IPCThreadState.cpp revision c11146106f94e07016e8e26e4f8628f9a0c73199 
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 "IPCThreadState"
18
19#include <binder/IPCThreadState.h>
20
21#include <binder/Binder.h>
22#include <binder/BpBinder.h>
23#include <binder/TextOutput.h>
24
25#include <cutils/sched_policy.h>
26#include <utils/Log.h>
27#include <utils/threads.h>
28
29#include <private/binder/binder_module.h>
30#include <private/binder/Static.h>
31
32#include <errno.h>
33#include <pthread.h>
34#include <sched.h>
35#include <signal.h>
36#include <stdio.h>
37#include <sys/ioctl.h>
38#include <sys/resource.h>
39#include <unistd.h>
40
41#if LOG_NDEBUG
42
43#define IF_LOG_TRANSACTIONS() if (false)
44#define IF_LOG_COMMANDS() if (false)
45#define LOG_REMOTEREFS(...)
46#define IF_LOG_REMOTEREFS() if (false)
47#define LOG_THREADPOOL(...)
48#define LOG_ONEWAY(...)
49
50#else
51
52#define IF_LOG_TRANSACTIONS() IF_ALOG(LOG_VERBOSE, "transact")
53#define IF_LOG_COMMANDS() IF_ALOG(LOG_VERBOSE, "ipc")
54#define LOG_REMOTEREFS(...) ALOG(LOG_DEBUG, "remoterefs", __VA_ARGS__)
55#define IF_LOG_REMOTEREFS() IF_ALOG(LOG_DEBUG, "remoterefs")
56#define LOG_THREADPOOL(...) ALOG(LOG_DEBUG, "threadpool", __VA_ARGS__)
57#define LOG_ONEWAY(...) ALOG(LOG_DEBUG, "ipc", __VA_ARGS__)
58
59#endif
60
61// ---------------------------------------------------------------------------
62
63namespace android {
64
65static const char* getReturnString(size_t idx);
66static const void* printReturnCommand(TextOutput& out, const void* _cmd);
67static const void* printCommand(TextOutput& out, const void* _cmd);
68
69// Static const and functions will be optimized out if not used,
70// when LOG_NDEBUG and references in IF_LOG_COMMANDS() are optimized out.
71static const char *kReturnStrings[] = {
72    "BR_ERROR",
73    "BR_OK",
74    "BR_TRANSACTION",
75    "BR_REPLY",
76    "BR_ACQUIRE_RESULT",
77    "BR_DEAD_REPLY",
78    "BR_TRANSACTION_COMPLETE",
79    "BR_INCREFS",
80    "BR_ACQUIRE",
81    "BR_RELEASE",
82    "BR_DECREFS",
83    "BR_ATTEMPT_ACQUIRE",
84    "BR_NOOP",
85    "BR_SPAWN_LOOPER",
86    "BR_FINISHED",
87    "BR_DEAD_BINDER",
88    "BR_CLEAR_DEATH_NOTIFICATION_DONE",
89    "BR_FAILED_REPLY"
90};
91
92static const char *kCommandStrings[] = {
93    "BC_TRANSACTION",
94    "BC_REPLY",
95    "BC_ACQUIRE_RESULT",
96    "BC_FREE_BUFFER",
97    "BC_INCREFS",
98    "BC_ACQUIRE",
99    "BC_RELEASE",
100    "BC_DECREFS",
101    "BC_INCREFS_DONE",
102    "BC_ACQUIRE_DONE",
103    "BC_ATTEMPT_ACQUIRE",
104    "BC_REGISTER_LOOPER",
105    "BC_ENTER_LOOPER",
106    "BC_EXIT_LOOPER",
107    "BC_REQUEST_DEATH_NOTIFICATION",
108    "BC_CLEAR_DEATH_NOTIFICATION",
109    "BC_DEAD_BINDER_DONE"
110};
111
112static const char* getReturnString(size_t idx)
113{
114    if (idx < sizeof(kReturnStrings) / sizeof(kReturnStrings[0]))
115        return kReturnStrings[idx];
116    else
117        return "unknown";
118}
119
120static const void* printBinderTransactionData(TextOutput& out, const void* data)
121{
122    const binder_transaction_data* btd =
123        (const binder_transaction_data*)data;
124    if (btd->target.handle < 1024) {
125        /* want to print descriptors in decimal; guess based on value */
126        out << "target.desc=" << btd->target.handle;
127    } else {
128        out << "target.ptr=" << btd->target.ptr;
129    }
130    out << " (cookie " << btd->cookie << ")" << endl
131        << "code=" << TypeCode(btd->code) << ", flags=" << (void*)(long)btd->flags << endl
132        << "data=" << btd->data.ptr.buffer << " (" << (void*)btd->data_size
133        << " bytes)" << endl
134        << "offsets=" << btd->data.ptr.offsets << " (" << (void*)btd->offsets_size
135        << " bytes)";
136    return btd+1;
137}
138
139static const void* printReturnCommand(TextOutput& out, const void* _cmd)
140{
141    static const size_t N = sizeof(kReturnStrings)/sizeof(kReturnStrings[0]);
142    const int32_t* cmd = (const int32_t*)_cmd;
143    uint32_t code = (uint32_t)*cmd++;
144    size_t cmdIndex = code & 0xff;
145    if (code == BR_ERROR) {
146        out << "BR_ERROR: " << (void*)(long)(*cmd++) << endl;
147        return cmd;
148    } else if (cmdIndex >= N) {
149        out << "Unknown reply: " << code << endl;
150        return cmd;
151    }
152    out << kReturnStrings[cmdIndex];
153
154    switch (code) {
155        case BR_TRANSACTION:
156        case BR_REPLY: {
157            out << ": " << indent;
158            cmd = (const int32_t *)printBinderTransactionData(out, cmd);
159            out << dedent;
160        } break;
161
162        case BR_ACQUIRE_RESULT: {
163            const int32_t res = *cmd++;
164            out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
165        } break;
166
167        case BR_INCREFS:
168        case BR_ACQUIRE:
169        case BR_RELEASE:
170        case BR_DECREFS: {
