IPCThreadState.cpp revision 7f0c6d6e19565e512fc42c2371bc99f4c5e3fe70 
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        pthread_key_delete(gTLS);
332        gHaveTLS = false;
333    }
334}
335
336void IPCThreadState::disableBackgroundScheduling(bool disable)
337{
338    gDisableBackgroundScheduling = disable;
339}
340
341sp<ProcessState> IPCThreadState::process()
342{
343    return mProcess;
344}
345
346status_t IPCThreadState::clearLastError()
347{
348    const status_t err = mLastError;
349    mLastError = NO_ERROR;
350    return err;
351}
352
353pid_t IPCThreadState::getCallingPid() const
354{
355    return mCallingPid;
356}
357
358uid_t IPCThreadState::getCallingUid() const
359{
360    return mCallingUid;
361}
362
363int64_t IPCThreadState::clearCallingIdentity()
364{
365    int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
366    clearCaller();
367    return token;
368}
369
370void IPCThreadState::setStrictModePolicy(int32_t policy)
371{
372    mStrictModePolicy = policy;
373}
374
375int32_t IPCThreadState::getStrictModePolicy() const
376{
377    return mStrictModePolicy;
378}
379
380void IPCThreadState::setLastTransactionBinderFlags(int32_t flags)
381{
382    mLastTransactionBinderFlags = flags;
383}
384
385int32_t IPCThreadState::getLastTransactionBinderFlags() const
386{
387    return mLastTransactionBinderFlags;
388}
389
390void IPCThreadState::restoreCallingIdentity(int64_t token)
391{
392    mCallingUid = (int)(token>>32);
393    mCallingPid = (int)token;
394}
395
396void IPCThreadState::clearCaller()
397{
398    mCallingPid = getpid();
399    mCallingUid = getuid();
400}
401
402void IPCThreadState::flushCommands()
403{
404    if (mProcess->mDriverFD <= 0)
405        return;
406    talkWithDriver(false);
407}
408
409void IPCThreadState::blockUntilThreadAvailable()
410{
411    pthread_mutex_lock(&mProcess->mThreadCountLock);
412    while (mProcess->mExecutingThreadsCount >= mProcess->mMaxThreads) {
413        ALOGW("Waiting for thread to be free. mExecutingThreadsCount=%lu mMaxThreads=%lu\n",
414                static_cast<unsigned long>(mProcess->mExecutingThreadsCount),
415                static_cast<unsigned long>(mProcess->mMaxThreads));
416        pthread_cond_wait(&mProcess->mThreadCountDecrement, &mProcess->mThreadCountLock);
417    }
418    pthread_mutex_unlock(&mProcess->mThreadCountLock);
419}
420
421status_t IPCThreadState::getAndExecuteCommand()
422{
423    status_t result;
424    int32_t cmd;
425
426    result = talkWithDriver();
427    if (result >= NO_ERROR) {
428        size_t IN = mIn.dataAvail();
429        if (IN < sizeof(int32_t)) return result;
430        cmd = mIn.readInt32();
431        IF_LOG_COMMANDS() {
432            alog << "Processing top-level Command: "
433                 << getReturnString(cmd) << endl;
434        }
435
436        pthread_mutex_lock(&mProcess->mThreadCountLock);
437        mProcess->mExecutingThreadsCount++;
438        pthread_mutex_unlock(&mProcess->mThreadCountLock);
439
440        result = executeCommand(cmd);
441
442        pthread_mutex_lock(&mProcess->mThreadCountLock);
443        mProcess->mExecutingThreadsCount--;
444        pthread_cond_broadcast(&mProcess->mThreadCountDecrement);
445        pthread_mutex_unlock(&mProcess->mThreadCountLock);
446
447        // After executing the command, ensure that the thread is returned to the
448        // foreground cgroup before rejoining the pool.  The driver takes care of
449        // restoring the priority, but doesn't do anything with cgroups so we
450        // need to take care of that here in userspace.  Note that we do make
451        // sure to go in the foreground after executing a transaction, but
452        // there are other callbacks into user code that could have changed
453        // our group so we want to make absolutely sure it is put back.
