CHANGELOG.md

   1 # Changelog
   2
   3 All notable changes to this project will be documented in this file.
   4
   5 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
   6 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   7
   8 ## [Unreleased]
   9
  10 ## [2.6.36] - 2023-08-27
  11
  12 ### Fixed
  13
  14 - Fix pool `execute()` arguments check.
  15
  16 ### Changed
  17
  18 - Make continuous tasks stealing algorithm less aggressive.
  19 - Fine tune tasks stealing algorithm under back pressure.
  20
  21 ## [2.6.35] - 2023-08-25
  22
  23 ### Fixed
  24
  25 - Don't account worker usage statistics for tasks that have failed.
  26 - Fix pool information runtime and wait time median computation.
  27
  28 ### Changed
  29
  30 - Update simple moving average implementation to use a circular buffer.
  31 - Update simple moving median implementation to use a circular buffer.
  32 - Account for stolen tasks in worker usage statistics and pool information.
  33
  34 ### Added
  35
  36 - Continuous tasks stealing algorithm.
  37
  38 ## [2.6.34] - 2023-08-24
  39
  40 ### Fixes
  41
  42 - Avoid cascading tasks stealing under back pressure.
  43
  44 ### Changed
  45
  46 - Add fastpath to queued tasks rescheduling.
  47
  48 ## [2.6.33] - 2023-08-24
  49
  50 ### Fixed
  51
  52 - Fix queued tasks rescheduling.
  53
  54 ### Changed
  55
  56 - Rename tasks queue options `queueMaxSize` to `size`.
  57
  58 ### Added
  59
  60 - Task stealing scheduling algorithm if tasks queueing is enabled.
  61
  62 ## [2.6.32] - 2023-08-23
  63
  64 ### Fixed
  65
  66 - Ensure no task can be executed when the pool is destroyed.
  67
  68 ### Added
  69
  70 - Add `queueMaxSize` option to tasks queue options.
  71 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
  72 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
  73
  74 ## [2.6.31] - 2023-08-20
  75
  76 ### Fixed
  77
  78 - Fix worker choice strategy retries mechanism in some edge cases.
  79
  80 ### Changed
  81
  82 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
  83 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
  84
  85 ## [2.6.30] - 2023-08-19
  86
  87 ### Fixed
  88
  89 - Ensure pool event `backPressure` is emitted.
  90 - Ensure pool event `full` is emitted only once.
  91 - Ensure worker node cannot be instantiated without proper arguments.
  92
  93 ## [2.6.29] - 2023-08-18
  94
  95 ### Fixed
  96
  97 - Fix race condition between ready and task functions worker message handling at startup.
  98 - Fix duplicate task function worker usage statistics computation per task function.
  99 - Update task function worker usage statistics if and only if there's at least two different task functions.
 100 - Fix race condition at task function worker usage executing task computation leading to negative value.
 101
 102 ### Added
 103
 104 - Add back pressure detection on the worker node queue. Event `backPressure` is emitted when all worker node queues are full (worker node queue size >= poolMaxSize^2).
 105 - Use back pressure detection in worker choice strategies.
 106 - Add worker choice strategies retries mechanism if no worker is eligible.
 107
 108 ## [2.6.28] - 2023-08-16
 109
 110 ### Fixed
 111
 112 - Ensure pool workers are properly initialized.
 113
 114 ### Added
 115
 116 - HTTP server pool examples: express-cluster, express-hybrid.
 117
 118 ### Changed
 119
 120 - Remove now useless branching in worker hot code path.
 121
 122 ## [2.6.27] - 2023-08-15
 123
 124 ### Fixed
 125
 126 - Add `KillHandler` type definition to exported types.
 127
 128 ### Added
 129
 130 - Add `destroy` event to pool API.
 131
 132 ## [2.6.26] - 2023-08-15
 133
 134 ### Added
 135
 136 - Add kill handler to worker options allowing to execute custom code when worker is killed.
 137 - Add `listTaskFunctions()` method to pool API.
 138 - SMTP server pool example: nodemailer.