171            const int32_t b = *cmd++;
172            const int32_t c = *cmd++;
173            out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c << ")";
174        } break;
175
176        case BR_ATTEMPT_ACQUIRE: {
177            const int32_t p = *cmd++;
178            const int32_t b = *cmd++;
179            const int32_t c = *cmd++;
180            out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c
181                << "), pri=" << p;
182        } break;
183
184        case BR_DEAD_BINDER:
185        case BR_CLEAR_DEATH_NOTIFICATION_DONE: {
186            const int32_t c = *cmd++;
187            out << ": death cookie " << (void*)(long)c;
188        } break;
189
190        default:
191            // no details to show for: BR_OK, BR_DEAD_REPLY,
192            // BR_TRANSACTION_COMPLETE, BR_FINISHED
193            break;
194    }
195
196    out << endl;
197    return cmd;
198}
199
200static const void* printCommand(TextOutput& out, const void* _cmd)
201{
202    static const size_t N = sizeof(kCommandStrings)/sizeof(kCommandStrings[0]);
203    const int32_t* cmd = (const int32_t*)_cmd;
204    uint32_t code = (uint32_t)*cmd++;
205    size_t cmdIndex = code & 0xff;
206
207    if (cmdIndex >= N) {
208        out << "Unknown command: " << code << endl;
209        return cmd;
210    }
211    out << kCommandStrings[cmdIndex];
212
213    switch (code) {
214        case BC_TRANSACTION:
215        case BC_REPLY: {
216            out << ": " << indent;
217            cmd = (const int32_t *)printBinderTransactionData(out, cmd);
218            out << dedent;
219        } break;
220
221        case BC_ACQUIRE_RESULT: {
222            const int32_t res = *cmd++;
223            out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
224        } break;
225
226        case BC_FREE_BUFFER: {
227            const int32_t buf = *cmd++;
228            out << ": buffer=" << (void*)(long)buf;
229        } break;
230
231        case BC_INCREFS:
232        case BC_ACQUIRE:
233        case BC_RELEASE:
234        case BC_DECREFS: {
235            const int32_t d = *cmd++;
236            out << ": desc=" << d;
237        } break;
238
239        case BC_INCREFS_DONE:
240        case BC_ACQUIRE_DONE: {
241            const int32_t b = *cmd++;
242            const int32_t c = *cmd++;
243            out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c << ")";
244        } break;
245
246        case BC_ATTEMPT_ACQUIRE: {
247            const int32_t p = *cmd++;
248            const int32_t d = *cmd++;
249            out << ": desc=" << d << ", pri=" << p;
250        } break;
251
252        case BC_REQUEST_DEATH_NOTIFICATION:
253        case BC_CLEAR_DEATH_NOTIFICATION: {
254            const int32_t h = *cmd++;
255            const int32_t c = *cmd++;
256            out << ": handle=" << h << " (death cookie " << (void*)(long)c << ")";
257        } break;
258
259        case BC_DEAD_BINDER_DONE: {
260            const int32_t c = *cmd++;
261            out << ": death cookie " << (void*)(long)c;
262        } break;
263
264        default:
265            // no details to show for: BC_REGISTER_LOOPER, BC_ENTER_LOOPER,
266            // BC_EXIT_LOOPER
267            break;
268    }
269
270    out << endl;
271    return cmd;
272}
273
274static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
275static bool gHaveTLS = false;
276static pthread_key_t gTLS = 0;
277static bool gShutdown = false;
278static bool gDisableBackgroundScheduling = false;
279
280IPCThreadState* IPCThreadState::self()
281{
282    if (gHaveTLS) {
283restart:
284        const pthread_key_t k = gTLS;
285        IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
286        if (st) return st;
287        return new IPCThreadState;
288    }
289
290    if (gShutdown) {
291        ALOGW("Calling IPCThreadState::self() during shutdown is dangerous, expect a crash.\n");
292        return NULL;
293    }
294
295    pthread_mutex_lock(&gTLSMutex);
296    if (!gHaveTLS) {
297        int key_create_value = pthread_key_create(&gTLS, threadDestructor);
298        if (key_create_value != 0) {
299            pthread_mutex_unlock(&gTLSMutex);
300            ALOGW("IPCThreadState::self() unable to create TLS key, expect a crash: %s\n",
301                    strerror(key_create_value));
302            return NULL;
303        }
304        gHaveTLS = true;
305    }
306    pthread_mutex_unlock(&gTLSMutex);
307    goto restart;
308}
309
310IPCThreadState* IPCThreadState::selfOrNull()
311{
312    if (gHaveTLS) {
313        const pthread_key_t k = gTLS;
314        IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
315        return st;
316    }
317    return NULL;
318}
319
320void IPCThreadState::shutdown()
321{
322    gShutdown = true;
323
324    if (gHaveTLS) {
325        // XXX Need to wait for all thread pool threads to exit!
