simulator: Optimize bottlenecks in resource layer

This pull request addresses several bottlenecks that were present in the 
`opendc-simulator-resources` layer and  `TimerScheduler`.
These changes result into a 4x performance improvement for the energy experiments 
we are currently doing.

* The use of `StateFlow` has been removed where possible. Profiling shows that 
emitting changes to `StateFlow` becomes a bottleneck in a single-thread context.
* `SimSpeedConsumerAdapter` is an alternative for obtaining the changes in 
speed of a resource.

 **Breaking API Changes**
* `SimResourceSource` does not expose `speed` as `StateFlow` anymore. To monitor speed changes, use `SimSpeedConsumerAdapter`.
* Power draw in `SimBareMetalMachine` is not exposed as `StateFlow` anymore.

1 files changed, 2 insertions, 2 deletions

diff --git a/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt b/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
index 02cfdc06..0441cfed 100644
--- a/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
+++ b/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
@@ -119,7 +119,7 @@ class CapelinIntegrationTest {
             { assertEquals(0, monitorResults.unscheduledVms, "No VM should not be unscheduled") },
             { assertEquals(0, monitorResults.queuedVms, "No VM should not be in the queue") },
             { assertEquals(1672916917970, monitor.totalRequestedBurst) { "Incorrect requested burst" } },
-            { assertEquals(435179794565, monitor.totalGrantedBurst) { "Incorrect granted burst" } },
+            { assertEquals(434262255818, monitor.totalGrantedBurst) { "Incorrect granted burst" } },
             { assertEquals(1236692477983, monitor.totalOvercommissionedBurst) { "Incorrect overcommitted burst" } },
             { assertEquals(0, monitor.totalInterferedBurst) { "Incorrect interfered burst" } }
         )
@@ -157,7 +157,7 @@ class CapelinIntegrationTest {
         // Note that these values have been verified beforehand
         assertAll(
             { assertEquals(702636229989, monitor.totalRequestedBurst) { "Total requested work incorrect" } },
-            { assertEquals(172807361391, monitor.totalGrantedBurst) { "Total granted work incorrect" } },
+            { assertEquals(172636987071, monitor.totalGrantedBurst) { "Total granted work incorrect" } },
             { assertEquals(528959213229, monitor.totalOvercommissionedBurst) { "Total overcommitted work incorrect" } },
             { assertEquals(0, monitor.totalInterferedBurst) { "Total interfered work incorrect" } }
         )