 139
 140 ## [2.6.25] - 2023-08-13
 141
 142 ### Added
 143
 144 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
 145 - WebSocket server pool examples: ws-cluster, ws-hybrid.
 146
 147 ## [2.6.24] - 2023-08-12
 148
 149 ### Added
 150
 151 - Add array of transferable objects to the `execute()` method arguments.
 152 - WebSocket server pool examples: ws-worker_threads.
 153
 154 ## [2.6.23] - 2023-08-11
 155
 156 ### Fixed
 157
 158 - Fix pool busyness semantic when tasks queueing is enabled: the pool is busy when the number of executing tasks on each worker has reached the maximum tasks concurrency per worker.
 159
 160 ### Added
 161
 162 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
 163 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
 164
 165 ## [2.6.22] - 2023-08-10
 166
 167 ### Fixed
 168
 169 - Add missing `types` field to package.json `exports`.
 170
 171 ### Changed
 172
 173 - Structure markdown documentation (PR #811).
 174
 175 ## [2.6.21] - 2023-08-03
 176
 177 ### Changed
 178
 179 - Improve code documentation.
 180 - Code refactoring and cleanup for better maintainability and readability.
 181
 182 ## [2.6.20] - 2023-07-21
 183
 184 ### Fixed
 185
 186 - Fix queued tasks redistribution on error task execution starvation.
 187 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
 188
 189 ### Changed
 190
 191 - Drastically reduce lookups by worker in the worker nodes.
 192
 193 ## [2.6.19] - 2023-07-20
 194
 195 ### Added
 196
 197 - Dedicated internal communication channel for worker_threads pools.
 198
 199 ## [2.6.18] - 2023-07-19
 200
 201 ### Changed
 202
 203 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
 204
 205 ## [2.6.17] - 2023-07-16
 206
 207 ### Added
 208
 209 - Add `listTaskFunctions()` method to worker API.
 210
 211 ## [2.6.16] - 2023-07-12
 212
 213 ### Fixed
 214
 215 - Fix pool startup detection.
 216 - Fix worker task functions handling.
 217
 218 ## [2.6.15] - 2023-07-11
 219
 220 ### Added
 221
 222 - Take into account worker node readiness in worker choice strategies.
 223
 224 ## [2.6.14] - 2023-07-10
 225
 226 ### Fixed
 227
 228 - Fix task function statistics tracking.
 229
 230 ## [2.6.13] - 2023-07-10
 231
 232 ### Added
 233
 234 - Add per task function statistics tracking.
 235 - Add public methods to manipulate the worker task functions at runtime.
 236
 237 ## [2.6.12] - 2023-07-09
 238
 239 ### Fixed
 240
 241 - Workaround import issue with `node:os` module in node 16.x.x.
 242
 243 ## [2.6.11] - 2023-07-09
 244
 245 ### Fixed
 246
 247 - Fix pool readiness semantic.
 248
 249 ## [2.6.10] - 2023-07-08
 250
 251 ### Fixed
 252
 253 - Ensure workers are not recreated on error at pool startup.
 254
 255 ### Added
 256
 257 - Add `ready` and `strategy` fields to pool information.
 258 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
 259 - Add dynamic pool sizing checks.
 260
 261 ## [2.6.9] - 2023-07-07
 262
 263 ### Fixed
 264
 265 - Recreate the right worker type on uncaught exception.
 266
 267 ### Added
 268
 269 - Add minimum and maximum to internal measurement statistics.
 270 - Add `runTime` and `waitTime` to pool information.
 271 - Check worker inactive time only on dynamic worker.
 272
 273 ## [2.6.8] - 2023-07-03
 274
 275 ### Fixed
 276
 277 - Brown paper bag release to fix version handling in pool information.
 278
 279 ## [2.6.7] - 2023-07-03
 280
 281 ### Fixed
 282
 283 - Ensure worker queued tasks at error are reassigned to other pool workers.
 284
 285 ### Added
 286
 287 - Add pool `utilization` ratio to pool information.
 288 - Add `version` to pool information.
 289 - Add worker information to worker nodes.
