simulator: Add virtual network switch

This change adds a virtual network switch to the OpenDC networking
module. Currently, the switch bridges the traffic equally across all
ports. In the future, we'll also add routing support to the switch.

3 files changed, 117 insertions, 2 deletions

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
index e5b85dd1..102e5625 100644
--- 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
@@ -55,8 +55,13 @@ public abstract class SimNetworkPort {
         port._link = link
 
         // Start bi-directional flow channel between the two ports
-        provider.startConsumer(port.createConsumer())
-        port.provider.startConsumer(createConsumer())
+        try {
+            provider.startConsumer(port.createConsumer())
+            port.provider.startConsumer(createConsumer())
+        } catch (e: Throwable) {
+            disconnect()
+            throw e
+        }
     }
 
     /**
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..05daaa5c
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-network/src/main/kotlin/org/opendc/simulator/network/SimNetworkSwitchVirtual.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 org.opendc.simulator.resources.*
+
+/**
+ * A [SimNetworkSwitch] that can support new networking ports on demand.
+ */
+public class SimNetworkSwitchVirtual(interpreter: SimResourceInterpreter) : SimNetworkSwitch {
+    /**
+     * The ports of this switch.
+     */
+    override val ports: List<Port>
+        get() = _ports
+    private val _ports = mutableListOf<Port>()
+
+    /**
+     * The [SimResourceSwitchMaxMin] to actually perform the switching.
+     */
+    private val switch = SimResourceSwitchMaxMin(interpreter)
+
+    /**
+     * 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: SimResourceProvider
+            get() = _provider
+        private val _provider = switch.newOutput()
+
+        override fun createConsumer(): SimResourceConsumer {
+            val forwarder = SimResourceForwarder(isCoupled = true)
+            switch.addInput(forwarder)
+            return forwarder
+        }
+
+        override fun close() {
+            isClosed = true
+            _provider.close()
+            _ports.remove(this)
+        }
+    }
+}