From f2f54441b79bb6d44be7a5618540c79a6c2f147f Mon Sep 17 00:00:00 2001
From: fitermay <fiterman@gmail.com>
Date: Wed, 28 Feb 2018 21:33:03 -0500
Subject: [PATCH 1/2] make values in TypeEvalContextBasedCache soft

to let gc collect not-recently-used values
---
 .../python/psi/types/TypeEvalContextBasedCache.java      | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContextBasedCache.java b/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContextBasedCache.java
index cd094a073208..338adc7ccc45 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContextBasedCache.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContextBasedCache.java
@@ -20,9 +20,9 @@ import com.intellij.psi.util.CachedValueProvider;
 import com.intellij.psi.util.CachedValuesManager;
 import com.intellij.psi.util.PsiModificationTracker;
 import com.intellij.util.Function;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 /**
@@ -68,8 +68,9 @@ public final class TypeEvalContextBasedCache<T> {
       return value;
     }
     final T newValue = myProvider.fun(context);
-    map.put(key, newValue); // ConcurrentMap guarantees happens-before so from this moment get() should work in other threads
-    return newValue;
+    T oldValue =
+      map.putIfAbsent(key, newValue);// ConcurrentMap guarantees happens-before so from this moment get() should work in other threads
+    return oldValue == null ? newValue : oldValue;
   }
 
   /**
@@ -81,7 +82,7 @@ public final class TypeEvalContextBasedCache<T> {
     public Result<ConcurrentMap<TypeEvalConstraints, T>> compute() {
       // This method is called if cache is empty. Create new map for it.
       // Concurrent map allows several threads to call get and put, so it is thread safe but not atomic
-      final ConcurrentHashMap<TypeEvalConstraints, T> map = new ConcurrentHashMap<>();
+      final ConcurrentMap<TypeEvalConstraints, T> map = ContainerUtil.createConcurrentSoftValueMap();
       return new Result<>(map, PsiModificationTracker.MODIFICATION_COUNT);
     }
   }

From 44d758b1dbfabae62a19de96046051ead667f579 Mon Sep 17 00:00:00 2001
From: fitermay <fiterman@gmail.com>
Date: Wed, 28 Feb 2018 21:36:46 -0500
Subject: [PATCH 2/2] minor: anonymous ThreadLocal class ->
 ThreadLocal.withInitial

minor benefit is avoiding a reference cycle from anonymous class to
TypeEvalContext as anonymous inner classes always hold a reference to
the containing class
---
 .../python/psi/types/TypeEvalContext.java        | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContext.java b/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContext.java
index fba9dfdb38d8..2cfa83700986 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContext.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/types/TypeEvalContext.java
@@ -47,18 +47,8 @@ public class TypeEvalContext {
 
   private final Map<PyTypedElement, PyType> myEvaluated = new HashMap<>();
   private final Map<PyCallable, PyType> myEvaluatedReturn = new HashMap<>();
-  private final ThreadLocal<Set<PyTypedElement>> myEvaluating = new ThreadLocal<Set<PyTypedElement>>() {
-    @Override
-    protected Set<PyTypedElement> initialValue() {
-      return new HashSet<>();
-    }
-  };
-  private final ThreadLocal<Set<PyCallable>> myEvaluatingReturn = new ThreadLocal<Set<PyCallable>>() {
-    @Override
-    protected Set<PyCallable> initialValue() {
-      return new HashSet<>();
-    }
-  };
+  private final ThreadLocal<Set<PyTypedElement>> myEvaluating = ThreadLocal.withInitial(HashSet::new);
+  private final ThreadLocal<Set<PyCallable>> myEvaluatingReturn = ThreadLocal.withInitial(HashSet::new);
 
   private TypeEvalContext(boolean allowDataFlow, boolean allowStubToAST, boolean allowCallContext, @Nullable PsiFile origin) {
     myConstraints = new TypeEvalConstraints(allowDataFlow, allowStubToAST, allowCallContext, origin);
@@ -254,7 +244,7 @@ public class TypeEvalContext {
   }
 
   /**
-   * @return context constraints (see {@link com.jetbrains.python.psi.types.TypeEvalConstraints}
+   * @return context constraints (see {@link TypeEvalConstraints}
    */
   @NotNull
   TypeEvalConstraints getConstraints() {