refactor: Use InstantSource as time source

This change updates the modules of OpenDC to always accept
the `InstantSource` interface as source of time. Previously we used
`java.time.Clock`, but this class is bound to a time zone which does not
make sense for our use-cases.

Since `java.time.Clock` implements `java.time.InstantSource`, it can be
used in places that require an `InstantSource` as parameter. Conversion
from `InstantSource` to `Clock` is also possible by invoking
`InstantSource#withZone`.

3 files changed, 6 insertions, 6 deletions

diff --git a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/FaaSService.kt b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/FaaSService.kt
index 7b40d867..53706c57 100644
--- a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/FaaSService.kt
+++ b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/FaaSService.kt
@@ -30,8 +30,8 @@ import org.opendc.faas.service.internal.FaaSServiceImpl
 import org.opendc.faas.service.router.RoutingPolicy
 import org.opendc.faas.service.telemetry.FunctionStats
 import org.opendc.faas.service.telemetry.SchedulerStats
-import java.time.Clock
 import java.time.Duration
+import java.time.InstantSource
 import kotlin.coroutines.CoroutineContext
 
 /**
@@ -71,7 +71,7 @@ public interface FaaSService : AutoCloseable {
          */
         public operator fun invoke(
             context: CoroutineContext,
-            clock: Clock,
+            clock: InstantSource,
             deployer: FunctionDeployer,
             routingPolicy: RoutingPolicy,
             terminationPolicy: FunctionTerminationPolicy,
diff --git a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/autoscaler/FunctionTerminationPolicyFixed.kt b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/autoscaler/FunctionTerminationPolicyFixed.kt
index d579ad0c..f494adb1 100644
--- a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/autoscaler/FunctionTerminationPolicyFixed.kt
+++ b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/autoscaler/FunctionTerminationPolicyFixed.kt
@@ -25,8 +25,8 @@ package org.opendc.faas.service.autoscaler
 import org.opendc.common.util.TimerScheduler
 import org.opendc.faas.service.deployer.FunctionInstance
 import org.opendc.faas.service.deployer.FunctionInstanceState
-import java.time.Clock
 import java.time.Duration
+import java.time.InstantSource
 import kotlin.coroutines.CoroutineContext
 
 /**
@@ -36,7 +36,7 @@ import kotlin.coroutines.CoroutineContext
  */
 public class FunctionTerminationPolicyFixed(
     context: CoroutineContext,
-    clock: Clock,
+    clock: InstantSource,
     public val timeout: Duration
 ) : FunctionTerminationPolicy {
     /**
diff --git a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/internal/FaaSServiceImpl.kt b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/internal/FaaSServiceImpl.kt
index 901213af..3235ff1a 100644
--- a/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/internal/FaaSServiceImpl.kt
+++ b/opendc-faas/opendc-faas-service/src/main/kotlin/org/opendc/faas/service/internal/FaaSServiceImpl.kt
@@ -43,8 +43,8 @@ import org.opendc.faas.service.router.RoutingPolicy
 import org.opendc.faas.service.telemetry.FunctionStats
 import org.opendc.faas.service.telemetry.SchedulerStats
 import java.lang.IllegalStateException
-import java.time.Clock
 import java.time.Duration
+import java.time.InstantSource
 import java.util.ArrayDeque
 import java.util.Random
 import java.util.UUID
@@ -61,7 +61,7 @@ import kotlin.coroutines.resumeWithException
  */
 internal class FaaSServiceImpl(
     context: CoroutineContext,
-    private val clock: Clock,
+    private val clock: InstantSource,
     private val deployer: FunctionDeployer,
     private val routingPolicy: RoutingPolicy,
     private val terminationPolicy: FunctionTerminationPolicy,