 290
 291 ## [2.6.6] - 2023-07-01
 292
 293 ### Added
 294
 295 - Add safe helper `availableParallelism()` to help sizing the pool.
 296
 297 ### Fixed
 298
 299 - Ensure message handler is only registered in worker.
 300
 301 ## [2.6.5] - 2023-06-27
 302
 303 ### Known issues
 304
 305 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 306
 307 ### Fixed
 308
 309 - Artificial version bump to 2.6.5 to workaround publication issue.
 310 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 311 - Ensure pool event is emitted before task error promise rejection.
 312 - Fix queued tasks count computation.
 313
 314 ### Removed
 315
 316 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 317
 318 ## [2.6.4] - 2023-06-27
 319
 320 ### Known issues
 321
 322 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 323
 324 ### Fixed
 325
 326 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 327 - Ensure pool event is emitted before task error promise rejection.
 328 - Fix queued tasks count computation.
 329
 330 ### Removed
 331
 332 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 333
 334 ## [2.6.3] - 2023-06-19
 335
 336 ### Fixed
 337
 338 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
 339 - Update strategies internals after statistics computation.
 340
 341 ### Changed
 342
 343 - Optimize O(1) queue implementation.
 344
 345 ## [2.6.2] - 2023-06-12
 346
 347 ### Fixed
 348
 349 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
 350
 351 ## [2.6.1] - 2023-06-10
 352
 353 ### Added
 354
 355 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
 356
 357 ### Fixed
 358
 359 - Fix average statistics computation: ensure failed tasks are not accounted.
 360
 361 ## [2.6.0] - 2023-06-09
 362
 363 ### Added
 364
 365 - Add `LEAST_ELU` worker choice strategy (experimental).
 366 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
 367
 368 ### Changed
 369
 370 - Refactor pool worker node usage internals.
 371 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
 372 - Breaking change: pool information `info` property object fields have been renamed.
 373
 374 ### Fixed
 375
 376 - Fix wait time accounting.
 377 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
 378 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
 379
 380 ## [2.5.4] - 2023-06-07
 381
 382 ### Added
 383
 384 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
 385
 386 ### Changed
 387
 388 - Compute statistics at the worker level only if needed.
 389 - Add `worker_threads` options to thread pool options.
 390
 391 ### Fixed
 392
 393 - Make the `LEAST_BUSY` strategy only relies on task runtime.
 394
 395 ## [2.5.3] - 2023-06-04
 396
 397 ### Changed
 398
 399 - Refine pool information content.
 400 - Limit pool internals public exposure.
 401
 402 ## [2.5.2] - 2023-06-02
 403
 404 ### Added
 405
 406 - Add `taskError` pool event for task execution error.
 407 - Add pool information `info` property to pool.
 408 - Emit pool information on `busy` and `full` pool events.
 409
 410 ## [2.5.1] - 2023-06-01
 411
 412 ### Added
 413
 414 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
 415 - Add `error` pool event for uncaught worker error.
 416
 417 ## [2.5.0] - 2023-05-31
 418
 419 ### Added
 420
 421 - Switch pool event emitter to `EventEmitterAsyncResource`.
 422 - Add tasks wait time accounting in per worker tasks usage.
 423 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
 424
 425 ### Changed
 426
 427 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
 428
 429 ## [2.4.14] - 2023-05-09
 430
 431 ### Fixed
 432
 433 - Ensure no undefined task runtime can land in the tasks history.
 434 - Fix median computation implementation once again.
 435
 436 ### Added
 437
 438 - Unit tests for median and queue implementations.
 439
 440 ## [2.4.13] - 2023-05-08
 441
 442 ### Fixed
 443
 444 - Fix worker choice strategy options validation.
 445 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
 446
 447 ## [2.4.12] - 2023-05-06
 448
 449 ### Added
 450
 451 - Support multiple task functions per worker.
 452 - Add custom worker weights support to worker choice strategies options.
 453
 454 ### Changed
 455
 456 - Use O(1) queue implementation for tasks queueing.
 457
 458 ### Fixed
 459
 460 - Fix median computation implementation.
