bug: Fix crashed processes from being resumed (#28)

This change fixes a bug where a process would be resumed again after it
had crashed, bringing down the kernel.

Fixes #27

1 files changed, 8 insertions, 4 deletions

diff --git a/opendc-kernel-omega/src/main/kotlin/com/atlarge/opendc/omega/OmegaSimulation.kt b/opendc-kernel-omega/src/main/kotlin/com/atlarge/opendc/omega/OmegaSimulation.kt
index 4e3aa16c..fbb4a270 100644
--- a/opendc-kernel-omega/src/main/kotlin/com/atlarge/opendc/omega/OmegaSimulation.kt
+++ b/opendc-kernel-omega/src/main/kotlin/com/atlarge/opendc/omega/OmegaSimulation.kt
@@ -184,11 +184,15 @@ internal class OmegaSimulation<M>(bootstrap: Bootstrap<M>) : Simulation<M>, Boot
             }
 
             val context = envelope.destination.context ?: continue
+            val continuation = context.continuation ?: continue
 
-            if (envelope.message !is Interrupt) {
-                context.continuation.resume(envelope)
+            // Clear the continuation to prevent resuming an already resumed continuation
+            context.continuation = null
+
+            if (envelope.message is Interrupt) {
+                continuation.resumeWithException(envelope.message)
             } else {
-                context.continuation.resumeWithException(envelope.message)
+                continuation.resume(envelope)
             }
 
             context.last = time
@@ -335,7 +339,7 @@ internal class OmegaSimulation<M>(bootstrap: Bootstrap<M>) : Simulation<M>, Boot
         /**
          * The continuation to resume the execution of the process.
          */
-        lateinit var continuation: Continuation<Envelope>
+        var continuation: Continuation<Envelope>? = null
 
         /**
          * The last point in time the process has done some work.