locking of boot directory can be disabled by with [boot].lock: true in boot.properties

compile/src/test/scala/WithCompiler.scala

@@ -11,7 +11,7 @@ object WithCompiler
 	{
 		launcher { (launch, log) =>
 			withTemporaryDirectory { componentDirectory =>
-				val manager = new ComponentManager(xsbt.boot.Locks, new boot.ComponentProvider(componentDirectory), log)
+				val manager = new ComponentManager(xsbt.boot.Locks, new boot.ComponentProvider(componentDirectory, true), log)
 				val compiler = new AnalyzingCompiler(ScalaInstance(scalaVersion, launch), manager, log)
 				compiler.newComponentCompiler(log).clearCache(ComponentCompiler.compilerInterfaceID)
 				define(manager, ComponentCompiler.compilerInterfaceSrcID, getResource("CompilerInterface.scala"), getClassResource(classOf[jline.Completor]))

ivy/src/test/scala/ComponentManagerTest.scala

@@ -77,5 +77,5 @@ object ComponentManagerTest extends Specification
 	private def writeRandomContent(file: File) = IO.write(file, randomString)
 	private def randomString = "asdf"
 	private def withManager[T](f: ComponentManager => T): T =
-		TestLogger( logger => withTemporaryDirectory { temp =>  f(new ComponentManager(xsbt.boot.Locks, new xsbt.boot.ComponentProvider(temp), logger)) } )
+		TestLogger( logger => withTemporaryDirectory { temp =>  f(new ComponentManager(xsbt.boot.Locks, new xsbt.boot.ComponentProvider(temp, true), logger)) } )
 }

launch/ConfigurationParser.scala

@@ -108,8 +108,9 @@ class ConfigurationParser
 		val (enableQuick, m4) = bool(m3, "quick-option", false)
 		val (promptFill, m5) = bool(m4, "prompt-fill", false)
 		val (promptCreate, m6) = id(m5, "prompt-create", "")
-		check(m6, "label")
-		BootSetup(dir, props, search, promptCreate, enableQuick, promptFill)
+		val (lock, m7) = bool(m6, "lock", true)
+		check(m7, "label")
+		BootSetup(dir, lock, props, search, promptCreate, enableQuick, promptFill)
 	}
 	def getLogging(m: LabelMap): Logging = check("label", process(m, "level", getLevel))
 	def getLevel(m: Option[String]) = m.map(LogLevel.apply).getOrElse(new Logging(LogLevel.Info))

launch/Launch.scala

@@ -76,7 +76,7 @@ object Launch
 final class RunConfiguration(val scalaVersion: String, val app: xsbti.ApplicationID, val workingDirectory: File, val arguments: List[String])
 
 import BootConfiguration.{appDirectoryName, baseDirectoryName, ScalaDirectoryName, TestLoadScalaClasses}
-class Launch private[xsbt](val bootDirectory: File, val ivyOptions: IvyOptions) extends xsbti.Launcher
+class Launch private[xsbt](val bootDirectory: File, val lockBoot: Boolean, val ivyOptions: IvyOptions) extends xsbti.Launcher
 {
 	import ivyOptions.{classifiers, repositories}
 	bootDirectory.mkdirs
@@ -85,7 +85,7 @@ class Launch private[xsbt](val bootDirectory: File, val ivyOptions: IvyOptions)
 	def getScala(version: String, reason: String): xsbti.ScalaProvider = scalaProviders(version, reason)
 
 	lazy val topLoader = (new JNAProvider).loader
-	val updateLockFile = new File(bootDirectory, "sbt.boot.lock")
+	val updateLockFile = if(lockBoot) Some(new File(bootDirectory, "sbt.boot.lock")) else None
 
 	def globalLock: xsbti.GlobalLock = Locks
 	def ivyHome = ivyOptions.ivyHome.orNull
@@ -145,7 +145,7 @@ class Launch private[xsbt](val bootDirectory: File, val ivyOptions: IvyOptions)
 			}
 			def newMain(): xsbti.AppMain = mainClass.newInstance
 