454        set_sched_policy(mMyThreadId, SP_FOREGROUND);
455    }
456
457    return result;
458}
459
460// When we've cleared the incoming command queue, process any pending derefs
461void IPCThreadState::processPendingDerefs()
462{
463    if (mIn.dataPosition() >= mIn.dataSize()) {
464        size_t numPending = mPendingWeakDerefs.size();
465        if (numPending > 0) {
466            for (size_t i = 0; i < numPending; i++) {
467                RefBase::weakref_type* refs = mPendingWeakDerefs[i];
468                refs->decWeak(mProcess.get());
469            }
470            mPendingWeakDerefs.clear();
471        }
472
473        numPending = mPendingStrongDerefs.size();
474        if (numPending > 0) {
475            for (size_t i = 0; i < numPending; i++) {
476                BBinder* obj = mPendingStrongDerefs[i];
477                obj->decStrong(mProcess.get());
478            }
479            mPendingStrongDerefs.clear();
480        }
481    }
482}
483
484void IPCThreadState::joinThreadPool(bool isMain)
485{
486    LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
487
488    mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
489
490    // This thread may have been spawned by a thread that was in the background
491    // scheduling group, so first we will make sure it is in the foreground
492    // one to avoid performing an initial transaction in the background.
493    set_sched_policy(mMyThreadId, SP_FOREGROUND);
494
495    status_t result;
496    do {
497        processPendingDerefs();
498        // now get the next command to be processed, waiting if necessary
499        result = getAndExecuteCommand();
500
501        if (result < NO_ERROR && result != TIMED_OUT && result != -ECONNREFUSED && result != -EBADF) {
502            ALOGE("getAndExecuteCommand(fd=%d) returned unexpected error %d, aborting",
503                  mProcess->mDriverFD, result);
504            abort();
505        }
506
507        // Let this thread exit the thread pool if it is no longer
508        // needed and it is not the main process thread.
509        if(result == TIMED_OUT && !isMain) {
510            break;
511        }
512    } while (result != -ECONNREFUSED && result != -EBADF);
513
514    LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%p\n",
515        (void*)pthread_self(), getpid(), (void*)result);
516
517    mOut.writeInt32(BC_EXIT_LOOPER);
518    talkWithDriver(false);
519}
520
521int IPCThreadState::setupPolling(int* fd)
522{
523    if (mProcess->mDriverFD <= 0) {
524        return -EBADF;
525    }
526
527    mOut.writeInt32(BC_ENTER_LOOPER);
528    *fd = mProcess->mDriverFD;
529    return 0;
530}
531
532status_t IPCThreadState::handlePolledCommands()
533{
534    status_t result;
535
536    do {
537        result = getAndExecuteCommand();
538    } while (mIn.dataPosition() < mIn.dataSize());
539
540    processPendingDerefs();
541    flushCommands();
542    return result;
543}
544
545void IPCThreadState::stopProcess(bool /*immediate*/)
546{
547    //ALOGI("**** STOPPING PROCESS");
548    flushCommands();
549    int fd = mProcess->mDriverFD;
550    mProcess->mDriverFD = -1;
551    close(fd);
552    //kill(getpid(), SIGKILL);
553}
554
555status_t IPCThreadState::transact(int32_t handle,
556                                  uint32_t code, const Parcel& data,
557                                  Parcel* reply, uint32_t flags)
558{
559    status_t err = data.errorCheck();
560
561    flags |= TF_ACCEPT_FDS;
562
563    IF_LOG_TRANSACTIONS() {
564        TextOutput::Bundle _b(alog);
565        alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
566            << handle << " / code " << TypeCode(code) << ": "
567            << indent << data << dedent << endl;
568    }
569
570    if (err == NO_ERROR) {
571        LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
572            (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
573        err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
574    }
575
576    if (err != NO_ERROR) {
577        if (reply) reply->setError(err);
578        return (mLastError = err);
579    }
580
581    if ((flags & TF_ONE_WAY) == 0) {
582        #if 0
583        if (code == 4) { // relayout
584            ALOGI(">>>>>> CALLING transaction 4");
585        } else {
586            ALOGI(">>>>>> CALLING transaction %d", code);
