SensorService.cpp revision 8c3e55f4149deda3ec7c7a67fda81216d5f9af25 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <inttypes.h>
18#include <math.h>
19#include <stdint.h>
20#include <sys/types.h>
21#include <sys/socket.h>
22
23#include <cutils/properties.h>
24
25#include <utils/SortedVector.h>
26#include <utils/KeyedVector.h>
27#include <utils/threads.h>
28#include <utils/Atomic.h>
29#include <utils/Errors.h>
30#include <utils/RefBase.h>
31#include <utils/Singleton.h>
32#include <utils/String16.h>
33
34#include <binder/AppOpsManager.h>
35#include <binder/BinderService.h>
36#include <binder/IServiceManager.h>
37#include <binder/PermissionCache.h>
38
39#include <gui/ISensorServer.h>
40#include <gui/ISensorEventConnection.h>
41#include <gui/SensorEventQueue.h>
42
43#include <hardware/sensors.h>
44#include <hardware_legacy/power.h>
45
46#include "BatteryService.h"
47#include "CorrectedGyroSensor.h"
48#include "GravitySensor.h"
49#include "LinearAccelerationSensor.h"
50#include "OrientationSensor.h"
51#include "RotationVectorSensor.h"
52#include "SensorFusion.h"
53#include "SensorService.h"
54
55namespace android {
56// ---------------------------------------------------------------------------
57
58/*
59 * Notes:
60 *
61 * - what about a gyro-corrected magnetic-field sensor?
62 * - run mag sensor from time to time to force calibration
63 * - gravity sensor length is wrong (=> drift in linear-acc sensor)
64 *
65 */
66
67const char* SensorService::WAKE_LOCK_NAME = "SensorService_wakelock";
68// Permissions.
69static const String16 sDump("android.permission.DUMP");
70
71SensorService::SensorService()
72    : mInitCheck(NO_INIT), mSocketBufferSize(SOCKET_BUFFER_SIZE_NON_BATCHED),
73      mWakeLockAcquired(false)
74{
75}
76
77void SensorService::onFirstRef()
78{
79    ALOGD("nuSensorService starting...");
80    SensorDevice& dev(SensorDevice::getInstance());
81
82    if (dev.initCheck() == NO_ERROR) {
83        sensor_t const* list;
84        ssize_t count = dev.getSensorList(&list);
85        if (count > 0) {
86            ssize_t orientationIndex = -1;
87            bool hasGyro = false, hasAccel = false, hasMag = false;
88            uint32_t virtualSensorsNeeds =
89                    (1<<SENSOR_TYPE_GRAVITY) |
90                    (1<<SENSOR_TYPE_LINEAR_ACCELERATION) |
91                    (1<<SENSOR_TYPE_ROTATION_VECTOR);
92
93            mLastEventSeen.setCapacity(count);
94            for (ssize_t i=0 ; i<count ; i++) {
95                registerSensor( new HardwareSensor(list[i]) );
96                switch (list[i].type) {
97                    case SENSOR_TYPE_ACCELEROMETER:
98                        hasAccel = true;
99                        break;
100                    case SENSOR_TYPE_MAGNETIC_FIELD:
101                        hasMag = true;
102                        break;
103                    case SENSOR_TYPE_ORIENTATION:
104                        orientationIndex = i;
105                        break;
106                    case SENSOR_TYPE_GYROSCOPE:
107                    case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
108                        hasGyro = true;
109                        break;
110                    case SENSOR_TYPE_GRAVITY:
111                    case SENSOR_TYPE_LINEAR_ACCELERATION:
112                    case SENSOR_TYPE_ROTATION_VECTOR:
113                        virtualSensorsNeeds &= ~(1<<list[i].type);
114                        break;
115                }
116            }
117
118            // it's safe to instantiate the SensorFusion object here
119            // (it wants to be instantiated after h/w sensors have been
120            // registered)
121            const SensorFusion& fusion(SensorFusion::getInstance());
122
123            // build the sensor list returned to users
124            mUserSensorList = mSensorList;
125
126            if (hasGyro && hasAccel && hasMag) {
127                Sensor aSensor;
128
129                // Add Android virtual sensors if they're not already
130                // available in the HAL
131
132                aSensor = registerVirtualSensor( new RotationVectorSensor() );
133                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_ROTATION_VECTOR)) {
134                    mUserSensorList.add(aSensor);
135                }
136
137                aSensor = registerVirtualSensor( new GravitySensor(list, count) );
138                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_GRAVITY)) {
139                    mUserSensorList.add(aSensor);
140                }
141
142                aSensor = registerVirtualSensor( new LinearAccelerationSensor(list, count) );
143                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_LINEAR_ACCELERATION)) {
144                    mUserSensorList.add(aSensor);
145                }
146
147                aSensor = registerVirtualSensor( new OrientationSensor() );
148                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_ROTATION_VECTOR)) {
149                    // if we are doing our own rotation-vector, also add
150                    // the orientation sensor and remove the HAL provided one.
151                    mUserSensorList.replaceAt(aSensor, orientationIndex);
152                }
153
154                // virtual debugging sensors are not added to mUserSensorList
155                registerVirtualSensor( new CorrectedGyroSensor(list, count) );
156                registerVirtualSensor( new GyroDriftSensor() );
157            }
158
159            // debugging sensor list
160            mUserSensorListDebug = mSensorList;
161
162            // Check if the device really supports batching by looking at the FIFO event
163            // counts for each sensor.
164            bool batchingSupported = false;
165            for (size_t i = 0; i < mSensorList.size(); ++i) {
166                if (mSensorList[i].getFifoMaxEventCount() > 0) {
167                    batchingSupported = true;
168                    break;
169                }
170            }
171
172            if (batchingSupported) {
173                // Increase socket buffer size to a max of 100 KB for batching capabilities.
174                mSocketBufferSize = MAX_SOCKET_BUFFER_SIZE_BATCHED;
175            } else {
176                mSocketBufferSize = SOCKET_BUFFER_SIZE_NON_BATCHED;
177            }
178
179            // Compare the socketBufferSize value against the system limits and limit
180            // it to maxSystemSocketBufferSize if necessary.
181            FILE *fp = fopen("/proc/sys/net/core/wmem_max", "r");
182            char line[128];
183            if (fp != NULL && fgets(line, sizeof(line), fp) != NULL) {
184                line[sizeof(line) - 1] = '\0';
185                size_t maxSystemSocketBufferSize;
186                sscanf(line, "%zu", &maxSystemSocketBufferSize);
187                if (mSocketBufferSize > maxSystemSocketBufferSize) {
188                    mSocketBufferSize = maxSystemSocketBufferSize;
189                }
190            }
191            if (fp) {
192                fclose(fp);
193            }
194
195            mWakeLockAcquired = false;
196            mLooper = new Looper(false);
197            const size_t minBufferSize = SensorEventQueue::MAX_RECEIVE_BUFFER_EVENT_COUNT;
198            mSensorEventBuffer = new sensors_event_t[minBufferSize];
199            mSensorEventScratch = new sensors_event_t[minBufferSize];
200            mMapFlushEventsToConnections = new SensorEventConnection const * [minBufferSize];
201            mCurrentOperatingMode = NORMAL;
202
203            mNextSensorRegIndex = 0;
204            for (int i = 0; i < SENSOR_REGISTRATIONS_BUF_SIZE; ++i) {
205                mLastNSensorRegistrations.push();
206            }
207
208            mInitCheck = NO_ERROR;
209            mAckReceiver = new SensorEventAckReceiver(this);
210            mAckReceiver->run("SensorEventAckReceiver", PRIORITY_URGENT_DISPLAY);
211            run("SensorService", PRIORITY_URGENT_DISPLAY);
212        }
213    }
214}
215
216Sensor SensorService::registerSensor(SensorInterface* s)
217{
218    sensors_event_t event;
219    memset(&event, 0, sizeof(event));
220
221    const Sensor sensor(s->getSensor());
222    // add to the sensor list (returned to clients)
223    mSensorList.add(sensor);
224    // add to our handle->SensorInterface mapping
225    mSensorMap.add(sensor.getHandle(), s);
226    // create an entry in the mLastEventSeen array
227    mLastEventSeen.add(sensor.getHandle(), NULL);
228
229    return sensor;
230}
231
232Sensor SensorService::registerVirtualSensor(SensorInterface* s)
233{
234    Sensor sensor = registerSensor(s);
235    mVirtualSensorList.add( s );
236    return sensor;
237}
238
239SensorService::~SensorService()
240{
241    for (size_t i=0 ; i<mSensorMap.size() ; i++)
242        delete mSensorMap.valueAt(i);
243}
244
245status_t SensorService::dump(int fd, const Vector<String16>& args)
246{
247    String8 result;
248    if (!PermissionCache::checkCallingPermission(sDump)) {
249        result.appendFormat("Permission Denial: "
250                "can't dump SensorService from pid=%d, uid=%d\n",
251                IPCThreadState::self()->getCallingPid(),
252                IPCThreadState::self()->getCallingUid());
253    } else {
254        if (args.size() > 2) {
255           return INVALID_OPERATION;
256        }
257        Mutex::Autolock _l(mLock);
258        SensorDevice& dev(SensorDevice::getInstance());
259        if (args.size() == 2 && args[0] == String16("restrict")) {
260            // If already in restricted mode. Ignore.
