A context to be notified byscala.concurrent.blocking when a thread is about to block. In effect this trait provides the implementation forscala.concurrent.Await.scala.concurrent.Await.result andscala.concurrent.Await.ready locates an instance ofBlockContext by first looking for one provided throughBlockContext.withBlockContext and failing that, checking whetherThread.currentThread is an instance ofBlockContext. So a thread pool can have itsjava.lang.Thread instances implementBlockContext. There's a defaultBlockContext used if the thread doesn't implementBlockContext.

Typically, you'll want to chain to the previousBlockContext, like this:

val oldContext = BlockContext.currentval myContext = new BlockContext {  override def blockOn[T](thunk: => T)(implicit permission: CanAwait): T = {    // you'd have code here doing whatever you need to do    // when the thread is about to block.    // Then you'd chain to the previous context:    oldContext.blockOn(thunk)  }}BlockContext.withBlockContext(myContext) {  // then this block runs with myContext as the handler  // for scala.concurrent.blocking}