diff options
Diffstat (limited to 'opendc-simulator')
4 files changed, 848 insertions, 0 deletions
diff --git a/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/SimulationScheduler.java b/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/SimulationScheduler.java new file mode 100644 index 00000000..a70c1cda --- /dev/null +++ b/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/SimulationScheduler.java @@ -0,0 +1,246 @@ +/* + * 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.simulator; + +import java.time.Clock; +import java.time.Instant; +import java.time.ZoneId; +import java.util.concurrent.Executor; + +/** + * A scheduler is used by simulations to manage execution of (future) tasks, providing a controllable (virtual) clock to + * skip over delays. + * + * <p> + * The scheduler can be queried to advance the time (via {@link #advanceBy}), run all the scheduled tasks advancing the + * virtual time as needed (via {@link #advanceUntilIdle}), or run the tasks that are scheduled to run as soon as + * possible but have not yet been dispatched (via {@link #runCurrent}). These methods execute the pending tasks using + * a single thread. + * + * <p> + * This class is not thread-safe and must not be used concurrently by multiple threads. + */ +public final class SimulationScheduler implements Executor { + /** + * The {@link TaskQueue} containing the pending tasks. + */ + private final TaskQueue queue = new TaskQueue(); + + /** + * The current time of the scheduler in milliseconds since epoch. + */ + private long currentTime; + + /** + * A counter to establish total order on the events that happen at the same virtual time. + */ + private int count = 0; + + /** + * The {@link Clock} instance linked to this scheduler. + */ + private final SimulationClock clock = new SimulationClock(this, ZoneId.systemDefault()); + + /** + * Construct a {@link SimulationScheduler} instance with the specified initial time. + * + * @param initialTimeMs The initial virtual time of the scheduler in milliseconds since epoch. + */ + public SimulationScheduler(long initialTimeMs) { + this.currentTime = initialTimeMs; + } + + /** + * Construct a {@link SimulationScheduler} instance with the initial time set to UNIX Epoch 0. + */ + public SimulationScheduler() { + this(0); + } + + /** + * Return the virtual clock associated with this dispatcher. + * + * @return A {@link Clock} tracking the virtual time of the dispatcher. + */ + public Clock getClock() { + return clock; + } + + /** + * Return the current virtual timestamp of the dispatcher (in milliseconds since epoch). + * + * @return A long value representing the virtual timestamp of the dispatcher in milliseconds since epoch. + */ + public long getCurrentTime() { + return currentTime; + } + + /** + * Schedule a <code>task</code> that executes after the specified <code>delayMs</code>. + * + * @param delayMs The time from now until the execution of the task (in milliseconds). + * @param task The task to execute after the delay. + * @return The identifier of the task that can be used together with the timestamp of the task to cancel it. + */ + public int schedule(long delayMs, Runnable task) { + if (delayMs < 0) { + throw new IllegalArgumentException("Attempted scheduling an event earlier in time (delay " + delayMs + " ms)"); + } + + long target = currentTime + delayMs; + if (target < 0) { + target = Long.MAX_VALUE; + } + + int id = count++; + queue.add(target, id, task); + return id; + } + + /** + * Cancel a pending task. + * + * @param deadline The deadline of the task. + * @param id The identifier of the task (returned by {@link #schedule(long, Runnable)}). + * @return A boolean indicating whether a task was actually cancelled. + */ + public boolean cancel(long deadline, int id) { + return queue.remove(deadline, id); + } + + /** + * Run the enqueued tasks in the specified order, advancing the virtual time as needed until there are no more + * tasks in the queue of this scheduler. + */ + public void advanceUntilIdle() { + final TaskQueue queue = this.queue; + + while (true) { + long deadline = queue.peekDeadline(); + Runnable task = queue.poll(); + + if (task == null) { + break; + } + + currentTime = deadline; + task.run(); + } + } + + /** + * Move the virtual clock of this dispatcher forward by the specified amount, running the scheduled tasks in the + * meantime. + * + * @param delayMs The amount of time to move the virtual clock forward (in milliseconds). + * @throws IllegalStateException if passed a negative <code>delay</code>. + */ + public void advanceBy(long delayMs) { + if (delayMs < 0) { + throw new IllegalArgumentException("Can not advance time by a negative delay: " + delayMs + " ms"); + } + + long target = currentTime + delayMs; + if (target < 