commit 441dcb1ed150d40cc27e6e86ebb60754e44ba89f
author Janak Ramakrishnan <janakr@google.com> Fri Oct 09 22:44:31 2015 +0000
committer Han-Wen Nienhuys <hanwen@google.com> Mon Oct 12 08:36:17 2015 +0000
tree c02c372884292384832bd9eacc29ca5565403b51
parent 10c363d892f4b290bb95954f8ccf81767904c7d3

Delay additions as well as removals of reverse deps. Now that removals are not all done during invalidation, repeated adding/removing means that we are consolidating more often, negating the benefit of delayed removals. To work around this, delay adds as well until we consolidate and verify the integrity of our data.

Since there is no well-defined point that a consolidation should trigger for a done node, we delay until our pending list is as large as the done list. We can tweak this if necessary for a memory/performance tradeoff.

The alternative to this that I could think of is giving up our strong integrity checks, which I'm not a fan of.

--
MOS_MIGRATED_REVID=105095886

src/main/java/com/google/devtools/build/skyframe/BuildingState.java

diff --git a/src/main/java/com/google/devtools/build/skyframe/BuildingState.java b/src/main/java/com/google/devtools/build/skyframe/BuildingState.java
index 59c18b8..0969d17 100644
--- a/src/main/java/com/google/devtools/build/skyframe/BuildingState.java
+++ b/src/main/java/com/google/devtools/build/skyframe/BuildingState.java
@@ -119,7 +119,7 @@
   // node will be removed by the time evaluation starts, so reverse deps to signal can just be
   // reverse deps in the main ValueEntry object.
   private Object reverseDepsToSignal = ImmutableList.of();
-  private Object reverseDepsDataToConsolidate = null;
+  private List<Object> reverseDepsDataToConsolidate = null;
   private boolean reverseDepIsSingleObject = false;
 
   private static final ReverseDepsUtil<BuildingState> REVERSE_DEPS_UTIL =
@@ -135,7 +135,7 @@
         }
 
         @Override
-        void setDataToConsolidate(BuildingState container, Object dataToConsolidate) {
+        void setDataToConsolidate(BuildingState container, List<Object> dataToConsolidate) {
           container.reverseDepsDataToConsolidate = dataToConsolidate;
         }
 
@@ -150,7 +150,7 @@
         }
 
         @Override
-        Object getDataToConsolidate(BuildingState container) {
+        List<Object> getDataToConsolidate(BuildingState container) {
           return container.reverseDepsDataToConsolidate;
         }
       };
@@ -404,7 +404,6 @@
    * @see NodeEntry#addReverseDepAndCheckIfDone(SkyKey)
    */
   void addReverseDepToSignal(SkyKey newReverseDep) {
-    REVERSE_DEPS_UTIL.consolidateData(this);
     REVERSE_DEPS_UTIL.addReverseDeps(this, Collections.singleton(newReverseDep));
   }