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 identifies and gives access to controlling the isolate, and the pauseCapability and terminateCapability guard access to some control operations. For example, calling pause on an Isolate object created without a pauseCapability, has no effect.

The Isolate object provided by a spawn operation will have the control port and capabilities needed to control the isolate. New isolate objects can be created without some of these capabilities if necessary, using the Isolate.Isolate constructor.

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.


Argument to ping and kill: Ask for immediate action.


Static Properties

current Isolate

Return an Isolate object representing the current isolate.

packageConfig Future<Uri>

Returns the package root of the current isolate, if any.

packageRoot Future<Uri>

Returns the package root of the current isolate, if any.


Static Methods

resolvePackageUri(Uri packageUri) Future<Uri>

Maps a package: URI to a non-package Uri.

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, Uri packageConfig, bool automaticPackageResolution: false }) 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.

pauseCapability Capability

Capability granting the ability to pause the isolate.

terminateCapability Capability

Capability granting the ability to terminate the isolate.

hashCode int

The hash code for this object.

read-only, inherited
runtimeType Type

A representation of the runtime type of the object.

read-only, inherited


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

Requests an exist message on responsePort when the isolate terminates.

kill({int priority: BEFORE_NEXT_EVENT }) → void

Requests the isolate to shut down.

pause([Capability resumeCapability ]) Capability

Requests the isolate to pause.

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

Requests that the isolate send response on the responsePort.

removeErrorListener(SendPort port) → void

Stops listening for uncaught errors from the isolate.

removeOnExitListener(SendPort responsePort) → void

Stops listening for exit messages from the isolate.

resume(Capability resumeCapability) → void

Resumes a paused isolate.

setErrorsFatal(bool errorsAreFatal) → void

Sets whether uncaught errors will terminate the isolate.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed.

toString() String

Returns a string representation of this object.