Support custom start-up and clean-up time for VMs (#112)

This pull request implements customizable startup and clean-up time for virtual machine. 
We achieve this by implementing `SimWorkload` chaining and modelling start-up and 
clean-up time using `SimWorkload` as well.

Implements #33

## Implementation Notes :hammer_and_pick:

* Store method parameters in class files
* Add completion parameter to startWorkload
* Provide workload constructors in SimWorkloads 
* Add support for resetting machine context 
* Add support for chaining workloads 
* Use workload chaining for boot delay 
* Model host boot time 
* Do not suspend on guest start 
* Use static logger field 

## Breaking API Changes :warning:

* `SimMachine#startWorkload` now has a third parameter `completion` which is invoked when
   the workload finishes executing (either due to failure or success).
* `SimFlopsWorkload` and `SimRuntimeWorkload` can be instantiated via `SimWorkloads`.

1 files changed, 3 insertions, 26 deletions

diff --git a/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/Coroutines.kt b/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/Coroutines.kt
index c23f48dc..b354caff 100644
--- a/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/Coroutines.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/Coroutines.kt
@@ -39,31 +39,8 @@ public suspend fun SimMachine.runWorkload(workload: SimWorkload, meta: Map<Strin
     return suspendCancellableCoroutine { cont ->
         cont.invokeOnCancellation { this@runWorkload.cancel() }
 
-        startWorkload(
-            object : SimWorkload {
-                override fun onStart(ctx: SimMachineContext) {
-                    try {
-                        workload.onStart(ctx)
-                    } catch (cause: Throwable) {
-                        cont.resumeWithException(cause)
-                        throw cause
-                    }
-                }
-
-                override fun onStop(ctx: SimMachineContext) {
-                    try {
-                        workload.onStop(ctx)
-
-                        if (!cont.isCompleted) {
-                            cont.resume(Unit)
-                        }
-                    } catch (cause: Throwable) {
-                        cont.resumeWithException(cause)
-                        throw cause
-                    }
-                }
-            },
-            meta
-        )
+        startWorkload(workload, meta) { cause ->
+            if (cause != null) cont.resumeWithException(cause) else cont.resume(Unit)
+        }
     }
 }