From 482e0a739a5cf7e2d1dd81fef845be0c65e87568 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Thu, 30 Mar 2017 20:35:21 +0200
Subject: [PATCH] try to stabilize performance test timings even more

---
 .../src/com/intellij/testFramework/CpuTimings.java | 14 ++++++++------
 .../intellij/testFramework/PlatformTestUtil.java   |  2 +-
 .../src/com/intellij/testFramework/Timings.java    |  7 ++++---
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/platform/testFramework/src/com/intellij/testFramework/CpuTimings.java b/platform/testFramework/src/com/intellij/testFramework/CpuTimings.java
index 7e17d05c54dd..022daaa9d880 100644
--- a/platform/testFramework/src/com/intellij/testFramework/CpuTimings.java
+++ b/platform/testFramework/src/com/intellij/testFramework/CpuTimings.java
@@ -23,7 +23,6 @@ import javax.management.MBeanServer;
 import javax.management.ObjectName;
 import java.lang.management.ManagementFactory;
 import java.math.BigInteger;
-import java.util.Arrays;
 import java.util.stream.LongStream;
 
 /**
@@ -33,9 +32,11 @@ public class CpuTimings {
   final long[] rawData;
   long average;
   private final double myStandardDeviation;
+  private final int attempt;
 
-  private CpuTimings(long[] rawData) {
+  private CpuTimings(long[] rawData, int attempt) {
     this.rawData = rawData;
+    this.attempt = attempt;
     average = ArrayUtil.averageAmongMedians(rawData, 2);
     myStandardDeviation = standardDeviation(rawData);
   }
@@ -52,14 +53,14 @@ public class CpuTimings {
 
   @Override
   public String toString() {
-    return "CpuTimings{" + average + ", raw=" + Arrays.toString(rawData) + ", sd=" + myStandardDeviation + '}';
+    return average + "[sd=" + myStandardDeviation + ", attempt=" + attempt + "]";
   }
 
   @SuppressWarnings("UseOfSystemOutOrSystemErr")
   static CpuTimings calcStableCpuTiming() {
     int maxIterations = UsefulTestCase.IS_UNDER_TEAMCITY ? 100 : 10;
     for (int i = 0;; i++) {
-      CpuTimings timings = calcCpuTiming(20, CpuTimings::addBigIntegers);
+      CpuTimings timings = calcCpuTiming(20, CpuTimings::addBigIntegers, i);
       if (timings.myStandardDeviation < 1.8) {
         return timings;
       }
@@ -71,17 +72,18 @@ public class CpuTimings {
         System.out.println(i + ": Unstable timings: " + timings+" (getProcessCpuLoad() = " + getProcessCpuLoad()+"; getSystemCpuLoad() = " + getSystemCpuLoad()+")");
       }
       System.gc();
+      PlatformTestUtil.waitForAllBackgroundActivityToCalmDown();
     }
   }
 
-  private static CpuTimings calcCpuTiming(int iterationCount, Runnable oneIteration)  {
+  private static CpuTimings calcCpuTiming(int iterationCount, Runnable oneIteration, int attempt)  {
     long[] elapsed = new long[iterationCount];
     for (int i = 0; i < iterationCount; i++) {
       long start = System.currentTimeMillis();
       oneIteration.run();
       elapsed[i] = System.currentTimeMillis() - start;
     }
-    return new CpuTimings(elapsed);
+    return new CpuTimings(elapsed, attempt);
   }
 
   private static void addBigIntegers() {
diff --git a/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java b/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
index 60de37e321e4..f3f38c733063 100644
--- a/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
+++ b/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
@@ -680,7 +680,7 @@ public class PlatformTestUtil {
     }
   }
 
-  private static void waitForAllBackgroundActivityToCalmDown() {
+  static void waitForAllBackgroundActivityToCalmDown() {
     for (int i = 0; i < 50; i++) {
       CpuUsageData data = CpuUsageData.measureCpuUsage(() -> TimeoutUtil.sleep(100));
       if (!data.hasAnyActivityBesides(Thread.currentThread())) {
diff --git a/platform/testFramework/src/com/intellij/testFramework/Timings.java b/platform/testFramework/src/com/intellij/testFramework/Timings.java
index 7c4d864a2d5f..c3927ddd2727 100644
--- a/platform/testFramework/src/com/intellij/testFramework/Timings.java
+++ b/platform/testFramework/src/com/intellij/testFramework/Timings.java
@@ -28,6 +28,7 @@ public class Timings {
   private static final int IO_PROBES = 42;
 
   public static final long CPU_TIMING;
+  private static final CpuTimings CPU_TIMING_DATA;
   public static final long IO_TIMING;
 
   /**
@@ -37,8 +38,8 @@ public class Timings {
   public static final long REFERENCE_IO_TIMING = 100;
 
   static {
-    CpuTimings timings = CpuTimings.calcStableCpuTiming();
-    CPU_TIMING = timings.average;
+    CPU_TIMING_DATA = CpuTimings.calcStableCpuTiming();
+    CPU_TIMING = CPU_TIMING_DATA.average;
 
     long start = System.currentTimeMillis();
     for (int i = 0; i < IO_PROBES; i++) {
@@ -96,7 +97,7 @@ public class Timings {
 
   public static String getStatistics() {
     return
-      " Timings: CPU=" + CPU_TIMING + " (" + (int)(CPU_TIMING * 1.0 / REFERENCE_CPU_TIMING * 100) + "% of the reference CPU)" +
+      " Timings: CPU=" + CPU_TIMING_DATA + " (" + (int)(CPU_TIMING * 1.0 / REFERENCE_CPU_TIMING * 100) + "% of the reference CPU)" +
       ", I/O=" + IO_TIMING + " (" + (int)(IO_TIMING * 1.0 / REFERENCE_IO_TIMING * 100) + "% of the reference IO)" +
       ", " + Runtime.getRuntime().availableProcessors() + " cores.";
   }