326        IPCThreadState* st = (IPCThreadState*)pthread_getspecific(gTLS);
327        if (st) {
328            delete st;
329            pthread_setspecific(gTLS, NULL);
330        }
331        gHaveTLS = false;
332    }
333}
334
335void IPCThreadState::disableBackgroundScheduling(bool disable)
336{
337    gDisableBackgroundScheduling = disable;
338}
339
340sp<ProcessState> IPCThreadState::process()
341{
342    return mProcess;
343}
344
345status_t IPCThreadState::clearLastError()
346{
347    const status_t err = mLastError;
348    mLastError = NO_ERROR;
349    return err;
350}
351
352pid_t IPCThreadState::getCallingPid() const
353{
354    return mCallingPid;
355}
356
357uid_t IPCThreadState::getCallingUid() const
358{
359    return mCallingUid;
360}
361
362int64_t IPCThreadState::clearCallingIdentity()
363{
364    int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
365    clearCaller();
366    return token;
367}
368
369void IPCThreadState::setStrictModePolicy(int32_t policy)
370{
371    mStrictModePolicy = policy;
372}
373
374int32_t IPCThreadState::getStrictModePolicy() const
375{
376    return mStrictModePolicy;
377}
378
379void IPCThreadState::setLastTransactionBinderFlags(int32_t flags)
380{
381    mLastTransactionBinderFlags = flags;
382}
383
384int32_t IPCThreadState::getLastTransactionBinderFlags() const
385{
386    return mLastTransactionBinderFlags;
387}
388
389void IPCThreadState::restoreCallingIdentity(int64_t token)
390{
391    mCallingUid = (int)(token>>32);
392    mCallingPid = (int)token;
393}
394
395void IPCThreadState::clearCaller()
396{
397    mCallingPid = getpid();
398    mCallingUid = getuid();
399}
400
401void IPCThreadState::flushCommands()
402{
403    if (mProcess->mDriverFD <= 0)
404        return;
405    talkWithDriver(false);
406}
407
408void IPCThreadState::blockUntilThreadAvailable()
409{
410    pthread_mutex_lock(&mProcess->mThreadCountLock);
411    while (mProcess->mExecutingThreadsCount >= mProcess->mMaxThreads) {
412        ALOGW("Waiting for thread to be free. mExecutingThreadsCount=%lu mMaxThreads=%lu\n",
413                static_cast<unsigned long>(mProcess->mExecutingThreadsCount),
414                static_cast<unsigned long>(mProcess->mMaxThreads));
415        pthread_cond_wait(&mProcess->mThreadCountDecrement, &mProcess->mThreadCountLock);
416    }
417    pthread_mutex_unlock(&mProcess->mThreadCountLock);
418}
419
420status_t IPCThreadState::getAndExecuteCommand()
421{
422    status_t result;
423    int32_t cmd;
424
425    result = talkWithDriver();
426    if (result >= NO_ERROR) {
427        size_t IN = mIn.dataAvail();
428        if (IN < sizeof(int32_t)) return result;
429        cmd = mIn.readInt32();
430        IF_LOG_COMMANDS() {
431            alog << "Processing top-level Command: "
432                 << getReturnString(cmd) << endl;
433        }
434
435        pthread_mutex_lock(&mProcess->mThreadCountLock);
436        mProcess->mExecutingThreadsCount++;
437        pthread_mutex_unlock(&mProcess->mThreadCountLock);
438
439        result = executeCommand(cmd);
440
441        pthread_mutex_lock(&mProcess->mThreadCountLock);
442        mProcess->mExecutingThreadsCount--;
443        pthread_cond_broadcast(&mProcess->mThreadCountDecrement);
444        pthread_mutex_unlock(&mProcess->mThreadCountLock);
445
446        // After executing the command, ensure that the thread is returned to the
447        // foreground cgroup before rejoining the pool.  The driver takes care of
448        // restoring the priority, but doesn't do anything with cgroups so we
449        // need to take care of that here in userspace.  Note that we do make
450        // sure to go in the foreground after executing a transaction, but
451        // there are other callbacks into user code that could have changed
452        // our group so we want to make absolutely sure it is put back.
