An isolated Dart execution context.

All Dart code runs in an isolate, and code can access classes and values only from the same isolate. Different isolates can communicate by sending values through ports (see ReceivePort, SendPort).

An Isolate object is a reference to an isolate, usually different from the current isolate. It represents, and can be used control, the other isolate.

When spawning a new isolate, the spawning isolate receives an Isolate object representing the new isolate when the spawn operation succeeds.

Isolates run code in its own event loop, and each event may run smaller tasks in a nested microtask queue.

An Isolate object allows other isolates to control the event loop of the isolate that it represents, and to inspect the isolate, for example by pausing the isolate or by getting events when the isolate has an uncaught error.

The controlPort gives access to controlling the isolate, and the pauseCapability and terminateCapability guard access to some control operations. The Isolate object provided by a spawn operation will have the control port and capabilities needed to control the isolate. New isolates objects can be created without some of these capabilities if necessary.

An Isolate object cannot be sent over a SendPort, but the control port and capabilities can be sent, and can be used to create a new functioning Isolate object in the receiving port's isolate.



Argument to ping and kill: Ask for action before the next event.

const 1

Argument to ping and kill: Ask for immediate action.

const 0

Static Properties

current Isolate

Return the current Isolate.


Static Methods

spawn(void entryPoint(message), message, {bool paused: false, bool errorsAreFatal, SendPort onExit, SendPort onError}) Future<Isolate>

Creates and spawns an isolate that shares the same code as the current isolate.

spawnUri(Uri uri, List<String> args, message, {bool paused: false, SendPort onExit, SendPort onError, bool errorsAreFatal, bool checked, Map<String, String> environment, Uri packageRoot}) Future<Isolate>

Creates and spawns an isolate that runs the code from the library with the specified URI.


Isolate(SendPort controlPort, {Capability pauseCapability, Capability terminateCapability})

Create a new Isolate object with a restricted set of capabilities.


controlPort SendPort

Control port used to send control messages to the isolate.

errors Stream

Returns a broadcast stream of uncaught errors from the isolate.

hashCode int

Get a hash code for this object.

read-only, inherited
pauseCapability Capability

Capability granting the ability to pause the isolate.

runtimeType Type

A representation of the runtime type of the object.

read-only, inherited
terminateCapability Capability

Capability granting the ability to terminate the isolate.



operator ==(other) bool

The equality operator.



addErrorListener(SendPort port) → void

Requests that uncaught errors of the isolate are sent back to port.

addOnExitListener(SendPort responsePort, {Object response}) → void

Asks the isolate to send response on responsePort when it terminates.

kill({int priority: BEFORE_NEXT_EVENT}) → void

Requests the isolate to shut down.

noSuchMethod(Invocation invocation) → dynamic

noSuchMethod is invoked when users invoke a non-existent method on an object. The name of the method and the arguments of the invocation are passed to noSuchMethod in an Invocation. If noSuchMethod returns a value, that value becomes the result of the original invocation.

pause([Capability resumeCapability]) Capability

Requests the isolate to pause.

ping(SendPort responsePort, {Object response, int priority: IMMEDIATE}) → void

Request that the isolate send response on the responsePort.

removeErrorListener(SendPort port) → void

Stop listening for uncaught errors through port.

removeOnExitListener(SendPort responsePort) → void

Stop listening on exit messages from the isolate.

resume(Capability resumeCapability) → void

Resumes a paused isolate.

setErrorsFatal(bool errorsAreFatal) → void

Set whether uncaught errors will terminate the isolate.

toString() String

Returns a string representation of this object.