build: Migrate to flat project structure

This change updates the project structure to become flattened.
Previously, the simulator, frontend and API each lived into their own
directory.

With this change, all modules of the project live in the top-level
directory of the repository. This should improve discoverability of
modules of the project.

8 files changed, 1373 insertions, 0 deletions

diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceAggregatorMaxMinTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceAggregatorMaxMinTest.kt
new file mode 100644
index 00000000..e272abb8
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceAggregatorMaxMinTest.kt
@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import kotlinx.coroutines.*
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimSpeedConsumerAdapter
+import org.opendc.simulator.resources.consumer.SimWorkConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * Test suite for the [SimResourceAggregatorMaxMin] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimResourceAggregatorMaxMinTest {
+    @Test
+    fun testSingleCapacity() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val forwarder = SimResourceForwarder()
+        val sources = listOf(
+            forwarder,
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = SimWorkConsumer(1.0, 0.5)
+        val usage = mutableListOf<Double>()
+        val source = SimResourceSource(1.0, clock, scheduler)
+        val adapter = SimSpeedConsumerAdapter(forwarder, usage::add)
+        source.startConsumer(adapter)
+
+        try {
+            aggregator.output.consume(consumer)
+            yield()
+
+            assertAll(
+                { assertEquals(1000, clock.millis()) },
+                { assertEquals(listOf(0.0, 0.5, 0.0), usage) }
+            )
+        } finally {
+            aggregator.output.close()
+        }
+    }
+
+    @Test
+    fun testDoubleCapacity() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val sources = listOf(
+            SimResourceSource(1.0, clock, scheduler),
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = SimWorkConsumer(2.0, 1.0)
+        val usage = mutableListOf<Double>()
+        val adapter = SimSpeedConsumerAdapter(consumer, usage::add)
+
+        try {
+            aggregator.output.consume(adapter)
+            yield()
+            assertAll(
+                { assertEquals(1000, clock.millis()) },
+                { assertEquals(listOf(0.0, 2.0, 0.0), usage) }
+            )
+        } finally {
+            aggregator.output.close()
+        }
+    }
+
+    @Test
+    fun testOvercommit() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val sources = listOf(
+            SimResourceSource(1.0, clock, scheduler),
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(4.0, 4.0, 1000))
+            .andThen(SimResourceCommand.Exit)
+
+        try {
+            aggregator.output.consume(consumer)
+            yield()
+            assertEquals(1000, clock.millis())
+
+            verify(exactly = 2) { consumer.onNext(any()) }
+        } finally {
+            aggregator.output.close()
+        }
+    }
+
+    @Test
+    fun testException() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val sources = listOf(
+            SimResourceSource(1.0, clock, scheduler),
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1.0, 1.0))
+            .andThenThrows(IllegalStateException())
+
+        try {
+            assertThrows<IllegalStateException> { aggregator.output.consume(consumer) }
+            yield()
+            assertEquals(SimResourceState.Pending, sources[0].state)
+        } finally {
+            aggregator.output.close()
+        }
+    }
+
+    @Test
+    fun testAdjustCapacity() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val sources = listOf(
+            SimResourceSource(1.0, clock, scheduler),
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = SimWorkConsumer(4.0, 1.0)
+        try {
+            coroutineScope {
+                launch { aggregator.output.consume(consumer) }
+                delay(1000)
+                sources[0].capacity = 0.5
+            }
+            yield()
+            assertEquals(2334, clock.millis())
+        } finally {
+            aggregator.output.close()
+        }
+    }
+
+    @Test
+    fun testFailOverCapacity() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val aggregator = SimResourceAggregatorMaxMin(clock)
+        val sources = listOf(
+            SimResourceSource(1.0, clock, scheduler),
+            SimResourceSource(1.0, clock, scheduler)
+        )
+        sources.forEach(aggregator::addInput)
+
+        val consumer = SimWorkConsumer(1.0, 0.5)
+        try {
+            coroutineScope {
+                launch { aggregator.output.consume(consumer) }
+                delay(500)
+                sources[0].capacity = 0.5
+            }
+            yield()
+            assertEquals(1000, clock.millis())
+        } finally {
+            aggregator.output.close()
+        }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceCommandTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceCommandTest.kt
new file mode 100644
index 00000000..02d456ff
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceCommandTest.kt
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertDoesNotThrow
+import org.junit.jupiter.api.assertThrows
+
+/**
+ * Test suite for [SimResourceCommand].
