Merge pull request #1200 from Vampire/make-coverage-test-execution-li…

…stener-thread-safe

Make the coverage test execution listener thread-safe

pitest/src/main/java/org/pitest/coverage/execute/CoverageTestExecutionListener.java

@@ -7,6 +7,9 @@
 
 import java.lang.management.ManagementFactory;
 import java.lang.management.ThreadMXBean;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Logger;
 
 import static java.util.concurrent.TimeUnit.NANOSECONDS;
@@ -17,8 +20,9 @@ public class CoverageTestExecutionListener implements TestUnitExecutionListener
     private final ThreadMXBean threads = ManagementFactory.getThreadMXBean();
 
     private final CoverageReceiver invokeQueue;
-    private long t0;
-    private int threadsBeforeTest;
+    private final Map<Description, Long> startTimes = new ConcurrentHashMap<>();
+    private final Map<Description, Integer> threadsBeforeTest = new ConcurrentHashMap<>();
+    private final AtomicLong firstThreadId = new AtomicLong();
 
     public CoverageTestExecutionListener(CoverageReceiver invokeQueue) {
         this.invokeQueue = invokeQueue;
@@ -27,26 +31,42 @@ public CoverageTestExecutionListener(CoverageReceiver invokeQueue) {
     @Override
     public void executionStarted(Description description) {
         LOG.fine(() -> "Gathering coverage for test " + description);
-        t0 = System.nanoTime();
-        threadsBeforeTest = this.threads.getThreadCount();
+        startTimes.put(description, System.nanoTime());
+        if (!firstThreadId.compareAndSet(0, Thread.currentThread().getId())
+                && (firstThreadId.get() != Thread.currentThread().getId())
+                && (threadsBeforeTest.size() > 0)) {
+            LOG.warning("Tests are run in parallel. Coverage recording most likely will not work properly.");
+        }
+        threadsBeforeTest.put(description, threads.getThreadCount());
     }
 
     @Override
     public void executionFinished(Description description, boolean passed) {
-        int executionTime = (int) NANOSECONDS.toMillis(System.nanoTime() - t0);
-        if (executionTime < 0) {
-            LOG.warning("Recorded negative test time. Test life cycle not as expected.");
-            // substitute an unimportant, but high, time for this test so it is unlikely to
+        Long t0 = startTimes.remove(description);
+        int executionTime;
+        if (t0 == null) {
+            LOG.warning("Recorded no start time. Test life cycle not as expected.");
+            // substitute an unimportant, but high, time for this test, so it is unlikely to
             // be prioritised above others.
-            executionTime = 120000;
+            executionTime = 120_000;
+        } else {
+            executionTime = (int) NANOSECONDS.toMillis(System.nanoTime() - t0);
+            if (executionTime < 0) {
+                LOG.warning("Recorded negative test time. Test life cycle not as expected.");
+                // substitute an unimportant, but high, time for this test, so it is unlikely to
+                // be prioritised above others.
+                executionTime = 120_000;
+            }
         }
 
-        final int threadsAfterTest = this.threads.getThreadCount();
-        if (threadsAfterTest > threadsBeforeTest) {
+        final int threadsAfterTest = threads.getThreadCount();
+        if (threadsAfterTest > threadsBeforeTest.getOrDefault(description, 0)) {
             LOG.warning("More threads at end of test (" + threadsAfterTest + ") "
                     + description + " than start. ("
                     + threadsBeforeTest + ")");
         }
-        this.invokeQueue.recordTestOutcome(description, passed, executionTime);
+        threadsBeforeTest.remove(description);
+
+        invokeQueue.recordTestOutcome(description, passed, executionTime);
     }
 }