587        }
588        #endif
589        if (reply) {
590            err = waitForResponse(reply);
591        } else {
592            Parcel fakeReply;
593            err = waitForResponse(&fakeReply);
594        }
595        #if 0
596        if (code == 4) { // relayout
597            ALOGI("<<<<<< RETURNING transaction 4");
598        } else {
599            ALOGI("<<<<<< RETURNING transaction %d", code);
600        }
601        #endif
602
603        IF_LOG_TRANSACTIONS() {
604            TextOutput::Bundle _b(alog);
605            alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
606                << handle << ": ";
607            if (reply) alog << indent << *reply << dedent << endl;
608            else alog << "(none requested)" << endl;
609        }
610    } else {
611        err = waitForResponse(NULL, NULL);
612    }
613
614    return err;
615}
616
617void IPCThreadState::incStrongHandle(int32_t handle)
618{
619    LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
620    mOut.writeInt32(BC_ACQUIRE);
621    mOut.writeInt32(handle);
622}
623
624void IPCThreadState::decStrongHandle(int32_t handle)
625{
626    LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
627    mOut.writeInt32(BC_RELEASE);
628    mOut.writeInt32(handle);
629}
630
631void IPCThreadState::incWeakHandle(int32_t handle)
632{
633    LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
634    mOut.writeInt32(BC_INCREFS);
635    mOut.writeInt32(handle);
636}
637
638void IPCThreadState::decWeakHandle(int32_t handle)
639{
640    LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
641    mOut.writeInt32(BC_DECREFS);
642    mOut.writeInt32(handle);
643}
644
645status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
646{
647#if HAS_BC_ATTEMPT_ACQUIRE
648    LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
649    mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
650    mOut.writeInt32(0); // xxx was thread priority
651    mOut.writeInt32(handle);
652    status_t result = UNKNOWN_ERROR;
653
654    waitForResponse(NULL, &result);
655
656#if LOG_REFCOUNTS
657    printf("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
658        handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
659#endif
660
661    return result;
662#else
663    (void)handle;
664    ALOGE("%s(%d): Not supported\n", __func__, handle);
665    return INVALID_OPERATION;
666#endif
667}
668
669void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
670{
671#if LOG_REFCOUNTS
672    printf("IPCThreadState::expungeHandle(%ld)\n", handle);
673#endif
674    self()->mProcess->expungeHandle(handle, binder);
675}
676
677status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
678{
679    mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
680    mOut.writeInt32((int32_t)handle);
681    mOut.writePointer((uintptr_t)proxy);
682    return NO_ERROR;
683}
684
685status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
686{
687    mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
688    mOut.writeInt32((int32_t)handle);
689    mOut.writePointer((uintptr_t)proxy);
690    return NO_ERROR;
691}
692
693IPCThreadState::IPCThreadState()
694    : mProcess(ProcessState::self()),
695      mMyThreadId(gettid()),
696      mStrictModePolicy(0),
697      mLastTransactionBinderFlags(0)
698{
699    pthread_setspecific(gTLS, this);
700    clearCaller();
701    mIn.setDataCapacity(256);
702    mOut.setDataCapacity(256);
703}
704
705IPCThreadState::~IPCThreadState()
706{
707}
708
709status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
710{
711    status_t err;
712    status_t statusBuffer;
713    err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
714    if (err < NO_ERROR) return err;
715
716    return waitForResponse(NULL, NULL);
717}
718
719status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
720{
721    uint32_t cmd;
722    int32_t err;
723
724    while (1) {
725        if ((err=talkWithDriver()) < NO_ERROR) break;
726        err = mIn.errorCheck();
727        if (err < NO_ERROR) break;
728        if (mIn.dataAvail() == 0) continue;
729
730        cmd = (uint32_t)mIn.readInt32();
731
732        IF_LOG_COMMANDS() {
733            alog << "Processing waitForResponse Command: "
734                << getReturnString(cmd) << endl;
735        }
736