 461 - Fix fair share worker choice strategy internals update.
 462
 463 ## [2.4.11] - 2023-04-23
 464
 465 ### Changed
 466
 467 - Optimize free worker finding in worker choice strategies.
 468
 469 ## [2.4.10] - 2023-04-15
 470
 471 ### Fixed
 472
 473 - Fix typescript type definition for task function: ensure the input data is optional.
 474 - Fix typescript type definition for pool execute(): ensure the input data is optional.
 475
 476 ## [2.4.9] - 2023-04-15
 477
 478 ### Added
 479
 480 - Add tasks queue enablement runtime setter to pool.
 481 - Add tasks queue options runtime setter to pool.
 482 - Add worker choice strategy options runtime setter to pool.
 483
 484 ### Changed
 485
 486 - Remove the tasks queuing experimental status.
 487
 488 ### Fixed
 489
 490 - Fix task function type definition and validation.
 491 - Fix worker choice strategy options handling.
 492
 493 ## [2.4.8] - 2023-04-12
 494
 495 ### Fixed
 496
 497 - Fix message between main worker and worker type definition for tasks.
 498 - Fix code documentation.
 499
 500 ## [2.4.7] - 2023-04-11
 501
 502 ### Added
 503
 504 - Add worker tasks queue options to pool options.
 505
 506 ### Fixed
 507
 508 - Fix missing documentation.
 509
 510 ## [2.4.6] - 2023-04-10
 511
 512 ### Fixed
 513
 514 - Ensure one task at a time is executed per worker with tasks queueing enabled.
 515 - Properly count worker executing tasks with tasks queueing enabled.
 516
 517 ## [2.4.5] - 2023-04-09
 518
 519 ### Added
 520
 521 - Use monotonic high resolution timer for worker tasks runtime.
 522 - Add worker tasks median runtime to statistics.
 523 - Add worker tasks queue (experimental).
 524
 525 ## [2.4.4] - 2023-04-07
 526
 527 ### Added
 528
 529 - Add `PoolEvents` enumeration and `PoolEvent` type.
 530
 531 ### Fixed
 532
 533 - Destroy worker only on alive check.
 534
 535 ## [2.4.3] - 2023-04-07
 536
 537 ### Fixed
 538
 539 - Fix typedoc generation with inheritance.
 540
 541 ## [2.4.2] - 2023-04-06
 542
 543 ### Added
 544
 545 - Add `full` event to dynamic pool.
 546 - Keep worker choice strategy in memory for conditional reuse.
 547
 548 ### Fixed
 549
 550 - Fix possible negative worker key at worker removal in worker choice strategies.
 551
 552 ## [2.4.1] - 2023-04-05
 553
 554 ### Changed
 555
 556 - Optimize worker choice strategy for dynamic pool.
 557
 558 ### Fixed
 559
 560 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
 561
 562 ## [2.4.0] - 2023-04-04
 563
 564 ### Added
 565
 566 - Add `LESS_BUSY` worker choice strategy.
 567
 568 ### Changed
 569
 570 - Optimize worker storage in pool.
 571 - Optimize worker alive status check.
 572 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 573 - Optimize `LESS_USED` worker choice strategy.
 574 - Update benchmarks versus external threads pools.
 575 - Optimize tasks usage statistics requirements for worker choice strategy.
 576
 577 ### Fixed
 578
 579 - Ensure trimmable characters are checked at pool initialization.
 580 - Fix message id integer overflow.
 581 - Fix pool worker removal in worker choice strategy internals.
 582 - Fix package publication with pnpm.
 583
 584 ## [2.4.0-3] - 2023-04-04
 585
 586 ### Added
 587
 588 - Add `LESS_BUSY` worker choice strategy.
 589
 590 ### Changed
 591
 592 - Optimize worker storage in pool.
 593 - Optimize worker alive status check.
 594 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 595 - Optimize `LESS_USED` worker choice strategy.
 596 - Update benchmarks versus external threads pools.
 597
 598 ### Fixed
 599
 600 - Ensure trimmable characters are checked at pool initialization.