+ */
+class SimResourceCommandTest {
+    @Test
+    fun testZeroWork() {
+        assertThrows<IllegalArgumentException> {
+            SimResourceCommand.Consume(0.0, 1.0)
+        }
+    }
+
+    @Test
+    fun testNegativeWork() {
+        assertThrows<IllegalArgumentException> {
+            SimResourceCommand.Consume(-1.0, 1.0)
+        }
+    }
+
+    @Test
+    fun testZeroLimit() {
+        assertThrows<IllegalArgumentException> {
+            SimResourceCommand.Consume(1.0, 0.0)
+        }
+    }
+
+    @Test
+    fun testNegativeLimit() {
+        assertThrows<IllegalArgumentException> {
+            SimResourceCommand.Consume(1.0, -1.0, 1)
+        }
+    }
+
+    @Test
+    fun testConsumeCorrect() {
+        assertDoesNotThrow {
+            SimResourceCommand.Consume(1.0, 1.0)
+        }
+    }
+
+    @Test
+    fun testIdleCorrect() {
+        assertDoesNotThrow {
+            SimResourceCommand.Idle(1)
+        }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceContextTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceContextTest.kt
new file mode 100644
index 00000000..be909556
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceContextTest.kt
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.*
+import kotlinx.coroutines.*
+import org.junit.jupiter.api.*
+import org.opendc.simulator.core.runBlockingSimulation
+
+/**
+ * A test suite for the [SimAbstractResourceContext] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+class SimResourceContextTest {
+    @Test
+    fun testFlushWithoutCommand() = runBlockingSimulation {
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Consume(10.0, 1.0) andThen SimResourceCommand.Exit
+
+        val context = object : SimAbstractResourceContext(4200.0, clock, consumer) {
+            override fun onIdle(deadline: Long) {}
+            override fun onConsume(work: Double, limit: Double, deadline: Long) {}
+            override fun onFinish(cause: Throwable?) {}
+        }
+
+        context.flush()
+    }
+
+    @Test
+    fun testIntermediateFlush() = runBlockingSimulation {
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Consume(10.0, 1.0) andThen SimResourceCommand.Exit
+
+        val context = spyk(object : SimAbstractResourceContext(4200.0, clock, consumer) {
+            override fun onIdle(deadline: Long) {}
+            override fun onFinish(cause: Throwable?) {}
+            override fun onConsume(work: Double, limit: Double, deadline: Long) {}
+        })
+
+        context.start()
+        delay(1) // Delay 1 ms to prevent hitting the fast path
+        context.flush(isIntermediate = true)
+
+        verify(exactly = 2) { context.onConsume(any(), any(), any()) }
+    }
+
+    @Test
+    fun testIntermediateFlushIdle() = runBlockingSimulation {
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Idle(10) andThen SimResourceCommand.Exit
+
+        val context = spyk(object : SimAbstractResourceContext(4200.0, clock, consumer) {
+            override fun onIdle(deadline: Long) {}
+            override fun onFinish(cause: Throwable?) {}
+            override fun onConsume(work: Double, limit: Double, deadline: Long) {}
+        })
+
+        context.start()
+        delay(5)
+        context.flush(isIntermediate = true)
+        delay(5)
+        context.flush(isIntermediate = true)
+
+        assertAll(
+            { verify(exactly = 2) { context.onIdle(any()) } },
+            { verify(exactly = 1) { context.onFinish(null) } }
+        )
+    }
+
+    @Test
+    fun testDoubleStart() = runBlockingSimulation {
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Idle(10) andThen SimResourceCommand.Exit
+
+        val context = object : SimAbstractResourceContext(4200.0, clock, consumer) {
+            override fun onIdle(deadline: Long) {}
+            override fun onFinish(cause: Throwable?) {}
+            override fun onConsume(work: Double, limit: Double, deadline: Long) {}
+        }
+
+        context.start()
+        assertThrows<IllegalStateException> { context.start() }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSourceTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSourceTest.kt
new file mode 100644
index 00000000..39f74481
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSourceTest.kt
@@ -0,0 +1,351 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.spyk
+import io.mockk.verify
+import kotlinx.coroutines.*
+import org.junit.jupiter.api.*
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimSpeedConsumerAdapter
+import org.opendc.simulator.resources.consumer.SimWorkConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * A test suite for the [SimResourceSource] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+class SimResourceSourceTest {
