refactor: Replace use of CoroutineContext by Dispatcher

This change replaces the use of `CoroutineContext` for passing the
`SimulationDispatcher` across the different modules of OpenDC by the
lightweight `Dispatcher` interface of the OpenDC common module.

1 files changed, 0 insertions, 230 deletions

diff --git a/opendc-common/src/main/kotlin/org/opendc/common/util/TimerScheduler.kt b/opendc-common/src/main/kotlin/org/opendc/common/util/TimerScheduler.kt
deleted file mode 100644
index 864512d3..00000000
--- a/opendc-common/src/main/kotlin/org/opendc/common/util/TimerScheduler.kt
+++ /dev/null
@@ -1,230 +0,0 @@
-/*
- * Copyright (c) 2022 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.common.util
-
-import kotlinx.coroutines.Delay
-import kotlinx.coroutines.DisposableHandle
-import kotlinx.coroutines.InternalCoroutinesApi
-import java.time.InstantSource
-import java.util.ArrayDeque
-import java.util.PriorityQueue
-import kotlin.coroutines.ContinuationInterceptor
-import kotlin.coroutines.CoroutineContext
-
-/**
- * A TimerScheduler facilitates scheduled execution of future tasks.
- *
- * @param context The [CoroutineContext] to run the tasks with.
- * @param clock The clock to keep track of the time.
- */
-public class TimerScheduler<T>(private val context: CoroutineContext, private val clock: InstantSource) {
-    /**
-     * The [Delay] instance that provides scheduled execution of [Runnable]s.
-     */
-    @OptIn(InternalCoroutinesApi::class)
-    private val delay =
-        requireNotNull(context[ContinuationInterceptor] as? Delay) { "Invalid CoroutineDispatcher: no delay implementation" }
-
-    /**
-     * The stack of the invocations to occur in the future.
-     */
-    private val invocations = ArrayDeque<Invocation>()
-
-    /**
-     * A priority queue containing the tasks to be scheduled in the future.
-     */
-    private val queue = PriorityQueue<Timer<T>>()
-
-    /**
-     * A map that keeps track of the timers.
-     */
-    private val timers = mutableMapOf<T, Timer<T>>()
-
-    /**
-     * Start a timer that will invoke the specified [block] after [delay].
-     *
-     * Each timer has a key and if a new timer with same key is started the previous is cancelled.
-     *
-     * @param key The key of the timer to start.
-     * @param delay The delay before invoking the block.
-     * @param block The block to invoke.
-     */
-    public fun startSingleTimer(key: T, delay: Long, block: () -> Unit) {
-        startSingleTimerTo(key, clock.millis() + delay, block)
-    }
-
-    /**
-     * Start a timer that will invoke the specified [block] at [timestamp].
-     *
-     * Each timer has a key and if a new timer with same key is started the previous is cancelled.
-     *
-     * @param key The key of the timer to start.
-     * @param timestamp The timestamp at which to invoke the block.
-     * @param block The block to invoke.
-     */
-    public fun startSingleTimerTo(key: T, timestamp: Long, block: () -> Unit) {
-        val now = clock.millis()
-        val queue = queue
-        val invocations = invocations
-
-        require(timestamp >= now) { "Timestamp must be in the future" }
-
-        timers.compute(key) { _, old ->
-            if (old != null && old.timestamp == timestamp) {
-                // Fast-path: timer for the same timestamp already exists
-                old.block = block
-                old
-            } else {
-                // Slow-path: cancel old timer and replace it with new timer
-                val timer = Timer(key, timestamp, block)
-
-                old?.isCancelled = true
-                queue.add(timer)
-                trySchedule(now, invocations, timestamp)
-
-                timer
-            }
-        }
-    }
-
-    /**
-     * Check if a timer with a given key is active.
-     *
-     * @param key The key to check if active.
-     * @return `true` if the timer with the specified [key] is active, `false` otherwise.
-     */
-    public fun isTimerActive(key: T): Boolean = key in timers
-
-    /**
-     * Cancel a timer with a given key.
-     *
-     * If canceling a timer that was already canceled, or key never was used to start
-     * a timer this operation will do nothing.
-     *
-     * @param key The key of the timer to cancel.
-     */
-    public fun cancel(key: T) {
-        val timer = timers.remove(key)
-
-        // Mark the timer as cancelled
-        timer?.isCancelled = true
-    }
-
-    /**
-     * Cancel all timers.
-     */
-    public fun cancelAll() {
-        queue.clear()
-        timers.clear()
-
-        // Cancel all pending invocations
-        for (invocation in invocations) {
-            invocation.cancel()
-        }
-        invocations.clear()
-    }
-
-    /**
-     * Try to schedule an engine invocation at the specified [target].
-     *
-     * @param now The current virtual timestamp.
-     * @param target The virtual timestamp at which the engine invocation should happen.
-     * @param scheduled The queue of scheduled invocations.
-     */
-    private fun trySchedule(now: Long, scheduled: ArrayDeque<Invocation>, target: Long) {
-        val head = scheduled.peek()
-
-        // Only schedule a new scheduler invocation in case the target is earlier than all other pending
-        // scheduler invocations
-        if (head == null || target < head.timestamp) {
-            @OptIn(InternalCoroutinesApi::class)
-            val handle = delay.invokeOnTimeout(target - now, ::doRunTimers, context)
-            scheduled.addFirst(Invocation(target, handle))
-        }
-    }
-
-    /**
-     * This method is invoked when the earliest timer expires.
-     */
-    private fun doRunTimers() {
-        val invocations = invocations
-        val invocation = checkNotNull(invocations.poll()) // Clear invocation from future invocation queue
-        val now = invocation.timestamp
-
-        while (queue.isNotEmpty()) {
-            val timer = queue.peek()
-
-            val timestamp = timer.timestamp
-            val isCancelled = timer.isCancelled
-
-            assert(timestamp >= now) { "Found task in the past" }
-
-            if (timestamp > now && !isCancelled) {
-                // Schedule a task for the next event to occur.
-                trySchedule(now, invocations, timestamp)
-                break
-            }
-
-            queue.poll()
-
-            if (!isCancelled) {
-                timers.remove(timer.key)
-                timer()
-            }
-        }
-    }
-
-    /**
-     * A task that is scheduled to run in the future.
-     */
-    private class Timer<T>(val key: T, val timestamp: Long, var block: () -> Unit) : Comparable<Timer<T>> {
-        /**
-         * A flag to indicate that the task has been cancelled.
-         */
-        @JvmField
-        var isCancelled: Boolean = false
-
-        /**
-         * Run the task.
-         */
-        operator fun invoke(): Unit = block()
-
-        override fun compareTo(other: Timer<T>): Int = timestamp.compareTo(other.timestamp)
-    }
-
-    /**
-     * A future engine invocation.
-     *
-     * This class is used to keep track of the future engine invocations created using the [Delay] instance. In case
-     * the invocation is not needed anymore, it can be cancelled via [cancel].
-     */
-    private class Invocation(
-        @JvmField val timestamp: Long,
-        @JvmField val handle: DisposableHandle
-    ) {
-        /**
-         * Cancel the engine invocation.
-         */
-        fun cancel() = handle.dispose()
-    }
-}