 601 - Fix message id integer overflow.
 602 - Fix pool worker removal in worker choice strategy internals.
 603 - Fix package publication with pnpm.
 604
 605 ## [2.4.0-2] - 2023-04-03
 606
 607 ### Added
 608
 609 - Add `LESS_BUSY` worker choice strategy.
 610
 611 ### Changed
 612
 613 - Optimize worker storage in pool.
 614 - Optimize worker alive status check.
 615 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 616 - Optimize `LESS_USED` worker choice strategy.
 617
 618 ### Fixed
 619
 620 - Ensure trimmable characters are checked at pool initialization.
 621 - Fix message id integer overflow.
 622 - Fix pool worker removal in worker choice strategy internals.
 623 - Fix package publication with pnpm.
 624
 625 ## [2.4.0-1] - 2023-04-03
 626
 627 ### Added
 628
 629 - Add `LESS_BUSY` worker choice strategy.
 630
 631 ### Changed
 632
 633 - Optimize worker storage in pool.
 634 - Optimize worker alive status check.
 635 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 636 - Optimize `LESS_USED` worker choice strategy.
 637
 638 ### Fixed
 639
 640 - Ensure trimmable characters are checked at pool initialization.
 641 - Fix message id integer overflow.
 642 - Fix pool worker removal in worker choice strategy internals.
 643
 644 ## [2.4.0-0] - 2023-04-03
 645
 646 ### Added
 647
 648 - Add `LESS_BUSY` worker choice strategy.
 649
 650 ### Changed
 651
 652 - Optimize worker storage in pool.
 653 - Optimize worker alive status check.
 654 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 655 - Optimize `LESS_USED` worker choice strategy.
 656
 657 ### Fixed
 658
 659 - Ensure trimmable characters are checked at pool initialization.
 660 - Fix message id integer overflow.
 661 - Fix pool worker removal in worker choice strategy internals.
 662
 663 ## [2.3.10] - 2023-03-18
 664
 665 ### Fixed
 666
 667 - Fix package.json `exports` syntax for ESM and CommonJS.
 668
 669 ### Changed
 670
 671 - Permit SemVer pre-release publication.
 672
 673 ## [2.3.10-2] - 2023-03-18
 674
 675 ### Fixed
 676
 677 - Fix package.json `exports` syntax for ESM and CommonJS.
 678
 679 ## [2.3.10-1] - 2023-03-18
 680
 681 ### Changed
 682
 683 - Permit SemVer pre-release publication.
 684
 685 ## [2.3.10-0] - 2023-03-18
 686
 687 ### Fixed
 688
 689 - Fix package.json `exports` syntax for ESM and CommonJS.
 690
 691 ## [2.3.9] - 2023-03-18
 692
 693 ### Changed
 694
 695 - Introduce ESM module support along with CommonJS one.
 696
 697 ### Fixed
 698
 699 - Fix brown paper bag bug referencing the same object literal.
 700
 701 ## [2.3.8] - 2023-03-18
 702
 703 ### Changed
 704
 705 - Switch internal benchmarking code to benny.
 706 - Switch to TypeScript 5.x.x.
 707 - Switch rollup bundler plugins to core ones.
 708 - Switch to TSDoc syntax.
 709 - Enforce conventional commits.
 710
 711 ### Fixed
 712
 713 - Fix random integer generator.
 714 - Fix worker choice strategy pool type identification at initialization.
 715
 716 ## [2.3.7] - 2022-10-23
 717
 718 ### Changed
 719
 720 - Switch to open collective FOSS project funding platform.
 721 - Switch to ts-standard linter configuration on TypeScript code.
 722
 723 ### Fixed
 724
 725 - Fixed missing async on pool execute method.
 726 - Fixed typing in TypeScript example.
 727 - Fixed types in unit tests.
 728
 729 ## [2.3.6] - 2022-10-22
 730
 731 ### Changed
 732
 733 - Cleanup pool attributes and methods.
 734 - Refine error types thrown.
 735
 736 ### Fixed
 737
 738 - Fix continuous integration build on windows.