737        switch (cmd) {
738        case BR_TRANSACTION_COMPLETE:
739            if (!reply && !acquireResult) goto finish;
740            break;
741
742        case BR_DEAD_REPLY:
743            err = DEAD_OBJECT;
744            goto finish;
745
746        case BR_FAILED_REPLY:
747            err = FAILED_TRANSACTION;
748            goto finish;
749
750        case BR_ACQUIRE_RESULT:
751            {
752                ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
753                const int32_t result = mIn.readInt32();
754                if (!acquireResult) continue;
755                *acquireResult = result ? NO_ERROR : INVALID_OPERATION;
756            }
757            goto finish;
758
759        case BR_REPLY:
760            {
761                binder_transaction_data tr;
762                err = mIn.read(&tr, sizeof(tr));
763                ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
764                if (err != NO_ERROR) goto finish;
765
766                if (reply) {
767                    if ((tr.flags & TF_STATUS_CODE) == 0) {
768                        reply->ipcSetDataReference(
769                            reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
770                            tr.data_size,
771                            reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
772                            tr.offsets_size/sizeof(binder_size_t),
773                            freeBuffer, this);
774                    } else {
775                        err = *reinterpret_cast<const status_t*>(tr.data.ptr.buffer);
776                        freeBuffer(NULL,
777                            reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
778                            tr.data_size,
779                            reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
780                            tr.offsets_size/sizeof(binder_size_t), this);
781                    }
782                } else {
783                    freeBuffer(NULL,
784                        reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
785                        tr.data_size,
786                        reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
787                        tr.offsets_size/sizeof(binder_size_t), this);
788                    continue;
789                }
790            }
791            goto finish;
792
793        default:
794            err = executeCommand(cmd);
795            if (err != NO_ERROR) goto finish;
796            break;
797        }
798    }
799
800finish:
801    if (err != NO_ERROR) {
802        if (acquireResult) *acquireResult = err;
803        if (reply) reply->setError(err);
804        mLastError = err;
805    }
806
807    return err;
808}
809
810status_t IPCThreadState::talkWithDriver(bool doReceive)
811{
812    if (mProcess->mDriverFD <= 0) {
813        return -EBADF;
814    }
815
816    binder_write_read bwr;
817
818    // Is the read buffer empty?
819    const bool needRead = mIn.dataPosition() >= mIn.dataSize();
820
821    // We don't want to write anything if we are still reading
822    // from data left in the input buffer and the caller
823    // has requested to read the next data.
824    const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
825
826    bwr.write_size = outAvail;
827    bwr.write_buffer = (uintptr_t)mOut.data();
828
829    // This is what we'll read.
830    if (doReceive && needRead) {
831        bwr.read_size = mIn.dataCapacity();
832        bwr.read_buffer = (uintptr_t)mIn.data();
833    } else {
834        bwr.read_size = 0;
835        bwr.read_buffer = 0;
836    }
837
838    IF_LOG_COMMANDS() {
839        TextOutput::Bundle _b(alog);
840        if (outAvail != 0) {
841            alog << "Sending commands to driver: " << indent;
842            const void* cmds = (const void*)bwr.write_buffer;
843            const void* end = ((const uint8_t*)cmds)+bwr.write_size;
844            alog << HexDump(cmds, bwr.write_size) << endl;
845            while (cmds < end) cmds = printCommand(alog, cmds);
846            alog << dedent;
847        }
848        alog << "Size of receive buffer: " << bwr.read_size
849            << ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
850    }
851
852    // Return immediately if there is nothing to do.
