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1 // Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file |
2 // for details. All rights reserved. Use of this source code is governed by a | 2 // for details. All rights reserved. Use of this source code is governed by a |
3 // BSD-style license that can be found in the LICENSE file. | 3 // BSD-style license that can be found in the LICENSE file. |
4 | 4 |
5 library dart.pkg.isolate.sample.runners; | 5 library dart.pkg.isolate.sample.runners; |
6 | 6 |
7 import "package:isolate/loadbalancer.dart"; | 7 import "package:isolate/loadbalancer.dart"; |
8 import "package:isolate/isolaterunner.dart"; | 8 import "package:isolate/isolaterunner.dart"; |
9 import "dart:async" show Future, Completer; | 9 import "dart:async" show Future, Completer; |
10 | 10 |
11 | |
12 void main() { | 11 void main() { |
13 int N = 44; | 12 int N = 44; |
14 var sw = new Stopwatch()..start(); | 13 var sw = new Stopwatch()..start(); |
15 // Compute fib up to 42 with 4 isolates. | 14 // Compute fib up to 42 with 4 isolates. |
16 parfib(N, 4).then((v1) { | 15 parfib(N, 4).then((v1) { |
17 var t1 = sw.elapsedMilliseconds; | 16 var t1 = sw.elapsedMilliseconds; |
18 sw.stop(); | 17 sw.stop(); |
19 sw.reset(); | 18 sw.reset(); |
20 print("fib#4(${N}) = ${v1[N]}, ms: $t1"); | 19 print("fib#4(${N}) = ${v1[N]}, ms: $t1"); |
21 sw.start(); | 20 sw.start(); |
22 // Then compute fib up to 42 with 2 isolates. | 21 // Then compute fib up to 42 with 2 isolates. |
23 parfib(N, 2).then((v2) { | 22 parfib(N, 2).then((v2) { |
24 var t2 = sw.elapsedMilliseconds; | 23 var t2 = sw.elapsedMilliseconds; |
25 sw.stop(); | 24 sw.stop(); |
26 print("fib#2(${N}) = ${v2[N]}, ms: $t2"); | 25 print("fib#2(${N}) = ${v2[N]}, ms: $t2"); |
27 }); | 26 }); |
28 }); | 27 }); |
29 } | 28 } |
30 | 29 |
31 // Compute fibonnacci 1..limit | 30 // Compute fibonnacci 1..limit |
32 Future<List<int>> parfib(int limit, int parallelity) { | 31 Future<List<int>> parfib(int limit, int parallelity) { |
33 return LoadBalancer.create(parallelity, IsolateRunner.spawn).then( | 32 return LoadBalancer |
34 (LoadBalancer pool) { | 33 .create(parallelity, IsolateRunner.spawn) |
35 List<Future> fibs = new List(limit + 1); | 34 .then((LoadBalancer pool) { |
36 // Schedule all calls with exact load value and the heaviest task | 35 List<Future> fibs = new List(limit + 1); |
Lasse Reichstein Nielsen
2015/02/26 10:59:13
I really dislike having the body indented less tha
| |
37 // assigned first. | 36 // Schedule all calls with exact load value and the heaviest task |
38 schedule(a, b, i) { | 37 // assigned first. |
39 if (i < limit) { | 38 schedule(a, b, i) { |
40 schedule(a + b, a, i + 1); | 39 if (i < limit) { |
41 } | 40 schedule(a + b, a, i + 1); |
42 fibs[i] = pool.run(fib, i, load: a); | |
43 } | 41 } |
44 schedule(0, 1, 0); | 42 fibs[i] = pool.run(fib, i, load: a); |
45 // And wait for them all to complete. | 43 } |
46 return Future.wait(fibs).whenComplete(pool.close); | 44 schedule(0, 1, 0); |
47 }); | 45 // And wait for them all to complete. |
46 return Future.wait(fibs).whenComplete(pool.close); | |
47 }); | |
48 } | 48 } |
49 | 49 |
50 int computeFib(n) { | 50 int computeFib(n) { |
51 int result = fib(n); | 51 int result = fib(n); |
52 return result; | 52 return result; |
53 } | 53 } |
54 | 54 |
55 int fib(n) { | 55 int fib(n) { |
56 if (n < 2) return n; | 56 if (n < 2) return n; |
57 return fib(n - 1) + fib(n - 2); | 57 return fib(n - 1) + fib(n - 2); |
58 } | 58 } |
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