+    @Test
+    fun testSpeed() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1000 * capacity, capacity))
+            .andThen(SimResourceCommand.Exit)
+
+        try {
+            val res = mutableListOf<Double>()
+            val adapter = SimSpeedConsumerAdapter(consumer, res::add)
+
+            provider.consume(adapter)
+
+            assertEquals(listOf(0.0, capacity, 0.0), res) { "Speed is reported correctly" }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testAdjustCapacity() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val provider = SimResourceSource(1.0, clock, scheduler)
+
+        val consumer = spyk(SimWorkConsumer(2.0, 1.0))
+
+        try {
+            coroutineScope {
+                launch { provider.consume(consumer) }
+                delay(1000)
+                provider.capacity = 0.5
+            }
+            assertEquals(3000, clock.millis())
+            verify(exactly = 1) { consumer.onCapacityChanged(any(), true) }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testSpeedLimit() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1000 * capacity, 2 * capacity))
+            .andThen(SimResourceCommand.Exit)
+
+        try {
+            val res = mutableListOf<Double>()
+            val adapter = SimSpeedConsumerAdapter(consumer, res::add)
+
+            provider.consume(adapter)
+
+            assertEquals(listOf(0.0, capacity, 0.0), res) { "Speed is reported correctly" }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    /**
+     * Test to see whether no infinite recursion occurs when interrupting during [SimResourceConsumer.onStart] or
+     * [SimResourceConsumer.onNext].
+     */
+    @Test
+    fun testIntermediateInterrupt() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = object : SimResourceConsumer {
+            override fun onStart(ctx: SimResourceContext) {
+                ctx.interrupt()
+            }
+
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+                return SimResourceCommand.Exit
+            }
+        }
+
+        try {
+            provider.consume(consumer)
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testInterrupt() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+        lateinit var resCtx: SimResourceContext
+
+        val consumer = object : SimResourceConsumer {
+            var isFirst = true
+            override fun onStart(ctx: SimResourceContext) {
+                resCtx = ctx
+            }
+
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+                assertEquals(0.0, ctx.remainingWork)
+                return if (isFirst) {
+                    isFirst = false
+                    SimResourceCommand.Consume(4.0, 1.0)
+                } else {
+                    SimResourceCommand.Exit
+                }
+            }
+        }
+
+        try {
+            launch {
+                yield()
+                resCtx.interrupt()
+            }
+            provider.consume(consumer)
+
+            assertEquals(0, clock.millis())
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testFailure() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onStart(any()) }
+            .throws(IllegalStateException())
+
+        try {
+            assertThrows<IllegalStateException> {
+                provider.consume(consumer)
+            }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testExceptionPropagationOnNext() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1.0, 1.0))
+            .andThenThrows(IllegalStateException())
+
+        try {
+            assertThrows<IllegalStateException> {
+                provider.consume(consumer)
+            }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testConcurrentConsumption() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1.0, 1.0))
+            .andThenThrows(IllegalStateException())
+
+        try {
+            assertThrows<IllegalStateException> {
+                coroutineScope {
+                    launch { provider.consume(consumer) }
+                    provider.consume(consumer)
+                }
+            }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testClosedConsumption() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1.0, 1.0))
+            .andThenThrows(IllegalStateException())
+
+        try {
+            assertThrows<IllegalStateException> {
+                provider.close()
+                provider.consume(consumer)
+            }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testCloseDuringConsumption() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Consume(1.0, 1.0))
+            .andThenThrows(IllegalStateException())
+