853    if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
854
855    bwr.write_consumed = 0;
856    bwr.read_consumed = 0;
857    status_t err;
858    do {
859        IF_LOG_COMMANDS() {
860            alog << "About to read/write, write size = " << mOut.dataSize() << endl;
861        }
862#if defined(__ANDROID__)
863        if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
864            err = NO_ERROR;
865        else
866            err = -errno;
867#else
868        err = INVALID_OPERATION;
869#endif
870        if (mProcess->mDriverFD <= 0) {
871            err = -EBADF;
872        }
873        IF_LOG_COMMANDS() {
874            alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
875        }
876    } while (err == -EINTR);
877
878    IF_LOG_COMMANDS() {
879        alog << "Our err: " << (void*)(intptr_t)err << ", write consumed: "
880            << bwr.write_consumed << " (of " << mOut.dataSize()
881                        << "), read consumed: " << bwr.read_consumed << endl;
882    }
883
884    if (err >= NO_ERROR) {
885        if (bwr.write_consumed > 0) {
886            if (bwr.write_consumed < mOut.dataSize())
887                mOut.remove(0, bwr.write_consumed);
888            else
889                mOut.setDataSize(0);
890        }
891        if (bwr.read_consumed > 0) {
892            mIn.setDataSize(bwr.read_consumed);
893            mIn.setDataPosition(0);
894        }
895        IF_LOG_COMMANDS() {
896            TextOutput::Bundle _b(alog);
897            alog << "Remaining data size: " << mOut.dataSize() << endl;
898            alog << "Received commands from driver: " << indent;
899            const void* cmds = mIn.data();
900            const void* end = mIn.data() + mIn.dataSize();
901            alog << HexDump(cmds, mIn.dataSize()) << endl;
902            while (cmds < end) cmds = printReturnCommand(alog, cmds);
903            alog << dedent;
904        }
905        return NO_ERROR;
906    }
907
908    return err;
909}
910
911status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
912    int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
913{
914    binder_transaction_data tr;
915
916    tr.target.ptr = 0; /* Don't pass uninitialized stack data to a remote process */
917    tr.target.handle = handle;
918    tr.code = code;
919    tr.flags = binderFlags;
920    tr.cookie = 0;
921    tr.sender_pid = 0;
922    tr.sender_euid = 0;
923
924    const status_t err = data.errorCheck();
925    if (err == NO_ERROR) {
926        tr.data_size = data.ipcDataSize();
927        tr.data.ptr.buffer = data.ipcData();
928        tr.offsets_size = data.ipcObjectsCount()*sizeof(binder_size_t);
929        tr.data.ptr.offsets = data.ipcObjects();
930    } else if (statusBuffer) {
931        tr.flags |= TF_STATUS_CODE;
932        *statusBuffer = err;
933        tr.data_size = sizeof(status_t);
934        tr.data.ptr.buffer = reinterpret_cast<uintptr_t>(statusBuffer);
935        tr.offsets_size = 0;
936        tr.data.ptr.offsets = 0;
937    } else {
938        return (mLastError = err);
939    }
940
941    mOut.writeInt32(cmd);
942    mOut.write(&tr, sizeof(tr));
943
944    return NO_ERROR;
945}
946
947sp<BBinder> the_context_object;
948
949void setTheContextObject(sp<BBinder> obj)
950{
951    the_context_object = obj;
952}
953
954status_t IPCThreadState::executeCommand(int32_t cmd)
955{
956    BBinder* obj;
957    RefBase::weakref_type* refs;
958    status_t result = NO_ERROR;
959
960    switch ((uint32_t)cmd) {
961    case BR_ERROR:
962        result = mIn.readInt32();
963        break;
964
965    case BR_OK:
966        break;
967
968    case BR_ACQUIRE:
969        refs = (RefBase::weakref_type*)mIn.readPointer();
970        obj = (BBinder*)mIn.readPointer();
971        ALOG_ASSERT(refs->refBase() == obj,
972                   "BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
973                   refs, obj, refs->refBase());
974        obj->incStrong(mProcess.get());
975        IF_LOG_REMOTEREFS() {
976            LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
977            obj->printRefs();
978        }
979        mOut.writeInt32(BC_ACQUIRE_DONE);
980        mOut.writePointer((uintptr_t)refs);
981        mOut.writePointer((uintptr_t)obj);
982        break;
983
984    case BR_RELEASE:
985        refs = (RefBase::weakref_type*)mIn.readPointer();
986        obj = (BBinder*)mIn.readPointer();
987        ALOG_ASSERT(refs->refBase() == obj,
988                   "BR_RELEASE: object %p does not match cookie %p (expected %p)",
989                   refs, obj, refs->refBase());
990        IF_LOG_REMOTEREFS() {
991            LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
992            obj->printRefs();
993        }
994        mPendingStrongDerefs.push(obj);
995        break;
996
997    case BR_INCREFS:
998        refs = (RefBase::weakref_type*)mIn.readPointer();
999        obj = (BBinder*)mIn.readPointer();
1000        refs->incWeak(mProcess.get());
1001        mOut.writeInt32(BC_INCREFS_DONE);
1002        mOut.writePointer((uintptr_t)refs);
1003        mOut.writePointer((uintptr_t)obj);
1004        break;
1005
1006    case BR_DECREFS:
1007        refs = (RefBase::weakref_type*)mIn.readPointer();
1008        obj = (BBinder*)mIn.readPointer();
1009        // NOTE: This assertion is not valid, because the object may no
1010        // longer exist (thus the (BBinder*)cast above resulting in a different
1011        // memory address).
