1 files changed, 88 insertions, 0 deletions
diff --git a/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala b/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala
new file mode 100644
index 0000000000..e1eb7a57fe
--- /dev/null
+++ b/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala
@@ -0,0 +1,88 @@
+package scala.reflect
+package runtime
+
+/** This trait overrides methods in reflect.internal, bracketing
+ *  them in synchronized { ... } to make them thread-safe
+ */
+trait SynchronizedTypes extends internal.Types { self: SymbolTable =>
+
+  // No sharing of map objects:
+  override protected def commonOwnerMap = new CommonOwnerMap
+
+  private object uniqueLock
+
+  override def unique[T <: Type](tp: T): T = uniqueLock.synchronized { super.unique(tp) }
+
+  class SynchronizedUndoLog extends UndoLog {
+
+    override def clear() =
+      synchronized { super.clear() }
+
+    override def undo[T](block: => T): T =
+      synchronized { super.undo(block) }
+
+    override def undoUnless(block: => Boolean): Boolean =
+      synchronized { super.undoUnless(block) }
+  }
+
+  override protected def newUndoLog = new SynchronizedUndoLog
+
+  override protected def baseTypeOfNonClassTypeRef(tpe: NonClassTypeRef, clazz: Symbol) =
+    synchronized { super.baseTypeOfNonClassTypeRef(tpe, clazz) }
+
+  private object subsametypeLock
+
+  override def isSameType(tp1: Type, tp2: Type): Boolean =
+    subsametypeLock.synchronized { super.isSameType(tp1, tp2) }
+
+  override def isDifferentType(tp1: Type, tp2: Type): Boolean =
+    subsametypeLock.synchronized { super.isDifferentType(tp1, tp2) }
+
+  override def isSubType(tp1: Type, tp2: Type, depth: Int): Boolean =
+    subsametypeLock.synchronized { super.isSubType(tp1, tp2, depth) }
+
+  private object lubglbLock
+
+  override def glb(ts: List[Type]): Type =
+    lubglbLock.synchronized { super.glb(ts) }
+
+  override def lub(ts: List[Type]): Type =
+    lubglbLock.synchronized { super.lub(ts) }
+
+  private object indentLock
+
+  override protected def explain[T](op: String, p: (Type, T) => Boolean, tp1: Type, arg2: T): Boolean = {
+    indentLock.synchronized { super.explain(op, p, tp1, arg2) }
+  }
+
+  private object toStringLock
+
+  override protected def typeToString(tpe: Type): String =
+    toStringLock.synchronized(super.typeToString(tpe))
+
+  /* The idea of caches is as follows.
+   * When in reflexive mode, a cache is either null, or one sentinal
+   * value representing undefined or the final defined
+   * value. Hence, we can ask in non-synchronized ode whether the cache field
+   * is non null and different from the sentinel (if a sentinel exists).
+   * If that's true, the cache value is current.
+   * Otherwise we arrive in one of the defined... methods listed below
+   * which go through all steps in synchronized mode.
+   */
+
+  override protected def defineUnderlyingOfSingleType(tpe: SingleType) =
+    tpe.synchronized { super.defineUnderlyingOfSingleType(tpe) }
+
+  override protected def defineBaseTypeSeqOfCompoundType(tpe: CompoundType) =
+    tpe.synchronized { super.defineBaseTypeSeqOfCompoundType(tpe) }
+
+  override protected def defineBaseClassesOfCompoundType(tpe: CompoundType) =
+    tpe.synchronized { super.defineBaseClassesOfCompoundType(tpe) }
+
+  override protected def defineParentsOfTypeRef(tpe: TypeRef) =
+    tpe.synchronized { super.defineParentsOfTypeRef(tpe) }
+
+  override protected def defineBaseTypeSeqOfTypeRef(tpe: TypeRef) =
+    tpe.synchronized { super.defineBaseTypeSeqOfTypeRef(tpe) }
+
+}