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