README.md

Module kotlinx-coroutines-core

Core primitives to work with coroutines.

Coroutine builder functions:

Name	Result	Scope	Description
launch	Job	CoroutineScope	Launches coroutine that does not have any result
async	Deferred	CoroutineScope	Returns a single value with the future result
produce	ReceiveChannel	ProducerScope	Produces a stream of elements
runBlocking	T	CoroutineScope	Blocks the thread while the coroutine runs

Coroutine dispatchers implementing CoroutineDispatcher:

Name	Description
Dispatchers.Default	Confines coroutine execution to a shared pool of background threads
Dispatchers.Unconfined	Does not confine coroutine execution in any way

More context elements:

Name	Description
NonCancellable	A non-cancelable job that is always active
CoroutineExceptionHandler	Handler for uncaught exception

Synchronization primitives for coroutines:

Name	Suspending functions	Description
Mutex	lock	Mutual exclusion
Channel	send, receive	Communication channel (aka queue or exchanger)

Top-level suspending functions:

Name	Description
delay	Non-blocking sleep
yield	Yields thread in single-threaded dispatchers
withContext	Switches to a different context
withTimeout	Set execution time-limit with exception on timeout
withTimeoutOrNull	Set execution time-limit will null result on timeout
awaitAll	Awaits for successful completion of all given jobs or exceptional completion of any
joinAll	Joins on all given jobs

Cancellation support for user-defined suspending functions is available with suspendCancellableCoroutine helper function. NonCancellable job object is provided to suppress cancellation with withContext(NonCancellable) {...} block of code.

Select expression waits for the result of multiple suspending functions simultaneously:

Receiver	Suspending function	Select clause	Non-suspending version
Job	join	onJoin	isCompleted
Deferred	await	onAwait	isCompleted
SendChannel	send	onSend	trySend
ReceiveChannel	receive	onReceive	tryReceive
ReceiveChannel	receiveCatching	onReceiveCatching	tryReceive
none	delay	onTimeout	none

Package kotlinx.coroutines

General-purpose coroutine builders, contexts, and helper functions.

Package kotlinx.coroutines.sync

Synchronization primitives (mutex).

Package kotlinx.coroutines.channels

Channels — non-blocking primitives for communicating a stream of elements between coroutines.

Package kotlinx.coroutines.flow

Flow — asynchronous cold stream of elements.

Package kotlinx.coroutines.selects

Select expression to perform multiple suspending operations simultaneously until one of them succeeds.

Package kotlinx.coroutines.intrinsics

Low-level primitives for finer-grained control of coroutines.

Package kotlinx.coroutines.test

Obsolete and deprecated module to test coroutines. Replaced with kotlinx-coroutines-test module.