Add support for the Json trace file format

Add a --experimental_generate_json_trace_profile option that puts a file into
the output base (or uses --profile if set).

There are still a lot of problems with this.
- unexplained holes
- way too many threads
- nonsensical event titles
- too many detail events, too little overview
- it may also cause unnecessary load
- it silently overwrites the existing file on subsequent invocations

The format is documented here: goo.gl/oMZPLh

PiperOrigin-RevId: 200259431

1 files changed, 3 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/skyframe/AbstractParallelEvaluator.java b/src/main/java/com/google/devtools/build/skyframe/AbstractParallelEvaluator.java
index 2373959857..0c94277a4b 100644
--- a/src/main/java/com/google/devtools/build/skyframe/AbstractParallelEvaluator.java
+++ b/src/main/java/com/google/devtools/build/skyframe/AbstractParallelEvaluator.java
@@ -375,19 +375,19 @@ public abstract class AbstractParallelEvaluator {
                 state);
 
         SkyValue value = null;
-        long startTime = BlazeClock.instance().nanoTime();
+        long startTimeNanos = BlazeClock.instance().nanoTime();
         try {
           try {
             evaluatorContext.getProgressReceiver().stateStarting(skyKey, NodeState.COMPUTE);
             value = factory.compute(skyKey, env);
           } finally {
-            long elapsedTimeNanos = BlazeClock.instance().nanoTime() - startTime;
+            long elapsedTimeNanos = BlazeClock.instance().nanoTime() - startTimeNanos;
             if (elapsedTimeNanos > 0) {
               evaluatorContext.getProgressReceiver().stateEnding(skyKey, NodeState.COMPUTE,
                   elapsedTimeNanos);
               Profiler.instance()
                   .logSimpleTaskDuration(
-                      startTime,
+                      startTimeNanos,
                       Duration.ofNanos(elapsedTimeNanos),
                       ProfilerTask.SKYFUNCTION,
                       skyKey.functionName().getName());