453        set_sched_policy(mMyThreadId, SP_FOREGROUND);
454    }
455
456    return result;
457}
458
459// When we've cleared the incoming command queue, process any pending derefs
460void IPCThreadState::processPendingDerefs()
461{
462    if (mIn.dataPosition() >= mIn.dataSize()) {
463        size_t numPending = mPendingWeakDerefs.size();
464        if (numPending > 0) {
465            for (size_t i = 0; i < numPending; i++) {
466                RefBase::weakref_type* refs = mPendingWeakDerefs[i];
467                refs->decWeak(mProcess.get());
468            }
469            mPendingWeakDerefs.clear();
470        }
471
472        numPending = mPendingStrongDerefs.size();
473        if (numPending > 0) {
474            for (size_t i = 0; i < numPending; i++) {
475                BBinder* obj = mPendingStrongDerefs[i];
476                obj->decStrong(mProcess.get());
477            }
478            mPendingStrongDerefs.clear();
479        }
480    }
481}
482
483void IPCThreadState::joinThreadPool(bool isMain)
484{
485    LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
486
487    mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
488
489    // This thread may have been spawned by a thread that was in the background
490    // scheduling group, so first we will make sure it is in the foreground
491    // one to avoid performing an initial transaction in the background.
492    set_sched_policy(mMyThreadId, SP_FOREGROUND);
493
494    status_t result;
495    do {
496        processPendingDerefs();
497        // now get the next command to be processed, waiting if necessary
498        result = getAndExecuteCommand();
499
500        if (result < NO_ERROR && result != TIMED_OUT && result != -ECONNREFUSED && result != -EBADF) {
501            ALOGE("getAndExecuteCommand(fd=%d) returned unexpected error %d, aborting",
502                  mProcess->mDriverFD, result);
503            abort();
504        }
505
506        // Let this thread exit the thread pool if it is no longer
507        // needed and it is not the main process thread.
508        if(result == TIMED_OUT && !isMain) {
509            break;
510        }
511    } while (result != -ECONNREFUSED && result != -EBADF);
512
513    LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%p\n",
514        (void*)pthread_self(), getpid(), (void*)result);
515
516    mOut.writeInt32(BC_EXIT_LOOPER);
517    talkWithDriver(false);
518}
519
520int IPCThreadState::setupPolling(int* fd)
521{
522    if (mProcess->mDriverFD <= 0) {
523        return -EBADF;
524    }
525
526    mOut.writeInt32(BC_ENTER_LOOPER);
527    *fd = mProcess->mDriverFD;
528    return 0;
529}
530
531status_t IPCThreadState::handlePolledCommands()
532{
533    status_t result;
534
535    do {
536        result = getAndExecuteCommand();
537    } while (mIn.dataPosition() < mIn.dataSize());
538
539    processPendingDerefs();
540    flushCommands();
541    return result;
542}
543
544void IPCThreadState::stopProcess(bool /*immediate*/)
545{
546    //ALOGI("**** STOPPING PROCESS");
547    flushCommands();
548    int fd = mProcess->mDriverFD;
549    mProcess->mDriverFD = -1;
550    close(fd);
551    //kill(getpid(), SIGKILL);
552}
553
554status_t IPCThreadState::transact(int32_t handle,
555                                  uint32_t code, const Parcel& data,
556                                  Parcel* reply, uint32_t flags)
557{
558    status_t err = data.errorCheck();
559
560    flags |= TF_ACCEPT_FDS;
561
562    IF_LOG_TRANSACTIONS() {
563        TextOutput::Bundle _b(alog);
564        alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
565            << handle << " / code " << TypeCode(code) << ": "
566            << indent << data << dedent << endl;
567    }
568
569    if (err == NO_ERROR) {
570        LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
571            (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
572        err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
573    }
574
575    if (err != NO_ERROR) {
576        if (reply) reply->setError(err);
577        return (mLastError = err);
578    }
579
580    if ((flags & TF_ONE_WAY) == 0) {
581        #if 0
582        if (code == 4) { // relayout
583            ALOGI(">>>>>> CALLING transaction 4");
584        } else {
585            ALOGI(">>>>>> CALLING transaction %d", code);
586        }
587        #endif
588        if (reply) {
589            err = waitForResponse(reply);
590        } else {
591            Parcel fakeReply;
592            err = waitForResponse(&fakeReply);
593        }
594        #if 0
595        if (code == 4) { // relayout
596            ALOGI("<<<<<< RETURNING transaction 4");
597        } else {
598            ALOGI("<<<<<< RETURNING transaction %d", code);
599        }
600        #endif
601
602        IF_LOG_TRANSACTIONS() {
603            TextOutput::Bundle _b(alog);
604            alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
605                << handle << ": ";
606            if (reply) alog << indent << *reply << dedent << endl;
607            else alog << "(none requested)" << endl;
608        }
609    } else {
610        err = waitForResponse(NULL, NULL);
611    }
612
613    return err;
614}
615
616void IPCThreadState::incStrongHandle(int32_t handle)
617{
618    LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
619    mOut.writeInt32(BC_ACQUIRE);
620    mOut.writeInt32(handle);
621}
622
623void IPCThreadState::decStrongHandle(int32_t handle)
624{
625    LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
626    mOut.writeInt32(BC_RELEASE);
627    mOut.writeInt32(handle);
628}
629
630void IPCThreadState::incWeakHandle(int32_t handle)
631{
632    LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
633    mOut.writeInt32(BC_INCREFS);
634    mOut.writeInt32(handle);
