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 #define LOG_TAG "hw-ProcessState" 18 19 #include <hwbinder/ProcessState.h> 20 21 #include <utils/Atomic.h> 22 #include <hwbinder/BpHwBinder.h> 23 #include <hwbinder/IPCThreadState.h> 24 #include <utils/Log.h> 25 #include <utils/String8.h> 26 #include <utils/String8.h> 27 #include <utils/threads.h> 28 29 #include <private/binder/binder_module.h> 30 #include <hwbinder/Static.h> 31 32 #include <errno.h> 33 #include <fcntl.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <unistd.h> 37 #include <sys/ioctl.h> 38 #include <sys/mman.h> 39 #include <sys/stat.h> 40 #include <sys/types.h> 41 42 #define BINDER_VM_SIZE ((1*1024*1024) - (4096 *2)) 43 #define DEFAULT_MAX_BINDER_THREADS 0 44 45 // ------------------------------------------------------------------------- 46 47 namespace android { 48 namespace hardware { 49 50 class PoolThread : public Thread 51 { 52 public: 53 explicit PoolThread(bool isMain) 54 : mIsMain(isMain) 55 { 56 } 57 58 protected: 59 virtual bool threadLoop() 60 { 61 IPCThreadState::self()->joinThreadPool(mIsMain); 62 return false; 63 } 64 65 const bool mIsMain; 66 }; 67 68 sp<ProcessState> ProcessState::self() 69 { 70 Mutex::Autolock _l(gProcessMutex); 71 if (gProcess != NULL) { 72 return gProcess; 73 } 74 gProcess = new ProcessState; 75 return gProcess; 76 } 77 78 void ProcessState::setContextObject(const sp<IBinder>& object) 79 { 80 setContextObject(object, String16("default")); 81 } 82 83 sp<IBinder> ProcessState::getContextObject(const sp<IBinder>& /*caller*/) 84 { 85 return getStrongProxyForHandle(0); 86 } 87 88 void ProcessState::setContextObject(const sp<IBinder>& object, const String16& name) 89 { 90 AutoMutex _l(mLock); 91 mContexts.add(name, object); 92 } 93 94 sp<IBinder> ProcessState::getContextObject(const String16& name, const sp<IBinder>& caller) 95 { 96 mLock.lock(); 97 sp<IBinder> object( 98 mContexts.indexOfKey(name) >= 0 ? mContexts.valueFor(name) : NULL); 99 mLock.unlock(); 100 101 //printf("Getting context object %s for %p\n", String8(name).string(), caller.get()); 102 103 if (object != NULL) return object; 104 105 // Don't attempt to retrieve contexts if we manage them 106 if (mManagesContexts) { 107 ALOGE("getContextObject(%s) failed, but we manage the contexts!\n", 108 String8(name).string()); 109 return NULL; 110 } 111 112 IPCThreadState* ipc = IPCThreadState::self(); 113 { 114 Parcel data, reply; 115 // no interface token on this magic transaction 116 data.writeString16(name); 117 data.writeStrongBinder(caller); 118 status_t result = ipc->transact(0 /*magic*/, 0, data, &reply, 0); 119 if (result == NO_ERROR) { 120 object = reply.readStrongBinder(); 121 } 122 } 123 124 ipc->flushCommands(); 125 126 if (object != NULL) setContextObject(object, name); 127 return object; 128 } 129 130 void ProcessState::startThreadPool() 131 { 132 AutoMutex _l(mLock); 133 if (!mThreadPoolStarted) { 134 mThreadPoolStarted = true; 135 if (mSpawnThreadOnStart) { 136 spawnPooledThread(true); 137 } 138 } 139 } 140 141 bool ProcessState::isContextManager(void) const 142 { 143 return mManagesContexts; 144 } 145 146 bool ProcessState::becomeContextManager(context_check_func checkFunc, void* userData) 147 { 148 if (!mManagesContexts) { 149 AutoMutex _l(mLock); 150 mBinderContextCheckFunc = checkFunc; 151 mBinderContextUserData = userData; 152 153 int dummy = 0; 154 status_t result = ioctl(mDriverFD, BINDER_SET_CONTEXT_MGR, &dummy); 155 if (result == 0) { 156 mManagesContexts = true; 157 } else if (result == -1) { 158 mBinderContextCheckFunc = NULL; 159 mBinderContextUserData = NULL; 160 ALOGE("Binder ioctl to become context manager failed: %s\n", strerror(errno)); 161 } 162 } 163 return mManagesContexts; 164 } 165 166 ProcessState::handle_entry* ProcessState::lookupHandleLocked(int32_t handle) 167 { 168 const size_t N=mHandleToObject.size(); 169 if (N <= (size_t)handle) { 170 handle_entry e; 171 e.binder = NULL; 172 e.refs = NULL; 173 status_t err = mHandleToObject.insertAt(e, N, handle+1-N); 174 if (err < NO_ERROR) return NULL; 175 } 176 return &mHandleToObject.editItemAt(handle); 177 } 178 179 sp<IBinder> ProcessState::getStrongProxyForHandle(int32_t handle) 180 { 181 sp<IBinder> result; 182 183 AutoMutex _l(mLock); 184 185 handle_entry* e = lookupHandleLocked(handle); 186 187 if (e != NULL) { 188 // We need to create a new BpHwBinder if there isn't currently one, OR we 189 // are unable to acquire a weak reference on this current one. See comment 190 // in getWeakProxyForHandle() for more info about this. 191 IBinder* b = e->binder; 192 if (b == NULL || !e->refs->attemptIncWeak(this)) { 193 b = new BpHwBinder(handle); 194 e->binder = b; 195 if (b) e->refs = b->getWeakRefs(); 196 result = b; 197 } else { 198 // This little bit of nastyness is to allow us to add a primary 199 // reference to the remote proxy when this team doesn't have one 200 // but another team is sending the handle to us. 201 result.force_set(b); 202 e->refs->decWeak(this); 203 } 204 } 205 206 return result; 207 } 208 209 wp<IBinder> ProcessState::getWeakProxyForHandle(int32_t handle) 210 { 211 wp<IBinder> result; 212 213 AutoMutex _l(mLock); 214 215 handle_entry* e = lookupHandleLocked(handle); 216 217 if (e != NULL) { 218 // We need to create a new BpHwBinder if there isn't currently one, OR we 219 // are unable to acquire a weak reference on this current one. The 220 // attemptIncWeak() is safe because we know the BpHwBinder destructor will always 221 // call expungeHandle(), which acquires the same lock we are holding now. 222 // We need to do this because there is a race condition between someone 223 // releasing a reference on this BpHwBinder, and a new reference on its handle 224 // arriving from the driver. 225 IBinder* b = e->binder; 226 if (b == NULL || !e->refs->attemptIncWeak(this)) { 227 b = new BpHwBinder(handle); 228 result = b; 229 e->binder = b; 230 if (b) e->refs = b->getWeakRefs(); 231 } else { 232 result = b; 233 e->refs->decWeak(this); 234 } 235 } 236 237 return result; 238 } 239 240 void ProcessState::expungeHandle(int32_t handle, IBinder* binder) 241 { 242 AutoMutex _l(mLock); 243 244 handle_entry* e = lookupHandleLocked(handle); 245 246 // This handle may have already been replaced with a new BpHwBinder 247 // (if someone failed the AttemptIncWeak() above); we don't want 248 // to overwrite it. 249 if (e && e->binder == binder) e->binder = NULL; 250 } 251 252 String8 ProcessState::makeBinderThreadName() { 253 int32_t s = android_atomic_add(1, &mThreadPoolSeq); 254 pid_t pid = getpid(); 255 String8 name; 256 name.appendFormat("HwBinder:%d_%X", pid, s); 257 return name; 258 } 259 260 void ProcessState::spawnPooledThread(bool isMain) 261 { 262 if (mThreadPoolStarted) { 263 String8 name = makeBinderThreadName(); 264 ALOGV("Spawning new pooled