Made the thread behavior of the repl a little b...

Made the thread behavior of the repl a little bit configurable. Every
line will run in the same thread:

  scala -Dscala.repl.no-threads

This mechanism is likely to change. Repl is obscenely overdue for a
config file. No review.

2 files changed, 7 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/interpreter/IMain.scala b/src/compiler/scala/tools/nsc/interpreter/IMain.scala
index e78af9fb67..d6ef04dbc1 100644
--- a/src/compiler/scala/tools/nsc/interpreter/IMain.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/IMain.scala
@@ -237,7 +237,8 @@ class IMain(val settings: Settings, protected val out: JPrintWriter) extends Imp
   lazy val isettings = new ISettings(this)
 
   /** Create a line manager.  Overridable.  */
-  protected def createLineManager(): Line.Manager = new Line.Manager
+  protected def createLineManager(): Line.Manager =
+    if (replProps.noThreads) null else new Line.Manager
 
   /** Instantiate a compiler.  Overridable. */
   protected def newCompiler(settings: Settings, reporter: Reporter) = {
@@ -909,6 +910,10 @@ class IMain(val settings: Settings, protected val out: JPrintWriter) extends Imp
 
     /** load and run the code using reflection */
     def loadAndRun: (String, Boolean) = {
+      if (replProps.noThreads) return {
+        try   { ("" + (lineRep call sessionNames.print), true) }
+        catch { case ex => (lineRep.bindError(ex), false) }
+      }
       import interpreter.Line._
 
       try {
diff --git a/src/compiler/scala/tools/nsc/interpreter/ReplProps.scala b/src/compiler/scala/tools/nsc/interpreter/ReplProps.scala
index 5eb1e0ae18..72bfb2eeff 100644
--- a/src/compiler/scala/tools/nsc/interpreter/ReplProps.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/ReplProps.scala
@@ -13,6 +13,7 @@ class ReplProps {
 
   val jlineDebug = bool("scala.tools.jline.internal.Log.debug")
   val jlineTrace = bool("scala.tools.jline.internal.Log.trace")
+  val noThreads  = bool("scala.repl.no-threads")
 
   val info  = bool("scala.repl.info")
   val debug = bool("scala.repl.debug")