Explicitly set default value to "UNFINISHED" for TraceBuilder's ResultType

[junchuanwang]

Summary

Symptom

There has been a report that some race condition can cause resultType being referenced as required constructor argument from a builder (during trace build) before it is being set.

StackTrace is as below:

java.lang.NullPointerException: resultType must not be null"java.lang.NullPointerException: resultType must not be null
  at com.linkedin.parseq.internal.ArgumentUtil.requireNotNull(ArgumentUtil.java:28)
  at com.linkedin.parseq.trace.ShallowTraceImp.<init>(ShallowTraceImp.java:52)
  at com.linkedin.parseq.trace.ShallowTraceBuilder.build(ShallowTraceBuilder.java:304)
  at com.linkedin.parseq.trace.TraceBuilder.lambda$build$1(TraceBuilder.java:85)
  at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1133)
  at com.linkedin.parseq.trace.TraceBuilder.build(TraceBuilder.java:85)
  at com.linkedin.parseq.BaseTask.getTrace(BaseTask.java:292)
  at com.linkedin.parseq.trace.TraceUtil.getJsonTrace(TraceUtil.java:22)
  at com.linkedin.parseq.ParSeqUnitTestHelper.logTracingResults(ParSeqUnitTestHelper.java:346)
  at com.linkedin.parseq.ParSeqUnitTestHelper.runAndWait(ParSeqUnitTestHelper.java:172)
  at com.linkedin.parseq.ParSeqUnitTestHelper.runAndWait(ParSeqUnitTestHelper.java:147)
  at com.linkedin.parseq.AbstractBaseEngineTest.runAndWait(AbstractBaseEngineTest.java:59)

Invesetigation

It is intermittent so it is rather hard to reproduce. By inspecting the code, it is also not clear when setResultType was be exempted from being called sometimes.

Impact assessment

The issue should only impact trace and we don't get such report for years. Only two users ever reported and both claim to be intermittent. I think we can set a default value of "UNFINISHED" so the exception won't be thrown during the run time. We therefore let the "bad" trace to be surfaced and investigated if the trace itself does not make sense.

Details about code change

• Set an explicit default value of ResultType.UNFINISHED
• Also fix another location where invalid ascii character were used and cannot build on certain machine (e.g. my machine which uses CBL-Mariner distribution)

Testing done

./gradlew build and ./gradlew test

[mchen07]

Thanks @junchuanwang for the quick fix.