• Hot publish, segmented publish, reserve, commit, abort, acquire, release,
  remove, reclaim, recovery help, and diagnostics use mapped lock-free atomics
  and bounded helping; OS synchronization is limited to cold create/open/close
  coordination.
• Managed diagnostics now expose the canonical five-field protocol identity,
  SMS2 participant and directory state, and local retry/help/token/recovery
  telemetry without obsolete tombstone or compaction fields.
• Updated NuGet metadata and XML documentation for version 3.0.0, CMake
  metadata for version 1.0.0/ABI 2.0, and Python metadata for version
  1.0.0/required ABI 2.0.

Migration

• Stop writers and readers, drain leases and reservations, close every handle,
  remove or replace the noncurrent physical store, create a fresh SMS2 store,
  and republish values from an application-owned authoritative source.
• A side-by-side cutover must use a distinct public store name. Current clients
  do not read an old mapping as a migration source.

v2.0.0

Added

• Added an explicitly selected C# lock-free key-value profile using mapped
  layout 2.0 and resource protocol 2, with direct reservation publication,
  shared zero-copy leases, generation-fenced removal/reuse, participant
  incarnations, explicit recovery, and bounded diagnostics.
• Added StoreProfile, CreateLockFree, profile-aware sizing,
  ParticipantRecordCount, immutable StoreProtocolInfo, and the appended
  ParticipantTableFull open status.

Changed

• NuGet SharedMemoryStore advances to 2.0.0. Lock-free wait options bound
  local retry, revalidation, helping, and backoff; they do not acquire a named
  operation lock or wait for keys/capacity to appear.
• Documented reservation tokens as exclusive single-producer lifetimes and
  clarified logical removal, RemovePending, borrowed-view, recovery, and
  local-handle disposal semantics.

Compatibility

• The legacy profile remains the default and preserves layout 1.2, resource
  protocol 1, public workflow signatures, and existing status numbers.
• Layout 1.2 and 2.0 are never reinterpreted in place or used by mixed
  synchronization participants. Same-name upgrade and rollback require draining
  handles, recreating the mapping, and republishing application-owned values.
• C++ and Python 0.1.0 remain layout-1.2-only and reject layout 2.0; their
  independently versioned packages and C ABI 1.0 are unchanged.

v1.0.2

Added

• Added an independently versioned CMake SharedMemoryStore 0.1.0
  distribution with a C++20 protocol core, Windows and Linux adapters,
  fixed-width C ABI 1.0, move-only C++ RAII wrappers, install/export rules,
  native tests, a clean-consumer project, and a basic sample.
• Added the independently versioned Python shared-memory-store 0.1.0
  distribution sources for Python 3.10 or newer. Its standard-library ctypes
  API loads the packaged native library and exposes context-managed stores,
  leases, reservations, recovery, bounded waits, and diagnostics.
• Added canonical language-neutral specifications and conformance fixtures for
  mapped layout 1.2 and resource naming 1, plus a complete ordered 3x3
  .NET/C++/Python interoperability harness.

Fixed

• Corrected managed Linux opening of an existing store so the actual backing
  file is mapped before layout validation; mismatched capacities now report
  IncompatibleLayout instead of a mapping failure.
• Made the managed implementation reject non-64-bit or non-little-endian
  processes with UnsupportedPlatform before opening platform resources.

Packaging

• Updated the release workflow to Node 24-based immutable action pins while
  retaining trusted NuGet publishing and draft-first GitHub release behavior.

Security

• Restricted Python native loading to the library packaged beside its modules;
  it does not search the current directory, PATH, or system library paths.
• Preserved the trusted same-host participant boundary across all three
  implementations; no implementation claims protection from a malicious writer
  that already has legitimate access to the shared resources.

Validation

• Validated native configure, build, CTest, install, clean CMake consumption,
  Python source and installed-wheel behavior, and ordered .NET/C++/Python
  interoperability on Windows x64 and Linux x64.
• Validated mixed lifecycle, bounded-contention, crash-recovery, diagnostics,
  Linux ownership cleanup, protocol fixtures, package consumption, and existing
  managed regression scenarios.

Compatibility

• NuGet SharedMemoryStore advances to 1.0.2 while preserving the managed
  public API, status values, .NET BCL-only runtime dependency surface, mapped
  layout 1.2, and resource naming 1.
• CMake SharedMemoryStore and Python shared-memory-store remain independently
  versioned 0.1.0 alpha sibling distributions. They are not included in the
  NuGet package, and this release does not publish them to PyPI or a native
  package registry.
• All three runtimes interoperate through mapped layout 1.2 and resource
  naming 1; the native and Python distributions use C ABI 1.0.

v1.0.1

Packaging

• Added Linux and Windows GitHub Actions validation and a manually triggered,
  trusted-publishing release workflow for NuGet.org and GitHub Releases.
• Added portable .snupkg symbols to improve package debugging without growing
  the primary package.

Fixed

• Enforced one caller-selected wait budget across same-handle synchronization,
  Linux lifecycle locking, and shared store locking.
• Replaced destructive key-index rebuilds with crash-safe backward-shift
  compaction and duplicate-tolerant cleanup.
• Made Linux owner metadata replacement atomic and resistant to PID reuse, and
  prevented failed opens from leaving live-looking owner records.
• Rejected layout dimensions whose index, alignment, or section calculations
  cannot be represented safely.
• Moved stores that detect usage-count underflow into shared safe error mode.
• Prevented Windows mapping-handle leaks when view creation fails and removed
  process-local Linux lock registry growth after handles are disposed.
• Matched Windows Global\ mapping names with global synchronization so
  cross-session participants cannot mutate one mapping under different mutexes.
• Made segmented publish use one synchronized operation so bounded contention
  cannot strand an internal reservation.

Security

• Linux shared-memory directories now use owner-only 0700 permissions and
  region, synchronization, owner, and lifecycle files use owner-only 0600
  permissions.

Compatibility

• Public API names, status values, and shared-memory layout remain compatible
  with the 1.0.0 production contract.