261            if (mCurrentOperatingMode == RESTRICTED) {
262                return status_t(NO_ERROR);
263            }
264            // If in any mode other than normal, ignore.
265            if (mCurrentOperatingMode != NORMAL) {
266                return INVALID_OPERATION;
267            }
268            mCurrentOperatingMode = RESTRICTED;
269            dev.disableAllSensors();
270            // Clear all pending flush connections for all active sensors. If one of the active
271            // connections has called flush() and the underlying sensor has been disabled before a
272            // flush complete event is returned, we need to remove the connection from this queue.
273            for (size_t i=0 ; i< mActiveSensors.size(); ++i) {
274                mActiveSensors.valueAt(i)->clearAllPendingFlushConnections();
275            }
276            mWhiteListedPackage.setTo(String8(args[1]));
277            return status_t(NO_ERROR);
278        } else if (args.size() == 1 && args[0] == String16("enable")) {
279            // If currently in restricted mode, reset back to NORMAL mode else ignore.
280            if (mCurrentOperatingMode == RESTRICTED) {
281                mCurrentOperatingMode = NORMAL;
282                dev.enableAllSensors();
283            }
284            if (mCurrentOperatingMode == DATA_INJECTION) {
285               resetToNormalModeLocked();
286            }
287            mWhiteListedPackage.clear();
288            return status_t(NO_ERROR);
289        } else if (args.size() == 2 && args[0] == String16("data_injection")) {
290            if (mCurrentOperatingMode == NORMAL) {
291                dev.disableAllSensors();
292                status_t err = dev.setMode(DATA_INJECTION);
293                if (err == NO_ERROR) {
294                    mCurrentOperatingMode = DATA_INJECTION;
295                } else {
296                    // Re-enable sensors.
297                    dev.enableAllSensors();
298                }
299                mWhiteListedPackage.setTo(String8(args[1]));
300                return NO_ERROR;
301            } else if (mCurrentOperatingMode == DATA_INJECTION) {
302                // Already in DATA_INJECTION mode. Treat this as a no_op.
303                return NO_ERROR;
304            } else {
305                // Transition to data injection mode supported only from NORMAL mode.
306                return INVALID_OPERATION;
307            }
308        } else if (mSensorList.size() == 0) {
309            result.append("No Sensors on the device\n");
310        } else {
311            // Default dump the sensor list and debugging information.
312            result.append("Sensor List:\n");
313            for (size_t i=0 ; i<mSensorList.size() ; i++) {
314                const Sensor& s(mSensorList[i]);
315                result.appendFormat(
316                        "%-15s| %-10s| version=%d |%-20s| 0x%08x | \"%s\" | type=%d |",
317                        s.getName().string(),
318                        s.getVendor().string(),
319                        s.getVersion(),
320                        s.getStringType().string(),
321                        s.getHandle(),
322                        s.getRequiredPermission().string(),
323                        s.getType());
324
325                const int reportingMode = s.getReportingMode();
326                if (reportingMode == AREPORTING_MODE_CONTINUOUS) {
327                    result.append(" continuous | ");
328                } else if (reportingMode == AREPORTING_MODE_ON_CHANGE) {
329                    result.append(" on-change | ");
330                } else if (reportingMode == AREPORTING_MODE_ONE_SHOT) {
331                    result.append(" one-shot | ");
332                } else {
333                    result.append(" special-trigger | ");
334                }
335
336                if (s.getMaxDelay() > 0) {
337                    result.appendFormat("minRate=%.2fHz | ", 1e6f / s.getMaxDelay());
338                } else {
339                    result.appendFormat("maxDelay=%dus |", s.getMaxDelay());
340                }
341
342                if (s.getMinDelay() > 0) {
343                    result.appendFormat("maxRate=%.2fHz | ", 1e6f / s.getMinDelay());
344                } else {
345                    result.appendFormat("minDelay=%dus |", s.getMinDelay());
346                }
347
348                if (s.getFifoMaxEventCount() > 0) {
349                    result.appendFormat("FifoMax=%d events | ",
350                            s.getFifoMaxEventCount());
351                } else {
352                    result.append("no batching | ");
353                }
354
355                if (s.isWakeUpSensor()) {
356                    result.appendFormat("wakeUp | ");
357                } else {
358                    result.appendFormat("non-wakeUp | ");
359                }
360
361                int bufIndex = mLastEventSeen.indexOfKey(s.getHandle());
362                if (bufIndex >= 0) {
363                    const CircularBuffer* buf = mLastEventSeen.valueAt(bufIndex);
364                    if (buf != NULL && s.getRequiredPermission().isEmpty()) {
365                        buf->printBuffer(result);
366                    } else {
367                        result.append("last=<> \n");
368                    }
369                }
370                result.append("\n");
371            }
372            SensorFusion::getInstance().dump(result);
373            SensorDevice::getInstance().dump(result);
374
375            result.append("Active sensors:\n");
376            for (size_t i=0 ; i<mActiveSensors.size() ; i++) {
377                int handle = mActiveSensors.keyAt(i);
378                result.appendFormat("%s (handle=0x%08x, connections=%zu)\n",
379                        getSensorName(handle).string(),
380                        handle,
381                        mActiveSensors.valueAt(i)->getNumConnections());
382            }
383
384            result.appendFormat("Socket Buffer size = %d events\n",
385                                mSocketBufferSize/sizeof(sensors_event_t));
386            result.appendFormat("WakeLock Status: %s \n", mWakeLockAcquired ? "acquired" :
387                    "not held");
388            result.appendFormat("Mode :");
389            switch(mCurrentOperatingMode) {
390               case NORMAL:
391                   result.appendFormat(" NORMAL\n");
392                   break;
393               case RESTRICTED:
394                   result.appendFormat(" RESTRICTED : %s\n", mWhiteListedPackage.string());
395                   break;
396               case DATA_INJECTION:
397                   result.appendFormat(" DATA_INJECTION : %s\n", mWhiteListedPackage.string());
398            }
399            result.appendFormat("%zd active connections\n", mActiveConnections.size());
400
401            for (size_t i=0 ; i < mActiveConnections.size() ; i++) {
402                sp<SensorEventConnection> connection(mActiveConnections[i].promote());
403                if (connection != 0) {
404                    result.appendFormat("Connection Number: %zu \n", i);
405                    connection->dump(result);
406                }
407            }
408
409            result.appendFormat("Previous Registrations:\n");
410            // Log in the reverse chronological order.
