merge: Integrate v2.1 progress into public repository

This pull request integrates the changes planned for the v2.1 release of
OpenDC into the public Github repository in order to sync the progress
of both repositories.

9 files changed, 632 insertions, 0 deletions

diff --git a/opendc-simulator/opendc-simulator-network/build.gradle.kts b/opendc-simulator/opendc-simulator-network/build.gradle.kts
new file mode 100644
index 00000000..f8931053
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/build.gradle.kts
@@ -0,0 +1,37 @@
+/*
+ * 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.
+ */
+
+description = "Library for simulating datacenter network components"
+
+plugins {
+    `kotlin-library-conventions`
+    `testing-conventions`
+    `jacoco-conventions`
+}
+
+dependencies {
+    api(platform(projects.opendcPlatform))
+    api(projects.opendcSimulator.opendcSimulatorFlow)
+    implementation(projects.opendcSimulator.opendcSimulatorCore)
+
+    testImplementation(libs.slf4j.simple)
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkLink.kt b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkLink.kt
new file mode 100644
index 00000000..67562640
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkLink.kt
@@ -0,0 +1,49 @@
+/*
+ * 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.network
+
+/**
+ * A physical bi-directional communication link between two [SimNetworkPort]s.
+ *
+ * @param left The first port of the link.
+ * @param right The second port of the link.
+ */
+public class SimNetworkLink(public val left: SimNetworkPort, public val right: SimNetworkPort) {
+    /**
+     * Determine whether the specified [port] participates in this network link.
+     */
+    public operator fun contains(port: SimNetworkPort): Boolean = port == left || port == right
+
+    /**
+     * Obtain the opposite port to which the specified [port] is connected through this link.
+     */
+    public fun opposite(port: SimNetworkPort): SimNetworkPort {
+        return when (port) {
+            left -> right
+            right -> left
+            else -> throw IllegalArgumentException("Invalid port given")
+        }
+    }
+
+    override fun toString(): String = "SimNetworkLink[left=$left,right=$right]"
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkPort.kt b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkPort.kt
new file mode 100644
index 00000000..4b66d5cf
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkPort.kt
@@ -0,0 +1,91 @@
+/*
+ * 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.network
+
+import org.opendc.simulator.flow.FlowConsumer
+import org.opendc.simulator.flow.FlowSource
+
+/**
+ * A network port allows network devices to be connected to network through links.
+ */
+public abstract class SimNetworkPort {
+    /**
+     * A flag to indicate that the network port is connected to another port.
+     */
+    public val isConnected: Boolean
+        get() = _link != null
+
+    /**
+     * The network link which connects this port to another port.
+     */
+    public val link: SimNetworkLink?
+        get() = _link
+    private var _link: SimNetworkLink? = null
+
+    /**
+     * Connect this port to the specified [port].
+     */
+    public fun connect(port: SimNetworkPort) {
+        require(port !== this) { "Circular reference" }
+        check(!isConnected) { "Port already connected" }
+        check(!port.isConnected) { "Target port already connected" }
+
+        val link = SimNetworkLink(this, port)
+        _link = link
+        port._link = link
+
+        // Start bi-directional flow channel between the two ports
+        try {
+            provider.startConsumer(port.createConsumer())
+            port.provider.startConsumer(createConsumer())
+        } catch (e: Throwable) {
+            disconnect()
+            throw e
+        }
+    }
+
+    /**
+     * Disconnect the current network link if it exists.
+     */
+    public fun disconnect() {
+        val link = _link ?: return
+        val opposite = link.opposite(this)
+        _link = null
+        opposite._link = null
+
+        provider.cancel()
+        opposite.provider.cancel()
+    }
+
+    /**
+     * Create a [FlowSource] which generates the outgoing traffic of this port.
+     */
+    protected abstract fun createConsumer(): FlowSource
+
+    /**
+     * The [FlowConsumer] which processes the ingoing traffic of this port.
+     */
+    protected abstract val provider: FlowConsumer
+
+    override fun toString(): String = "SimNetworkPort[isConnected=$isConnected]"
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSink.kt b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSink.kt
new file mode 100644
index 00000000..4b0d7bbd
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSink.kt
@@ -0,0 +1,43 @@
+/*
+ * 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.network
+
+import org.opendc.simulator.flow.*
+
+/**
+ * A network sink which discards all received traffic and does not generate any traffic itself.