-			lazy val components = new ComponentProvider(appHome)
+			lazy val components = new ComponentProvider(appHome, lockBoot)
 		}
 	}
 }
@@ -156,11 +156,11 @@ object Launcher
 	def apply(bootDirectory: File, ivyOptions: IvyOptions): xsbti.Launcher =
 		apply(bootDirectory, ivyOptions, GetLocks.find)
 	def apply(bootDirectory: File, ivyOptions: IvyOptions, locks: xsbti.GlobalLock): xsbti.Launcher =
-		new Launch(bootDirectory, ivyOptions) {
+		new Launch(bootDirectory, true, ivyOptions) {
 			override def globalLock = locks
 		}
 	def apply(explicit: LaunchConfiguration): xsbti.Launcher =
-		new Launch(explicit.boot.directory, explicit.ivyConfiguration)
+		new Launch(explicit.boot.directory, explicit.boot.lock, explicit.ivyConfiguration)
 	def defaultAppProvider(baseDirectory: File): xsbti.AppProvider = getAppProvider(baseDirectory, Configuration.configurationOnClasspath)
 	def getAppProvider(baseDirectory: File, configLocation: URL): xsbti.AppProvider =
 	{
@@ -172,7 +172,7 @@ object Launcher
 		scalaProvider.app(config.app.toID)
 	}
 }
-class ComponentProvider(baseDirectory: File) extends xsbti.ComponentProvider
+class ComponentProvider(baseDirectory: File, lockBoot: Boolean) extends xsbti.ComponentProvider
 {
 	def componentLocation(id: String): File = new File(baseDirectory, id)
 	def component(id: String) = Provider.wrapNull(componentLocation(id).listFiles).filter(_.isFile)
@@ -184,7 +184,7 @@ class ComponentProvider(baseDirectory: File) extends xsbti.ComponentProvider
 		else
 			Copy(files.toList, location)
 	}
-	def lockFile = ComponentProvider.lockFile(baseDirectory)
+	def lockFile = if(lockBoot) ComponentProvider.lockFile(baseDirectory) else null // null for the Java interface
 }
 object ComponentProvider
 {

launch/LaunchConfiguration.scala

@@ -93,9 +93,9 @@ object Search extends Enumeration
 	def apply(s: String, paths: List[File]): Search = Search(toValue(s), paths)
 }
 
-final case class BootSetup(directory: File, properties: File, search: Search, promptCreate: String, enableQuick: Boolean, promptFill: Boolean)
+final case class BootSetup(directory: File, lock: Boolean, properties: File, search: Search, promptCreate: String, enableQuick: Boolean, promptFill: Boolean)
 {
-	def map(f: File => File) = BootSetup(f(directory), f(properties), search, promptCreate, enableQuick, promptFill)
+	def map(f: File => File) = BootSetup(f(directory), lock, f(properties), search, promptCreate, enableQuick, promptFill)
 }
 final case class AppProperty(name: String)(val quick: Option[PropertyInit], val create: Option[PropertyInit], val fill: Option[PropertyInit])
 

launch/Locks.scala

@@ -24,7 +24,8 @@ object GetLocks
 object Locks extends xsbti.GlobalLock
 {
 	private[this] val locks = new Cache[File, Unit, GlobalLock]( (f, _) => new GlobalLock(f))
-	def apply[T](file: File, action: Callable[T]): T =
+	def apply[T](file: File, action: Callable[T]): T = if(file eq null) action.call else apply0(file, action)
+	private[this] def apply0[T](file: File, action: Callable[T]): T =
 	{
 		val lock =
 			synchronized

launch/Provider.scala

@@ -17,7 +17,7 @@ trait Provider
 	def target: UpdateTarget
 	def failLabel: String
 	def parentLoader: ClassLoader
-	def lockFile: File
+	def lockFile: Option[File]
 
 	def classpath: Array[File] = Provider.getJars(baseDirectories)
 	def fullClasspath:Array[File] = concat(classpath, extraClasspath)
@@ -29,7 +29,8 @@ trait Provider
 		throw new xsbti.RetrieveException(versionString, "Could not retrieve " + failLabel + extra)
 	private def versionString: String = target match { case _: UpdateScala => configuration.scalaVersion; case a: UpdateApp => Value.get(a.id.version) }
 
-	val (jars, loader) = Locks(lockFile, new initialize)
+	val (jars, loader) = Locks(orNull(lockFile), new initialize)
+	private[this] def orNull[T >: Null](opt: Option[T]): T = opt match { case None => null; case Some(x) => x }
 	private final class initialize extends Callable[(Array[File], ClassLoader)]
 	{
 		def call =

launch/interface/src/main/java/xsbti/ComponentProvider.java

@@ -6,5 +6,6 @@ public interface ComponentProvider
 {
 	public File[] component(String componentID);
 	public void defineComponent(String componentID, File[] components);
+	 // null if locking disabled
 	public File lockFile();
 }