refactor: reorder pool options validation

[poolifier.git] / tests / pools / selection-strategies / selection-strategies.test.js

diff --git a/tests/pools/selection-strategies/selection-strategies.test.js b/tests/pools/selection-strategies/selection-strategies.test.js
index 8894ba3126102faef6ab1dbea23ef20676c21a37..3329e1dc718f3565202e1344479248013a6171c8 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -1,13 +1,12 @@
 const { expect } = require('expect')
 const {
+  DynamicClusterPool,
   DynamicThreadPool,
   FixedClusterPool,
   FixedThreadPool,
-  PoolEvents,
   WorkerChoiceStrategies
 } = require('../../../lib')
 const { CircularArray } = require('../../../lib/circular-array')
-const { waitPoolEvents } = require('../../test-utils')
 
 describe('Selection strategies test suite', () => {
   const min = 0
@@ -67,6 +66,43 @@ describe('Selection strategies test suite', () => {
       expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
         workerChoiceStrategy
       )
+      expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
+        retries: 6,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      expect(pool.workerChoiceStrategyContext.opts).toStrictEqual({
+        retries: 6,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      await pool.destroy()
+    }
+    for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
+      const pool = new DynamicClusterPool(
+        min,
+        max,
+        './tests/worker-files/cluster/testWorker.js'
+      )
+      pool.setWorkerChoiceStrategy(workerChoiceStrategy, { retries: 3 })
+      expect(pool.opts.workerChoiceStrategy).toBe(workerChoiceStrategy)
+      expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
+        workerChoiceStrategy
+      )
+      expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
+        retries: 3,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      expect(pool.workerChoiceStrategyContext.opts).toStrictEqual({
+        retries: 3,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
       await pool.destroy()
     }
   })
@@ -77,41 +113,62 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js'
     )
     for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
-      if (workerChoiceStrategy === WorkerChoiceStrategies.ROUND_ROBIN) {
+      expect(
+        pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+          workerChoiceStrategy
+        ).nextWorkerNodeKey
+      ).toBe(0)
+      expect(
+        pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+          workerChoiceStrategy
+        ).previousWorkerNodeKey
+      ).toBe(0)
+      if (
+        workerChoiceStrategy === WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
+      ) {
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).defaultWorkerWeight
+        ).toBeGreaterThan(0)
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).nextWorkerNodeKey
+          ).workerNodeVirtualTaskRunTime
         ).toBe(0)
-      } else if (workerChoiceStrategy === WorkerChoiceStrategies.FAIR_SHARE) {
+      } else if (
+        workerChoiceStrategy ===
+        WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN
+      ) {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).workersVirtualTaskEndTimestamp
-        ).toBeInstanceOf(Array)
+          ).defaultWorkerWeight
+        ).toBeGreaterThan(0)
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).workersVirtualTaskEndTimestamp.length
+          ).workerNodeVirtualTaskRunTime
         ).toBe(0)
-      } else if (
-        workerChoiceStrategy === WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
-      ) {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).nextWorkerNodeKey
+          ).roundId
         ).toBe(0)
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).defaultWorkerWeight
-        ).toBeGreaterThan(0)
+          ).workerNodeId
+        ).toBe(0)
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).workerVirtualTaskRunTime
-        ).toBe(0)
+          ).roundWeights
+        ).toStrictEqual([
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).defaultWorkerWeight
+        ])
       }
     }
     await pool.destroy()
@@ -125,7 +182,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -135,7 +193,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -198,10 +257,11 @@ describe('Selection strategies test suite', () => {
   })
 
   it('Verify ROUND_ROBIN strategy can be run in a fixed pool', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     const pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
+      { workerChoiceStrategy }
     )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = new Set()
@@ -217,39 +277,46 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        WorkerChoiceStrategies.ROUND_ROBIN
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
   it('Verify ROUND_ROBIN strategy can be run in a dynamic pool', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     const pool = new DynamicThreadPool(
       min,
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
+      { workerChoiceStrategy }
     )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = new Set()
@@ -261,33 +328,43 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        WorkerChoiceStrategies.ROUND_ROBIN
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -327,15 +404,25 @@ describe('Selection strategies test suite', () => {
     )
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
@@ -345,15 +432,25 @@ describe('Selection strategies test suite', () => {
     )
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -366,7 +463,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -376,7 +474,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -458,20 +557,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -480,6 +580,16 @@ describe('Selection strategies test suite', () => {
         max * maxMultiplier
       )
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -505,20 +615,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -527,6 +638,16 @@ describe('Selection strategies test suite', () => {
         max * maxMultiplier
       )
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -539,7 +660,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -549,7 +671,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -625,26 +748,27 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -663,6 +787,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.waitTime.aggregate).toBeGreaterThan(0)
