1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.support.test.internal.runner;
18
19import static android.support.test.internal.util.Checks.checkNotNull;
20
21import android.app.Instrumentation;
22
23import java.util.concurrent.atomic.AtomicReference;
24
25/**
26 * Holds a reference to the instrumentation running in the process.
27 */
28public final class InstrumentationRegistry {
29
30    private static final AtomicReference<Instrumentation> sInstrumentationRef =
31            new AtomicReference<Instrumentation>(null);
32
33    /**
34     * Returns the instrumentation currently running.
35     *
36     * @throws IllegalStateException if instrumentation hasn't been registered
37     */
38    public static Instrumentation getInstance() {
39        return checkNotNull(sInstrumentationRef.get(), "No instrumentation registered. " +
40                "Must run under a registering instrumentation.");
41    }
42
43    /**
44     * Records/exposes the instrumentation currently running.
45     * <p>
46     * This is a global registry - so be aware of the impact of calling this method!
47     * </p>
48     */
49    public static void registerInstance(Instrumentation instrumentation) {
50        sInstrumentationRef.set(instrumentation);
51    }
52
53    private InstrumentationRegistry() { }
54}
55