serverless: Add initial implementation of OpenDC Serverless (#100)

This change adds the initial implementation of OpenDC Serverless to the
main repository, which is based on Soufiane Jounaid's work. This commit
introduces the main interfaces into the repository. Later commits will
introduce the other features that Soufiane has implemented previously in
OpenDC.

5 files changed, 367 insertions, 0 deletions

diff --git a/simulator/opendc-serverless/opendc-serverless-simulator/build.gradle.kts b/simulator/opendc-serverless/opendc-serverless-simulator/build.gradle.kts
new file mode 100644
index 00000000..fe3dca41
--- /dev/null
+++ b/simulator/opendc-serverless/opendc-serverless-simulator/build.gradle.kts
@@ -0,0 +1,39 @@
+/*
+ * 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 = "Simulator for OpenDC Serverles"
+
+/* Build configuration */
+plugins {
+    `kotlin-library-conventions`
+    `testing-conventions`
+    `jacoco-conventions`
+}
+
+dependencies {
+    api(platform(project(":opendc-platform")))
+    api(project(":opendc-serverless:opendc-serverless-service"))
+    api(project(":opendc-simulator:opendc-simulator-compute"))
+
+    testImplementation(project(":opendc-simulator:opendc-simulator-core"))
+    testRuntimeOnly("org.slf4j:slf4j-simple:${versions.slf4j}")
+}
diff --git a/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/SimFunctionDeployer.kt b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/SimFunctionDeployer.kt
new file mode 100644
index 00000000..7a48609c
--- /dev/null
+++ b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/SimFunctionDeployer.kt
@@ -0,0 +1,159 @@
+/*
+ * 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.serverless.simulator
+
+import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.Channel
+import org.opendc.serverless.api.ServerlessFunction
+import org.opendc.serverless.service.deployer.FunctionDeployer
+import org.opendc.serverless.service.deployer.FunctionInstance
+import org.opendc.serverless.service.deployer.FunctionInstanceState
+import org.opendc.serverless.simulator.workload.SimServerlessWorkloadMapper
+import org.opendc.simulator.compute.SimBareMetalMachine
+import org.opendc.simulator.compute.SimMachine
+import org.opendc.simulator.compute.SimMachineModel
+import java.time.Clock
+import java.util.ArrayDeque
+import kotlin.coroutines.Continuation
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
+
+/**
+ * A [FunctionDeployer] that uses that simulates the [FunctionInstance]s.
+ */
+public class SimFunctionDeployer(
+    private val clock: Clock,
+    private val scope: CoroutineScope,
+    private val model: SimMachineModel,
+    private val mapper: SimServerlessWorkloadMapper
+) : FunctionDeployer {
+
+    override fun deploy(function: ServerlessFunction): Instance {
+        val instance = Instance(function)
+        instance.start()
+        return instance
+    }
+
+    /**
+     * A simulated [FunctionInstance].
+     */
+    public inner class Instance(override val function: ServerlessFunction) : FunctionInstance {
+        /**
+         * The workload associated with this instance.
+         */
+        private val workload = mapper.createWorkload(function)
+
+        /**
+         * The machine that will execute the workloads.
+         */
+        public val machine: SimMachine = SimBareMetalMachine(scope.coroutineContext, clock, model)
+
+        /**
+         * The job associated with the lifecycle of the instance.
+         */
+        private var job: Job? = null
+
+        /**
+         * The invocation request queue.
+         */
+        private val queue = ArrayDeque<InvocationRequest>()
+
+        /**
+         * A channel used to signal that new invocations have been enqueued.
+         */
+        private val chan = Channel<Unit>(Channel.RENDEZVOUS)
+
+        override var state: FunctionInstanceState = FunctionInstanceState.Provisioning
+
+        override suspend fun invoke() {
+            check(state != FunctionInstanceState.Deleted) { "Function instance has been released" }
+            return suspendCancellableCoroutine { cont ->
+                queue.add(InvocationRequest(cont))
+                chan.offer(Unit)
+            }
+        }
+
+        override fun close() {
+            state = FunctionInstanceState.Deleted
+            stop()
+            machine.close()
+        }
+
+        override fun toString(): String = "FunctionInstance[state=$state]"
+
+        /**
+         * Start the function instance.
+         */
+        @OptIn(InternalCoroutinesApi::class)
+        internal fun start() {
+            check(state == FunctionInstanceState.Provisioning) { "Invalid state of function instance" }
+            job = scope.launch {
+                workload.onStart()
+
+                try {
+                    while (isActive) {
+                        chan.receive()
+
+                        if (queue.isNotEmpty()) {
+                            state = FunctionInstanceState.Active
+                        }
+
+                        while (queue.isNotEmpty()) {
+                            val request = queue.poll()
+                            try {
+                                machine.run(workload.onInvoke())
+                                request.cont.resume(Unit)
+                            } catch (cause: CancellationException) {
+                                request.cont.resumeWithException(cause)
+                                throw cause