+ */
+public class SimNetworkSink(
+    engine: FlowEngine,
+    public val capacity: Double
+) : SimNetworkPort() {
+    override fun createConsumer(): FlowSource = object : FlowSource {
+        override fun onPull(conn: FlowConnection, now: Long, delta: Long): Long = Long.MAX_VALUE
+
+        override fun toString(): String = "SimNetworkSink.Consumer"
+    }
+
+    override val provider: FlowConsumer = FlowSink(engine, capacity)
+
+    override fun toString(): String = "SimNetworkSink[capacity=$capacity]"
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitch.kt b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitch.kt
new file mode 100644
index 00000000..7dc249ab
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitch.kt
@@ -0,0 +1,33 @@
+/*
+ * 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.network
+
+/**
+ * A network device connects devices on a network by switching the traffic over its ports.
+ */
+public interface SimNetworkSwitch {
+    /**
+     * The ports of the switch.
+     */
+    public val ports: List<SimNetworkPort>
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtual.kt b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtual.kt
new file mode 100644
index 00000000..6667c80c
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtual.kt
@@ -0,0 +1,76 @@
+/*
+ * 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.network
+
+import org.opendc.simulator.flow.*
+import org.opendc.simulator.flow.mux.MaxMinFlowMultiplexer
+
+/**
+ * A [SimNetworkSwitch] that can support new networking ports on demand.
+ */
+public class SimNetworkSwitchVirtual(private val engine: FlowEngine) : SimNetworkSwitch {
+    /**
+     * The ports of this switch.
+     */
+    override val ports: List<Port>
+        get() = _ports
+    private val _ports = mutableListOf<Port>()
+
+    /**
+     * The [MaxMinFlowMultiplexer] to actually perform the switching.
+     */
+    private val mux = MaxMinFlowMultiplexer(engine)
+
+    /**
+     * Open a new port on the switch.
+     */
+    public fun newPort(): Port {
+        val port = Port()
+        _ports.add(port)
+        return port
+    }
+
+    /**
+     * A port on the network switch.
+     */
+    public inner class Port : SimNetworkPort(), AutoCloseable {
+        /**
+         * A flag to indicate that this virtual port was removed from the switch.
+         */
+        private var isClosed: Boolean = false
+
+        override val provider: FlowConsumer
+            get() = _provider
+        private val _provider = mux.newInput()
+
+        private val _source = mux.newOutput()
+
+        override fun createConsumer(): FlowSource = _source
+
+        override fun close() {
+            isClosed = true
+            mux.removeInput(_provider)
+            _ports.remove(this)
+        }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkLinkTest.kt b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkLinkTest.kt
new file mode 100644
index 00000000..3480c9df
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkLinkTest.kt
@@ -0,0 +1,89 @@
+/*
+ * 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.network
+
+import io.mockk.mockk
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+
+/**
+ * Test suite for [SimNetworkLink] class.
+ */
+class SimNetworkLinkTest {
+    @Test
+    fun testContainsLeft() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertTrue(left in link)
+    }
+
+    @Test
+    fun testContainsRight() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertTrue(right in link)
+    }
+
+    @Test
+    fun testContainsNone() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+        val none = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertFalse(none in link)
+    }
+
+    @Test
+    fun testOppositeLeft() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertEquals(right, link.opposite(left))
+    }
+
+    @Test
+    fun testOppositeRight() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertEquals(left, link.opposite(right))
+    }
+
+    @Test
+    fun testOppositeNone() {
+        val left = mockk<SimNetworkPort>()
+        val right = mockk<SimNetworkPort>()
+        val none = mockk<SimNetworkPort>()
+
+        val link = SimNetworkLink(left, right)
+        assertThrows<IllegalArgumentException> { link.opposite(none) }
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSinkTest.kt b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSinkTest.kt
new file mode 100644
index 00000000..14d22162
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSinkTest.kt
@@ -0,0 +1,137 @@
+/*
+ * 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.network
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.spyk
+import io.mockk.verify
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertDoesNotThrow
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.flow.*
+import org.opendc.simulator.flow.source.FixedFlowSource
+
+/**
+ * Test suite for the [SimNetworkSink] class.