1012        //ALOG_ASSERT(refs->refBase() == obj,
1013        //           "BR_DECREFS: object %p does not match cookie %p (expected %p)",
1014        //           refs, obj, refs->refBase());
1015        mPendingWeakDerefs.push(refs);
1016        break;
1017
1018    case BR_ATTEMPT_ACQUIRE:
1019        refs = (RefBase::weakref_type*)mIn.readPointer();
1020        obj = (BBinder*)mIn.readPointer();
1021
1022        {
1023            const bool success = refs->attemptIncStrong(mProcess.get());
1024            ALOG_ASSERT(success && refs->refBase() == obj,
1025                       "BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
1026                       refs, obj, refs->refBase());
1027
1028            mOut.writeInt32(BC_ACQUIRE_RESULT);
1029            mOut.writeInt32((int32_t)success);
1030        }
1031        break;
1032
1033    case BR_TRANSACTION:
1034        {
1035            binder_transaction_data tr;
1036            result = mIn.read(&tr, sizeof(tr));
1037            ALOG_ASSERT(result == NO_ERROR,
1038                "Not enough command data for brTRANSACTION");
1039            if (result != NO_ERROR) break;
1040
1041            Parcel buffer;
1042            buffer.ipcSetDataReference(
1043                reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
1044                tr.data_size,
1045                reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
1046                tr.offsets_size/sizeof(binder_size_t), freeBuffer, this);
1047
1048            const pid_t origPid = mCallingPid;
1049            const uid_t origUid = mCallingUid;
1050            const int32_t origStrictModePolicy = mStrictModePolicy;
1051            const int32_t origTransactionBinderFlags = mLastTransactionBinderFlags;
1052
1053            mCallingPid = tr.sender_pid;
1054            mCallingUid = tr.sender_euid;
1055            mLastTransactionBinderFlags = tr.flags;
1056
1057            int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
1058            if (gDisableBackgroundScheduling) {
1059                if (curPrio > ANDROID_PRIORITY_NORMAL) {
1060                    // We have inherited a reduced priority from the caller, but do not
1061                    // want to run in that state in this process.  The driver set our
1062                    // priority already (though not our scheduling class), so bounce
1063                    // it back to the default before invoking the transaction.
1064                    setpriority(PRIO_PROCESS, mMyThreadId, ANDROID_PRIORITY_NORMAL);
1065                }
1066            } else {
1067                if (curPrio >= ANDROID_PRIORITY_BACKGROUND) {
1068                    // We want to use the inherited priority from the caller.
1069                    // Ensure this thread is in the background scheduling class,
1070                    // since the driver won't modify scheduling classes for us.
1071                    // The scheduling group is reset to default by the caller
1072                    // once this method returns after the transaction is complete.
1073                    set_sched_policy(mMyThreadId, SP_BACKGROUND);
1074                }
1075            }
1076
1077            //ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
1078
1079            Parcel reply;
1080            status_t error;
1081            IF_LOG_TRANSACTIONS() {
1082                TextOutput::Bundle _b(alog);
1083                alog << "BR_TRANSACTION thr " << (void*)pthread_self()
1084                    << " / obj " << tr.target.ptr << " / code "
1085                    << TypeCode(tr.code) << ": " << indent << buffer
1086                    << dedent << endl
1087                    << "Data addr = "
1088                    << reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
1089                    << ", offsets addr="
1090                    << reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
1091            }
1092            if (tr.target.ptr) {
1093                // We only have a weak reference on the target object, so we must first try to
1094                // safely acquire a strong reference before doing anything else with it.