635}
636
637void IPCThreadState::decWeakHandle(int32_t handle)
638{
639    LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
640    mOut.writeInt32(BC_DECREFS);
641    mOut.writeInt32(handle);
642}
643
644status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
645{
646#if HAS_BC_ATTEMPT_ACQUIRE
647    LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
648    mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
649    mOut.writeInt32(0); // xxx was thread priority
650    mOut.writeInt32(handle);
651    status_t result = UNKNOWN_ERROR;
652
653    waitForResponse(NULL, &result);
654
655#if LOG_REFCOUNTS
656    printf("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
657        handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
658#endif
659
660    return result;
661#else
662    (void)handle;
663    ALOGE("%s(%d): Not supported\n", __func__, handle);
664    return INVALID_OPERATION;
665#endif
666}
667
668void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
669{
670#if LOG_REFCOUNTS
671    printf("IPCThreadState::expungeHandle(%ld)\n", handle);
672#endif
673    self()->mProcess->expungeHandle(handle, binder);
674}
675
676status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
677{
678    mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
679    mOut.writeInt32((int32_t)handle);
680    mOut.writePointer((uintptr_t)proxy);
681    return NO_ERROR;
682}
683
684status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
685{
686    mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
687    mOut.writeInt32((int32_t)handle);
688    mOut.writePointer((uintptr_t)proxy);
689    return NO_ERROR;
690}
691
692IPCThreadState::IPCThreadState()
693    : mProcess(ProcessState::self()),
694      mMyThreadId(gettid()),
695      mStrictModePolicy(0),
696      mLastTransactionBinderFlags(0)
697{
698    pthread_setspecific(gTLS, this);
699    clearCaller();
700    mIn.setDataCapacity(256);
701    mOut.setDataCapacity(256);
702}
703
704IPCThreadState::~IPCThreadState()
705{
706}
707
708status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
709{
710    status_t err;
711    status_t statusBuffer;
712    err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
713    if (err < NO_ERROR) return err;
714
715    return waitForResponse(NULL, NULL);
716}
717
718status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
719{
720    uint32_t cmd;
721    int32_t err;
722
723    while (1) {
724        if ((err=talkWithDriver()) < NO_ERROR) break;
725        err = mIn.errorCheck();
726        if (err < NO_ERROR) break;
727        if (mIn.dataAvail() == 0) continue;
728
729        cmd = (uint32_t)mIn.readInt32();
730
731        IF_LOG_COMMANDS() {
732            alog << "Processing waitForResponse Command: "
733                << getReturnString(cmd) << endl;
734        }
735
736        switch (cmd) {
737        case BR_TRANSACTION_COMPLETE:
738            if (!reply && !acquireResult) goto finish;
739            break;
740
741        case BR_DEAD_REPLY:
742            err = DEAD_OBJECT;
743            goto finish;
744
745        case BR_FAILED_REPLY:
746            err = FAILED_TRANSACTION;
747            goto finish;
748
749        case BR_ACQUIRE_RESULT:
750            {
751                ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
752                const int32_t result = mIn.readInt32();
753                if (!acquireResult) continue;
754                *acquireResult = result ? NO_ERROR : INVALID_OPERATION;
755            }
756            goto finish;
757
758        case BR_REPLY:
759            {
760                binder_transaction_data tr;
761                err = mIn.read(&tr, sizeof(tr));
762                ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
763                if (err != NO_ERROR) goto finish;
764
765                if (reply) {
766                    if ((tr.flags & TF_STATUS_CODE) == 0) {
767                        reply->ipcSetDataReference(
768                            reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
769                            tr.data_size,
770                            reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
771                            tr.offsets_size/sizeof(binder_size_t),
772                            freeBuffer, this);
773                    } else {
774                        err = *reinterpret_cast<const status_t*>(tr.data.ptr.buffer);
775                        freeBuffer(NULL,
776                            reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
777                            tr.data_size,
778                            reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
779                            tr.offsets_size/sizeof(binder_size_t), this);
780                    }
781                } else {
782                    freeBuffer(NULL,
783                        reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
784                        tr.data_size,
785                        reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
786                        tr.offsets_size/sizeof(binder_size_t), this);
787                    continue;
788                }
789            }
790            goto finish;
791
792        default:
793            err = executeCommand(cmd);
794            if (err != NO_ERROR) goto finish;
795            break;
796        }
797    }
798
799finish:
800    if (err != NO_ERROR) {
801        if (acquireResult) *acquireResult = err;
802        if (reply) reply->setError(err);
803        mLastError = err;
804    }
805
806    return err;
807}
808
809status_t IPCThreadState::talkWithDriver(bool doReceive)
810{
811    if (mProcess->mDriverFD <= 0) {
812        return -EBADF;
813    }
814
815    binder_write_read bwr;
816
817    // Is the read buffer empty?
