Revert "Merge branch 'better_cpu_adjustement' into '1.6'"

This reverts merge request !1218

app/ProcessCpuProfiler.ts

-const SAMPLING_PERIOD = 150 // milliseconds
-const MAX_SAMPLES_DISTANCE = 20 * 1000000 // seconds
-
-function getMicrosecondsTime() {
-  const [ seconds, nanoseconds ] = process.hrtime()
-  return seconds * 1000000 + nanoseconds / 1000
-}
-
-interface CpuUsage {
-  user: number
-  system:number
-}
-
-interface CpuUsageAt {
-  usage:number
-  at:number // microseconds timestamp
-  elapsed:number // microseconds elapsed for this result
-}
-
-export class ProcessCpuProfiler {
-
-  private cumulatedUsage: CpuUsage
-  private startedAt:number // microseconds timestamp
-  private samples:CpuUsageAt[] = []
-
-  constructor(samplingPeriod = SAMPLING_PERIOD) {
-    // Initial state
-    const start = getMicrosecondsTime()
-    this.startedAt = start
-    this.cumulatedUsage = process.cpuUsage()
-    this.samples.push({ usage: 0, at: start, elapsed: 1 })
-    // Periodic sample
-    setInterval(() => {
-      const newSampleAt = getMicrosecondsTime()
-      const newUsage:CpuUsage = process.cpuUsage()
-      const elapsed = newSampleAt - this.lastSampleAt
-      const userDiff = newUsage.user - this.cumulatedUsage.user
-      const usagePercent = userDiff / elapsed // The percent of time consumed by the process since last sample
-      this.samples.push({ usage: usagePercent, at: newSampleAt, elapsed })
-      while(this.samplesDistance > MAX_SAMPLES_DISTANCE) {
-        this.samples.shift()
-      }
-      this.cumulatedUsage = newUsage
-      // console.log('Time elapsed: %s microseconds, = %s %CPU', elapsed, (usagePercent*100).toFixed(2))
-    }, samplingPeriod)
-  }
-
-  private get lastSampleAt() {
-    return this.samples[this.samples.length - 1].at
-  }
-
-  private get samplesDistance() {
-    return this.samples[this.samples.length - 1].at - this.samples[0].at
-  }
-
-  cpuUsageOverLastMilliseconds(elapsedMilliseconds:number) {
-    return this.cpuUsageOverLastX(elapsedMilliseconds * 1000)
-  }
-
-  private cpuUsageOverLastX(nbMicrosecondsElapsed:number) {
-    return this.getSamplesResult(getMicrosecondsTime() - nbMicrosecondsElapsed)
-  }
-
-  private getSamplesResult(minTimestamp:number) {
-    const matchingSamples = this.samples.filter(s => s.at >= minTimestamp - SAMPLING_PERIOD * 1000)
-    const cumulativeElapsed = matchingSamples.reduce((sum, s) => sum + s.elapsed, 0)
-    return matchingSamples.reduce((cumulated, percent) => {
-      const weight = percent.elapsed / cumulativeElapsed
-      return cumulated + percent.usage * weight
-    }, 0)
-  }
-}
\ No newline at end of file

app/modules/prover/lib/blockProver.ts

@@ -44,9 +44,6 @@ export class WorkerFarm {
     })
   }
 
-  get nbWorkers() {
-    return this.theEngine.getNbWorkers()
-  }
 
   changeCPU(cpu:any) {
     return this.theEngine.setConf({ cpu })
@@ -178,6 +175,7 @@ export class BlockProver {
       const start = Date.now();
       let result = await powFarm.askNewProof({
         newPoW: {
+          turnDuration: os.arch().match(/arm/) ? CommonConstants.POW_TURN_DURATION_ARM : CommonConstants.POW_TURN_DURATION_PC,
           conf: {
             cpu: this.conf.cpu,
             prefix: this.conf.prefix,
@@ -196,10 +194,10 @@ export class BlockProver {
         throw 'Proof-of-work computation canceled because block received';
       } else {
         const proof = result.block;
-        const testsCount = result.testsCount * powFarm.nbWorkers
+        const testsCount = result.testsCount;
         const duration = (Date.now() - start);
-        const testsPerSecond = testsCount / (duration / 1000)
-        this.logger.info('Done: #%s, %s in %ss (~%s tests, ~%s tests/s, using %s cores, CPU %s%)', block.number, proof.hash, (duration / 1000).toFixed(2), testsCount, testsPerSecond.toFixed(2), powFarm.nbWorkers, Math.floor(100*this.conf.cpu))
+        const testsPerSecond = (testsCount / (duration / 1000)).toFixed(2);
+        this.logger.info('Done: #%s, %s in %ss (%s tests, ~%s tests/s)', block.number, proof.hash, (duration / 1000).toFixed(2), testsCount, testsPerSecond);
         this.logger.info('FOUND proof-of-work with %s leading zeros followed by [0-' + highMark + ']!', nbZeros);
         return BlockDTO.fromJSONObject(proof)
       }

app/modules/prover/lib/engine.ts

@@ -25,10 +25,6 @@ export class PowEngine {
     this.id = this.cluster.clusterId
   }
 
-  getNbWorkers() {
-    return this.cluster.nbWorkers
-  }
-
   forceInit() {
     return this.cluster.initCluster()
   }
@@ -39,6 +35,9 @@ export class PowEngine {
       await this.cluster.cancelWork()
     }
 
+    if (os.arch().match(/arm/)) {
+      stuff.newPoW.conf.cpu /= 2; // Don't know exactly why is ARM so much saturated by PoW, so let's divide by 2
+    }
     return await this.cluster.proveByWorkers(stuff)
   }
 