+                            } catch (cause: Throwable) {
+                                request.cont.resumeWithException(cause)
+                            }
+                        }
+                        state = FunctionInstanceState.Idle
+                    }
+                } finally {
+                    state = FunctionInstanceState.Terminated
+                    workload.onStop()
+                }
+            }
+        }
+
+        /**
+         * Stop the function instance.
+         */
+        private fun stop() {
+            val job = job
+
+            if (job != null) {
+                this.job = null
+                job.cancel()
+            }
+        }
+    }
+
+    /**
+     * A function invocation request.
+     */
+    private data class InvocationRequest(val cont: Continuation<Unit>)
+}
diff --git a/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkload.kt b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkload.kt
new file mode 100644
index 00000000..afdc05af
--- /dev/null
+++ b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkload.kt
@@ -0,0 +1,45 @@
+/*
+ * 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.serverless.simulator.workload
+
+import org.opendc.simulator.compute.workload.SimWorkload
+
+/**
+ * A model for a serverless workload, which may be invoked multiple times.
+ */
+public interface SimServerlessWorkload {
+    /**
+     * This method is invoked when a function instance is launched.
+     */
+    public fun onStart() {}
+
+    /**
+     * This method is invoked when an active function instance is invoked.
+     */
+    public fun onInvoke(): SimWorkload
+
+    /**
+     * This method is invoked when the function instance is stopped.
+     */
+    public fun onStop() {}
+}
diff --git a/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkloadMapper.kt b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkloadMapper.kt
new file mode 100644
index 00000000..670f978d
--- /dev/null
+++ b/simulator/opendc-serverless/opendc-serverless-simulator/src/main/kotlin/org/opendc/serverless/simulator/workload/SimServerlessWorkloadMapper.kt
@@ -0,0 +1,36 @@
+/*
+ * 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.serverless.simulator.workload
+
+import org.opendc.serverless.api.ServerlessFunction
+
+/**
+ * A [SimServerlessWorkloadMapper] is responsible for mapping a [ServerlessFunction] to a [SimServerlessWorkload] that
+ * can be simulated.
+ */
+public fun interface SimServerlessWorkloadMapper {
+    /**
+     * Map the specified [function] to a [SimServerlessWorkload] that can be simulated.
+     */
+    public fun createWorkload(function: ServerlessFunction): SimServerlessWorkload
+}
diff --git a/simulator/opendc-serverless/opendc-serverless-simulator/src/test/kotlin/org/opendc/serverless/simulator/SimServerlessServiceTest.kt b/simulator/opendc-serverless/opendc-serverless-simulator/src/test/kotlin/org/opendc/serverless/simulator/SimServerlessServiceTest.kt
new file mode 100644
index 00000000..a80365de
--- /dev/null
+++ b/simulator/opendc-serverless/opendc-serverless-simulator/src/test/kotlin/org/opendc/serverless/simulator/SimServerlessServiceTest.kt
@@ -0,0 +1,88 @@
+/*
+ * 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.serverless.simulator
+
+import io.mockk.spyk
+import io.mockk.verify
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.test.runBlockingTest
+import kotlinx.coroutines.yield
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import org.opendc.serverless.service.ServerlessService
+import org.opendc.serverless.service.router.RandomRoutingPolicy
+import org.opendc.serverless.simulator.workload.SimServerlessWorkload
+import org.opendc.simulator.compute.SimMachineModel
+import org.opendc.simulator.compute.model.SimMemoryUnit
+import org.opendc.simulator.compute.model.SimProcessingNode
+import org.opendc.simulator.compute.model.SimProcessingUnit
+import org.opendc.simulator.compute.workload.SimFlopsWorkload
+import org.opendc.simulator.compute.workload.SimWorkload
+import org.opendc.simulator.utils.DelayControllerClockAdapter
+
+/**
+ * A test suite for the [ServerlessService] implementation under simulated conditions.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+internal class SimServerlessServiceTest {
+
+    private lateinit var machineModel: SimMachineModel
+
+    @BeforeEach
+    fun setUp() {
+        val cpuNode = SimProcessingNode("Intel", "Xeon", "amd64", 2)
+
+        machineModel = SimMachineModel(
+            cpus = List(cpuNode.coreCount) { SimProcessingUnit(cpuNode, it, 1000.0) },
+            memory = List(4) { SimMemoryUnit("Crucial", "MTA18ASF4G72AZ-3G2B1", 3200.0, 32_000) }
+        )
+    }
+
+    @Test
+    fun testSmoke() = runBlockingTest {
+        val clock = DelayControllerClockAdapter(this)
+        val workload = spyk(object : SimServerlessWorkload {
+            override fun onInvoke(): SimWorkload = SimFlopsWorkload(1000)
+        })
+        val deployer = SimFunctionDeployer(clock, this, machineModel) { workload }
+        val service = ServerlessService(coroutineContext, clock, deployer, RandomRoutingPolicy())
+
+        val client = service.newClient()
+
+        val function = client.newFunction("test")
+        function.invoke()
+        delay(2000)
+
+        service.close()
+
+        yield()
+
+        assertAll(
+            { verify { workload.onStart() } },
+            { verify { workload.onInvoke() } },
+            { verify { workload.onStop() } }
+        )
+    }
+}