Allow cycle detector to be injected into ParallelEvaluator, so that callers can use different cycle detection algorithms if they wish.

--
MOS_MIGRATED_REVID=131347160

1 files changed, 27 insertions, 14 deletions

diff --git a/src/main/java/com/google/devtools/build/skyframe/ParallelEvaluatorContext.java b/src/main/java/com/google/devtools/build/skyframe/ParallelEvaluatorContext.java
index dbfd56760e..f364a71f4b 100644
--- a/src/main/java/com/google/devtools/build/skyframe/ParallelEvaluatorContext.java
+++ b/src/main/java/com/google/devtools/build/skyframe/ParallelEvaluatorContext.java
@@ -36,6 +36,12 @@ import javax.annotation.Nullable;
  * <p>Also used during cycle detection.
  */
 class ParallelEvaluatorContext {
+  enum EnqueueParentBehavior {
+    ENQUEUE,
+    SIGNAL,
+    NO_ACTION
+  }
+
   private final QueryableGraph graph;
   private final Version graphVersion;
   private final ImmutableMap<SkyFunctionName, ? extends SkyFunction> skyFunctions;
@@ -133,27 +139,34 @@ class ParallelEvaluatorContext {
    * cycles).
    */
   void signalValuesAndEnqueueIfReady(
-      SkyKey skyKey, Iterable<SkyKey> keys, Version version, boolean enqueueParents)
+      SkyKey skyKey, Iterable<SkyKey> keys, Version version, EnqueueParentBehavior enqueueParents)
       throws InterruptedException {
     // No fields of the entry are needed here, since we're just enqueuing for evaluation, but more
     // importantly, these hints are not respected for not-done nodes. If they are, we may need to
     // alter this hint.
     Map<SkyKey, ? extends NodeEntry> batch = graph.getBatch(skyKey, Reason.SIGNAL_DEP, keys);
-    if (enqueueParents) {
-      for (SkyKey key : keys) {
-        NodeEntry entry = Preconditions.checkNotNull(batch.get(key), key);
-        if (entry.signalDep(version)) {
-          getVisitor().enqueueEvaluation(key);
+    switch (enqueueParents) {
+      case ENQUEUE:
+        for (SkyKey key : keys) {
+          NodeEntry entry = Preconditions.checkNotNull(batch.get(key), key);
+          if (entry.signalDep(version)) {
+            getVisitor().enqueueEvaluation(key);
+          }
         }
-      }
-    } else {
-      for (SkyKey key : keys) {
-        NodeEntry entry = Preconditions.checkNotNull(batch.get(key), key);
-        if (!entry.isDone()) {
-          // In cycles, we can have parents that are already done.
-          entry.signalDep(version);
+        return;
+      case SIGNAL:
+        for (SkyKey key : keys) {
+          NodeEntry entry = Preconditions.checkNotNull(batch.get(key), key);
+          if (!entry.isDone()) {
+            // In cycles, we can have parents that are already done.
+            entry.signalDep(version);
+          }
         }
-      }
+        return;
+      case NO_ACTION:
+        return;
+      default:
+        throw new IllegalStateException(enqueueParents + ", " + skyKey);
     }
   }