1 files changed, 120 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/AbstractCriticalPathComponent.java b/src/main/java/com/google/devtools/build/lib/runtime/AbstractCriticalPathComponent.java
new file mode 100644
index 0000000000..9bf7a3f27b
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+++ b/src/main/java/com/google/devtools/build/lib/runtime/AbstractCriticalPathComponent.java
@@ -0,0 +1,120 @@
+// Copyright 2014 Google Inc. 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.runtime;
+
+import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.actions.Action;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadCompatible;
+
+import javax.annotation.Nullable;
+
+/**
+ * This class records the critical path for the graph of actions executed.
+ */
+@ThreadCompatible
+public class AbstractCriticalPathComponent<C extends AbstractCriticalPathComponent<C>> {
+
+  /** Wall time start time for the action. In milliseconds. */
+  private final long startTime;
+  /** Wall time finish time for the action. In milliseconds. */
+  private long finishTime = 0;
+  protected volatile boolean isRunning = true;
+
+  /** We keep here the critical path time for the most expensive child. */
+  private long childAggregatedWallTime = 0;
+
+  /** The action for which we are storing the stat. */
+  private final Action action;
+
+  /**
+   * Child with the maximum critical path.
+   */
+  @Nullable
+  private C child;
+
+  public AbstractCriticalPathComponent(Action action, long startTime) {
+    this.action = action;
+    this.startTime = startTime;
+  }
+
+  /** Sets the finish time for the action in milliseconds. */
+  public void setFinishTimeMillis(long finishTime) {
+    Preconditions.checkState(isRunning, "Already stopped! %s.", action);
+    this.finishTime = finishTime;
+    isRunning = false;
+  }
+
+  /** The action for which we are storing the stat. */
+  public Action getAction() {
+    return action;
+  }
+
+  /**
+   * Add statistics for one dependency of this action.
+   */
+  public void addDepInfo(C dep) {
+    Preconditions.checkState(!dep.isRunning,
+        "Cannot add critical path stats when the action is not finished. %s. %s", action,
+        dep.getAction());
+    long childAggregatedWallTime = dep.getAggregatedWallTime();
+    // Replace the child if its critical path had the maximum wall time.
+    if (child == null || childAggregatedWallTime > this.childAggregatedWallTime) {
+      this.childAggregatedWallTime = childAggregatedWallTime;
+      child = dep;
+    }
+  }
+
+  public long getActionWallTime() {
+    Preconditions.checkState(!isRunning, "Still running %s", action);
+    return finishTime - startTime;
+  }
+
+  /**
+   * Returns the current critical path for the action in milliseconds.
+   *
+   * <p>Critical path is defined as : action_execution_time + max(child_critical_path).
+   */
+  public long getAggregatedWallTime() {
+    Preconditions.checkState(!isRunning, "Still running %s", action);
+    return getActionWallTime() + childAggregatedWallTime;
+  }
+
+  /** Time when the action started to execute. Milliseconds since epoch time. */
+  public long getStartTime() {
+    return startTime;
+  }
+
+  /**
+   * Get the child critical path component.
+   *
+   * <p>The component dependency with the maximum total critical path time.
+   */
+  @Nullable
+  public C getChild() {
+    return child;
+  }
+
+  /**
+   * Returns a human readable representation of the critical path stats with all the details.
+   */
+  @Override
+  public String toString() {
+    String currentTime = "still running ";
+    if (!isRunning) {
+      currentTime = String.format("%.2f", getActionWallTime() / 1000.0) + "s ";
+    }
+    return currentTime + action.describe();
+  }
+}
+