Remove lock around DiGraph in BlazeQueryEnvironment

- New lock introduced around Node.succs and Node.preds. These locks always hold in direction Node.succs -> Node.preds that's why reordering deadlock never happens.
- All logic related to changing collection implementation from ArrayList to CompactHasSet and vise versa encapsulated in dedicated class ConcurrentCollectionWrapper.
- Remove some code related to removing node from DiGraph to Node.

RELNOTES:none
PiperOrigin-RevId: 192282628

1 files changed, 2 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryEnvironment.java b/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryEnvironment.java
index 3c5bf30491..68ab117f37 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryEnvironment.java
@@ -348,7 +348,7 @@ public class BlazeQueryEnvironment extends AbstractBlazeQueryEnvironment<Target>
   private class GraphBuildingObserver implements TargetEdgeObserver {
 
     @Override
-    public synchronized void edge(Target from, Attribute attribute, Target to) {
+    public void edge(Target from, Attribute attribute, Target to) {
       Preconditions.checkState(attribute == null ||
           dependencyFilter.apply(((Rule) from), attribute),
           "Disallowed edge from LabelVisitor: %s --> %s", from, to);
@@ -356,7 +356,7 @@ public class BlazeQueryEnvironment extends AbstractBlazeQueryEnvironment<Target>
     }
 
     @Override
-    public synchronized void node(Target node) {
+    public void node(Target node) {
       graph.createNode(node);
     }