0) { + target = Long.MAX_VALUE; + } + + final TaskQueue queue = this.queue; + long deadline; + + while ((deadline = queue.peekDeadline()) < target) { + Runnable task = queue.poll(); // Cannot be null since while condition is always false on an empty queue + + task.run(); + currentTime = deadline; + } + + currentTime = target; + } + + /** + * Execute the tasks that are scheduled to execute at this moment of virtual time. + */ + public void runCurrent() { + final TaskQueue queue = this.queue; + long currentTime = this.currentTime; + + while (queue.peekDeadline() == currentTime) { + Runnable task = queue.poll(); + + if (task == null) { + break; + } + + task.run(); + } + } + + /** + * Schedule the specified command to run at this moment of virtual time. + * + * @param command The command to execute. + */ + @Override + public void execute(Runnable command) { + schedule(0, command); + } + + /** + * A {@link Clock} implementation for a {@link SimulationScheduler}. + */ + private static class SimulationClock extends Clock { + private final SimulationScheduler scheduler; + private final ZoneId zone; + + SimulationClock(SimulationScheduler scheduler, ZoneId zone) { + this.scheduler = scheduler; + this.zone = zone; + } + + @Override + public ZoneId getZone() { + return zone; + } + + @Override + public Clock withZone(ZoneId zoneId) { + return new SimulationClock(scheduler, zone); + } + + @Override + public Instant instant() { + return Instant.ofEpochMilli(scheduler.currentTime); + } + + @Override + public long millis() { + return scheduler.currentTime; + } + + @Override + public String toString() { + return "SimulationClock[time=" + millis() + "ms]"; + } + } +} diff --git a/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/TaskQueue.java b/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/TaskQueue.java new file mode 100644 index 00000000..7d867b5d --- /dev/null +++ b/opendc-simulator/opendc-simulator-core/src/main/java/org/opendc/simulator/TaskQueue.java @@ -0,0 +1,265 @@ +/* + * 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.simulator; + +import java.util.Arrays; + +/** + * Specialized priority queue for pending tasks. + * + * <p> + * This class uses a specialized priority queue (as opposed to a generic {@link java.util.PriorityQueue}), which reduces + * unnecessary allocations in the simulator's hot path. + */ +final class TaskQueue { + /** + * The deadlines of the pending tasks. + */ + private long[] deadlines; + + /** + * The identifiers of the pending tasks. Identifiers are used to provide a total order for pending tasks in case + * the deadline of two tasks is the same. + */ + private int[] ids; + + /** + * The {@link Runnable}s representing the tasks that have been scheduled. + */ + private Runnable[] tasks; + + /** + * The number of elements in the priority queue. + */ + private int size = 0; + + /** + * Construct a {@link TaskQueue} with the specified initial capacity. + * + * @param initialCapacity The initial capacity of the queue. + */ + public TaskQueue(int initialCapacity) { + this.deadlines = new long[initialCapacity]; + this.ids = new int[initialCapacity]; + this.tasks = new Runnable[initialCapacity]; + } + + /** + * Construct a {@link TaskQueue} with an initial capacity of 256 elements. + */ + public TaskQueue() { + this(256); + } + + /** + * Add a new task to this queue. + * + * @param deadline The deadline of the task. + * @param id The identifier of the task. + * @param task The {@link Runnable} representing the task to execute. + */ + public void add(long deadline, int id, Runnable task) { + int i = size; + long[] deadlines = this.deadlines; + + if (i >= deadlines.length) { + grow(); + + // Re-fetch the resized array + deadlines = this.deadlines; + } + + siftUp(deadlines, ids, tasks, i, deadline, id, task); + + size = i + 1; + } + + /** + * Retrieve the next task to be executed. + * + * @return The head of the queue or <code>null</code> if the queue is empty. + */ + public Runnable poll() { + final Runnable[] tasks = this.tasks; + final Runnable result = tasks[0]; + + if (result != null) { + int n = --size; + + if (n > 0) { + long[] deadlines = this.deadlines; + int[] ids = this.ids; + + siftDown(deadlines, ids, tasks, 0, n, deadlines[n], ids[n], tasks[n]); + } + + // Clear the last element of the queue + tasks[n] = null; + } + + return result; + } + + /** + * Find the earliest deadline in the queue. + * + * @return The earliest deadline in the queue or {@link Long#MAX_VALUE} if the queue is empty. + */ + public long peekDeadline() { + if (size == 0) { + return Long.MAX_VALUE; + } + + return deadlines[0]; + } + + /** + * Remove the timer entry with the specified <code>deadline</code> and <code>id</code>. + */ + public boolean remove(long deadline, int id) { + long[] deadlines = this.deadlines; + int[] ids = this.ids; + + int size = this.size; + int i = -1; + + for (int j = 0; j < size; j++) { + if (deadlines[j] == deadline && ids[j] == id) { + i = j; + break; + } + } + + if (i < 0) { + return false; + } + + Runnable[] tasks = this.tasks; + int s = size - 1; + this.size = s; + + if (s == i) { + tasks[i] = null; + } else { + long movedDeadline = deadlines[s]; + int movedId = ids[s]; + Runnable movedTask = tasks[s]; + + tasks[s] = null; + + siftDown(deadlines, ids, tasks, i, s, movedDeadline, movedId, movedTask); + if (tasks[i] == movedTask) { + siftUp(deadlines, ids, tasks, i, movedDeadline, movedId, movedTask); + } + } + + return true; + } + + /** + * Increases the capacity of the priority queue. + */ + private void grow() { + int oldCapacity = deadlines.length; + + // Double size if small; else grow by 50% + int newCapacity = oldCapacity + oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1; + + deadlines = Arrays.copyOf(deadlines, newCapacity); + ids = Arrays.copyOf(ids, newCapacity); + tasks = Arrays.copyOf(tasks, newCapacity); + } + + /** + * Sift up an entry in the heap. + */ + private static void siftUp(long[] deadlines, int[] ids, Runnable[] tasks, int k, long deadline, int id, Runnable task) { + while (k > 0) { + int parent = (k - 1) >>> 1; + long parentDeadline = deadlines[parent]; + int parentId = ids[parent]; + + if (compare(deadline, id, parentDeadline, parentId) >= 0) { + break; + } + + deadlines[k] = parentDeadline; + ids[k] = parentId; + tasks[k] = tasks[parent]; + + k = parent; + } + + deadlines[k] = deadline; + ids[k] = id; + tasks[k] = task; + } + + /** + * Sift down an entry in the heap. + */ + private static void siftDown(long[] deadlines, int[] ids, Runnable[] tasks, int k, int n, long deadline, int id, Runnable task) { + int half = n >>> 1; // loop while a non-leaf + + while (k < half) { + int child = (k << 1) + 1; // assume left child is least + + long childDeadline = deadlines[child]; + int childId = ids[child]; + + int right = child + 1; + if (right < n) { + long rightDeadline = deadlines[right]; + int rightId = ids[right]; + + if (compare(childDeadline, childId, rightDeadline, rightId) > 0) { + child = right; + childDeadline = rightDeadline; + childId = rightId; + } + } + + if (compare(deadline, id, childDeadline, childId) <= 0) { + break; + } + + deadlines[k] = childDeadline; + ids[k] = childId; + tasks[k] = tasks[child]; + + k = child; + } + + deadlines[k] = deadline; + ids[k] = id; + tasks[k] = task; + } + + /** + * Helper method to compare two task entries. + */ + private static int compare(long leftDeadline, int leftId, long rightDeadline, int rightId) { + int cmp = Long.compare(leftDeadline, rightDeadline); + return cmp == 0 ? Integer.compare(leftId, rightId) : cmp; + } +} diff --git a/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/SimulationSchedulerTest.kt b/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/SimulationSchedulerTest.kt new file mode 100644 index 00000000..eca3b582 --- /dev/null +++ b/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/SimulationSchedulerTest.kt @@ -0,0 +1,106 @@ +/* + * 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.simulator + +import org.junit.jupiter.api.Assertions.assertEquals +import org.junit.jupiter.api.Test +import org.junit.jupiter.api.assertThrows +import java.time.Instant + +/** + * Test suite for the [SimulationScheduler] class. + */ +class SimulationSchedulerTest { + /** + * Test the basic functionality of [SimulationScheduler.runCurrent]. + */ + @Test + fun testRunCurrent() { + val scheduler = SimulationScheduler() + var count = 0 + + scheduler.schedule(1) { count += 1 } + scheduler.schedule(2) { count += 1 } + + scheduler.advanceBy(1) + assertEquals(0, count) + scheduler.runCurrent() + assertEquals(1, count) + scheduler.advanceBy(1) + assertEquals(1, count) + scheduler.runCurrent() + assertEquals(2, count) + assertEquals(2, scheduler.currentTime) + + scheduler.advanceBy(Long.MAX_VALUE) + scheduler.runCurrent() + assertEquals(Long.MAX_VALUE, scheduler.currentTime) + } + + /** + * Test the clock of the [SimulationScheduler]. + */ + @Test + fun testClock() { + val scheduler = SimulationScheduler() + var count = 0 + + scheduler.schedule(1) { count += 1 } + scheduler.schedule(2) { count += 1 } + + scheduler.advanceBy(2) + assertEquals(2, scheduler.currentTime) + assertEquals(2, scheduler.clock.millis()) + assertEquals(Instant.ofEpochMilli(2), scheduler.clock.instant()) + } + + /** + * Test large delays. + */ + @Test + fun testAdvanceByLargeDelays() { + val scheduler = SimulationScheduler() + var count = 0 + + scheduler.schedule(1) { count += 1 } + + scheduler.advanceBy(10) + + scheduler.schedule(Long.MAX_VALUE) { count += 1 } + scheduler.schedule(100_000_000) { count += 1 } + + scheduler.advanceUntilIdle() + assertEquals(3, count) + } + + /** + * Test negative delays. + */ + @Test + fun testNegativeDelays() { + val scheduler = SimulationScheduler() + + assertThrows<IllegalArgumentException> { scheduler.schedule(-100) { } } + assertThrows<IllegalArgumentException> { scheduler.advanceBy(-100) } + } +} diff --git a/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/TaskQueueTest.kt b/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/TaskQueueTest.kt new file mode 100644 index 00000000..a4d779cb --- /dev/null +++ b/opendc-simulator/opendc-simulator-core/src/test/kotlin/org/opendc/simulator/TaskQueueTest.kt @@ -0,0 +1,231 @@ +/* + * 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.simulator + +import org.junit.jupiter.api.Assertions.* +import org.junit.jupiter.api.BeforeEach +import org.junit.jupiter.api.Test + +/** + * Test suite for the [TaskQueue] class. + */ +class TaskQueueTest { + private lateinit var queue: TaskQueue + + @BeforeEach + fun setUp() { + queue = TaskQueue(3) + } + + /** + * Test whether a call to [TaskQueue.poll] returns `null` for an empty queue. + */ + @Test + fun testPollEmpty() { + assertAll( + { assertEquals(Long.MAX_VALUE, queue.peekDeadline()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test whether a call to [TaskQueue.poll] returns the proper value for a queue with a single entry. + */ + @Test + fun testSingleEntry() { + val entry = Runnable {} + + queue.add(100, 1, entry) + + assertAll( + { assertEquals(100, queue.peekDeadline()) }, + { assertEquals(entry, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test whether [TaskQueue.poll] returns values in the queue in the proper order. + */ + @Test + fun testMultipleEntries() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(48, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + assertAll( + { assertEquals(48, queue.peekDeadline()) }, + { assertEquals(entryB, queue.poll()) }, + { assertEquals(entryC, queue.poll()) }, + { assertEquals(entryA, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test whether [TaskQueue.poll] returns values in the queue in the proper order with duplicates. + */ + @Test + fun testMultipleEntriesDuplicate() { + val entryA = Runnable {} + queue.add(48, 0, entryA) + + val entryB = Runnable {} + queue.add(48, 1, entryB) + + val entryC = Runnable {} + queue.add(48, 2, entryC) + + assertAll( + { assertEquals(48, queue.peekDeadline()) }, + { assertEquals(entryA, queue.poll()) }, + { assertEquals(entryB, queue.poll()) }, + { assertEquals(entryC, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test that the queue is properly resized when the number of entries exceed the capacity. + */ + @Test + fun testResize() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(20, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + val entryD = Runnable {} + queue.add(38, 1, entryD) + + assertAll( + { assertEquals(20, queue.peekDeadline()) }, + { assertEquals(entryB, queue.poll()) }, + { assertEquals(entryD, queue.poll()) }, + { assertEquals(entryC, queue.poll()) }, + { assertEquals(entryA, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test that we can remove an entry from the end of the queue. + */ + @Test + fun testRemoveEntryTail() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(20, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + queue.remove(100, 1) + + assertAll( + { assertEquals(20, queue.peekDeadline()) }, + { assertEquals(entryB, queue.poll()) }, + { assertEquals(entryC, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test that we can remove an entry from the head of the queue. + */ + @Test + fun testRemoveEntryHead() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(20, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + queue.remove(20, 1) + + assertAll( + { assertEquals(58, queue.peekDeadline()) }, + { assertEquals(entryC, queue.poll()) }, + { assertEquals(entryA, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test that we can remove an entry from the middle of a queue. + */ + @Test + fun testRemoveEntryMiddle() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(20, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + queue.remove(58, 1) + + assertAll( + { assertEquals(20, queue.peekDeadline()) }, + { assertEquals(entryB, queue.poll()) }, + { assertEquals(entryA, queue.poll()) }, + { assertNull(queue.poll()) }, + ) + } + + /** + * Test that we can "remove" an unknown entry without error. + */ + @Test + fun testRemoveUnknown() { + val entryA = Runnable {} + queue.add(100, 1, entryA) + + val entryB = Runnable {} + queue.add(20, 1, entryB) + + val entryC = Runnable {} + queue.add(58, 1, entryC) + + assertAll( + { assertFalse(queue.remove(10, 1)) }, + { assertFalse(queue.remove(58, 2)) } + ) + } +} |