411            int currentIndex = (mNextSensorRegIndex - 1 + SENSOR_REGISTRATIONS_BUF_SIZE) %
412                SENSOR_REGISTRATIONS_BUF_SIZE;
413            const int startIndex = currentIndex;
414            do {
415                const SensorRegistrationInfo& reg_info = mLastNSensorRegistrations[currentIndex];
416                if (SensorRegistrationInfo::isSentinel(reg_info)) {
417                    // Ignore sentinel, proceed to next item.
418                    currentIndex = (currentIndex - 1 + SENSOR_REGISTRATIONS_BUF_SIZE) %
419                        SENSOR_REGISTRATIONS_BUF_SIZE;
420                    continue;
421                }
422                if (reg_info.mActivated) {
423                   result.appendFormat("%02d:%02d:%02d activated package=%s handle=0x%08x "
424                           "samplingRate=%dus maxReportLatency=%dus\n",
425                           reg_info.mHour, reg_info.mMin, reg_info.mSec,
426                           reg_info.mPackageName.string(), reg_info.mSensorHandle,
427                           reg_info.mSamplingRateUs, reg_info.mMaxReportLatencyUs);
428                } else {
429                   result.appendFormat("%02d:%02d:%02d de-activated package=%s handle=0x%08x\n",
430                           reg_info.mHour, reg_info.mMin, reg_info.mSec,
431                           reg_info.mPackageName.string(), reg_info.mSensorHandle);
432                }
433                currentIndex = (currentIndex - 1 + SENSOR_REGISTRATIONS_BUF_SIZE) %
434                        SENSOR_REGISTRATIONS_BUF_SIZE;
435            } while(startIndex != currentIndex);
436        }
437    }
438    write(fd, result.string(), result.size());
439    return NO_ERROR;
440}
441
442void SensorService::cleanupAutoDisabledSensorLocked(const sp<SensorEventConnection>& connection,
443        sensors_event_t const* buffer, const int count) {
444    for (int i=0 ; i<count ; i++) {
445        int handle = buffer[i].sensor;
446        if (buffer[i].type == SENSOR_TYPE_META_DATA) {
447            handle = buffer[i].meta_data.sensor;
448        }
449        if (connection->hasSensor(handle)) {
450            SensorInterface* sensor = mSensorMap.valueFor(handle);
451            // If this buffer has an event from a one_shot sensor and this connection is registered
452            // for this particular one_shot sensor, try cleaning up the connection.
453            if (sensor != NULL &&
454                sensor->getSensor().getReportingMode() == AREPORTING_MODE_ONE_SHOT) {
455                sensor->autoDisable(connection.get(), handle);
456                cleanupWithoutDisableLocked(connection, handle);
457            }
458
459        }
460   }
461}
462
463bool SensorService::threadLoop()
464{
465    ALOGD("nuSensorService thread starting...");
466
467    // each virtual sensor could generate an event per "real" event, that's why we need
468    // to size numEventMax much smaller than MAX_RECEIVE_BUFFER_EVENT_COUNT.
469    // in practice, this is too aggressive, but guaranteed to be enough.
470    const size_t minBufferSize = SensorEventQueue::MAX_RECEIVE_BUFFER_EVENT_COUNT;
471    const size_t numEventMax = minBufferSize / (1 + mVirtualSensorList.size());
472
473    SensorDevice& device(SensorDevice::getInstance());
474    const size_t vcount = mVirtualSensorList.size();
475
476    const int halVersion = device.getHalDeviceVersion();
477    do {
478        ssize_t count = device.poll(mSensorEventBuffer, numEventMax);
479        if (count < 0) {
480            ALOGE("sensor poll failed (%s)", strerror(-count));
481            break;
482        }
483
484        // Reset sensors_event_t.flags to zero for all events in the buffer.
485        for (int i = 0; i < count; i++) {
486             mSensorEventBuffer[i].flags = 0;
487        }
488
489        // Make a copy of the connection vector as some connections may be removed during the
490        // course of this loop (especially when one-shot sensor events are present in the
491        // sensor_event buffer). Promote all connections to StrongPointers before the lock is
492        // acquired. If the destructor of the sp gets called when the lock is acquired, it may
493        // result in a deadlock as ~SensorEventConnection() needs to acquire mLock again for
494        // cleanup. So copy all the strongPointers to a vector before the lock is acquired.
495        SortedVector< sp<SensorEventConnection> > activeConnections;
496        populateActiveConnections(&activeConnections);
497        Mutex::Autolock _l(mLock);
498        // Poll has returned. Hold a wakelock if one of the events is from a wake up sensor. The
499        // rest of this loop is under a critical section protected by mLock. Acquiring a wakeLock,
500        // sending events to clients (incrementing SensorEventConnection::mWakeLockRefCount) should
501        // not be interleaved with decrementing SensorEventConnection::mWakeLockRefCount and
502        // releasing the wakelock.
503        bool bufferHasWakeUpEvent = false;
504        for (int i = 0; i < count; i++) {
505            if (isWakeUpSensorEvent(mSensorEventBuffer[i])) {
506                bufferHasWakeUpEvent = true;
507                break;
508            }
509        }
510
511        if (bufferHasWakeUpEvent && !mWakeLockAcquired) {
512            setWakeLockAcquiredLocked(true);
513        }
514        recordLastValueLocked(mSensorEventBuffer, count);
515
516        // handle virtual sensors
517        if (count && vcount) {
518            sensors_event_t const * const event = mSensorEventBuffer;
519            const size_t activeVirtualSensorCount = mActiveVirtualSensors.size();
520            if (activeVirtualSensorCount) {
521                size_t k = 0;
522                SensorFusion& fusion(SensorFusion::getInstance());
523                if (fusion.isEnabled()) {
524                    for (size_t i=0 ; i<size_t(count) ; i++) {
525                        fusion.process(event[i]);
526                    }
527                }
528                for (size_t i=0 ; i<size_t(count) && k<minBufferSize ; i++) {
529                    for (size_t j=0 ; j<activeVirtualSensorCount ; j++) {
530                        if (count + k >= minBufferSize) {
531                            ALOGE("buffer too small to hold all events: "
532                                    "count=%zd, k=%zu, size=%zu",
533                                    count, k, minBufferSize);
534                            break;
535                        }
536                        sensors_event_t out;
537                        SensorInterface* si = mActiveVirtualSensors.valueAt(j);
538                        if (si->process(&out, event[i])) {
539                            mSensorEventBuffer[count + k] = out;
540                            k++;
541                        }
542                    }
543                }
544                if (k) {
545                    // record the last synthesized values
546                    recordLastValueLocked(&mSensorEventBuffer[count], k);
547                    count += k;
548                    // sort the buffer by time-stamps
549                    sortEventBuffer(mSensorEventBuffer, count);
550                }
551            }
552        }
553
554        // handle backward compatibility for RotationVector sensor
555        if (halVersion < SENSORS_DEVICE_API_VERSION_1_0) {
556            for (int i = 0; i < count; i++) {
557                if (mSensorEventBuffer[i].type == SENSOR_TYPE_ROTATION_VECTOR) {
558                    // All the 4 components of the quaternion should be available
559                    // No heading accuracy. Set it to -1
560                    mSensorEventBuffer[i].data[4] = -1;
561                }
562            }
563        }
564
565        // Map flush_complete_events in the buffer to SensorEventConnections which called
566        // flush on the hardware sensor. mapFlushEventsToConnections[i] will be the
567        // SensorEventConnection mapped to the corresponding flush_complete_event in
568        // mSensorEventBuffer[i] if such a mapping exists (NULL otherwise).
569        for (int i = 0; i < count; ++i) {
570            mMapFlushEventsToConnections[i] = NULL;
571            if (mSensorEventBuffer[i].type == SENSOR_TYPE_META_DATA) {
572                const int sensor_handle = mSensorEventBuffer[i].meta_data.sensor;
573                SensorRecord* rec = mActiveSensors.valueFor(sensor_handle);
574                if (rec != NULL) {
575                    mMapFlushEventsToConnections[i] = rec->getFirstPendingFlushConnection();
576                    rec->removeFirstPendingFlushConnection();
577                }
578            }
579        }
580
581        // Send our events to clients. Check the state of wake lock for each client and release the
582        // lock if none of the clients need it.
