Reimplement blaze query using an async evaluation model. Use a concurrent backend for SkyQueryEnvironment's implementation in order to achieve parallelism.

Advantages:
-New design has no flaws that the old design had.
-Code is structured so that deadlocks due to thread starvation are impossible (yup!).

Disadvantages:
-The meat of this change needs to all be in a single CL because every single QueryFunction and QueryExpression needs to be rewritten in the async style.

Still TODO:
-Fully embrace the async model in all QueryFunctions (e.g. 'rdeps', 'allpaths').
-Use concurrency in BlazeQueryEnvironment to achieve parallel evaluation for (non SkyQuery) 'blaze query' and genquery.

--
PiperOrigin-RevId: 148690279
MOS_MIGRATED_REVID=148690279

1 files changed, 3 insertions, 25 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PrepareDepsOfPatternFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PrepareDepsOfPatternFunction.java
index df6351a513..3b4b768793 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/PrepareDepsOfPatternFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PrepareDepsOfPatternFunction.java
@@ -37,7 +37,6 @@ import com.google.devtools.build.lib.skyframe.EnvironmentBackedRecursivePackageP
 import com.google.devtools.build.lib.util.BatchCallback;
 import com.google.devtools.build.lib.util.BatchCallback.NullCallback;
 import com.google.devtools.build.lib.util.Preconditions;
-import com.google.devtools.build.lib.util.ThreadSafeBatchCallback;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.RootedPath;
@@ -47,7 +46,6 @@ import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.SkyValue;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.ForkJoinPool;
 import java.util.concurrent.atomic.AtomicReference;
 import javax.annotation.Nullable;
 
@@ -131,7 +129,7 @@ public class PrepareDepsOfPatternFunction implements SkyFunction {
    * transitive dependencies. Its methods may throw {@link MissingDepException} if the package
    * values this depends on haven't been calculated and added to its environment.
    */
-  static class DepsOfPatternPreparer implements TargetPatternResolver<Void> {
+  static class DepsOfPatternPreparer extends TargetPatternResolver<Void> {
 
     private final EnvironmentBackedRecursivePackageProvider packageProvider;
     private final Environment env;
@@ -230,7 +228,8 @@ public class PrepareDepsOfPatternFunction implements SkyFunction {
         String directory,
         boolean rulesOnly,
         ImmutableSet<PathFragment> excludedSubdirectories,
-        BatchCallback<Void, E> callback, Class<E> exceptionClass)
+        BatchCallback<Void, E> callback,
+        Class<E> exceptionClass)
         throws TargetParsingException, E, InterruptedException {
       FilteringPolicy policy =
           rulesOnly ? FilteringPolicies.RULES_ONLY : FilteringPolicies.NO_FILTER;
@@ -261,26 +260,5 @@ public class PrepareDepsOfPatternFunction implements SkyFunction {
         }
       }
     }
-
-    @Override
-    public <E extends Exception> void findTargetsBeneathDirectoryPar(
-        RepositoryName repository,
-        String originalPattern,
-        String directory,
-        boolean rulesOnly,
-        ImmutableSet<PathFragment> excludedSubdirectories,
-        ThreadSafeBatchCallback<Void, E> callback,
-        Class<E> exceptionClass,
-        ForkJoinPool forkJoinPool)
-        throws TargetParsingException, E, InterruptedException {
-      findTargetsBeneathDirectory(
-          repository,
-          originalPattern,
-          directory,
-          rulesOnly,
-          excludedSubdirectories,
-          callback,
-          exceptionClass);
-    }
   }
 }