@@ -47,6 +46,9 @@ export class PowEngine {
   }
 
   setConf(value:any) {
+    if (os.arch().match(/arm/) && value.cpu !== undefined) {
+      value.cpu /= 2; // Don't know exactly why is ARM so much saturated by PoW, so let's divide by 2
+    }
     return this.cluster.changeConf(value)
   }
 

app/modules/prover/lib/powCluster.ts

@@ -195,6 +195,7 @@ export class Master {
             highMark: stuff.newPoW.highMark,
             pair: _.clone(stuff.newPoW.pair),
             forcedTime: stuff.newPoW.forcedTime,
+            turnDuration: stuff.newPoW.turnDuration,
             conf: {
               medianTimeBlocks: stuff.newPoW.conf.medianTimeBlocks,
               avgGenTime: stuff.newPoW.conf.avgGenTime,

app/modules/prover/lib/proof.ts

@@ -6,11 +6,15 @@ import {Constants} from "./constants"
 import {KeyGen} from "../../../lib/common-libs/crypto/keyring"
 import {dos2unix} from "../../../lib/common-libs/dos2unix"
 import {rawer} from "../../../lib/common-libs/index"
-import {ProcessCpuProfiler} from "../../../ProcessCpuProfiler"
 
 const moment = require('moment');
 const querablep = require('querablep');
 
+const PAUSES_PER_TURN = 5;
+
+// This value can be changed
+let TURN_DURATION_IN_MILLISEC = 100;
+
 let computing = querablep(Promise.resolve(null));
 let askedStop = false;
 
@@ -86,6 +90,7 @@ function beginNewProofOfWork(stuff:any) {
       prefix *= 100 * Constants.NONCE_RANGE
     }
     const highMark = stuff.highMark;
+    const turnDuration = stuff.turnDuration || TURN_DURATION_IN_MILLISEC
     let sigFunc = null;
     if (signatureFunc && lastSecret === pair.sec) {
       sigFunc = signatureFunc;
@@ -103,17 +108,13 @@ function beginNewProofOfWork(stuff:any) {
 
     let testsCount = 0;
     let found = false;
+    let score = 0;
     let turn = 0;
-    const profiler = new ProcessCpuProfiler(100)
-    let cpuUsage = profiler.cpuUsageOverLastMilliseconds(1)
-    // We limit the number of tests according to CPU usage
-    let testsPerRound = 1
-    let turnDuration = 20 // We initially goes quickly to the max speed = 50 reevaluations per second (1000 / 20)
 
     while (!found && !askedStop) {
 
       /*****************
-       * A TURN ~ 100ms
+       * A TURN
        ****************/
 
       await Promise.race([
@@ -124,9 +125,26 @@ function beginNewProofOfWork(stuff:any) {
         // II. Process the turn's PoW
         (async () => {
 
+          /*****************
+           * A TURN OF POW ~= 100ms by default
+           * --------------------
+           *
+           * The concept of "turn" is required to limit the CPU usage.
+           * We need a time reference to have the speed = nb tests / period of time.
+           * Here we have:
+           *
+           *   - speed = testsCount / turn
+           *
+           * We have taken 1 turn = 100ms to control the CPU usage after 100ms of PoW. This means that during the
+           * very first 100ms of the PoW, CPU usage = 100%. Then it becomes controlled to the %CPU set.
+           ****************/
+
             // Prove
           let i = 0;
           const thisTurn = turn;
+          const pausePeriod = score ? score / PAUSES_PER_TURN : 10; // number of pauses per turn
+          // We limit the number of tests according to CPU usage
+          const testsPerRound = score ? Math.floor(score * currentCPU) : 1000 * 1000 * 1000
 
           // Time is updated regularly during the proof
           block.time = getBlockTime(block, conf, forcedTime)
@@ -178,7 +196,7 @@ function beginNewProofOfWork(stuff:any) {
             if (!found && !askedStop) {
               i++;
               testsCount++;
-              if (i % testsPerRound === 0) {
+              if (i % pausePeriod === 0) {
                 await countDown(0); // Very low pause, just the time to process eventual end of the turn
               }
             }
@@ -190,24 +208,12 @@ function beginNewProofOfWork(stuff:any) {
           if (!found) {
 
             // CPU speed recording
-            if (turn > 0) {
-              const oldTestsPerRound = testsPerRound
-              cpuUsage = profiler.cpuUsageOverLastMilliseconds(turnDuration)
-              if (cpuUsage > currentCPU + 0.005 || cpuUsage < currentCPU - 0.005) {
-                let powVariationFactor
-                // powVariationFactor = currentCPU / (cpuUsage || 0.01) / 5 // divide by 2 to avoid extreme responses
-                if (currentCPU > cpuUsage) {
-                  powVariationFactor = 1.01
-                  testsPerRound = Math.max(1, Math.ceil(testsPerRound * powVariationFactor))
-                } else {
-                  powVariationFactor = 0.99
-                  testsPerRound = Math.max(1, Math.floor(testsPerRound * powVariationFactor))
-                }
-              }
+            if (turn > 0 && !score) {
+              score = testsCount;
             }
 
             /*****************
-             * UNLOAD CPU CHARGE FOR THIS TURN
+             * UNLOAD CPU CHARGE
              ****************/
             // We wait for a maximum time of `turnDuration`.
             // This will trigger the end of the turn by the concurrent race I. During that time, the proof.js script
@@ -220,9 +226,6 @@ function beginNewProofOfWork(stuff:any) {
 
       // Next turn
       turn++
-
-      turnDuration += 1
-      turnDuration = Math.min(turnDuration, 1000) // Max 1 second per turn
     }
 
     /*****************