1 /* 2 * Copyright (C) 2011 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 17 package tests.io; 18 19 import java.lang.reflect.InvocationHandler; 20 import java.lang.reflect.InvocationTargetException; 21 import java.lang.reflect.Method; 22 import java.lang.reflect.Proxy; 23 import java.util.ArrayDeque; 24 import java.util.Deque; 25 import java.util.HashMap; 26 import java.util.Map; 27 import libcore.io.ErrnoException; 28 import libcore.io.Libcore; 29 import libcore.io.Os; 30 import libcore.io.OsConstants; 31 32 /** 33 * A mocking interceptor that wraps another {@link Os} to add faults. This can 34 * be useful to test otherwise hard-to-test scenarios such as a full disk. 35 */ 36 public final class MockOs { 37 private final InheritableThreadLocal<Map<String, Deque<InvocationHandler>>> handlers 38 = new InheritableThreadLocal<Map<String, Deque<InvocationHandler>>>() { 39 @Override protected Map<String, Deque<InvocationHandler>> initialValue() { 40 return new HashMap<String, Deque<InvocationHandler>>(); 41 } 42 }; 43 44 private Os delegate; 45 private final InvocationHandler delegateHandler = new InvocationHandler() { 46 @Override public Object invoke(Object o, Method method, Object[] args) throws Throwable { 47 try { 48 return method.invoke(delegate, args); 49 } catch (InvocationTargetException e) { 50 throw e.getCause(); 51 } 52 } 53 }; 54 55 private final InvocationHandler invocationHandler = new InvocationHandler() { 56 @Override public Object invoke(Object proxy, Method method, Object[] args) 57 throws Throwable { 58 InvocationHandler handler = getHandlers(method.getName()).poll(); 59 if (handler == null) { 60 handler = delegateHandler; 61 } 62 return handler.invoke(proxy, method, args); 63 } 64 }; 65 66 private final Os mockOs = (Os) Proxy.newProxyInstance(MockOs.class.getClassLoader(), 67 new Class[] { Os.class }, invocationHandler); 68 69 public void install() { 70 if (delegate != null) { 71 throw new IllegalStateException("MockOs already installed!"); 72 } 73 delegate = Libcore.os; 74 Libcore.os = mockOs; 75 } 76 77 public void uninstall() { 78 if (delegate == null) { 79 throw new IllegalStateException("MockOs not installed!"); 80 } 81 Libcore.os = delegate; 82 } 83 84 /** 85 * Returns the invocation handlers to handle upcoming invocations of 86 * {@code methodName}. If empty, calls will be handled by the delegate. 87 */ 88 public Deque<InvocationHandler> getHandlers(String methodName) { 89 Map<String, Deque<InvocationHandler>> threadFaults = handlers.get(); 90 Deque<InvocationHandler> result = threadFaults.get(methodName); 91 if (result == null) { 92 result = new ArrayDeque<InvocationHandler>(); 93 threadFaults.put(methodName, result); 94 } 95 return result; 96 } 97 98 /** 99 * Enqueues the specified number of normal operations. Useful to delay 100 * faults. 101 */ 102 public void enqueueNormal(String methodName, int count) { 103 Deque<InvocationHandler> handlers = getHandlers(methodName); 104 for (int i = 0; i < count; i++) { 105 handlers.add(delegateHandler); 106 } 107 } 108 109 public void enqueueFault(String methodName) { 110 enqueueFault(methodName, OsConstants.EIO); 111 } 112 113 public void enqueueFault(String methodName, final int errno) { 114 getHandlers(methodName).add(new InvocationHandler() { 115 @Override public Object invoke(Object proxy, Method method, Object[] args) throws ErrnoException { 116 throw new ErrnoException(method.getName(), errno); 117 } 118 }); 119 } 120 } 121
