# Changelog for [`stm` package](http://hackage.haskell.org/package/stm) ## 2.5.1.0 *Aug 2022* * Teach `flushTBQueue` to only flush queue when necessary * Introduce `Control.Concurrent.STM.TMVar.writeTMVar` * Add `Semigroup` and `Monoid` instances for `STM` ## 2.5.0.2 *Dec 2021* * Fix non-exhaustive patterns warning (#49) * Document particulars of effect-rollback of `Control.Monad.STM.throwSTM` (#32) ## 2.5.0.1 *May 2020* * Optimise implementation of `peekTQueue` and `peekTBQueue` to reduce probability of transaction conflicts. ## 2.5.0.0 *Sep 2018* * Removed `alwaysSucceeds` and `always`, GHC's invariant checking primitives. (GHC #14324) * Add `lengthTBQueue` to `Control.Concurrent.STM.TBQueue` (gh-9) * Add `stateTVar :: TVar s -> (s -> (a, s)) -> STM a` combinator (gh-14) * Switched `newTBQueue` and `newTBQueueIO` to accept `Natural` as size (gh-17) * Switched `signalTSemN` and `newTSem` to accept `Natural` and `Integer` respectively (gh-17) ---- #### 2.4.5.1 *Sep 2018* * Fix incorrect bookkeeping of write capacity in `flushTBQueue` (gh-9) * Avoid redundant `writeTVar`s in `flushTQueue` to avoid unnecessarily invalidating other transactions (gh-6) ### 2.4.5.0 *Feb 2018* * Fix space leak in `TBQueue` (gh-2, GHC#14494) * Make `signalTSem` resilient against `Int` overflows (gh-4) * Make definition of `readTQueue` consistent with `readTBQueue` (gh-3, GHC#9539) * Add `flushTQueue` to `Control.Concurrent.STM.TQueue` (gh-1) * Add `flushTBQueue` to `Control.Concurrent.STM.TBQueue` (gh-1) * Add `signalTSemN` operation (gh-5) #### 2.4.4.1 *Dec 2015* * Add support for `base-4.9.0.0` * Drop support for GHC 6.12 / `base-4.2` ### 2.4.4 *Dec 2014* * Add support for `base-4.8.0.0` * Tighten Safe Haskell bounds * Add `mkWeakTMVar` to `Control.Concurrent.STM.TMVar` * Add `@since`-annotations ### 2.4.3 *Mar 2014* * Update behaviour of `newBroadcastTChanIO` to match `newBroadcastTChan` in causing an error on a read from the broadcast channel * Add `mkWeakTVar` * Add `isFullTBQueue` * Fix `TChan` created via `newBroadcastTChanIO` to throw same exception on a `readTChan` as when created via `newBroadcastTChan` * Update to Cabal 1.10 format ### 2.4.2 *Nov 2012* * Add `Control.Concurrent.STM.TSem` (transactional semaphore) * Add Applicative/Alternative instances of STM for GHC <7.0 * Throw proper exception when `readTChan` called on a broadcast `TChan` ## 2.4 *Jul 2012* * Add `Control.Concurrent.STM.TQueue` (a faster `TChan`) * Add `Control.Concurrent.STM.TBQueue` (a bounded channel based on `TQueue`) * Add `Eq` instance for `TChan` * Add `newBroadcastTChan` and `newBroadcastTChanIO` * Some performance improvements for `TChan` * Add `cloneTChan`