818    const bool needRead = mIn.dataPosition() >= mIn.dataSize();
819
820    // We don't want to write anything if we are still reading
821    // from data left in the input buffer and the caller
822    // has requested to read the next data.
823    const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
824
825    bwr.write_size = outAvail;
826    bwr.write_buffer = (uintptr_t)mOut.data();
827
828    // This is what we'll read.
829    if (doReceive && needRead) {
830        bwr.read_size = mIn.dataCapacity();
831        bwr.read_buffer = (uintptr_t)mIn.data();
832    } else {
833        bwr.read_size = 0;
834        bwr.read_buffer = 0;
835    }
836
837    IF_LOG_COMMANDS() {
838        TextOutput::Bundle _b(alog);
839        if (outAvail != 0) {
840            alog << "Sending commands to driver: " << indent;
841            const void* cmds = (const void*)bwr.write_buffer;
842            const void* end = ((const uint8_t*)cmds)+bwr.write_size;
843            alog << HexDump(cmds, bwr.write_size) << endl;
844            while (cmds < end) cmds = printCommand(alog, cmds);
845            alog << dedent;
846        }
847        alog << "Size of receive buffer: " << bwr.read_size
848            << ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
849    }
850
851    // Return immediately if there is nothing to do.
852    if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
853
854    bwr.write_consumed = 0;
855    bwr.read_consumed = 0;
856    status_t err;
857    do {
858        IF_LOG_COMMANDS() {
859            alog << "About to read/write, write size = " << mOut.dataSize() << endl;
860        }
861#if defined(__ANDROID__)
862        if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
863            err = NO_ERROR;
864        else
865            err = -errno;
866#else
867        err = INVALID_OPERATION;
868#endif
869        if (mProcess->mDriverFD <= 0) {
870            err = -EBADF;
871        }
872        IF_LOG_COMMANDS() {
873            alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
874        }
875    } while (err == -EINTR);
876
877    IF_LOG_COMMANDS() {
878        alog << "Our err: " << (void*)(intptr_t)err << ", write consumed: "
879            << bwr.write_consumed << " (of " << mOut.dataSize()
880                        << "), read consumed: " << bwr.read_consumed << endl;
881    }
882
883    if (err >= NO_ERROR) {
884        if (bwr.write_consumed > 0) {
885            if (bwr.write_consumed < mOut.dataSize())
886                mOut.remove(0, bwr.write_consumed);
887            else
888                mOut.setDataSize(0);
889        }
890        if (bwr.read_consumed > 0) {
891            mIn.setDataSize(bwr.read_consumed);
892            mIn.setDataPosition(0);
893        }
894        IF_LOG_COMMANDS() {
895            TextOutput::Bundle _b(alog);
896            alog << "Remaining data size: " << mOut.dataSize() << endl;
897            alog << "Received commands from driver: " << indent;
898            const void* cmds = mIn.data();
899            const void* end = mIn.data() + mIn.dataSize();
900            alog << HexDump(cmds, mIn.dataSize()) << endl;
901            while (cmds < end) cmds = printReturnCommand(alog, cmds);
902            alog << dedent;
903        }
904        return NO_ERROR;
905    }
906
907    return err;
908}
909
910status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
911    int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
912{
913    binder_transaction_data tr;
914
915    tr.target.ptr = 0; /* Don't pass uninitialized stack data to a remote process */
916    tr.target.handle = handle;
917    tr.code = code;
918    tr.flags = binderFlags;
919    tr.cookie = 0;
920    tr.sender_pid = 0;
921    tr.sender_euid = 0;
922
923    const status_t err = data.errorCheck();
924    if (err == NO_ERROR) {
925        tr.data_size = data.ipcDataSize();
926        tr.data.ptr.buffer = data.ipcData();
927        tr.offsets_size = data.ipcObjectsCount()*sizeof(binder_size_t);
928        tr.data.ptr.offsets = data.ipcObjects();
929    } else if (statusBuffer) {
930        tr.flags |= TF_STATUS_CODE;
931        *statusBuffer = err;
932        tr.data_size = sizeof(status_t);
933        tr.data.ptr.buffer = reinterpret_cast<uintptr_t>(statusBuffer);
934        tr.offsets_size = 0;
935        tr.data.ptr.offsets = 0;
936    } else {
937        return (mLastError = err);
938    }
939
940    mOut.writeInt32(cmd);
941    mOut.write(&tr, sizeof(tr));
942
943    return NO_ERROR;
944}
945
946sp<BBinder> the_context_object;
947
948void setTheContextObject(sp<BBinder> obj)
949{
950    the_context_object = obj;