583        bool needsWakeLock = false;
584        size_t numConnections = activeConnections.size();
585        for (size_t i=0 ; i < numConnections; ++i) {
586            if (activeConnections[i] != 0) {
587                activeConnections[i]->sendEvents(mSensorEventBuffer, count, mSensorEventScratch,
588                        mMapFlushEventsToConnections);
589                needsWakeLock |= activeConnections[i]->needsWakeLock();
590                // If the connection has one-shot sensors, it may be cleaned up after first trigger.
591                // Early check for one-shot sensors.
592                if (activeConnections[i]->hasOneShotSensors()) {
593                    cleanupAutoDisabledSensorLocked(activeConnections[i], mSensorEventBuffer,
594                            count);
595                }
596            }
597        }
598
599        if (mWakeLockAcquired && !needsWakeLock) {
600            setWakeLockAcquiredLocked(false);
601        }
602    } while (!Thread::exitPending());
603
604    ALOGW("Exiting SensorService::threadLoop => aborting...");
605    abort();
606    return false;
607}
608
609sp<Looper> SensorService::getLooper() const {
610    return mLooper;
611}
612
613void SensorService::resetAllWakeLockRefCounts() {
614    SortedVector< sp<SensorEventConnection> > activeConnections;
615    populateActiveConnections(&activeConnections);
616    {
617        Mutex::Autolock _l(mLock);
618        for (size_t i=0 ; i < activeConnections.size(); ++i) {
619            if (activeConnections[i] != 0) {
620                activeConnections[i]->resetWakeLockRefCount();
621            }
622        }
623        setWakeLockAcquiredLocked(false);
624    }
625}
626
627void SensorService::setWakeLockAcquiredLocked(bool acquire) {
628    if (acquire) {
629        if (!mWakeLockAcquired) {
630            acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_NAME);
631            mWakeLockAcquired = true;
632        }
633        mLooper->wake();
634    } else {
635        if (mWakeLockAcquired) {
636            release_wake_lock(WAKE_LOCK_NAME);
637            mWakeLockAcquired = false;
638        }
639    }
640}
641
642bool SensorService::isWakeLockAcquired() {
643    Mutex::Autolock _l(mLock);
644    return mWakeLockAcquired;
645}
646
647bool SensorService::SensorEventAckReceiver::threadLoop() {
648    ALOGD("new thread SensorEventAckReceiver");
649    sp<Looper> looper = mService->getLooper();
650    do {
651        bool wakeLockAcquired = mService->isWakeLockAcquired();
652        int timeout = -1;
653        if (wakeLockAcquired) timeout = 5000;
654        int ret = looper->pollOnce(timeout);
655        if (ret == ALOOPER_POLL_TIMEOUT) {
656           mService->resetAllWakeLockRefCounts();
657        }
658    } while(!Thread::exitPending());
659    return false;
660}
661
662void SensorService::recordLastValueLocked(
663        const sensors_event_t* buffer, size_t count) {
664    for (size_t i = 0; i < count; i++) {
665        if (buffer[i].type != SENSOR_TYPE_META_DATA) {
666            CircularBuffer* &circular_buf = mLastEventSeen.editValueFor(buffer[i].sensor);
667            if (circular_buf == NULL) {
668                circular_buf = new CircularBuffer(buffer[i].type);
669            }
670            circular_buf->addEvent(buffer[i]);
671        }
672    }
673}
674
675void SensorService::sortEventBuffer(sensors_event_t* buffer, size_t count)
676{
677    struct compar {
678        static int cmp(void const* lhs, void const* rhs) {
679            sensors_event_t const* l = static_cast<sensors_event_t const*>(lhs);
680            sensors_event_t const* r = static_cast<sensors_event_t const*>(rhs);
681            return l->timestamp - r->timestamp;
682        }
683    };
684    qsort(buffer, count, sizeof(sensors_event_t), compar::cmp);
685}
686
687String8 SensorService::getSensorName(int handle) const {
688    size_t count = mUserSensorList.size();
689    for (size_t i=0 ; i<count ; i++) {
690        const Sensor& sensor(mUserSensorList[i]);
691        if (sensor.getHandle() == handle) {
692            return sensor.getName();
693        }
694    }
695    String8 result("unknown");
696    return result;
697}
698
699bool SensorService::isVirtualSensor(int handle) const {
700    SensorInterface* sensor = mSensorMap.valueFor(handle);
701    return sensor->isVirtual();
702}
703
704bool SensorService::isWakeUpSensorEvent(const sensors_event_t& event) const {
705    int handle = event.sensor;
706    if (event.type == SENSOR_TYPE_META_DATA) {
707        handle = event.meta_data.sensor;
708    }
709    SensorInterface* sensor = mSensorMap.valueFor(handle);
710    return sensor != NULL && sensor->getSensor().isWakeUpSensor();
711}
712
713SensorService::SensorRecord * SensorService::getSensorRecord(int handle) {
714     return mActiveSensors.valueFor(handle);
715}
716
717Vector<Sensor> SensorService::getSensorList(const String16& opPackageName)
718{
719    char value[PROPERTY_VALUE_MAX];
720    property_get("debug.sensors", value, "0");
721    const Vector<Sensor>& initialSensorList = (atoi(value)) ?
722            mUserSensorListDebug : mUserSensorList;
723    Vector<Sensor> accessibleSensorList;
724    for (size_t i = 0; i < initialSensorList.size(); i++) {
725        Sensor sensor = initialSensorList[i];
726        if (canAccessSensor(sensor, "getSensorList", opPackageName)) {
727            accessibleSensorList.add(sensor);
728        } else {
729            ALOGI("Skipped sensor %s because it requires permission %s and app op %d",
730                  sensor.getName().string(),
731                  sensor.getRequiredPermission().string(),
732                  sensor.getRequiredAppOp());
733        }
734    }
735    return accessibleSensorList;
736}
737
738sp<ISensorEventConnection> SensorService::createSensorEventConnection(const String8& packageName,
739        int requestedMode, const String16& opPackageName) {
740    // Only 2 modes supported for a SensorEventConnection ... NORMAL and DATA_INJECTION.
741    if (requestedMode != NORMAL && requestedMode != DATA_INJECTION) {
742        return NULL;
743    }
744
745    Mutex::Autolock _l(mLock);
746    // To create a client in DATA_INJECTION mode to inject data, SensorService should already be
747    // operating in DI mode.
748    if (requestedMode == DATA_INJECTION) {
749        if (mCurrentOperatingMode != DATA_INJECTION) return NULL;
750        if (!isWhiteListedPackage(packageName)) return NULL;
751    }
752
753    uid_t uid = IPCThreadState::self()->getCallingUid();
754    sp<SensorEventConnection> result(new SensorEventConnection(this, uid, packageName,
755            requestedMode == DATA_INJECTION, opPackageName));
756    if (requestedMode == DATA_INJECTION) {
757        if (mActiveConnections.indexOf(result) < 0) {
758            mActiveConnections.add(result);
759        }
760        // Add the associated file descriptor to the Looper for polling whenever there is data to
761        // be injected.
