1 files changed, 77 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/profiler/CollectLocalCpuUsage.java b/src/main/java/com/google/devtools/build/lib/profiler/CollectLocalCpuUsage.java
new file mode 100644
index 0000000000..2b64c128b8
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/profiler/CollectLocalCpuUsage.java
@@ -0,0 +1,77 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.profiler;
+
+import com.google.common.base.Preconditions;
+import com.sun.management.OperatingSystemMXBean;
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.TimeUnit;
+
+/** Thread to collect local cpu usage data and log into JSON profile. */
+public class CollectLocalCpuUsage extends Thread {
+  // TODO(twerth): Make these configurable.
+  private static final long BUCKET_SIZE_MILLIS = 1000;
+  private static final long LOCAL_CPU_SLEEP_MILLIS = 200;
+
+  private volatile boolean stopCpuUsage;
+  private long cpuProfileStartMillis;
+  private CpuUsageTimeSeries localCpuUsage;
+
+  @Override
+  public void run() {
+    stopCpuUsage = false;
+    cpuProfileStartMillis = System.currentTimeMillis();
+    localCpuUsage = new CpuUsageTimeSeries(cpuProfileStartMillis, BUCKET_SIZE_MILLIS);
+    OperatingSystemMXBean bean =
+        (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
+    long previousTimeMillis = System.currentTimeMillis();
+    long previousCpuTimeMillis = TimeUnit.NANOSECONDS.toMillis(bean.getProcessCpuTime());
+    while (!stopCpuUsage) {
+      try {
+        Thread.sleep(LOCAL_CPU_SLEEP_MILLIS);
+      } catch (InterruptedException e) {
+        return;
+      }
+      long nextTimeMillis = System.currentTimeMillis();
+      long nextCpuTimeMillis = TimeUnit.NANOSECONDS.toMillis(bean.getProcessCpuTime());
+      double deltaMillis = nextTimeMillis - previousTimeMillis;
+      double cpuLevel = (nextCpuTimeMillis - previousCpuTimeMillis) / deltaMillis;
+      localCpuUsage.addRange(previousTimeMillis, nextTimeMillis, cpuLevel);
+      previousTimeMillis = nextTimeMillis;
+      previousCpuTimeMillis = nextCpuTimeMillis;
+    }
+  }
+
+  public void stopCollecting() {
+    Preconditions.checkArgument(!stopCpuUsage);
+    stopCpuUsage = true;
+  }
+
+  public void logCollectedData() {
+    Preconditions.checkArgument(stopCpuUsage);
+    long currentTimeNanos = System.nanoTime();
+    long currentTimeMillis = System.currentTimeMillis();
+    int len = (int) ((currentTimeMillis - cpuProfileStartMillis) / BUCKET_SIZE_MILLIS) + 1;
+    double[] localCpuUsageValues = localCpuUsage.toDoubleArray(len);
+    Profiler profiler = Profiler.instance();
+    for (int i = 0; i < len; i++) {
+      long timeMillis = cpuProfileStartMillis + i * BUCKET_SIZE_MILLIS;
+      long timeNanos =
+          TimeUnit.MILLISECONDS.toNanos(timeMillis - currentTimeMillis) + currentTimeNanos;
+      profiler.logEventAtTime(
+          timeNanos, ProfilerTask.LOCAL_CPU_USAGE, String.valueOf(localCpuUsageValues[i]));
+    }
+    localCpuUsage = null;
+  }
+}