+        try {
+            launch { provider.consume(consumer) }
+            delay(500)
+            provider.close()
+
+            assertEquals(500, clock.millis())
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testIdle() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Idle(clock.millis() + 500))
+            .andThen(SimResourceCommand.Exit)
+
+        try {
+            provider.consume(consumer)
+
+            assertEquals(500, clock.millis())
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testInfiniteSleep() {
+        assertThrows<IllegalStateException> {
+            runBlockingSimulation {
+                val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+                val capacity = 4200.0
+                val provider = SimResourceSource(capacity, clock, scheduler)
+
+                val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+                every { consumer.onNext(any()) }
+                    .returns(SimResourceCommand.Idle())
+                    .andThenThrows(IllegalStateException())
+
+                try {
+                    provider.consume(consumer)
+                } finally {
+                    scheduler.close()
+                    provider.close()
+                }
+            }
+        }
+    }
+
+    @Test
+    fun testIncorrectDeadline() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val capacity = 4200.0
+        val provider = SimResourceSource(capacity, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) }
+            .returns(SimResourceCommand.Idle(2))
+            .andThen(SimResourceCommand.Exit)
+
+        try {
+            delay(10)
+
+            assertThrows<IllegalArgumentException> { provider.consume(consumer) }
+        } finally {
+            scheduler.close()
+            provider.close()
+        }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchExclusiveTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchExclusiveTest.kt
new file mode 100644
index 00000000..f7d17867
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchExclusiveTest.kt
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.every
+import io.mockk.mockk
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.yield
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimSpeedConsumerAdapter
+import org.opendc.simulator.resources.consumer.SimTraceConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * Test suite for the [SimResourceSwitchExclusive] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimResourceSwitchExclusiveTest {
+    /**
+     * Test a trace workload.
+     */
+    @Test
+    fun testTrace() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val speed = mutableListOf<Double>()
+
+        val duration = 5 * 60L
+        val workload =
+            SimTraceConsumer(
+                sequenceOf(
+                    SimTraceConsumer.Fragment(duration * 1000, 28.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 3500.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 0.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 183.0)
+                ),
+            )
+
+        val switch = SimResourceSwitchExclusive()
+        val source = SimResourceSource(3200.0, clock, scheduler)
+        val forwarder = SimResourceForwarder()
+        val adapter = SimSpeedConsumerAdapter(forwarder, speed::add)
+        source.startConsumer(adapter)
+        switch.addInput(forwarder)
+
+        val provider = switch.addOutput(3200.0)
+
+        try {
+            provider.consume(workload)
+            yield()
+        } finally {
+            provider.close()
+        }
+
+        assertAll(
+            { assertEquals(listOf(0.0, 28.0, 3200.0, 0.0, 183.0, 0.0), speed) { "Correct speed" } },
+            { assertEquals(5 * 60L * 4000, clock.millis()) { "Took enough time" } }
+        )
+    }
+
+    /**
+     * Test runtime workload on hypervisor.
+     */
+    @Test
+    fun testRuntimeWorkload() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val duration = 5 * 60L * 1000
+        val workload = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { workload.onNext(any()) } returns SimResourceCommand.Consume(duration / 1000.0, 1.0) andThen SimResourceCommand.Exit
+
+        val switch = SimResourceSwitchExclusive()
+        val source = SimResourceSource(3200.0, clock, scheduler)
+
+        switch.addInput(source)
+
+        val provider = switch.addOutput(3200.0)
+
+        try {
+            provider.consume(workload)
+            yield()
+        } finally {
+            provider.close()
+        }
+        assertEquals(duration, clock.millis()) { "Took enough time" }
+    }
+
+    /**
+     * Test two workloads running sequentially.
