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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// @dart = 2.12
part of dart.ui;
/// Static methods to allow for simple sharing of [SendPort]s across [Isolate]s.
/// All isolates share a global mapping of names to ports. An isolate can
/// register a [SendPort] with a given name using [registerPortWithName];
/// another isolate can then look up that port using [lookupPortByName].
/// To create a [SendPort], first create a [ReceivePort], then use
/// [ReceivePort.sendPort].
/// Since multiple isolates can each obtain the same [SendPort] associated with
/// a particular [ReceivePort], the protocol built on top of this mechanism
/// should typically consist of a single message. If more elaborate two-way
/// communication or multiple-message communication is necessary, it is
/// recommended to establish a separate communication channel in that first
/// message (e.g. by passing a dedicated [SendPort]).
class IsolateNameServer {
// This class is only a namespace, and should not be instantiated or
// extended directly.
factory IsolateNameServer._() => throw UnsupportedError('Namespace');
/// Looks up the [SendPort] associated with a given name.
/// Returns null if the name does not exist. To register the name in the first
/// place, consider [registerPortWithName].
/// The `name` argument must not be null.
static SendPort? lookupPortByName(String name) {
assert(name != null, "'name' cannot be null.");
return _lookupPortByName(name);
/// Registers a [SendPort] with a given name.
/// Returns true if registration is successful, and false if the name entry
/// already existed (in which case the earlier registration is left
/// unchanged). To remove a registration, consider [removePortNameMapping].
/// Once a port has been registered with a name, it can be obtained from any
/// [Isolate] using [lookupPortByName].
/// Multiple isolates should avoid attempting to register ports with the same
/// name, as there is an inherent race condition in doing so.
/// The `port` and `name` arguments must not be null.
static bool registerPortWithName(SendPort port, String name) {
assert(port != null, "'port' cannot be null.");
assert(name != null, "'name' cannot be null.");
return _registerPortWithName(port, name);
/// Removes a name-to-[SendPort] mapping given its name.
/// Returns true if the mapping was successfully removed, false if the mapping
/// did not exist. To add a registration, consider [registerPortWithName].
/// Generally, removing a port name mapping is an inherently racy operation
/// (another isolate could have obtained the name just prior to the name being
/// removed, and thus would still be able to communicate over the port even
/// after it has been removed).
/// The `name` argument must not be null.
static bool removePortNameMapping(String name) {
assert(name != null, "'name' cannot be null.");
return _removePortNameMapping(name);
static SendPort? _lookupPortByName(String name)
native 'IsolateNameServerNatives_LookupPortByName';
static bool _registerPortWithName(SendPort port, String name)
native 'IsolateNameServerNatives_RegisterPortWithName';
static bool _removePortNameMapping(String name)
native 'IsolateNameServerNatives_RemovePortNameMapping';