762        result->updateLooperRegistration(mLooper);
763    }
764    return result;
765}
766
767int SensorService::isDataInjectionEnabled() {
768    Mutex::Autolock _l(mLock);
769    return (mCurrentOperatingMode == DATA_INJECTION);
770}
771
772status_t SensorService::resetToNormalMode() {
773    Mutex::Autolock _l(mLock);
774    return resetToNormalModeLocked();
775}
776
777status_t SensorService::resetToNormalModeLocked() {
778    SensorDevice& dev(SensorDevice::getInstance());
779    dev.enableAllSensors();
780    status_t err = dev.setMode(NORMAL);
781    mCurrentOperatingMode = NORMAL;
782    return err;
783}
784
785void SensorService::cleanupConnection(SensorEventConnection* c)
786{
787    Mutex::Autolock _l(mLock);
788    const wp<SensorEventConnection> connection(c);
789    size_t size = mActiveSensors.size();
790    ALOGD_IF(DEBUG_CONNECTIONS, "%zu active sensors", size);
791    for (size_t i=0 ; i<size ; ) {
792        int handle = mActiveSensors.keyAt(i);
793        if (c->hasSensor(handle)) {
794            ALOGD_IF(DEBUG_CONNECTIONS, "%zu: disabling handle=0x%08x", i, handle);
795            SensorInterface* sensor = mSensorMap.valueFor( handle );
796            ALOGE_IF(!sensor, "mSensorMap[handle=0x%08x] is null!", handle);
797            if (sensor) {
798                sensor->activate(c, false);
799            }
800            c->removeSensor(handle);
801        }
802        SensorRecord* rec = mActiveSensors.valueAt(i);
803        ALOGE_IF(!rec, "mActiveSensors[%zu] is null (handle=0x%08x)!", i, handle);
804        ALOGD_IF(DEBUG_CONNECTIONS,
805                "removing connection %p for sensor[%zu].handle=0x%08x",
806                c, i, handle);
807
808        if (rec && rec->removeConnection(connection)) {
809            ALOGD_IF(DEBUG_CONNECTIONS, "... and it was the last connection");
810            mActiveSensors.removeItemsAt(i, 1);
811            mActiveVirtualSensors.removeItem(handle);
812            delete rec;
813            size--;
814        } else {
815            i++;
816        }
817    }
818    c->updateLooperRegistration(mLooper);
819    mActiveConnections.remove(connection);
820    BatteryService::cleanup(c->getUid());
821    if (c->needsWakeLock()) {
822        checkWakeLockStateLocked();
823    }
824}
825
826Sensor SensorService::getSensorFromHandle(int handle) const {
827    return mSensorMap.valueFor(handle)->getSensor();
828}
829
830status_t SensorService::enable(const sp<SensorEventConnection>& connection,
831        int handle, nsecs_t samplingPeriodNs, nsecs_t maxBatchReportLatencyNs, int reservedFlags,
832        const String16& opPackageName)
833{
834    if (mInitCheck != NO_ERROR)
835        return mInitCheck;
836
837    SensorInterface* sensor = mSensorMap.valueFor(handle);
838    if (sensor == NULL) {
839        return BAD_VALUE;
840    }
841
842    if (!canAccessSensor(sensor->getSensor(), "Tried enabling", opPackageName)) {
843        return BAD_VALUE;
844    }
845
846    Mutex::Autolock _l(mLock);
847    if ((mCurrentOperatingMode == RESTRICTED || mCurrentOperatingMode == DATA_INJECTION)
848           && !isWhiteListedPackage(connection->getPackageName())) {
849        return INVALID_OPERATION;
850    }
851
852    SensorRecord* rec = mActiveSensors.valueFor(handle);
853    if (rec == 0) {
854        rec = new SensorRecord(connection);
855        mActiveSensors.add(handle, rec);
856        if (sensor->isVirtual()) {
857            mActiveVirtualSensors.add(handle, sensor);
858        }
859    } else {
860        if (rec->addConnection(connection)) {
861            // this sensor is already activated, but we are adding a connection that uses it.
862            // Immediately send down the last known value of the requested sensor if it's not a
863            // "continuous" sensor.
864            if (sensor->getSensor().getReportingMode() == AREPORTING_MODE_ON_CHANGE) {
865                // NOTE: The wake_up flag of this event may get set to
866                // WAKE_UP_SENSOR_EVENT_NEEDS_ACK if this is a wake_up event.
867                CircularBuffer *circular_buf = mLastEventSeen.valueFor(handle);
868                if (circular_buf) {
869                    sensors_event_t event;
870                    memset(&event, 0, sizeof(event));
871                    // It is unlikely that this buffer is empty as the sensor is already active.
872                    // One possible corner case may be two applications activating an on-change
873                    // sensor at the same time.
874                    if(circular_buf->populateLastEvent(&event)) {
875                        event.sensor = handle;
876                        if (event.version == sizeof(sensors_event_t)) {
877                            if (isWakeUpSensorEvent(event) && !mWakeLockAcquired) {
878                                setWakeLockAcquiredLocked(true);
879                            }
880                            connection->sendEvents(&event, 1, NULL);
881                            if (!connection->needsWakeLock() && mWakeLockAcquired) {
882                                checkWakeLockStateLocked();
883                            }
884                        }
885                    }
886                }
887            }
888        }
889    }
890
891    if (connection->addSensor(handle)) {
892        BatteryService::enableSensor(connection->getUid(), handle);
893        // the sensor was added (which means it wasn't already there)
894        // so, see if this connection becomes active
895        if (mActiveConnections.indexOf(connection) < 0) {
896            mActiveConnections.add(connection);
897        }
898    } else {
899        ALOGW("sensor %08x already enabled in connection %p (ignoring)",
900            handle, connection.get());
901    }
902
903    nsecs_t minDelayNs = sensor->getSensor().getMinDelayNs();
904    if (samplingPeriodNs < minDelayNs) {
905        samplingPeriodNs = minDelayNs;
906    }
907
908    ALOGD_IF(DEBUG_CONNECTIONS, "Calling batch handle==%d flags=%d"
909                                "rate=%" PRId64 " timeout== %" PRId64"",
910             handle, reservedFlags, samplingPeriodNs, maxBatchReportLatencyNs);
911
912    status_t err = sensor->batch(connection.get(), handle, 0, samplingPeriodNs,
913                                 maxBatchReportLatencyNs);
914
915    // Call flush() before calling activate() on the sensor. Wait for a first
916    // flush complete event before sending events on this connection. Ignore
917    // one-shot sensors which don't support flush(). Ignore on-change sensors
918    // to maintain the on-change logic (any on-change events except the initial
919    // one should be trigger by a change in value). Also if this sensor isn't
920    // already active, don't call flush().
921    if (err == NO_ERROR &&
922            sensor->getSensor().getReportingMode() != AREPORTING_MODE_ONE_SHOT &&
923            sensor->getSensor().getReportingMode() != AREPORTING_MODE_ON_CHANGE &&
924            rec->getNumConnections() > 1) {
925        connection->setFirstFlushPending(handle, true);
926        status_t err_flush = sensor->flush(connection.get(), handle);
927        // Flush may return error if the underlying h/w sensor uses an older HAL.
928        if (err_flush == NO_ERROR) {
929            rec->addPendingFlushConnection(connection.get());
930        } else {
931            connection->setFirstFlushPending(handle, false);
932        }
933    }
934
935    if (err == NO_ERROR) {
936        ALOGD_IF(DEBUG_CONNECTIONS, "Calling activate on %d", handle);
937        err = sensor->activate(connection.get(), true);
938    }
939
940    if (err == NO_ERROR) {
941        connection->updateLooperRegistration(mLooper);
942        SensorRegistrationInfo &reg_info =
943            mLastNSensorRegistrations.editItemAt(mNextSensorRegIndex);
944        reg_info.mSensorHandle = handle;
945        reg_info.mSamplingRateUs = samplingPeriodNs/1000;
946        reg_info.mMaxReportLatencyUs = maxBatchReportLatencyNs/1000;
947        reg_info.mActivated = true;
948        reg_info.mPackageName = connection->getPackageName();
949        time_t rawtime = time(NULL);
950        struct tm * timeinfo = localtime(&rawtime);
951        reg_info.mHour = timeinfo->tm_hour;
952        reg_info.mMin = timeinfo->tm_min;
953        reg_info.mSec = timeinfo->tm_sec;
954        mNextSensorRegIndex = (mNextSensorRegIndex + 1) % SENSOR_REGISTRATIONS_BUF_SIZE;
955    }
956
957    if (err != NO_ERROR) {
958        // batch/activate has failed, reset our state.
