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 import type { RequiredStatistics
} from
'./selection-strategies-types'
8 * Virtual task runtime.
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.
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.
23 export class WeightedRoundRobinWorkerChoiceStrategy
<
24 Worker
extends AbstractPoolWorker
,
27 > extends AbstractWorkerChoiceStrategy
<Worker
, Data
, Response
> {
29 public requiredStatistics
: RequiredStatistics
= {
34 * Worker index where the previous task was submitted.
36 private previousWorkerIndex
: number = 0
38 * Worker index where the current task will be submitted.
40 private currentWorkerIndex
: number = 0
42 * Default worker weight.
44 private defaultWorkerWeight
: number
46 * Per worker virtual task runtime map.
48 private workersTaskRunTime
: Map
<Worker
, TaskRunTime
> = new Map
<
54 * Constructs a worker choice strategy that selects with a weighted round robin scheduling algorithm.
56 * @param pool The pool instance.
58 public constructor (pool
: IPoolInternal
<Worker
, Data
, Response
>) {
60 this.defaultWorkerWeight
= this.computeWorkerWeight()
61 this.initWorkersTaskRunTime()
65 public choose (): Worker
{
66 const currentWorker
= this.pool
.workers
[this.currentWorkerIndex
]
68 this.isDynamicPool
=== true &&
69 this.workersTaskRunTime
.has(currentWorker
) === false
71 this.initWorkerTaskRunTime(currentWorker
)
73 const workerVirtualTaskRunTime
=
74 this.getWorkerVirtualTaskRunTime(currentWorker
) ?? 0
75 const workerTaskWeight
=
76 this.workersTaskRunTime
.get(currentWorker
)?.weight
??
77 this.defaultWorkerWeight
78 if (this.currentWorkerIndex
=== this.previousWorkerIndex
) {
79 const workerTaskRunTime
=
80 (this.workersTaskRunTime
.get(currentWorker
)?.runTime
?? 0) +
81 workerVirtualTaskRunTime
82 this.setWorkerTaskRunTime(
88 this.setWorkerTaskRunTime(currentWorker
, workerTaskWeight
, 0)
91 workerVirtualTaskRunTime
<
92 (this.workersTaskRunTime
.get(currentWorker
)?.weight
??
93 this.defaultWorkerWeight
)
95 this.previousWorkerIndex
= this.currentWorkerIndex
97 this.previousWorkerIndex
= this.currentWorkerIndex
98 this.currentWorkerIndex
=
99 this.pool
.workers
.length
- 1 === this.currentWorkerIndex
101 : this.currentWorkerIndex
+ 1
103 return this.pool
.workers
[this.currentWorkerIndex
]
106 private initWorkersTaskRunTime (): void {
107 for (const worker
of this.pool
.workers
) {
108 this.initWorkerTaskRunTime(worker
)
112 private initWorkerTaskRunTime (worker
: Worker
): void {
113 this.setWorkerTaskRunTime(worker
, this.defaultWorkerWeight
, 0)
116 private setWorkerTaskRunTime (
121 this.workersTaskRunTime
.set(worker
, {
127 private getWorkerVirtualTaskRunTime (worker
: Worker
): number | undefined {
128 return this.pool
.getWorkerAverageTasksRunTime(worker
)
131 private computeWorkerWeight (): number {
132 let cpusCycleTimeWeight
= 0
133 for (const cpu
of cpus()) {
134 // CPU estimated cycle time
135 const numberOfDigit
= cpu
.speed
.toString().length
- 1
136 const cpuCycleTime
= 1 / (cpu
.speed
/ Math.pow(10, numberOfDigit
))
137 cpusCycleTimeWeight
+= cpuCycleTime
* Math.pow(10, numberOfDigit
)
139 return cpusCycleTimeWeight
/ cpus().length