       }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -682,26 +816,27 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -720,6 +855,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.waitTime.aggregate).toBeGreaterThan(0)
       }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -732,7 +877,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -742,7 +888,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -818,33 +965,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        elu: expect.objectContaining({
           idle: expect.objectContaining({
             history: expect.any(CircularArray)
           }),
           active: expect.objectContaining({
             history: expect.any(CircularArray)
           })
-        }
+        })
       })
       expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
+      if (workerNode.usage.elu.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(0)
+      }
       if (workerNode.usage.elu.utilization == null) {
         expect(workerNode.usage.elu.utilization).toBeUndefined()
       } else {
@@ -852,6 +1010,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
       }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -871,33 +1039,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        elu: expect.objectContaining({
           idle: expect.objectContaining({
             history: expect.any(CircularArray)
           }),
           active: expect.objectContaining({
             history: expect.any(CircularArray)
           })
-        }
+        })
       })
       expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
+      if (workerNode.usage.elu.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(0)
+      }
       if (workerNode.usage.elu.utilization == null) {
         expect(workerNode.usage.elu.utilization).toBeUndefined()
       } else {
@@ -905,6 +1084,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
       }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -917,7 +1106,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -927,7 +1117,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: false
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1003,28 +1194,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        elu: expect.objectContaining({
           idle: expect.objectContaining({
             history: expect.any(CircularArray)
           }),
           active: expect.objectContaining({
             history: expect.any(CircularArray)
           })
-        }
+        })
       })
       expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
@@ -1040,18 +1232,34 @@ describe('Selection strategies test suite', () => {
       } else {
         expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
       }
+      if (workerNode.usage.elu.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(0)
+      }
       if (workerNode.usage.elu.utilization == null) {
         expect(workerNode.usage.elu.utilization).toBeUndefined()
       } else {
         expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
         expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
       }
+      expect(workerNode.strategyData.virtualTaskEndTimestamp).toBeGreaterThan(0)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(pool.workerNodes.length)
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -1071,28 +1279,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        elu: expect.objectContaining({
           idle: expect.objectContaining({
             history: expect.any(CircularArray)
           }),
           active: expect.objectContaining({
             history: expect.any(CircularArray)
           })
-        }
+        })
       })
       expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
@@ -1108,18 +1317,34 @@ describe('Selection strategies test suite', () => {
       } else {
         expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
       }
+      if (workerNode.usage.elu.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(0)
+      }
       if (workerNode.usage.elu.utilization == null) {
         expect(workerNode.usage.elu.utilization).toBeUndefined()
       } else {
         expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
         expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
       }
+      expect(workerNode.strategyData.virtualTaskEndTimestamp).toBeGreaterThan(0)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(pool.workerNodes.length)
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -1144,28 +1369,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        elu: expect.objectContaining({
           idle: expect.objectContaining({
             history: expect.any(CircularArray)
           }),
           active: expect.objectContaining({
             history: expect.any(CircularArray)
           })
-        }
+        })
       })
       expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
@@ -1181,18 +1407,34 @@ describe('Selection strategies test suite', () => {
       } else {
         expect(workerNode.usage.runTime.median).toBeGreaterThan(0)
       }
+      if (workerNode.usage.elu.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(0)
+      }
       if (workerNode.usage.elu.utilization == null) {
         expect(workerNode.usage.elu.utilization).toBeUndefined()
       } else {
         expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
         expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
       }
+      expect(workerNode.strategyData.virtualTaskEndTimestamp).toBeGreaterThan(0)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(pool.workerNodes.length)
+      ).nextWorkerNodeKey
+    ).toEqual(expect.any(Number))
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -1203,70 +1445,30 @@ describe('Selection strategies test suite', () => {
       max,
       './tests/worker-files/thread/testWorker.js'
     )
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp
-    ).toBeInstanceOf(Array)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(0)
-    pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-      workerChoiceStrategy
-    ).workersVirtualTaskEndTimestamp[0] = performance.now()
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(1)
+    for (const workerNode of pool.workerNodes) {
+      workerNode.strategyData = {
+        virtualTaskEndTimestamp: performance.now()
+      }
+    }
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp
