Remove use of interrupts to in ClockUtils

node/src/main/kotlin/com/r3corda/node/utilities/ClockUtils.kt

@@ -1,15 +1,11 @@
 package com.r3corda.node.utilities
 
 import co.paralleluniverse.fibers.Suspendable
-import co.paralleluniverse.strands.AbstractFuture
 import co.paralleluniverse.strands.SettableFuture
-import co.paralleluniverse.strands.Strand
-import co.paralleluniverse.strands.SuspendableRunnable
 import com.google.common.util.concurrent.ListenableFuture
 import com.r3corda.core.then
 import rx.Observable
 import rx.Subscriber
-import rx.Subscription
 import rx.subscriptions.Subscriptions
 import java.time.Clock
 import java.time.Duration
@@ -17,6 +13,7 @@ import java.time.Instant
 import java.util.concurrent.*
 import java.util.concurrent.atomic.AtomicLong
 import java.util.function.BiConsumer
+import com.google.common.util.concurrent.SettableFuture as GuavaSettableFuture
 
 /**
  * The classes and methods in this file allow the use of custom Clocks in demos, simulations and testing
@@ -72,89 +69,60 @@ abstract class MutableClock : Clock() {
     }
 }
 
-/**
- * Internal method to do something that can be interrupted by a [MutableClock] in the case
- * of it being mutated.  Just returns if [MutableClock] mutates, so needs to be
- * called in a loop.
- *
- * @throws InterruptedException if interrupted by something other than a [MutableClock].
- */
-@Suspendable
-private fun Clock.doInterruptibly(runnable: SuspendableRunnable) {
-    var subscription: Subscription? = null
-    var interruptedByMutation = false
-    try {
-        if (this is MutableClock) {
-            val strand = Strand.currentStrand()
-            subscription = this.mutations.subscribe {
-                interruptedByMutation = true
-                strand.interrupt()
-            }
-        }
-        runnable.run()
-    } catch(e: InterruptedException) {
-        // If clock has not mutated, then re-throw
-        if (!interruptedByMutation) {
-            throw e
-        }
-    } finally {
-        if (this is MutableClock) {
-            subscription!!.unsubscribe()
-        }
-        Strand.interrupted()
-    }
-}
-
 /**
  * Wait until the given [Future] is complete or the deadline is reached, with support for [MutableClock] implementations
- * used in demos or testing.  This will also substitute a Fiber compatible Future if required.
+ * used in demos or testing.  This will substitute a Fiber compatible Future so the current [Strand] is not blocked.
  *
  * @return true if the [Future] is complete, false if the deadline was reached.
  */
 @Suspendable
-fun Clock.awaitWithDeadline(deadline: Instant, future: Future<*> = SettableFuture<Any>()): Boolean {
-    // convert the future to a strand friendly variety if possible so as not to accidentally block the underlying thread
-    val fiberFriendlyFuture = makeFutureCurrentStrandFriendly(future)
-
-    var nanos = 0L
+fun Clock.awaitWithDeadline(deadline: Instant, future: Future<*> = GuavaSettableFuture.create<Any>()): Boolean {
+    var nanos: Long
     do {
-        doInterruptibly(SuspendableRunnable @Suspendable {
-            nanos = Duration.between(this.instant(), deadline).toNanos()
-            if (nanos > 0) {
-                try {
-                    fiberFriendlyFuture.get(nanos, TimeUnit.NANOSECONDS)
-                } catch(e: ExecutionException) {
-                    // No need to take action as will fall out of the loop due to future.isDone
-                } catch(e: CancellationException) {
-                    // No need to take action as will fall out of the loop due to future.isDone
-                }
+        val originalFutureCompleted = makeStrandFriendlySettableFuture(future)
+        val subscription = if (this is MutableClock) {
+            mutations.first().subscribe {
+                originalFutureCompleted.set(false)
             }
-        })
-    } while (!future.isDone && nanos > 0)
+        } else {
+            null
+        }
+        nanos = Duration.between(this.instant(), deadline).toNanos()
+        if (nanos > 0) {
+            try {
+                // This will return when it times out, or when the clock mutates or when when the original future completes.
+                originalFutureCompleted.get(nanos, TimeUnit.NANOSECONDS)
+            } catch(e: ExecutionException) {
+                // No need to take action as will fall out of the loop due to future.isDone
+            } catch(e: CancellationException) {
+                // No need to take action as will fall out of the loop due to future.isDone
+            }
+        }
+        subscription?.unsubscribe()
+        originalFutureCompleted.cancel(false)
+    } while (nanos > 0 && !future.isDone)
     return future.isDone
 }
 
 /**
- * Convert a Guava [ListenableFuture] or JDK8 [CompletableFuture] to Quasar implementation if currently
- * on a Fiber and not already using Quasar futures.
+ * Convert a Guava [ListenableFuture] or JDK8 [CompletableFuture] to Quasar implementation and set to true when a result
+ * or [Throwable] is available in the original.
  *
  * We need this so that we do not block the actual thread when calling get(), but instead allow a Quasar context
  * switch.  There's no need to checkpoint our Fibers as there's no external effect of waiting.
  */
-private fun <T : Any> makeFutureCurrentStrandFriendly(future: Future<T>): Future<out T> {
-    return if (Strand.isCurrentFiber() && future !is AbstractFuture) {
-        if (future is ListenableFuture) {
-            val settable = SettableFuture<T>()
-            future.then { settable.set(null) }
-            settable
-        } else if (future is CompletableFuture) {
-            val settable = SettableFuture<T>()
-            future.whenComplete(BiConsumer { value, throwable -> settable.set(null) })
-            settable
-        } else {
-            throw IllegalArgumentException("Cannot make future $future Fiber friendly whilst on a Fiber")
-        }
-    } else future
+private fun <T : Any> makeStrandFriendlySettableFuture(future: Future<T>): SettableFuture<Boolean> {
+    return if (future is ListenableFuture) {
+        val settable = SettableFuture<Boolean>()
+        future.then { settable.set(true) }
+        settable
+    } else if (future is CompletableFuture) {
+        val settable = SettableFuture<Boolean>()
+        future.whenComplete(BiConsumer { value, throwable -> settable.set(true) })
+        settable
+    } else {
+        throw IllegalArgumentException("Cannot make future $future Fiber friendly.")
+    }
 }