+ */
+class SimNetworkSinkTest {
+    @Test
+    fun testInitialState() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+
+        assertFalse(sink.isConnected)
+        assertNull(sink.link)
+        assertEquals(100.0, sink.capacity)
+    }
+
+    @Test
+    fun testDisconnectIdempotent() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+
+        assertDoesNotThrow { sink.disconnect() }
+        assertFalse(sink.isConnected)
+    }
+
+    @Test
+    fun testConnectCircular() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+
+        assertThrows<IllegalArgumentException> {
+            sink.connect(sink)
+        }
+    }
+
+    @Test
+    fun testConnectAlreadyConnectedTarget() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val source = mockk<SimNetworkPort>(relaxUnitFun = true)
+        every { source.isConnected } returns true
+
+        assertThrows<IllegalStateException> {
+            sink.connect(source)
+        }
+    }
+
+    @Test
+    fun testConnectAlreadyConnected() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val source1 = Source(engine)
+
+        val source2 = mockk<SimNetworkPort>(relaxUnitFun = true)
+
+        every { source2.isConnected } returns false
+
+        sink.connect(source1)
+        assertThrows<IllegalStateException> {
+            sink.connect(source2)
+        }
+    }
+
+    @Test
+    fun testConnect() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val source = spyk(Source(engine))
+        val consumer = source.consumer
+
+        sink.connect(source)
+
+        assertTrue(sink.isConnected)
+        assertTrue(source.isConnected)
+
+        verify { source.createConsumer() }
+        verify { consumer.onStart(any(), any()) }
+    }
+
+    @Test
+    fun testDisconnect() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val source = spyk(Source(engine))
+        val consumer = source.consumer
+
+        sink.connect(source)
+        sink.disconnect()
+
+        assertFalse(sink.isConnected)
+        assertFalse(source.isConnected)
+
+        verify { consumer.onStop(any(), any(), any()) }
+    }
+
+    private class Source(engine: FlowEngine) : SimNetworkPort() {
+        val consumer = spyk(FixedFlowSource(Double.POSITIVE_INFINITY, utilization = 0.8))
+
+        public override fun createConsumer(): FlowSource = consumer
+
+        override val provider: FlowConsumer = FlowSink(engine, 0.0)
+    }
+}
diff --git a/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtualTest.kt b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtualTest.kt
new file mode 100644
index 00000000..62e54ffb
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/test/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtualTest.kt
@@ -0,0 +1,77 @@
+/*
+ * 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.network
+
+import io.mockk.spyk
+import io.mockk.verify
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.flow.*
+import org.opendc.simulator.flow.source.FixedFlowSource
+
+/**
+ * Test suite for the [SimNetworkSwitchVirtual] class.
+ */
+class SimNetworkSwitchVirtualTest {
+    @Test
+    fun testConnect() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val source = spyk(Source(engine))
+        val switch = SimNetworkSwitchVirtual(engine)
+        val consumer = source.consumer
+
+        switch.newPort().connect(sink)
+        switch.newPort().connect(source)
+
+        assertTrue(sink.isConnected)
+        assertTrue(source.isConnected)
+
+        verify { source.createConsumer() }
+        verify { consumer.onStart(any(), any()) }
+    }
+
+    @Test
+    fun testConnectClosedPort() = runBlockingSimulation {
+        val engine = FlowEngine(coroutineContext, clock)
+        val sink = SimNetworkSink(engine, capacity = 100.0)
+        val switch = SimNetworkSwitchVirtual(engine)
+
+        val port = switch.newPort()
+        port.close()
+
+        assertThrows<IllegalStateException> {
+            port.connect(sink)
+        }
+    }
+
+    private class Source(engine: FlowEngine) : SimNetworkPort() {
+        val consumer = spyk(FixedFlowSource(Double.POSITIVE_INFINITY, utilization = 0.8))
+
+        public override fun createConsumer(): FlowSource = consumer
+
+        override val provider: FlowConsumer = FlowSink(engine, 0.0)
+    }
+}