1095                if (reinterpret_cast<RefBase::weakref_type*>(
1096                        tr.target.ptr)->attemptIncStrong(this)) {
1097                    error = reinterpret_cast<BBinder*>(tr.cookie)->transact(tr.code, buffer,
1098                            &reply, tr.flags);
1099                    reinterpret_cast<BBinder*>(tr.cookie)->decStrong(this);
1100                } else {
1101                    error = UNKNOWN_TRANSACTION;
1102                }
1103
1104            } else {
1105                error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
1106            }
1107
1108            //ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
1109            //     mCallingPid, origPid, origUid);
1110
1111            if ((tr.flags & TF_ONE_WAY) == 0) {
1112                LOG_ONEWAY("Sending reply to %d!", mCallingPid);
1113                if (error < NO_ERROR) reply.setError(error);
1114                sendReply(reply, 0);
1115            } else {
1116                LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
1117            }
1118
1119            mCallingPid = origPid;
1120            mCallingUid = origUid;
1121            mStrictModePolicy = origStrictModePolicy;
1122            mLastTransactionBinderFlags = origTransactionBinderFlags;
1123
1124            IF_LOG_TRANSACTIONS() {
1125                TextOutput::Bundle _b(alog);
1126                alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
1127                    << tr.target.ptr << ": " << indent << reply << dedent << endl;
1128            }
1129
1130        }
1131        break;
1132
1133    case BR_DEAD_BINDER:
1134        {
1135            BpBinder *proxy = (BpBinder*)mIn.readPointer();
1136            proxy->sendObituary();
1137            mOut.writeInt32(BC_DEAD_BINDER_DONE);
1138            mOut.writePointer((uintptr_t)proxy);
1139        } break;
1140
1141    case BR_CLEAR_DEATH_NOTIFICATION_DONE:
1142        {
1143            BpBinder *proxy = (BpBinder*)mIn.readPointer();
1144            proxy->getWeakRefs()->decWeak(proxy);
1145        } break;
1146
1147    case BR_FINISHED:
1148        result = TIMED_OUT;
1149        break;
1150
1151    case BR_NOOP:
1152        break;
1153
1154    case BR_SPAWN_LOOPER:
1155        mProcess->spawnPooledThread(false);
1156        break;
1157
1158    default:
1159        printf("*** BAD COMMAND %d received from Binder driver\n", cmd);
1160        result = UNKNOWN_ERROR;
1161        break;
1162    }
1163
1164    if (result != NO_ERROR) {
1165        mLastError = result;
1166    }
1167
1168    return result;
1169}
1170
1171void IPCThreadState::threadDestructor(void *st)
1172{
1173        IPCThreadState* const self = static_cast<IPCThreadState*>(st);
1174        if (self) {
1175                self->flushCommands();
1176#if defined(__ANDROID__)
1177        if (self->mProcess->mDriverFD > 0) {
1178            ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
1179        }
1180#endif
1181                delete self;
1182        }
1183}
1184
1185
1186void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data,
1187                                size_t /*dataSize*/,
1188                                const binder_size_t* /*objects*/,
1189                                size_t /*objectsSize*/, void* /*cookie*/)
1190{
1191    //ALOGI("Freeing parcel %p", &parcel);
1192    IF_LOG_COMMANDS() {
1193        alog << "Writing BC_FREE_BUFFER for " << data << endl;
1194    }
1195    ALOG_ASSERT(data != NULL, "Called with NULL data");
1196    if (parcel != NULL) parcel->closeFileDescriptors();
1197    IPCThreadState* state = self();
1198    state->mOut.writeInt32(BC_FREE_BUFFER);
1199    state->mOut.writePointer((uintptr_t)data);
1200}
1201
1202}; // namespace android
1203