# libmultiprocess Versions
Library versions are tracked with simple
[tags](https://github.com/bitcoin-core/libmultiprocess/tags) and
[branches](https://github.com/bitcoin-core/libmultiprocess/branches).
Versioning policy is described in the [version.h](../include/mp/version.h)
include.
## v10
- Current unstable version.
## [v9.0](https://github.com/bitcoin-core/libmultiprocess/commits/v9.0)
- Fixes race conditions where worker thread could be used after destruction, where getParams() could be called after request cancel, and where m_on_cancel could be called after request finishes.
- Adds `CustomHasField` hook to map Cap'n Proto null values to C++ null values.
- Improves `CustomBuildField` for `std::optional` to use move semantics.
- Adds LLVM 22 compatibility fix in type-map.
- Used in Bitcoin Core master branch, pulled in by [#34804](https://github.com/bitcoin/bitcoin/pull/34804). Also pulled into Bitcoin Core 31.x stable branch by [#34952](https://github.com/bitcoin/bitcoin/pull/34952).
## [v8.0](https://github.com/bitcoin-core/libmultiprocess/commits/v8.0)
- Better support for non-libmultiprocess IPC clients: avoiding errors on unclean disconnects, and allowing simultaneous requests to worker threads which previously triggered "thread busy" errors.
- Intermediate version used in Bitcoin Core master branch between 30.x and 31.x branches, pulled in by [#34422](https://github.com/bitcoin/bitcoin/pull/34422).
## [v7.0](https://github.com/bitcoin-core/libmultiprocess/commits/v7.0)
- Adds SpawnProcess race fix, cmake `target_capnp_sources` option, ci and documentation improvements. Adds `version.h` header declaring major and minor version numbers.
- Intermediate version used in Bitcoin Core master branch between 30.x and 31.x branches, pulled in by [#34363](https://github.com/bitcoin/bitcoin/pull/34363).
## [v7.0-pre2](https://github.com/bitcoin-core/libmultiprocess/commits/v7.0-pre2)
- Fixes intermittent mptest hang and makes other minor improvements.
- Used in Bitcoin Core 30.1 and 30.2 releases and 30.x branch, pulled in by [#33518](https://github.com/bitcoin/bitcoin/pull/33518) and [#33519](https://github.com/bitcoin/bitcoin/pull/33519).
## [v7.0-pre1](https://github.com/bitcoin-core/libmultiprocess/commits/v7.0-pre1)
- Adds support for log levels to reduce logging and "thread busy" error to avoid a crash on misuse.
- Minimum required version since Bitcoin Core 30.1, pulled in by [#33412](https://github.com/bitcoin/bitcoin/pull/33412), [#33518](https://github.com/bitcoin/bitcoin/pull/33518), and [#33519](https://github.com/bitcoin/bitcoin/pull/33519).
## [v6.0](https://github.com/bitcoin-core/libmultiprocess/commits/v6.0)
- Adds CI scripts and build and test fixes.
- Used in Bitcoin Core 30.0 release, pulled in by [#32345](https://github.com/bitcoin/bitcoin/pull/32345), [#33241](https://github.com/bitcoin/bitcoin/pull/33241), and [#33322](https://github.com/bitcoin/bitcoin/pull/33322).
## [v6.0-pre1](https://github.com/bitcoin-core/libmultiprocess/commits/v6.0-pre1)
- Adds fixes for unclean shutdowns and thread sanitizer issues.
- Drops `EventLoop::addClient` and `EventLoop::removeClient` methods,
requiring clients to use new `EventLoopRef` class instead.
- Minimum required version for Bitcoin Core 30.0 release, pulled in by [#31741](https://github.com/bitcoin/bitcoin/pull/31741), [#32641](https://github.com/bitcoin/bitcoin/pull/32641), and [#32345](https://github.com/bitcoin/bitcoin/pull/32345).
## [v5.0](https://github.com/bitcoin-core/libmultiprocess/commits/v5.0)
- Adds build improvements and tidy/warning fixes.
- Used in Bitcoin Core 29 releases, pulled in by [#31945](https://github.com/bitcoin/bitcoin/pull/31945).
## [v5.0-pre1](https://github.com/bitcoin-core/libmultiprocess/commits/v5.0-pre1)
- Adds many improvements to Bitcoin Core mining interface: splitting up type headers, fixing shutdown bugs, adding subtree build support.
- Broke up `proxy-types.h` into `type-*.h` files requiring clients to explicitly
include overloads needed for C++ ↔️ Cap'n Proto type conversions.
- Now requires C++ 20 support.
- Minimum required version for Bitcoin Core 29 releases, pulled in by [#30509](https://github.com/bitcoin/bitcoin/pull/30509), [#30510](https://github.com/bitcoin/bitcoin/pull/30510), [#31105](https://github.com/bitcoin/bitcoin/pull/31105), [#31740](https://github.com/bitcoin/bitcoin/pull/31740).
## [v4.0](https://github.com/bitcoin-core/libmultiprocess/commits/v4.0)
- Added better cmake support, installing cmake package files so clients do not
need to use pkgconfig.
- Used in Bitcoin Core 28 releases, pulled in by [#30490](https://github.com/bitcoin/bitcoin/pull/30490) and [#30513](https://github.com/bitcoin/bitcoin/pull/30513).
## [v3.0](https://github.com/bitcoin-core/libmultiprocess/commits/v3.0)
- Dropped compatibility with Cap'n Proto versions before 0.7.
- Used in Bitcoin Core 27 releases, pulled in by [#28735](https://github.com/bitcoin/bitcoin/pull/28735), [#28907](https://github.com/bitcoin/bitcoin/pull/28907), and [#29276](https://github.com/bitcoin/bitcoin/pull/29276).
## [v2.0](https://github.com/bitcoin-core/libmultiprocess/commits/v2.0)
- Changed `PassField` function signature.
- Now requires C++17 support.
- Used in Bitcoin Core 25 and 26 releases, pulled in by [#26672](https://github.com/bitcoin/bitcoin/pull/26672).
## [v1.0](https://github.com/bitcoin-core/libmultiprocess/commits/v1.0)
- Dropped hardcoded includes in generated files, now requiring `include` and
`includeTypes` annotations.
- Used in Bitcoin Core 22, 23, and 24 releases, pulled in by [#19160](https://github.com/bitcoin/bitcoin/pull/19160).
## [v0.0](https://github.com/bitcoin-core/libmultiprocess/commits/v0.0)
- Initial version used in a downstream release.
- Used in Bitcoin Core 21 releases, pulled in by [#16367](https://github.com/bitcoin/bitcoin/pull/16367), [#18588](https://github.com/bitcoin/bitcoin/pull/18588), and [#18677](https://github.com/bitcoin/bitcoin/pull/18677).