blob: f114bb1904621796f211e8fe124d05272c978bbf [file] [log] [blame]
// Copyright 2014 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.
import 'dart:async';
import 'dart:developer';
import 'dart:isolate';
import 'package:meta/meta.dart';
import 'constants.dart';
import 'isolates.dart' as isolates;
/// The dart:io implementation of [isolate.compute].
Future<R> compute<Q, R>(isolates.ComputeCallback<Q, R> callback, Q message, { String debugLabel }) async {
debugLabel ??= kReleaseMode ? 'compute' : callback.toString();
final Flow flow = Flow.begin();
Timeline.startSync('$debugLabel: start', flow: flow);
final ReceivePort resultPort = ReceivePort();
final ReceivePort errorPort = ReceivePort();
Timeline.finishSync();
final Isolate isolate = await Isolate.spawn<_IsolateConfiguration<Q, FutureOr<R>>>(
_spawn,
_IsolateConfiguration<Q, FutureOr<R>>(
callback,
message,
resultPort.sendPort,
debugLabel,
flow.id,
),
errorsAreFatal: true,
onExit: resultPort.sendPort,
onError: errorPort.sendPort,
);
final Completer<R> result = Completer<R>();
errorPort.listen((dynamic errorData) {
assert(errorData is List<dynamic>);
assert(errorData.length == 2);
final Exception exception = Exception(errorData[0]);
final StackTrace stack = StackTrace.fromString(errorData[1] as String);
if (result.isCompleted) {
Zone.current.handleUncaughtError(exception, stack);
} else {
result.completeError(exception, stack);
}
});
resultPort.listen((dynamic resultData) {
assert(resultData == null || resultData is R);
if (!result.isCompleted)
result.complete(resultData as R);
});
await result.future;
Timeline.startSync('$debugLabel: end', flow: Flow.end(flow.id));
resultPort.close();
errorPort.close();
isolate.kill();
Timeline.finishSync();
return result.future;
}
@immutable
class _IsolateConfiguration<Q, R> {
const _IsolateConfiguration(
this.callback,
this.message,
this.resultPort,
this.debugLabel,
this.flowId,
);
final isolates.ComputeCallback<Q, R> callback;
final Q message;
final SendPort resultPort;
final String debugLabel;
final int flowId;
FutureOr<R> apply() => callback(message);
}
Future<void> _spawn<Q, R>(_IsolateConfiguration<Q, FutureOr<R>> configuration) async {
R result;
await Timeline.timeSync(
configuration.debugLabel,
() async {
final FutureOr<R> applicationResult = await configuration.apply();
result = await applicationResult;
},
flow: Flow.step(configuration.flowId),
);
Timeline.timeSync(
'${configuration.debugLabel}: returning result',
() { configuration.resultPort.send(result); },
flow: Flow.step(configuration.flowId),
);
}