959        cleanupWithoutDisableLocked(connection, handle);
960    }
961    return err;
962}
963
964status_t SensorService::disable(const sp<SensorEventConnection>& connection,
965        int handle)
966{
967    if (mInitCheck != NO_ERROR)
968        return mInitCheck;
969
970    Mutex::Autolock _l(mLock);
971    status_t err = cleanupWithoutDisableLocked(connection, handle);
972    if (err == NO_ERROR) {
973        SensorInterface* sensor = mSensorMap.valueFor(handle);
974        err = sensor ? sensor->activate(connection.get(), false) : status_t(BAD_VALUE);
975
976    }
977    if (err == NO_ERROR) {
978        SensorRegistrationInfo &reg_info =
979            mLastNSensorRegistrations.editItemAt(mNextSensorRegIndex);
980        reg_info.mActivated = false;
981        reg_info.mPackageName= connection->getPackageName();
982        reg_info.mSensorHandle = handle;
983        time_t rawtime = time(NULL);
984        struct tm * timeinfo = localtime(&rawtime);
985        reg_info.mHour = timeinfo->tm_hour;
986        reg_info.mMin = timeinfo->tm_min;
987        reg_info.mSec = timeinfo->tm_sec;
988        mNextSensorRegIndex = (mNextSensorRegIndex + 1) % SENSOR_REGISTRATIONS_BUF_SIZE;
989    }
990    return err;
991}
992
993status_t SensorService::cleanupWithoutDisable(
994        const sp<SensorEventConnection>& connection, int handle) {
995    Mutex::Autolock _l(mLock);
996    return cleanupWithoutDisableLocked(connection, handle);
997}
998
999status_t SensorService::cleanupWithoutDisableLocked(
1000        const sp<SensorEventConnection>& connection, int handle) {
1001    SensorRecord* rec = mActiveSensors.valueFor(handle);
1002    if (rec) {
1003        // see if this connection becomes inactive
1004        if (connection->removeSensor(handle)) {
1005            BatteryService::disableSensor(connection->getUid(), handle);
1006        }
1007        if (connection->hasAnySensor() == false) {
1008            connection->updateLooperRegistration(mLooper);
1009            mActiveConnections.remove(connection);
1010        }
1011        // see if this sensor becomes inactive
1012        if (rec->removeConnection(connection)) {
1013            mActiveSensors.removeItem(handle);
1014            mActiveVirtualSensors.removeItem(handle);
1015            delete rec;
1016        }
1017        return NO_ERROR;
1018    }
1019    return BAD_VALUE;
1020}
1021
1022status_t SensorService::setEventRate(const sp<SensorEventConnection>& connection,
1023        int handle, nsecs_t ns, const String16& opPackageName)
1024{
1025    if (mInitCheck != NO_ERROR)
1026        return mInitCheck;
1027
1028    SensorInterface* sensor = mSensorMap.valueFor(handle);
1029    if (!sensor)
1030        return BAD_VALUE;
1031
1032    if (!canAccessSensor(sensor->getSensor(), "Tried configuring", opPackageName)) {
1033        return BAD_VALUE;
1034    }
1035
1036    if (ns < 0)
1037        return BAD_VALUE;
1038
1039    nsecs_t minDelayNs = sensor->getSensor().getMinDelayNs();
1040    if (ns < minDelayNs) {
1041        ns = minDelayNs;
1042    }
1043
1044    return sensor->setDelay(connection.get(), handle, ns);
1045}
1046
1047status_t SensorService::flushSensor(const sp<SensorEventConnection>& connection,
1048        const String16& opPackageName) {
1049    if (mInitCheck != NO_ERROR) return mInitCheck;
1050    SensorDevice& dev(SensorDevice::getInstance());
1051    const int halVersion = dev.getHalDeviceVersion();
1052    status_t err(NO_ERROR);
1053    Mutex::Autolock _l(mLock);
1054    // Loop through all sensors for this connection and call flush on each of them.
1055    for (size_t i = 0; i < connection->mSensorInfo.size(); ++i) {
1056        const int handle = connection->mSensorInfo.keyAt(i);
1057        SensorInterface* sensor = mSensorMap.valueFor(handle);
1058        if (sensor->getSensor().getReportingMode() == AREPORTING_MODE_ONE_SHOT) {
1059            ALOGE("flush called on a one-shot sensor");
1060            err = INVALID_OPERATION;
1061            continue;
1062        }
1063        if (halVersion <= SENSORS_DEVICE_API_VERSION_1_0 || isVirtualSensor(handle)) {
1064            // For older devices just increment pending flush count which will send a trivial
1065            // flush complete event.
1066            connection->incrementPendingFlushCount(handle);
1067        } else {
1068            if (!canAccessSensor(sensor->getSensor(), "Tried flushing", opPackageName)) {
1069                err = INVALID_OPERATION;
1070                continue;
1071            }
1072            status_t err_flush = sensor->flush(connection.get(), handle);
1073            if (err_flush == NO_ERROR) {
1074                SensorRecord* rec = mActiveSensors.valueFor(handle);
1075                if (rec != NULL) rec->addPendingFlushConnection(connection);
1076            }
1077            err = (err_flush != NO_ERROR) ? err_flush : err;
1078        }
1079    }
1080    return err;
1081}
1082
1083bool SensorService::canAccessSensor(const Sensor& sensor, const char* operation,
1084        const String16& opPackageName) {
1085    const String8& requiredPermission = sensor.getRequiredPermission();
1086
1087    if (requiredPermission.length() <= 0) {
1088        return true;
1089    }
1090
1091    bool hasPermission = false;
1092
1093    // Runtime permissions can't use the cache as they may change.