+     */
+    @Test
+    fun testTwoWorkloads() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val duration = 5 * 60L * 1000
+        val workload = object : SimResourceConsumer {
+            var isFirst = true
+
+            override fun onStart(ctx: SimResourceContext) {
+                isFirst = true
+            }
+
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+                return if (isFirst) {
+                    isFirst = false
+                    SimResourceCommand.Consume(duration / 1000.0, 1.0)
+                } else {
+                    SimResourceCommand.Exit
+                }
+            }
+        }
+
+        val switch = SimResourceSwitchExclusive()
+        val source = SimResourceSource(3200.0, clock, scheduler)
+
+        switch.addInput(source)
+
+        val provider = switch.addOutput(3200.0)
+
+        try {
+            provider.consume(workload)
+            yield()
+            provider.consume(workload)
+        } finally {
+            provider.close()
+        }
+        assertEquals(duration * 2, clock.millis()) { "Took enough time" }
+    }
+
+    /**
+     * Test concurrent workloads on the machine.
+     */
+    @Test
+    fun testConcurrentWorkloadFails() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val duration = 5 * 60L * 1000
+        val workload = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { workload.onNext(any()) } returns SimResourceCommand.Consume(duration / 1000.0, 1.0) andThen SimResourceCommand.Exit
+
+        val switch = SimResourceSwitchExclusive()
+        val source = SimResourceSource(3200.0, clock, scheduler)
+
+        switch.addInput(source)
+
+        switch.addOutput(3200.0)
+        assertThrows<IllegalStateException> { switch.addOutput(3200.0) }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchMaxMinTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchMaxMinTest.kt
new file mode 100644
index 00000000..7416f277
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceSwitchMaxMinTest.kt
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.every
+import io.mockk.mockk
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.yield
+import org.junit.jupiter.api.*
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimTraceConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * Test suite for the [SimResourceSwitch] implementations
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimResourceSwitchMaxMinTest {
+    @Test
+    fun testSmoke() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val switch = SimResourceSwitchMaxMin(clock)
+
+        val sources = List(2) { SimResourceSource(2000.0, clock, scheduler) }
+        sources.forEach { switch.addInput(it) }
+
+        val provider = switch.addOutput(1000.0)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Consume(1.0, 1.0) andThen SimResourceCommand.Exit
+
+        try {
+            provider.consume(consumer)
+            yield()
+        } finally {
+            switch.close()
+            scheduler.close()
+        }
+    }
+
+    /**
+     * Test overcommitting of resources via the hypervisor with a single VM.
+     */
+    @Test
+    fun testOvercommittedSingle() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val listener = object : SimResourceSwitchMaxMin.Listener {
+            var totalRequestedWork = 0L
+            var totalGrantedWork = 0L
+            var totalOvercommittedWork = 0L
+
+            override fun onSliceFinish(
+                switch: SimResourceSwitchMaxMin,
+                requestedWork: Long,
+                grantedWork: Long,
+                overcommittedWork: Long,
+                interferedWork: Long,
+                cpuUsage: Double,
+                cpuDemand: Double
+            ) {
+                totalRequestedWork += requestedWork
+                totalGrantedWork += grantedWork
+                totalOvercommittedWork += overcommittedWork
+            }
+        }
+
+        val duration = 5 * 60L
+        val workload =
+            SimTraceConsumer(
+                sequenceOf(
+                    SimTraceConsumer.Fragment(duration * 1000, 28.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 3500.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 0.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 183.0)
+                ),
+            )
+
+        val switch = SimResourceSwitchMaxMin(clock, listener)
+        val provider = switch.addOutput(3200.0)
+
+        try {
+            switch.addInput(SimResourceSource(3200.0, clock, scheduler))
+            provider.consume(workload)
+            yield()
+        } finally {
+            switch.close()
+            scheduler.close()
+        }
+
+        assertAll(
+            { assertEquals(1113300, listener.totalRequestedWork, "Requested Burst does not match") },
+            { assertEquals(1023300, listener.totalGrantedWork, "Granted Burst does not match") },
+            { assertEquals(90000, listener.totalOvercommittedWork, "Overcommissioned Burst does not match") },
+            { assertEquals(1200000, clock.millis()) }
+        )
+    }
+
+    /**
+     * Test overcommitting of resources via the hypervisor with two VMs.
