Binder.cpp revision 32397c1cd3327905173b36baa6fd1c579bc328ff
1/* 2 * Copyright (C) 2005 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#include <binder/Binder.h> 18 19#include <utils/Atomic.h> 20#include <binder/BpBinder.h> 21#include <binder/IInterface.h> 22#include <binder/Parcel.h> 23 24#include <stdio.h> 25 26namespace android { 27 28// --------------------------------------------------------------------------- 29 30IBinder::IBinder() 31 : RefBase() 32{ 33} 34 35IBinder::~IBinder() 36{ 37} 38 39// --------------------------------------------------------------------------- 40 41sp<IInterface> IBinder::queryLocalInterface(const String16& descriptor) 42{ 43 return NULL; 44} 45 46BBinder* IBinder::localBinder() 47{ 48 return NULL; 49} 50 51BpBinder* IBinder::remoteBinder() 52{ 53 return NULL; 54} 55 56bool IBinder::checkSubclass(const void* /*subclassID*/) const 57{ 58 return false; 59} 60 61// --------------------------------------------------------------------------- 62 63class BBinder::Extras 64{ 65public: 66 Mutex mLock; 67 BpBinder::ObjectManager mObjects; 68}; 69 70// --------------------------------------------------------------------------- 71 72BBinder::BBinder() 73 : mExtras(NULL) 74{ 75} 76 77bool BBinder::isBinderAlive() const 78{ 79 return true; 80} 81 82status_t BBinder::pingBinder() 83{ 84 return NO_ERROR; 85} 86 87const String16& BBinder::getInterfaceDescriptor() const 88{ 89 // This is a local static rather than a global static, 90 // to avoid static initializer ordering issues. 91 static String16 sEmptyDescriptor; 92 ALOGW("reached BBinder::getInterfaceDescriptor (this=%p)", this); 93 return sEmptyDescriptor; 94} 95 96status_t BBinder::transact( 97 uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) 98{ 99 data.setDataPosition(0); 100 101 status_t err = NO_ERROR; 102 switch (code) { 103 case PING_TRANSACTION: 104 reply->writeInt32(pingBinder()); 105 break; 106 default: 107 err = onTransact(code, data, reply, flags); 108 break; 109 } 110 111 if (reply != NULL) { 112 reply->setDataPosition(0); 113 } 114 115 return err; 116} 117 118status_t BBinder::linkToDeath( 119 const sp<DeathRecipient>& recipient, void* cookie, uint32_t flags) 120{ 121 return INVALID_OPERATION; 122} 123 124status_t BBinder::unlinkToDeath( 125 const wp<DeathRecipient>& recipient, void* cookie, uint32_t flags, 126 wp<DeathRecipient>* outRecipient) 127{ 128 return INVALID_OPERATION; 129} 130 131status_t BBinder::dump(int fd, const Vector<String16>& args) 132{ 133 return NO_ERROR; 134} 135 136void BBinder::attachObject( 137 const void* objectID, void* object, void* cleanupCookie, 138 object_cleanup_func func) 139{ 140 Extras* e = mExtras; 141 142 if (!e) { 143 e = new Extras; 144 if (android_atomic_cmpxchg(0, reinterpret_cast<int32_t>(e), 145 reinterpret_cast<volatile int32_t*>(&mExtras)) != 0) { 146 delete e; 147 e = mExtras; 148 } 149 if (e == 0) return; // out of memory 150 } 151 152 AutoMutex _l(e->mLock); 153 e->mObjects.attach(objectID, object, cleanupCookie, func); 154} 155 156void* BBinder::findObject(const void* objectID) const 157{ 158 Extras* e = mExtras; 159 if (!e) return NULL; 160 161 AutoMutex _l(e->mLock); 162 return e->mObjects.find(objectID); 163} 164 165void BBinder::detachObject(const void* objectID) 166{ 167 Extras* e = mExtras; 168 if (!e) return; 169 170 AutoMutex _l(e->mLock); 171 e->mObjects.detach(objectID); 172} 173 174BBinder* BBinder::localBinder() 175{ 176 return this; 177} 178 179BBinder::~BBinder() 180{ 181 if (mExtras) delete mExtras; 182} 183 184 185status_t BBinder::onTransact( 186 uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) 187{ 188 switch (code) { 189 case INTERFACE_TRANSACTION: 190 reply->writeString16(getInterfaceDescriptor()); 191 return NO_ERROR; 192 193 case DUMP_TRANSACTION: { 194 int fd = data.readFileDescriptor(); 195 int argc = data.readInt32(); 196 Vector<String16> args; 197 for (int i = 0; i < argc && data.dataAvail() > 0; i++) { 198 args.add(data.readString16()); 199 } 200 return dump(fd, args); 201 } 202 default: 203 return UNKNOWN_TRANSACTION; 204 } 205} 206 207// --------------------------------------------------------------------------- 208 209enum { 210 // This is used to transfer ownership of the remote binder from 211 // the BpRefBase object holding it (when it is constructed), to the 212 // owner of the BpRefBase object when it first acquires that BpRefBase. 213 kRemoteAcquired = 0x00000001 214}; 215 216BpRefBase::BpRefBase(const sp<IBinder>& o) 217 : mRemote(o.get()), mRefs(NULL), mState(0) 218{ 219 extendObjectLifetime(OBJECT_LIFETIME_WEAK); 220 221 if (mRemote) { 222 mRemote->incStrong(this); // Removed on first IncStrong(). 223 mRefs = mRemote->createWeak(this); // Held for our entire lifetime. 224 } 225} 226 227BpRefBase::~BpRefBase() 228{ 229 if (mRemote) { 230 if (!(mState&kRemoteAcquired)) { 231 mRemote->decStrong(this); 232 } 233 mRefs->decWeak(this); 234 } 235} 236 237void BpRefBase::onFirstRef() 238{ 239 android_atomic_or(kRemoteAcquired, &mState); 240} 241 242void BpRefBase::onLastStrongRef(const void* id) 243{ 244 if (mRemote) { 245 mRemote->decStrong(this); 246 } 247} 248 249bool BpRefBase::onIncStrongAttempted(uint32_t flags, const void* id) 250{ 251 return mRemote ? mRefs->attemptIncStrong(this) : false; 252} 253 254// --------------------------------------------------------------------------- 255 256}; // namespace android 257