Add threading annotations

These describe threading requirements for a given method,
or threading promises made to a callback.

Change-Id: If496067b12df3a0adedc32e4b4005cd1c2d400f3

1 files changed, 42 insertions, 0 deletions

diff --git a/core/java/android/annotation/MainThread.java b/core/java/android/annotation/MainThread.java
new file mode 100644
index 0000000..18a4283
--- /dev/null
+++ b/core/java/android/annotation/MainThread.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.annotation;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.CONSTRUCTOR;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.SOURCE;
+
+/**
+ * Denotes that the annotated method should only be called on the main thread.
+ * If the annotated element is a class, then all methods in the class should be called
+ * on the main thread.
+ * <p>
+ * Example:
+ * <pre>{@code
+ *  &#64;MainThread
+ *  public void deliverResult(D data) { ... }
+ * }</pre>
+ *
+ * {@hide}
+ */
+@Retention(SOURCE)
+@Target({METHOD,CONSTRUCTOR,TYPE})
+public @interface MainThread {
+}
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