951}
952
953status_t IPCThreadState::executeCommand(int32_t cmd)
954{
955    BBinder* obj;
956    RefBase::weakref_type* refs;
957    status_t result = NO_ERROR;
958
959    switch ((uint32_t)cmd) {
960    case BR_ERROR:
961        result = mIn.readInt32();
962        break;
963
964    case BR_OK:
965        break;
966
967    case BR_ACQUIRE:
968        refs = (RefBase::weakref_type*)mIn.readPointer();
969        obj = (BBinder*)mIn.readPointer();
970        ALOG_ASSERT(refs->refBase() == obj,
971                   "BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
972                   refs, obj, refs->refBase());
973        obj->incStrong(mProcess.get());
974        IF_LOG_REMOTEREFS() {
975            LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
976            obj->printRefs();
977        }
978        mOut.writeInt32(BC_ACQUIRE_DONE);
979        mOut.writePointer((uintptr_t)refs);
980        mOut.writePointer((uintptr_t)obj);
981        break;
982
983    case BR_RELEASE:
984        refs = (RefBase::weakref_type*)mIn.readPointer();
985        obj = (BBinder*)mIn.readPointer();
986        ALOG_ASSERT(refs->refBase() == obj,
987                   "BR_RELEASE: object %p does not match cookie %p (expected %p)",
988                   refs, obj, refs->refBase());
989        IF_LOG_REMOTEREFS() {
990            LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
991            obj->printRefs();
992        }
993        mPendingStrongDerefs.push(obj);
994        break;
995
996    case BR_INCREFS:
997        refs = (RefBase::weakref_type*)mIn.readPointer();
998        obj = (BBinder*)mIn.readPointer();
999        refs->incWeak(mProcess.get());
1000        mOut.writeInt32(BC_INCREFS_DONE);
1001        mOut.writePointer((uintptr_t)refs);
1002        mOut.writePointer((uintptr_t)obj);
1003        break;
1004
1005    case BR_DECREFS:
1006        refs = (RefBase::weakref_type*)mIn.readPointer();
1007        obj = (BBinder*)mIn.readPointer();
1008        // NOTE: This assertion is not valid, because the object may no
1009        // longer exist (thus the (BBinder*)cast above resulting in a different
1010        // memory address).
1011        //ALOG_ASSERT(refs->refBase() == obj,
1012        //           "BR_DECREFS: object %p does not match cookie %p (expected %p)",
1013        //           refs, obj, refs->refBase());
1014        mPendingWeakDerefs.push(refs);
1015        break;
1016
1017    case BR_ATTEMPT_ACQUIRE:
1018        refs = (RefBase::weakref_type*)mIn.readPointer();
1019        obj = (BBinder*)mIn.readPointer();
1020
1021        {
1022            const bool success = refs->attemptIncStrong(mProcess.get());
1023            ALOG_ASSERT(success && refs->refBase() == obj,
1024                       "BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
1025                       refs, obj, refs->refBase());
1026
1027            mOut.writeInt32(BC_ACQUIRE_RESULT);
1028            mOut.writeInt32((int32_t)success);
1029        }
1030        break;
1031
1032    case BR_TRANSACTION:
1033        {
1034            binder_transaction_data tr;
1035            result = mIn.read(&tr, sizeof(tr));
1036            ALOG_ASSERT(result == NO_ERROR,
1037                "Not enough command data for brTRANSACTION");
1038            if (result != NO_ERROR) break;
1039
1040            Parcel buffer;
1041            buffer.ipcSetDataReference(
1042                reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
1043                tr.data_size,
1044                reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
1045                tr.offsets_size/sizeof(binder_size_t), freeBuffer, this);
1046
1047            const pid_t origPid = mCallingPid;
1048            const uid_t origUid = mCallingUid;
1049            const int32_t origStrictModePolicy = mStrictModePolicy;
1050            const int32_t origTransactionBinderFlags = mLastTransactionBinderFlags;
1051
1052            mCallingPid = tr.sender_pid;
1053            mCallingUid = tr.sender_euid;
1054            mLastTransactionBinderFlags = tr.flags;
1055
1056            int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
1057            if (gDisableBackgroundScheduling) {
1058                if (curPrio > ANDROID_PRIORITY_NORMAL) {
1059                    // We have inherited a reduced priority from the caller, but do not
1060                    // want to run in that state in this process.  The driver set our
1061                    // priority already (though not our scheduling class), so bounce
1062                    // it back to the default before invoking the transaction.