thread, name=%s\n", name.string()); 265 sp<Thread> t = new PoolThread(isMain); 266 t->run(name.string()); 267 } 268 } 269 270 status_t ProcessState::setThreadPoolConfiguration(size_t maxThreads, bool callerJoinsPool) { 271 LOG_ALWAYS_FATAL_IF(maxThreads < 1, "Binder threadpool must have a minimum of one thread."); 272 status_t result = NO_ERROR; 273 // the BINDER_SET_MAX_THREADS ioctl really tells the kernel how many threads 274 // it's allowed to spawn, *in addition* to any threads we may have already 275 // spawned locally. If 'callerJoinsPool' is true, it means that the caller 276 // will join the threadpool, and so the kernel needs to create one less thread. 277 // If 'callerJoinsPool' is false, we will still spawn a thread locally, and we should 278 // also tell the kernel to create one less thread than what was requested here. 279 size_t kernelMaxThreads = maxThreads - 1; 280 if (ioctl(mDriverFD, BINDER_SET_MAX_THREADS, &kernelMaxThreads) != -1) { 281 AutoMutex _l(mLock); 282 mMaxThreads = maxThreads; 283 mSpawnThreadOnStart = !callerJoinsPool; 284 } else { 285 result = -errno; 286 ALOGE("Binder ioctl to set max threads failed: %s", strerror(-result)); 287 } 288 return result; 289 } 290 291 void ProcessState::giveThreadPoolName() { 292 androidSetThreadName( makeBinderThreadName().string() ); 293 } 294 295 static int open_driver() 296 { 297 int fd = open("/dev/hwbinder", O_RDWR | O_CLOEXEC); 298 if (fd >= 0) { 299 int vers = 0; 300 status_t result = ioctl(fd, BINDER_VERSION, &vers); 301 if (result == -1) { 302 ALOGE("Binder ioctl to obtain version failed: %s", strerror(errno)); 303 close(fd); 304 fd = -1; 305 } 306 if (result != 0 || vers != BINDER_CURRENT_PROTOCOL_VERSION) { 307 ALOGE("Binder driver protocol(%d) does not match user space protocol(%d)!", vers, BINDER_CURRENT_PROTOCOL_VERSION); 308 close(fd); 309 fd = -1; 310 } 311 size_t maxThreads = DEFAULT_MAX_BINDER_THREADS; 312 result = ioctl(fd, BINDER_SET_MAX_THREADS, &maxThreads); 313 if (result == -1) { 314 ALOGE("Binder ioctl to set max threads failed: %s", strerror(errno)); 315 } 316 } else { 317 ALOGW("Opening '/dev/hwbinder' failed: %s\n", strerror(errno)); 318 } 319 return fd; 320 } 321 322 ProcessState::ProcessState() 323 : mDriverFD(open_driver()) 324 , mVMStart(MAP_FAILED) 325 , mThreadCountLock(PTHREAD_MUTEX_INITIALIZER) 326 , mThreadCountDecrement(PTHREAD_COND_INITIALIZER) 327 , mExecutingThreadsCount(0) 328 , mMaxThreads(DEFAULT_MAX_BINDER_THREADS) 329 , mStarvationStartTimeMs(0) 330 , mManagesContexts(false) 331 , mBinderContextCheckFunc(NULL) 332 , mBinderContextUserData(NULL) 333 , mThreadPoolStarted(false) 334 , mSpawnThreadOnStart(true) 335 , mThreadPoolSeq(1) 336 { 337 if (mDriverFD >= 0) { 338 // mmap the binder, providing a chunk of virtual address space to receive transactions. 339 mVMStart = mmap(0, BINDER_VM_SIZE, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0); 340 if (mVMStart == MAP_FAILED) { 341 // *sigh* 342 ALOGE("Using /dev/hwbinder failed: unable to mmap transaction memory.\n"); 343 close(mDriverFD); 344 mDriverFD = -1; 345 } 346 } 347 else { 348 ALOGE("Binder driver could not be opened. Terminating."); 349 } 350 } 351 352 ProcessState::~ProcessState() 353 { 354 if (mDriverFD >= 0) { 355 if (mVMStart != MAP_FAILED) { 356 munmap(mVMStart, BINDER_VM_SIZE); 357 } 358 close(mDriverFD); 359 } 360 mDriverFD = -1; 361 } 362 363 }; // namespace hardware 364 }; // namespace android 365