 739 - Fix code coverage reporting by using c8 instead of nyc.
 740
 741 ## [2.3.5] - 2022-10-21
 742
 743 ### Changed
 744
 745 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
 746 - Optimize tasks usage lookup implementation.
 747
 748 ### Fixed
 749
 750 - Fix missed pool event emitter type export.
 751 - Fix typedoc documentation generation.
 752
 753 ## [2.3.4] - 2022-10-17
 754
 755 ### Added
 756
 757 - Fully automate release process with release-it.
 758
 759 ### Changed
 760
 761 - Optimize fair share task scheduling algorithm implementation.
 762 - Update benchmarks versus external pools results with latest version.
 763
 764 ## [2.3.3] - 2022-10-15
 765
 766 ### Added
 767
 768 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
 769
 770 ## [2.3.2] - 2022-10-14
 771
 772 ### Changed
 773
 774 - Optimize fair share worker selection strategy implementation.
 775
 776 ### Fixed
 777
 778 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
 779
 780 ## [2.3.1] - 2022-10-13
 781
 782 ### Added
 783
 784 - Pool worker choice strategies:
 785   - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
 786   - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
 787
 788 ## [2.2.2] - 2022-10-09
 789
 790 ### Fixed
 791
 792 - Fixed `README.md` file.
 793
 794 ## [2.2.1] - 2022-10-08
 795
 796 ### Added
 797
 798 - Dynamic worker choice strategy change at runtime.
 799
 800 ## [2.2.0] - 2022-01-05
 801
 802 ### Breaking Changes
 803
 804 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
 805
 806 ## [2.1.0] - 2021-08-29
 807
 808 ### Added
 809
 810 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
 811
 812 ### Breaking Changes
 813
 814 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
 815 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
 816 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
 817 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
 818
 819 ## [2.0.2] - 2021-05-12
 820
 821 ### Bug fixes
 822
 823 - Fix `busy` event emission on fixed pool type
 824
 825 ## [2.0.1] - 2021-03-16
 826
 827 ### Bug fixes
 828
 829 - Check if pool options are properly set.
 830 - `busy` event is emitted on all pool types.
 831
 832 ## [2.0.0] - 2021-03-01
 833
 834 ### Bug fixes
 835
 836 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
 837
 838 ### Breaking Changes
 839
 840 - `FullPool` event is now renamed to `busy`.
 841 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
 842   _Find more details on our JSDoc._
 843
 844 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
 845
 846 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
 847
 848 ### Pool options types declaration merge
 849
 850 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
 851
 852 #### New `export` strategy
 853
 854 ```js
 855 // Before
 856 const DynamicThreadPool = require('poolifier/lib/dynamic')
 857 // After
 858 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
 859 ```
 860
 861 But you should always prefer just using
 862
 863 ```js
 864 const { DynamicThreadPool } = require('poolifier')
 865 ```
 866
 867 #### New type definitions for input data and response
 868
 869 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
 870 _This is not a limitation by poolifier but Node.js._
 871
 872 #### Public property replacements
 873
 874 `numWorkers` property is now `numberOfWorkers`
 875
 876 #### Internal (protected) properties and methods renaming
 877
 878 These properties are not intended for end users
 879
 880 - `id` => `nextMessageId`
 881
 882 These methods are not intended for end users
 883
 884 - `_chooseWorker` => `chooseWorker`
 885 - `_newWorker` => `createWorker`
 886 - `_execute` => `internalExecute`
 887 - `_chooseWorker` => `chooseWorker`
 888 - `_checkAlive` => `checkAlive`
 889 - `_run` => `run`
 890 - `_runAsync` => `runAsync`
 891
 892 ## [1.1.0] - 2020-05-21
 893
 894 ### Added
 895
 896 - ThreadWorker support async functions as option
 897 - Various external library patches
 898
 899 ## [1.0.0] - 2020-01-24
 900
 901 ### Added
 902
 903 - FixedThreadPool implementation
 904 - DynamicThreadPool implementation
 905 - WorkerThread implementation to improve developer experience