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 <stdatomic.h> 20 #include <utils/misc.h> 21 #include <binder/BpBinder.h> 22 #include <binder/IInterface.h> 23 #include <binder/Parcel.h> 24 25 #include <stdio.h> 26 27 namespace android { 28 29 // --------------------------------------------------------------------------- 30 31 IBinder::IBinder() 32 : RefBase() 33 { 34 } 35 36 IBinder::~IBinder() 37 { 38 } 39 40 // --------------------------------------------------------------------------- 41 42 sp<IInterface> IBinder::queryLocalInterface(const String16& /*descriptor*/) 43 { 44 return NULL; 45 } 46 47 BBinder* IBinder::localBinder() 48 { 49 return NULL; 50 } 51 52 BpBinder* IBinder::remoteBinder() 53 { 54 return NULL; 55 } 56 57 bool IBinder::checkSubclass(const void* /*subclassID*/) const 58 { 59 return false; 60 } 61 62 // --------------------------------------------------------------------------- 63 64 class BBinder::Extras 65 { 66 public: 67 Mutex mLock; 68 BpBinder::ObjectManager mObjects; 69 }; 70 71 // --------------------------------------------------------------------------- 72 73 BBinder::BBinder() 74 { 75 atomic_init(&mExtras, 0); 76 } 77 78 bool BBinder::isBinderAlive() const 79 { 80 return true; 81 } 82 83 status_t BBinder::pingBinder() 84 { 85 return NO_ERROR; 86 } 87 88 const String16& BBinder::getInterfaceDescriptor() const 89 { 90 // This is a local static rather than a global static, 91 // to avoid static initializer ordering issues. 92 static String16 sEmptyDescriptor; 93 ALOGW("reached BBinder::getInterfaceDescriptor (this=%p)", this); 94 return sEmptyDescriptor; 95 } 96 97 status_t BBinder::transact( 98 uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) 99 { 100 data.setDataPosition(0); 101 102 status_t err = NO_ERROR; 103 switch (code) { 104 case PING_TRANSACTION: 105 reply->writeInt32(pingBinder()); 106 break; 107 default: 108 err = onTransact(code, data, reply, flags); 109 break; 110 } 111 112 if (reply != NULL) { 113 reply->setDataPosition(0); 114 } 115 116 return err; 117 } 118 119 status_t BBinder::linkToDeath( 120 const sp<DeathRecipient>& /*recipient*/, void* /*cookie*/, 121 uint32_t /*flags*/) 122 { 123 return INVALID_OPERATION; 124 } 125 126 status_t BBinder::unlinkToDeath( 127 const wp<DeathRecipient>& /*recipient*/, void* /*cookie*/, 128 uint32_t /*flags*/, wp<DeathRecipient>* /*outRecipient*/) 129 { 130 return INVALID_OPERATION; 131 } 132 133 status_t BBinder::dump(int /*fd*/, const Vector<String16>& /*args*/) 134 { 135 return NO_ERROR; 136 } 137 138 void BBinder::attachObject( 139 const void* objectID, void* object, void* cleanupCookie, 140 object_cleanup_func func) 141 { 142 Extras* e = reinterpret_cast<Extras*>( 143 atomic_load_explicit(&mExtras, memory_order_acquire)); 144 145 if (!e) { 146 e = new Extras; 147 uintptr_t expected = 0; 148 if (!atomic_compare_exchange_strong_explicit( 149 &mExtras, &expected, 150 reinterpret_cast<uintptr_t>(e), 151 memory_order_release, 152 memory_order_acquire)) { 153 delete e; 154 e = reinterpret_cast<Extras*>(expected); // Filled in by CAS 155 } 156 if (e == 0) return; // out of memory 157 } 158 159 AutoMutex _l(e->mLock); 160 e->mObjects.attach(objectID, object, cleanupCookie, func); 161 } 162 163 void* BBinder::findObject(const void* objectID) const 164 { 165 Extras* e = reinterpret_cast<Extras*>( 166 atomic_load_explicit(&mExtras, memory_order_acquire)); 167 if (!e) return NULL; 168 169 AutoMutex _l(e->mLock); 170 return e->mObjects.find(objectID); 171 } 172 173 void BBinder::detachObject(const void* objectID) 174 { 175 Extras* e = reinterpret_cast<Extras*>( 176 atomic_load_explicit(&mExtras, memory_order_acquire)); 177 if (!e) return; 178 179 AutoMutex _l(e->mLock); 180 e->mObjects.detach(objectID); 181 } 182 183 BBinder* BBinder::localBinder() 184 { 185 return this; 186 } 187 188 BBinder::~BBinder() 189 { 190 Extras* e = reinterpret_cast<Extras*>( 191 atomic_load_explicit(&mExtras, memory_order_relaxed)); 192 if (e) delete e; 193 } 194 195 196 status_t BBinder::onTransact( 197 uint32_t code, const Parcel& data, Parcel* reply, uint32_t /*flags*/) 198 { 199 switch (code) { 200 case INTERFACE_TRANSACTION: 201 reply->writeString16(getInterfaceDescriptor()); 202 return NO_ERROR; 203 204 case DUMP_TRANSACTION: { 205 int fd = data.readFileDescriptor(); 206 int argc = data.readInt32(); 207 Vector<String16> args; 208 for (int i = 0; i < argc && data.dataAvail() > 0; i++) { 209 args.add(data.readString16()); 210 } 211 return dump(fd, args); 212 } 213 214 case SYSPROPS_TRANSACTION: { 215 report_sysprop_change(); 216 return NO_ERROR; 217 } 218 219 default: 220 return UNKNOWN_TRANSACTION; 221 } 222 } 223 224 // --------------------------------------------------------------------------- 225 226 enum { 227 // This is used to transfer ownership of the remote binder from 228 // the BpRefBase object holding it (when it is constructed), to the 229 // owner of the BpRefBase object when it first acquires that BpRefBase. 230 kRemoteAcquired = 0x00000001 231 }; 232 233 BpRefBase::BpRefBase(const sp<IBinder>& o) 234 : mRemote(o.get()), mRefs(NULL), mState(0) 235 { 236 extendObjectLifetime(OBJECT_LIFETIME_WEAK); 237 238 if (mRemote) { 239 mRemote->incStrong(this); // Removed on first IncStrong(). 240 mRefs = mRemote->createWeak(this); // Held for our entire lifetime. 241 } 242 } 243 244 BpRefBase::~BpRefBase() 245 { 246 if (mRemote) { 247 if (!(mState&kRemoteAcquired)) { 248 mRemote->decStrong(this); 249 } 250 mRefs->decWeak(this); 251 } 252 } 253 254 void BpRefBase::onFirstRef() 255 { 256 android_atomic_or(kRemoteAcquired, &mState); 257 } 258 259 void BpRefBase::onLastStrongRef(const void* /*id*/) 260 { 261 if (mRemote) { 262 mRemote->decStrong(this); 263 } 264 } 265 266 bool BpRefBase::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/) 267 { 268 return mRemote ? mRefs->attemptIncStrong(this) : false; 269 } 270 271 // --------------------------------------------------------------------------- 272 273 }; // namespace android 274
