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b3432a63 JB |
1 | import { cpus } from 'os' |
2 | import type { AbstractPoolWorker } from '../abstract-pool-worker' | |
3 | import type { IPoolInternal } from '../pool-internal' | |
4 | import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy' | |
10fcfaf4 | 5 | import type { RequiredStatistics } from './selection-strategies-types' |
b3432a63 JB |
6 | |
7 | /** | |
8 | * Task run time. | |
9 | */ | |
10 | type TaskRunTime = { | |
11 | weight: number | |
12 | runTime: number | |
13 | } | |
14 | ||
15 | /** | |
16 | * Selects the next worker with a weighted round robin scheduling algorithm. | |
17 | * Loosely modeled after the weighted round robin queueing algorithm: https://en.wikipedia.org/wiki/Weighted_round_robin. | |
18 | * | |
19 | * @template Worker Type of worker which manages the strategy. | |
20 | * @template Data Type of data sent to the worker. This can only be serializable data. | |
21 | * @template Response Type of response of execution. This can only be serializable data. | |
22 | */ | |
23 | export class WeightedRoundRobinWorkerChoiceStrategy< | |
24 | Worker extends AbstractPoolWorker, | |
25 | Data, | |
26 | Response | |
27 | > extends AbstractWorkerChoiceStrategy<Worker, Data, Response> { | |
10fcfaf4 JB |
28 | /** @inheritDoc */ |
29 | public requiredStatistics: RequiredStatistics = { | |
30 | runTime: true | |
31 | } | |
32 | ||
b3432a63 JB |
33 | /** |
34 | * Worker index where the previous task was submitted. | |
35 | */ | |
36 | private previousWorkerIndex: number = 0 | |
37 | /** | |
38 | * Worker index where the current task will be submitted. | |
39 | */ | |
40 | private currentWorkerIndex: number = 0 | |
41 | /** | |
42 | * Default worker weight. | |
43 | */ | |
44 | private defaultWorkerWeight: number | |
45 | /** | |
46 | * Per worker task runtime map. | |
47 | */ | |
48 | private workerTaskRunTime: Map<Worker, TaskRunTime> = new Map< | |
49 | Worker, | |
50 | TaskRunTime | |
51 | >() | |
52 | ||
53 | /** | |
23ff945a | 54 | * Constructs a worker choice strategy that selects with a weighted round robin scheduling algorithm. |
b3432a63 JB |
55 | * |
56 | * @param pool The pool instance. | |
57 | */ | |
58 | public constructor (pool: IPoolInternal<Worker, Data, Response>) { | |
59 | super(pool) | |
60 | this.defaultWorkerWeight = this.computeWorkerWeight() | |
61 | this.initWorkerTaskRunTime() | |
62 | } | |
63 | ||
64 | /** @inheritDoc */ | |
65 | public choose (): Worker { | |
66 | const currentWorker = this.pool.workers[this.currentWorkerIndex] | |
67 | if (this.isDynamicPool === true) { | |
68 | this.workerTaskRunTime.has(currentWorker) === false && | |
69 | this.workerTaskRunTime.set(currentWorker, { | |
70 | weight: this.defaultWorkerWeight, | |
71 | runTime: 0 | |
72 | }) | |
73 | } | |
74 | const workerVirtualTaskRunTime = | |
75 | this.getWorkerVirtualTaskRunTime(currentWorker) ?? 0 | |
76 | const workerTaskWeight = | |
77 | this.workerTaskRunTime.get(currentWorker)?.weight ?? | |
78 | this.defaultWorkerWeight | |
79 | if (this.currentWorkerIndex === this.previousWorkerIndex) { | |
80 | const workerTaskRunTime = | |
81 | (this.workerTaskRunTime.get(currentWorker)?.runTime ?? 0) + | |
82 | workerVirtualTaskRunTime | |
83 | this.workerTaskRunTime.set(currentWorker, { | |
84 | weight: workerTaskWeight, | |
85 | runTime: workerTaskRunTime | |
86 | }) | |
87 | } else { | |
88 | this.workerTaskRunTime.set(currentWorker, { | |
89 | weight: workerTaskWeight, | |
90 | runTime: 0 | |
91 | }) | |
92 | } | |
93 | if ( | |
94 | workerVirtualTaskRunTime < | |
95 | (this.workerTaskRunTime.get(currentWorker) ?? this.defaultWorkerWeight) | |
96 | ) { | |
97 | this.previousWorkerIndex = this.currentWorkerIndex | |
98 | } else { | |
99 | this.previousWorkerIndex = this.currentWorkerIndex | |
100 | this.currentWorkerIndex = | |
101 | this.pool.workers.length - 1 === this.currentWorkerIndex | |
102 | ? 0 | |
103 | : this.currentWorkerIndex + 1 | |
104 | } | |
105 | return this.pool.workers[this.currentWorkerIndex] | |
106 | } | |
107 | ||
108 | private computeWorkerWeight () { | |
109 | let cpusCycleTimeWeight = 0 | |
a59e741b | 110 | for (const cpu of cpus()) { |
b3432a63 | 111 | // CPU estimated cycle time |
a59e741b JB |
112 | const numberOfDigit = cpu.speed.toString().length - 1 |
113 | const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigit)) | |
b3432a63 JB |
114 | cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigit) |
115 | } | |
116 | return cpusCycleTimeWeight / cpus().length | |
117 | } | |
118 | ||
119 | private initWorkerTaskRunTime () { | |
120 | for (const worker of this.pool.workers) { | |
121 | this.workerTaskRunTime.set(worker, { | |
122 | weight: this.defaultWorkerWeight, | |
123 | runTime: 0 | |
124 | }) | |
125 | } | |
126 | } | |
127 | ||
128 | private getWorkerVirtualTaskRunTime (worker: Worker): number | undefined { | |
129 | return this.pool.getWorkerAverageTasksRunTime(worker) | |
130 | } | |
131 | } |