1094    if (sensor.isRequiredPermissionRuntime()) {
1095        hasPermission = checkPermission(String16(requiredPermission),
1096                IPCThreadState::self()->getCallingPid(), IPCThreadState::self()->getCallingUid());
1097    } else {
1098        hasPermission = PermissionCache::checkCallingPermission(String16(requiredPermission));
1099    }
1100
1101    if (!hasPermission) {
1102        ALOGE("%s a sensor (%s) without holding its required permission: %s",
1103                operation, sensor.getName().string(), sensor.getRequiredPermission().string());
1104        return false;
1105    }
1106
1107    const int32_t opCode = sensor.getRequiredAppOp();
1108    if (opCode >= 0) {
1109        AppOpsManager appOps;
1110        if (appOps.noteOp(opCode, IPCThreadState::self()->getCallingUid(), opPackageName)
1111                        != AppOpsManager::MODE_ALLOWED) {
1112            ALOGE("%s a sensor (%s) without enabled required app op: %D",
1113                    operation, sensor.getName().string(), opCode);
1114            return false;
1115        }
1116    }
1117
1118    return true;
1119}
1120
1121void SensorService::checkWakeLockState() {
1122    Mutex::Autolock _l(mLock);
1123    checkWakeLockStateLocked();
1124}
1125
1126void SensorService::checkWakeLockStateLocked() {
1127    if (!mWakeLockAcquired) {
1128        return;
1129    }
1130    bool releaseLock = true;
1131    for (size_t i=0 ; i<mActiveConnections.size() ; i++) {
1132        sp<SensorEventConnection> connection(mActiveConnections[i].promote());
1133        if (connection != 0) {
1134            if (connection->needsWakeLock()) {
1135                releaseLock = false;
1136                break;
1137            }
1138        }
1139    }
1140    if (releaseLock) {
1141        setWakeLockAcquiredLocked(false);
1142    }
1143}
1144
1145void SensorService::sendEventsFromCache(const sp<SensorEventConnection>& connection) {
1146    Mutex::Autolock _l(mLock);
1147    connection->writeToSocketFromCache();
1148    if (connection->needsWakeLock()) {
1149        setWakeLockAcquiredLocked(true);
1150    }
1151}
1152
1153void SensorService::populateActiveConnections(
1154        SortedVector< sp<SensorEventConnection> >* activeConnections) {
1155    Mutex::Autolock _l(mLock);
1156    for (size_t i=0 ; i < mActiveConnections.size(); ++i) {
1157        sp<SensorEventConnection> connection(mActiveConnections[i].promote());
1158        if (connection != 0) {
1159            activeConnections->add(connection);
1160        }
1161    }
1162}
1163
1164bool SensorService::isWhiteListedPackage(const String8& packageName) {
1165    return (packageName.contains(mWhiteListedPackage.string()));
1166}
1167
1168int SensorService::getNumEventsForSensorType(int sensor_event_type) {
1169    switch (sensor_event_type) {
1170        case SENSOR_TYPE_ROTATION_VECTOR:
1171        case SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR:
1172            return 5;
1173
1174        case SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED:
1175        case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
1176            return 6;
1177
1178        case SENSOR_TYPE_GAME_ROTATION_VECTOR:
1179            return 4;
1180
1181        case SENSOR_TYPE_SIGNIFICANT_MOTION:
1182        case SENSOR_TYPE_STEP_DETECTOR:
1183        case SENSOR_TYPE_STEP_COUNTER:
1184            return 1;
1185
1186         default:
1187            return 3;
1188    }
1189}
1190
1191// ---------------------------------------------------------------------------
1192SensorService::SensorRecord::SensorRecord(
1193        const sp<SensorEventConnection>& connection)
1194{
1195    mConnections.add(connection);
1196}
1197
1198bool SensorService::SensorRecord::addConnection(
1199        const sp<SensorEventConnection>& connection)
1200{
1201    if (mConnections.indexOf(connection) < 0) {
1202        mConnections.add(connection);
1203        return true;
1204    }
1205    return false;
1206}
1207
1208bool SensorService::SensorRecord::removeConnection(
1209        const wp<SensorEventConnection>& connection)
1210{
1211    ssize_t index = mConnections.indexOf(connection);
1212    if (index >= 0) {
1213        mConnections.removeItemsAt(index, 1);
1214    }
1215    // Remove this connections from the queue of flush() calls made on this sensor.
1216    for (Vector< wp<SensorEventConnection> >::iterator it =
1217            mPendingFlushConnections.begin(); it != mPendingFlushConnections.end();) {
1218
1219        if (it->unsafe_get() == connection.unsafe_get()) {
1220            it = mPendingFlushConnections.erase(it);
1221        } else {
1222            ++it;
1223        }
1224    }
1225    return mConnections.size() ? false : true;
1226}
1227
1228void SensorService::SensorRecord::addPendingFlushConnection(
1229        const sp<SensorEventConnection>& connection) {
1230    mPendingFlushConnections.add(connection);
1231}
1232
1233void SensorService::SensorRecord::removeFirstPendingFlushConnection() {
1234    if (mPendingFlushConnections.size() > 0) {
1235        mPendingFlushConnections.removeAt(0);
1236    }
1237}
1238
1239SensorService::SensorEventConnection *
1240SensorService::SensorRecord::getFirstPendingFlushConnection() {
1241   if (mPendingFlushConnections.size() > 0) {
1242        return mPendingFlushConnections[0].unsafe_get();
1243    }
1244    return NULL;
1245}
1246
1247void SensorService::SensorRecord::clearAllPendingFlushConnections() {
1248    mPendingFlushConnections.clear();
1249}
1250
1251
1252// ---------------------------------------------------------------------------
1253SensorService::TrimmedSensorEvent::TrimmedSensorEvent(int sensorType) {
1254    mTimestamp = -1;
1255    const int numData = SensorService::getNumEventsForSensorType(sensorType);
1256    if (sensorType == SENSOR_TYPE_STEP_COUNTER) {
1257        mStepCounter = 0;
1258    } else {
1259        mData = new float[numData];
1260        for (int i = 0; i < numData; ++i) {
1261            mData[i] = -1.0;
1262        }
1263    }
1264    mHour = mMin = mSec = INT32_MIN;
1265}
1266
1267bool SensorService::TrimmedSensorEvent::isSentinel(const TrimmedSensorEvent& event) {
1268    return (event.mHour == INT32_MIN && event.mMin == INT32_MIN && event.mSec == INT32_MIN);
1269}
1270// --------------------------------------------------------------------------
1271SensorService::CircularBuffer::CircularBuffer(int sensor_event_type) {
1272    mNextInd = 0;
1273    mBufSize = CIRCULAR_BUF_SIZE;
1274    if (sensor_event_type == SENSOR_TYPE_STEP_COUNTER ||
1275            sensor_event_type == SENSOR_TYPE_SIGNIFICANT_MOTION ||
1276            sensor_event_type == SENSOR_TYPE_ACCELEROMETER) {
1277        mBufSize = CIRCULAR_BUF_SIZE * 5;
1278    }
1279    mTrimmedSensorEventArr = new TrimmedSensorEvent *[mBufSize];
1280    mSensorType = sensor_event_type;
1281    for (int i = 0; i < mBufSize; ++i) {
1282        mTrimmedSensorEventArr[i] = new TrimmedSensorEvent(mSensorType);
1283    }
1284}
1285
1286void SensorService::CircularBuffer::addEvent(const sensors_event_t& sensor_event) {
1287    TrimmedSensorEvent *curr_event = mTrimmedSensorEventArr[mNextInd];
1288    curr_event->mTimestamp = sensor_event.timestamp;
1289    if (mSensorType == SENSOR_TYPE_STEP_COUNTER) {
1290        curr_event->mStepCounter = sensor_event.u64.step_counter;
1291    } else {
1292        memcpy(curr_event->mData, sensor_event.data,
1293                 sizeof(float) * SensorService::getNumEventsForSensorType(mSensorType));
1294    }
1295    time_t rawtime = time(NULL);
1296    struct tm * timeinfo = localtime(&rawtime);
1297    curr_event->mHour = timeinfo->tm_hour;
1298    curr_event->mMin = timeinfo->tm_min;
1299    curr_event->mSec = timeinfo->tm_sec;
1300    mNextInd = (mNextInd + 1) % mBufSize;
1301}
1302
1303void SensorService::CircularBuffer::printBuffer(String8& result) const {
1304    const int numData = SensorService::getNumEventsForSensorType(mSensorType);
1305    int i = mNextInd, eventNum = 1;
1306    result.appendFormat("last %d events = < ", mBufSize);
1307    do {
1308        if (TrimmedSensorEvent::isSentinel(*mTrimmedSensorEventArr[i])) {
1309            // Sentinel, ignore.
1310            i = (i + 1) % mBufSize;
1311            continue;
1312        }
1313        result.appendFormat("%d) ", eventNum++);
1314        if (mSensorType == SENSOR_TYPE_STEP_COUNTER) {
1315            result.appendFormat("%llu,", mTrimmedSensorEventArr[i]->mStepCounter);
1316        } else {
1317            for (int j = 0; j < numData; ++j) {
1318                result.appendFormat("%5.1f,", mTrimmedSensorEventArr[i]->mData[j]);
1319            }
1320        }
1321        result.appendFormat("%lld %02d:%02d:%02d ", mTrimmedSensorEventArr[i]->mTimestamp,
1322                mTrimmedSensorEventArr[i]->mHour, mTrimmedSensorEventArr[i]->mMin,
1323                mTrimmedSensorEventArr[i]->mSec);
1324        i = (i + 1) % mBufSize;
1325    } while (i != mNextInd);
1326    result.appendFormat(">\n");
1327}
1328
1329bool SensorService::CircularBuffer::populateLastEvent(sensors_event_t *event) {
1330    int lastEventInd = (mNextInd - 1 + mBufSize) % mBufSize;
1331    // Check if the buffer is empty.
