Binder.cpp revision 6f4f3ab36c5ed1df84eb3a9f7475f0ac42952f58
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 <utils/misc.h> 21#include <binder/BpBinder.h> 22#include <binder/IInterface.h> 23#include <binder/Parcel.h> 24 25#include <stdio.h> 26 27namespace android { 28 29// --------------------------------------------------------------------------- 30 31IBinder::IBinder() 32 : RefBase() 33{ 34} 35 36IBinder::~IBinder() 37{ 38} 39 40// --------------------------------------------------------------------------- 41 42sp<IInterface> IBinder::queryLocalInterface(const String16& /*descriptor*/) 43{ 44 return NULL; 45} 46 47BBinder* IBinder::localBinder() 48{ 49 return NULL; 50} 51 52BpBinder* IBinder::remoteBinder() 53{ 54 return NULL; 55} 56 57bool IBinder::checkSubclass(const void* /*subclassID*/) const 58{ 59 return false; 60} 61 62// --------------------------------------------------------------------------- 63 64class BBinder::Extras 65{ 66public: 67 Mutex mLock; 68 BpBinder::ObjectManager mObjects; 69}; 70 71// --------------------------------------------------------------------------- 72 73BBinder::BBinder() 74 : mExtras(NULL) 75{ 76} 77 78bool BBinder::isBinderAlive() const 79{ 80 return true; 81} 82 83status_t BBinder::pingBinder() 84{ 85 return NO_ERROR; 86} 87 88const 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 97status_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 119status_t BBinder::linkToDeath( 120 const sp<DeathRecipient>& /*recipient*/, void* /*cookie*/, 121 uint32_t /*flags*/) 122{ 123 return INVALID_OPERATION; 124} 125 126status_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 138void BBinder::attachObject( 139 const void* objectID, void* object, void* cleanupCookie, 140 object_cleanup_func func) 141{ 142 Extras* e = mExtras; 143 144 if (!e) { 145 e = new Extras; 146#ifdef __LP64__ 147 if (android_atomic_release_cas64(0, reinterpret_cast<int64_t>(e), 148 reinterpret_cast<volatile int64_t*>(&mExtras)) != 0) { 149#else 150 if (android_atomic_cmpxchg(0, reinterpret_cast<int32_t>(e), 151 reinterpret_cast<volatile int32_t*>(&mExtras)) != 0) { 152#endif 153 delete e; 154 e = mExtras; 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 163void* BBinder::findObject(const void* objectID) const 164{ 165 Extras* e = mExtras; 166 if (!e) return NULL; 167 168 AutoMutex _l(e->mLock); 169 return e->mObjects.find(objectID); 170} 171 172void BBinder::detachObject(const void* objectID) 173{ 174 Extras* e = mExtras; 175 if (!e) return; 176 177 AutoMutex _l(e->mLock); 178 e->mObjects.detach(objectID); 179} 180 181BBinder* BBinder::localBinder() 182{ 183 return this; 184} 185 186BBinder::~BBinder() 187{ 188 if (mExtras) delete mExtras; 189} 190 191 192status_t BBinder::onTransact( 193 uint32_t code, const Parcel& data, Parcel* reply, uint32_t /*flags*/) 194{ 195 switch (code) { 196 case INTERFACE_TRANSACTION: 197 reply->writeString16(getInterfaceDescriptor()); 198 return NO_ERROR; 199 200 case DUMP_TRANSACTION: { 201 int fd = data.readFileDescriptor(); 202 int argc = data.readInt32(); 203 Vector<String16> args; 204 for (int i = 0; i < argc && data.dataAvail() > 0; i++) { 205 args.add(data.readString16()); 206 } 207 return dump(fd, args); 208 } 209 210 case SYSPROPS_TRANSACTION: { 211 report_sysprop_change(); 212 return NO_ERROR; 213 } 214 215 default: 216 return UNKNOWN_TRANSACTION; 217 } 218} 219 220// --------------------------------------------------------------------------- 221 222enum { 223 // This is used to transfer ownership of the remote binder from 224 // the BpRefBase object holding it (when it is constructed), to the 225 // owner of the BpRefBase object when it first acquires that BpRefBase. 226 kRemoteAcquired = 0x00000001 227}; 228 229BpRefBase::BpRefBase(const sp<IBinder>& o) 230 : mRemote(o.get()), mRefs(NULL), mState(0) 231{ 232 extendObjectLifetime(OBJECT_LIFETIME_WEAK); 233 234 if (mRemote) { 235 mRemote->incStrong(this); // Removed on first IncStrong(). 236 mRefs = mRemote->createWeak(this); // Held for our entire lifetime. 237 } 238} 239 240BpRefBase::~BpRefBase() 241{ 242 if (mRemote) { 243 if (!(mState&kRemoteAcquired)) { 244 mRemote->decStrong(this); 245 } 246 mRefs->decWeak(this); 247 } 248} 249 250void BpRefBase::onFirstRef() 251{ 252 android_atomic_or(kRemoteAcquired, &mState); 253} 254 255void BpRefBase::onLastStrongRef(const void* /*id*/) 256{ 257 if (mRemote) { 258 mRemote->decStrong(this); 259 } 260} 261 262bool BpRefBase::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/) 263{ 264 return mRemote ? mRefs->attemptIncStrong(this) : false; 265} 266 267// --------------------------------------------------------------------------- 268 269}; // namespace android 270