v1.5.1

==================
This release contains an important Native targets overhaul, as well as numerous enhancements and bugfixes.
Kotlin 1.8.21 is used by default.

New set of Native targets

The official Kotlin target support policy has recently been published
describing new target policy: each target belongs to a certain tier, and different tiers have different stability guarantees.
The official recommendation for library authors is to support targets up to Tier 3,
and kotlinx.serialization now follows it.
It means that in this release, there are a lot of new targets added from this tier,
such as androidNativeX86 or watchosDeviceArm64.
Note that since they belong to Tier 3, they're not auto-tested on CI.

kotlinx.serialization also ships some deprecated Kotlin/Native targets that do not belong to any tier (e.g. iosArm32, mingwX86).
We'll continue to release them, but we do not provide support for them, nor do we plan to add new targets from the deprecated list.

Improvements in Json elements

There are two new function sets that should make creating raw Json elements easier.
First one contains overloads for JsonPrimitive constructor-like function
that accept unsigned types: JsonPrimitive(1u).
Second one adds new addAll functions to JsonArrayBuilder to be used with collections
of numbers, booleans or strings: buildJsonArray { addAll(listOf(1, 2, 3)) }
Both were contributed to us by aSemy.

Other enhancements

• Potential source-breaking change: Rename json-okio target variables to sink (#​2226)
• Function to retrieve KSerializer by KClass and type arguments serializers (#​2291)
• Added FormatLanguage annotation to Json methods (#​2234)
• Properties Format: Support sealed/polymorphic classes as class properties (#​2255)

Bugfixes

• KeyValueSerializer: Fix missing call to endStructure() (#​2272)
• ObjectSerializer: Respect sequential decoding (#​2273)
• Fix value class encoding in various corner cases (#​2242)
• Fix incorrect json decoding iterator's .hasNext() behavior on array-wrapped inputs (#​2268)
• Fix memory leak caused by invalid KTypeWrapper's equals method (#​2274)
• Fixed NoSuchMethodError when parsing a JSON stream on Java 8 (#​2219)
• Fix MissingFieldException duplication (#​2213)

v1.7.1

Compare Source

Bug fixes and improvements

• Special characters in coroutine names in JSON dumps are supported (#​3747)
• The binary compatibility of the experimental overload of runTest is restored (#​3673)
• Channels that don't use onUndeliveredElement now allocate less memory (#​3646)

v1.7.0

Compare Source

Core API significant improvements

• New Channel implementation with significant performance improvements across the API (#​3621).
• New select operator implementation: faster, more lightweight, and more robust (#​3020).
• Mutex and Semaphore now share the same underlying data structure (#​3020).
• Dispatchers.IO is added to K/N (#​3205)
  • newFixedThreadPool and Dispatchers.Default implementations on K/N were wholly rewritten to support graceful growth under load (#​3595).
• kotlinx-coroutines-test rework:
  • Add the timeout parameter to runTest for the whole-test timeout, 10 seconds by default (#​3270). This replaces the configuration of quiescence timeouts, which is now deprecated (#​3603).
  • The withTimeout exception messages indicate if the timeout used the virtual time (#​3588).
  • TestCoroutineScheduler, runTest, and TestScope API are promoted to stable (#​3622).
  • runTest now also fails if there were uncaught exceptions in coroutines not inherited from the test coroutine (#​1205).

Breaking changes

• Old K/N memory model is no longer supported (#​3375).
• New generic upper bounds were added to reactive integration API where the language since 1.8.0 dictates (#​3393).
• kotlinx-coroutines-core and kotlinx-coroutines-jdk8 artifacts were merged into a single artifact (#​3268).
• Artificial stackframes in stacktrace recovery no longer contain the \b symbol and are now navigable in IDE and supplied with proper documentation (#​2291).
• CoroutineContext.isActive returns true for contexts without any job in them (#​3300).

Bug fixes and improvements

• Kotlin version is updated to 1.8.20
• Atomicfu version is updated to 0.20.2.
• JavaFx version is updated to 17.0.2 in kotlinx-coroutines-javafx (#​3671)..
• JPMS is supported (#​2237). Thanks @​lion7!
• BroadcastChannel and all the corresponding API are deprecated (#​2680).
• Added all supported K/N targets (#​3601, #​812, #​855).
• K/N Dispatchers.Default is backed by the number of threads equal to the number of available cores (#​3366).
• Fixed an issue where some coroutines' internal exceptions were not properly serializable (#​3328).
• Introduced Job.parent API (#​3201).
• Fixed a bug when TestScheduler leaked cancelled jobs (#​3398).
• TestScope.timeSource now provides comparable time marks (#​3617). Thanks @​hfhbd!
• Fixed an issue when cancelled withTimeout handles were preserved in JS runtime (#​3440).
• Ensure awaitFrame only awaits a single frame when used from the main looper (#​3432). Thanks @​pablobaxter!
• Obsolete Class-Path attribute was removed from kotlinx-coroutines-debug.jar manifest (#​3361).
• Fixed a bug when updateThreadContext operated on the parent context (#​3411).
• Added new Flow.filterIsInstance extension (#​3240).
• Dispatchers.Default thread name prefixes are now configurable with system property (#​3231).
• Added Flow.timeout operator as @FlowPreview (#​2624). Thanks @​pablobaxter!
• Improved the performance of the future builder in case of exceptions (#​3475). Thanks @​He-Pin!
• Mono.awaitSingleOrNull now waits for the onComplete signal (#​3487).
• Channel.isClosedForSend and Channel.isClosedForReceive are promoted from experimental to delicate (#​3448).
• Fixed a data race in native EventLoop (#​3547).
• Dispatchers.IO.limitedParallelism(valueLargerThanIOSize) no longer creates an additional wrapper (#​3442). Thanks @​dovchinnikov!
• Various @FlowPreview and @ExperimentalCoroutinesApi are promoted to experimental and stable respectively (#​3542, #​3097, #​3548).
• Performance improvements in Dispatchers.Default and Dispatchers.IO (#​3416, #​3418).
• Fixed a bug when internal suspendCancellableCoroutineReusable might have hanged (#​3613).
• Introduced internal API to process events in the current system dispatcher (#​3439).
• Global CoroutineExceptionHandler is no longer invoked in case of unprocessed future failure (#​3452).
• Performance improvements and reduced thread-local pressure for the withContext operator (#​3592).
• Improved performance of DebugProbes (#​3527).
• Fixed a bug when the coroutine debugger might have detected the state of a coroutine incorrectly (#​3193).
• CoroutineDispatcher.asExecutor() runs tasks without dispatching if the dispatcher is unconfined (#​3683). Thanks @​odedniv!
• SharedFlow.toMutableList and SharedFlow.toSet lints are introduced (#​3706).
• Channel.invokeOnClose is promoted to stable API (#​3358).
• Improved lock contention in Dispatchers.Default and Dispatchers.IO during the startup phase (#​3652).
• Fixed a bug that led to threads oversubscription in Dispatchers.Default (#​3642).
• Fixed a bug that allowed limitedParallelism to perform dispatches even after the underlying dispatcher was closed (#​3672).
• Fixed a bug that prevented stacktrace recovery when the exception's constructor from cause was selected (#​3714).
• Improved sanitizing of stracktrace-recovered traces (#​3714).
• Introduced an internal flag to disable uncaught exceptions reporting in tests as a temporary migration mechanism (#​3736).
• Various documentation improvements and fixes.

Changelog for previous versions may be found in CHANGES_UP_TO_1.7.md