+     */
+    @Test
+    fun testOvercommittedDual() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+
+        val listener = object : SimResourceSwitchMaxMin.Listener {
+            var totalRequestedWork = 0L
+            var totalGrantedWork = 0L
+            var totalOvercommittedWork = 0L
+
+            override fun onSliceFinish(
+                switch: SimResourceSwitchMaxMin,
+                requestedWork: Long,
+                grantedWork: Long,
+                overcommittedWork: Long,
+                interferedWork: Long,
+                cpuUsage: Double,
+                cpuDemand: Double
+            ) {
+                totalRequestedWork += requestedWork
+                totalGrantedWork += grantedWork
+                totalOvercommittedWork += overcommittedWork
+            }
+        }
+
+        val duration = 5 * 60L
+        val workloadA =
+            SimTraceConsumer(
+                sequenceOf(
+                    SimTraceConsumer.Fragment(duration * 1000, 28.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 3500.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 0.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 183.0)
+                ),
+            )
+        val workloadB =
+            SimTraceConsumer(
+                sequenceOf(
+                    SimTraceConsumer.Fragment(duration * 1000, 28.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 3100.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 0.0),
+                    SimTraceConsumer.Fragment(duration * 1000, 73.0)
+                )
+            )
+
+        val switch = SimResourceSwitchMaxMin(clock, listener)
+        val providerA = switch.addOutput(3200.0)
+        val providerB = switch.addOutput(3200.0)
+
+        try {
+            switch.addInput(SimResourceSource(3200.0, clock, scheduler))
+
+            coroutineScope {
+                launch { providerA.consume(workloadA) }
+                providerB.consume(workloadB)
+            }
+
+            yield()
+        } finally {
+            switch.close()
+            scheduler.close()
+        }
+        assertAll(
+            { assertEquals(2082000, listener.totalRequestedWork, "Requested Burst does not match") },
+            { assertEquals(1062000, listener.totalGrantedWork, "Granted Burst does not match") },
+            { assertEquals(1020000, listener.totalOvercommittedWork, "Overcommissioned Burst does not match") },
+            { assertEquals(1200000, clock.millis()) }
+        )
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceTransformerTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceTransformerTest.kt
new file mode 100644
index 00000000..d2ad73bc
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimResourceTransformerTest.kt
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.spyk
+import io.mockk.verify
+import kotlinx.coroutines.*
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimWorkConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * A test suite for the [SimResourceTransformer] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimResourceTransformerTest {
+    @Test
+    fun testExitImmediately() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(2000.0, clock, scheduler)
+
+        launch {
+            source.consume(forwarder)
+            source.close()
+        }
+
+        forwarder.consume(object : SimResourceConsumer {
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+                return SimResourceCommand.Exit
+            }
+        })
+
+        forwarder.close()
+        scheduler.close()
+    }
+
+    @Test
+    fun testExit() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(2000.0, clock, scheduler)
+
+        launch {
+            source.consume(forwarder)
+            source.close()
+        }
+
+        forwarder.consume(object : SimResourceConsumer {
+            var isFirst = true
+
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+                return if (isFirst) {
+                    isFirst = false
+                    SimResourceCommand.Consume(10.0, 1.0)
+                } else {
+                    SimResourceCommand.Exit
+                }
+            }
+        })
+
+        forwarder.close()
+    }
+
+    @Test
+    fun testState() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val consumer = object : SimResourceConsumer {
+            override fun onNext(ctx: SimResourceContext): SimResourceCommand = SimResourceCommand.Exit
+        }
+
+        assertEquals(SimResourceState.Pending, forwarder.state)
+