-    ).toBeInstanceOf(Array)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(0)
+    for (const workerNode of pool.workerNodes) {
+      expect(workerNode.strategyData.virtualTaskEndTimestamp).toBeUndefined()
+    }
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
       max,
       './tests/worker-files/thread/testWorker.js'
     )
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp
-    ).toBeInstanceOf(Array)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(0)
-    pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-      workerChoiceStrategy
-    ).workersVirtualTaskEndTimestamp[0] = performance.now()
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(1)
+    for (const workerNode of pool.workerNodes) {
+      workerNode.strategyData = {
+        virtualTaskEndTimestamp: performance.now()
+      }
+    }
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp
-    ).toBeInstanceOf(Array)
-    expect(
-      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workersVirtualTaskEndTimestamp.length
-    ).toBe(0)
+    for (const workerNode of pool.workerNodes) {
+      expect(workerNode.strategyData.virtualTaskEndTimestamp).toBeUndefined()
+    }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -1279,7 +1481,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1289,7 +1492,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1371,20 +1575,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1403,6 +1608,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
       }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1411,7 +1626,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+      ).workerNodeVirtualTaskRunTime
     ).toBeGreaterThanOrEqual(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1438,24 +1653,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          maximum: expect.any(Number),
-          minimum: expect.any(Number),
-          average: expect.any(Number),
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1463,9 +1675,27 @@ describe('Selection strategies test suite', () => {
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.average == null) {
+        expect(workerNode.usage.runTime.average).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
+      }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1474,7 +1704,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+      ).workerNodeVirtualTaskRunTime
     ).toBeGreaterThanOrEqual(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1506,24 +1736,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          maximum: expect.any(Number),
-          minimum: expect.any(Number),
-          median: expect.any(Number),
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1531,9 +1758,27 @@ describe('Selection strategies test suite', () => {
       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.usage.runTime.median).toBeGreaterThan(0)
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.median == null) {
+        expect(workerNode.usage.runTime.median).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.median).toBeGreaterThan(0)
+      }
     }
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1542,7 +1787,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+      ).workerNodeVirtualTaskRunTime
     ).toBeGreaterThanOrEqual(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1559,6 +1804,11 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1567,7 +1817,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+      ).workerNodeVirtualTaskRunTime
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
@@ -1575,6 +1825,11 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1582,8 +1837,8 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeVirtualTaskRunTime
     ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1596,6 +1851,11 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1604,7 +1864,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+      ).workerNodeVirtualTaskRunTime
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
@@ -1612,6 +1872,11 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1619,8 +1884,8 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).workerVirtualTaskRunTime
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeVirtualTaskRunTime
     ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1635,7 +1900,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1645,7 +1911,8 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
-      useDynamicWorker: true
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1663,8 +1930,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1689,8 +1956,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1717,8 +1984,6 @@ describe('Selection strategies test suite', () => {
           WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN
       }
     )
-    // FIXME: shall not be needed
-    await waitPoolEvents(pool, PoolEvents.ready, 1)
     // TODO: Create a better test to cover `InterleavedWeightedRoundRobinWorkerChoiceStrategy#choose`
     const promises = new Set()
     const maxMultiplier = 2
@@ -1729,27 +1994,32 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1761,11 +2031,21 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundId
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeId
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1799,27 +2079,32 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1831,11 +2116,21 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundId
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeId
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1861,11 +2156,21 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).roundId
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1879,14 +2184,24 @@ describe('Selection strategies test suite', () => {
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundId
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeId
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1894,7 +2209,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1912,11 +2227,21 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).roundId
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1928,11 +2253,26 @@ describe('Selection strategies test suite', () => {
       ).roundWeights
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).roundId
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeId
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1940,7 +2280,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(