feat(common): Add common dispatcher interface

This change adds a new interface `Dispatcher` that is used throughout
OpenDC for scheduling the execution of future tasks. This replaces the
`CoroutineContext` and `Clock` that exist on many of the implementations
in OpenDC.

With this approach, we reduce the dependency on Kotlin Coroutines.

1 files changed, 33 insertions, 0 deletions

diff --git a/opendc-common/src/main/java/org/opendc/common/DispatcherHandle.java b/opendc-common/src/main/java/org/opendc/common/DispatcherHandle.java
new file mode 100644
index 00000000..e34e5e11
--- /dev/null
+++ b/opendc-common/src/main/java/org/opendc/common/DispatcherHandle.java
@@ -0,0 +1,33 @@
+/*
+ * 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;
+
+/**
+ * A handle returned by a {@link Dispatcher} representing a scheduled task.
+ */
+public interface DispatcherHandle {
+    /**
+     * Attempt to cancel execution of the task.
+     */
+    void cancel();
+}