1063                    setpriority(PRIO_PROCESS, mMyThreadId, ANDROID_PRIORITY_NORMAL);
1064                }
1065            } else {
1066                if (curPrio >= ANDROID_PRIORITY_BACKGROUND) {
1067                    // We want to use the inherited priority from the caller.
1068                    // Ensure this thread is in the background scheduling class,
1069                    // since the driver won't modify scheduling classes for us.
1070                    // The scheduling group is reset to default by the caller
1071                    // once this method returns after the transaction is complete.
1072                    set_sched_policy(mMyThreadId, SP_BACKGROUND);
1073                }
1074            }
1075
1076            //ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
1077
1078            Parcel reply;
1079            status_t error;
1080            IF_LOG_TRANSACTIONS() {
1081                TextOutput::Bundle _b(alog);
1082                alog << "BR_TRANSACTION thr " << (void*)pthread_self()
1083                    << " / obj " << tr.target.ptr << " / code "
1084                    << TypeCode(tr.code) << ": " << indent << buffer
1085                    << dedent << endl
1086                    << "Data addr = "
1087                    << reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
1088                    << ", offsets addr="
1089                    << reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
1090            }
1091            if (tr.target.ptr) {
1092                // We only have a weak reference on the target object, so we must first try to
1093                // safely acquire a strong reference before doing anything else with it.
1094                if (reinterpret_cast<RefBase::weakref_type*>(
1095                        tr.target.ptr)->attemptIncStrong(this)) {
1096                    error = reinterpret_cast<BBinder*>(tr.cookie)->transact(tr.code, buffer,
1097                            &reply, tr.flags);
1098                    reinterpret_cast<BBinder*>(tr.cookie)->decStrong(this);
1099                } else {
1100                    error = UNKNOWN_TRANSACTION;
1101                }
1102
1103            } else {
1104                error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
1105            }
1106
1107            //ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
1108            //     mCallingPid, origPid, origUid);
1109
1110            if ((tr.flags & TF_ONE_WAY) == 0) {
1111                LOG_ONEWAY("Sending reply to %d!", mCallingPid);
1112                if (error < NO_ERROR) reply.setError(error);
1113                sendReply(reply, 0);
1114            } else {
1115                LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
1116            }
1117
1118            mCallingPid = origPid;
1119            mCallingUid = origUid;
1120            mStrictModePolicy = origStrictModePolicy;
1121            mLastTransactionBinderFlags = origTransactionBinderFlags;
1122
1123            IF_LOG_TRANSACTIONS() {
1124                TextOutput::Bundle _b(alog);
1125                alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
1126                    << tr.target.ptr << ": " << indent << reply << dedent << endl;
1127            }
1128
1129        }
1130        break;
1131
1132    case BR_DEAD_BINDER:
1133        {
1134            BpBinder *proxy = (BpBinder*)mIn.readPointer();
1135            proxy->sendObituary();
1136            mOut.writeInt32(BC_DEAD_BINDER_DONE);
1137            mOut.writePointer((uintptr_t)proxy);
1138        } break;
1139
1140    case BR_CLEAR_DEATH_NOTIFICATION_DONE:
1141        {
1142            BpBinder *proxy = (BpBinder*)mIn.readPointer();
1143            proxy->getWeakRefs()->decWeak(proxy);
1144        } break;
1145
1146    case BR_FINISHED:
1147        result = TIMED_OUT;
1148        break;
1149
1150    case BR_NOOP:
1151        break;
1152
1153    case BR_SPAWN_LOOPER:
1154        mProcess->spawnPooledThread(false);
1155        break;
1156
1157    default:
1158        printf("*** BAD COMMAND %d received from Binder driver\n", cmd);
1159        result = UNKNOWN_ERROR;
1160        break;
1161    }
1162
1163    if (result != NO_ERROR) {
1164        mLastError = result;
1165    }
1166
1167    return result;
1168}
1169
1170void IPCThreadState::threadDestructor(void *st)
1171{
1172        IPCThreadState* const self = static_cast<IPCThreadState*>(st);
1173        if (self) {
1174                self->flushCommands();
1175#if defined(__ANDROID__)
1176        if (self->mProcess->mDriverFD > 0) {
1177            ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
1178        }
1179#endif
1180                delete self;
1181        }
1182}
1183
1184
1185void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data,
1186                                size_t /*dataSize*/,
1187                                const binder_size_t* /*objects*/,
1188                                size_t /*objectsSize*/, void* /*cookie*/)
1189{
1190    //ALOGI("Freeing parcel %p", &parcel);
1191    IF_LOG_COMMANDS() {
1192        alog << "Writing BC_FREE_BUFFER for " << data << endl;
1193    }
1194    ALOG_ASSERT(data != NULL, "Called with NULL data");
1195    if (parcel != NULL) parcel->closeFileDescriptors();
1196    IPCThreadState* state = self();
1197    state->mOut.writeInt32(BC_FREE_BUFFER);
1198    state->mOut.writePointer((uintptr_t)data);
1199}
1200
1201}; // namespace android
1202