+        forwarder.startConsumer(consumer)
+        assertEquals(SimResourceState.Active, forwarder.state)
+
+        assertThrows<IllegalStateException> { forwarder.startConsumer(consumer) }
+
+        forwarder.cancel()
+        assertEquals(SimResourceState.Pending, forwarder.state)
+
+        forwarder.close()
+        assertEquals(SimResourceState.Stopped, forwarder.state)
+    }
+
+    @Test
+    fun testCancelPendingDelegate() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Exit
+
+        forwarder.startConsumer(consumer)
+        forwarder.cancel()
+
+        verify(exactly = 0) { consumer.onFinish(any(), null) }
+    }
+
+    @Test
+    fun testCancelStartedDelegate() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(2000.0, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Idle(10)
+
+        source.startConsumer(forwarder)
+        yield()
+        forwarder.startConsumer(consumer)
+        yield()
+        forwarder.cancel()
+
+        verify(exactly = 1) { consumer.onStart(any()) }
+        verify(exactly = 1) { consumer.onFinish(any(), null) }
+    }
+
+    @Test
+    fun testCancelPropagation() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(2000.0, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Idle(10)
+
+        source.startConsumer(forwarder)
+        yield()
+        forwarder.startConsumer(consumer)
+        yield()
+        source.cancel()
+
+        verify(exactly = 1) { consumer.onStart(any()) }
+        verify(exactly = 1) { consumer.onFinish(any(), null) }
+    }
+
+    @Test
+    fun testExitPropagation() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder(isCoupled = true)
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(2000.0, clock, scheduler)
+
+        val consumer = mockk<SimResourceConsumer>(relaxUnitFun = true)
+        every { consumer.onNext(any()) } returns SimResourceCommand.Exit
+
+        source.startConsumer(forwarder)
+        forwarder.consume(consumer)
+        yield()
+
+        assertEquals(SimResourceState.Pending, source.state)
+    }
+
+    @Test
+    fun testAdjustCapacity() = runBlockingSimulation {
+        val forwarder = SimResourceForwarder()
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(1.0, clock, scheduler)
+
+        val consumer = spyk(SimWorkConsumer(2.0, 1.0))
+        source.startConsumer(forwarder)
+
+        coroutineScope {
+            launch { forwarder.consume(consumer) }
+            delay(1000)
+            source.capacity = 0.5
+        }
+
+        assertEquals(3000, clock.millis())
+        verify(exactly = 1) { consumer.onCapacityChanged(any(), true) }
+    }
+
+    @Test
+    fun testTransformExit() = runBlockingSimulation {
+        val forwarder = SimResourceTransformer { _, _ -> SimResourceCommand.Exit }
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val source = SimResourceSource(1.0, clock, scheduler)
+
+        val consumer = spyk(SimWorkConsumer(2.0, 1.0))
+        source.startConsumer(forwarder)
+        forwarder.consume(consumer)
+
+        assertEquals(0, clock.millis())
+        verify(exactly = 1) { consumer.onNext(any()) }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimWorkConsumerTest.kt b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimWorkConsumerTest.kt
new file mode 100644
index 00000000..bf58b1b6
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-resources/src/test/kotlin/org/opendc/simulator/resources/SimWorkConsumerTest.kt
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.simulator.resources
+
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.resources.consumer.SimWorkConsumer
+import org.opendc.utils.TimerScheduler
+
+/**
+ * A test suite for the [SimWorkConsumer] class.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimWorkConsumerTest {
+    @Test
+    fun testSmoke() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val provider = SimResourceSource(1.0, clock, scheduler)
+
+        val consumer = SimWorkConsumer(1.0, 1.0)
+
+        try {
+            provider.consume(consumer)
+            assertEquals(1000, clock.millis())
+        } finally {
+            provider.close()
+        }
+    }
+
+    @Test
+    fun testUtilization() = runBlockingSimulation {
+        val scheduler = TimerScheduler<Any>(coroutineContext, clock)
+        val provider = SimResourceSource(1.0, clock, scheduler)
+
+        val consumer = SimWorkConsumer(1.0, 0.5)
+
+        try {
+            provider.consume(consumer)
+            assertEquals(2000, clock.millis())
+        } finally {
+            provider.close()
+        }
+    }
+}