1332    if (TrimmedSensorEvent::isSentinel(*mTrimmedSensorEventArr[lastEventInd])) {
1333        return false;
1334    }
1335    event->version = sizeof(sensors_event_t);
1336    event->type = mSensorType;
1337    event->timestamp = mTrimmedSensorEventArr[lastEventInd]->mTimestamp;
1338    if (mSensorType == SENSOR_TYPE_STEP_COUNTER) {
1339          event->u64.step_counter = mTrimmedSensorEventArr[lastEventInd]->mStepCounter;
1340    } else {
1341        memcpy(event->data, mTrimmedSensorEventArr[lastEventInd]->mData,
1342                 sizeof(float) * SensorService::getNumEventsForSensorType(mSensorType));
1343    }
1344    return true;
1345}
1346
1347SensorService::CircularBuffer::~CircularBuffer() {
1348    for (int i = 0; i < mBufSize; ++i) {
1349        delete mTrimmedSensorEventArr[i];
1350    }
1351    delete [] mTrimmedSensorEventArr;
1352}
1353
1354// ---------------------------------------------------------------------------
1355
1356SensorService::SensorEventConnection::SensorEventConnection(
1357        const sp<SensorService>& service, uid_t uid, String8 packageName, bool isDataInjectionMode,
1358        const String16& opPackageName)
1359    : mService(service), mUid(uid), mWakeLockRefCount(0), mHasLooperCallbacks(false),
1360      mDead(false), mDataInjectionMode(isDataInjectionMode), mEventCache(NULL),
1361      mCacheSize(0), mMaxCacheSize(0), mPackageName(packageName), mOpPackageName(opPackageName) {
1362    mChannel = new BitTube(mService->mSocketBufferSize);
1363#if DEBUG_CONNECTIONS
1364    mEventsReceived = mEventsSentFromCache = mEventsSent = 0;
1365    mTotalAcksNeeded = mTotalAcksReceived = 0;
1366#endif
1367}
1368
1369SensorService::SensorEventConnection::~SensorEventConnection() {
1370    ALOGD_IF(DEBUG_CONNECTIONS, "~SensorEventConnection(%p)", this);
1371    mService->cleanupConnection(this);
1372    if (mEventCache != NULL) {
1373        delete mEventCache;
1374    }
1375}
1376
1377void SensorService::SensorEventConnection::onFirstRef() {
1378    LooperCallback::onFirstRef();
1379}
1380
1381bool SensorService::SensorEventConnection::needsWakeLock() {
1382    Mutex::Autolock _l(mConnectionLock);
1383    return !mDead && mWakeLockRefCount > 0;
1384}
1385
1386void SensorService::SensorEventConnection::resetWakeLockRefCount() {
1387    Mutex::Autolock _l(mConnectionLock);
1388    mWakeLockRefCount = 0;
1389}
1390
1391void SensorService::SensorEventConnection::dump(String8& result) {
1392    Mutex::Autolock _l(mConnectionLock);
1393    result.appendFormat("\tOperating Mode: %s\n",mDataInjectionMode ? "DATA_INJECTION" : "NORMAL");
1394    result.appendFormat("\t %s | WakeLockRefCount %d | uid %d | cache size %d | "
1395            "max cache size %d\n", mPackageName.string(), mWakeLockRefCount, mUid, mCacheSize,
1396            mMaxCacheSize);
1397    for (size_t i = 0; i < mSensorInfo.size(); ++i) {
1398        const FlushInfo& flushInfo = mSensorInfo.valueAt(i);
1399        result.appendFormat("\t %s 0x%08x | status: %s | pending flush events %d \n",
1400                            mService->getSensorName(mSensorInfo.keyAt(i)).string(),
1401                            mSensorInfo.keyAt(i),
1402                            flushInfo.mFirstFlushPending ? "First flush pending" :
1403                                                           "active",
1404                            flushInfo.mPendingFlushEventsToSend);
1405    }
1406#if DEBUG_CONNECTIONS
1407    result.appendFormat("\t events recvd: %d | sent %d | cache %d | dropped %d |"
1408            " total_acks_needed %d | total_acks_recvd %d\n",
1409            mEventsReceived,
1410            mEventsSent,
1411            mEventsSentFromCache,
1412            mEventsReceived - (mEventsSentFromCache + mEventsSent + mCacheSize),
1413            mTotalAcksNeeded,
1414            mTotalAcksReceived);
1415#endif
1416}
1417
1418bool SensorService::SensorEventConnection::addSensor(int32_t handle) {
1419    Mutex::Autolock _l(mConnectionLock);
1420    if (!canAccessSensor(mService->getSensorFromHandle(handle),
1421            "Tried adding", mOpPackageName)) {
1422        return false;
1423    }
1424    if (mSensorInfo.indexOfKey(handle) < 0) {
1425        mSensorInfo.add(handle, FlushInfo());
1426        return true;
1427    }
1428    return false;
1429}
1430
1431bool SensorService::SensorEventConnection::removeSensor(int32_t handle) {
1432    Mutex::Autolock _l(mConnectionLock);
1433    if (mSensorInfo.removeItem(handle) >= 0) {
1434        return true;
1435    }
1436    return false;
1437}
1438
1439bool SensorService::SensorEventConnection::hasSensor(int32_t handle) const {
1440    Mutex::Autolock _l(mConnectionLock);
1441    return mSensorInfo.indexOfKey(handle) >= 0;
1442}
1443
1444bool SensorService::SensorEventConnection::hasAnySensor() const {
1445    Mutex::Autolock _l(mConnectionLock);
1446    return mSensorInfo.size() ? true : false;
1447}
1448
1449bool SensorService::SensorEventConnection::hasOneShotSensors() const {
1450    Mutex::Autolock _l(mConnectionLock);
1451    for (size_t i = 0; i < mSensorInfo.size(); ++i) {
1452        const int handle = mSensorInfo.keyAt(i);
1453        if (mService->getSensorFromHandle(handle).getReportingMode() == AREPORTING_MODE_ONE_SHOT) {
1454            return true;
1455        }
1456    }
1457    return false;
1458}
1459
1460String8 SensorService::SensorEventConnection::getPackageName() const {
1461    return mPackageName;
1462}
1463
1464void SensorService::SensorEventConnection::setFirstFlushPending(int32_t handle,
1465                                bool value) {
1466    Mutex::Autolock _l(mConnectionLock);
1467    ssize_t index = mSensorInfo.indexOfKey(handle);
1468    if (index >= 0) {
1469        FlushInfo& flushInfo = mSensorInfo.editValueAt(index);
1470        flushInfo.mFirstFlushPending = value;
1471    }
1472}
1473
1474void SensorService::SensorEventConnection::updateLooperRegistration(const sp<Looper>& looper) {
1475    Mutex::Autolock _l(mConnectionLock);
1476    updateLooperRegistrationLocked(looper);
1477}
1478
1479void SensorService::SensorEventConnection::updateLooperRegistrationLocked(
1480        const sp<Looper>& looper) {
1481    bool isConnectionActive = (mSensorInfo.size() > 0 && !mDataInjectionMode) ||
1482                              mDataInjectionMode;
1483    // If all sensors are unregistered OR Looper has encountered an error, we
1484    // can remove the Fd from the Looper if it has been previously added.
1485    if (!isConnectionActive || mDead) {
1486        if (mHasLooperCallbacks) {
1487            ALOGD_IF(DEBUG_CONNECTIONS, "%p removeFd fd=%d", this, mChannel->getSendFd());
1488            looper->removeFd(mChannel->getSendFd());
1489            mHasLooperCallbacks = false;
1490        }
1491        return;
1492    }
1493
1494    int looper_flags = 0;
1495    if (mCacheSize > 0) looper_flags |= ALOOPER_EVENT_OUTPUT;
1496    if (mDataInjectionMode) looper_flags |= ALOOPER_EVENT_INPUT;
1497    for (size_t i = 0; i < mSensorInfo.size(); ++i) {
1498        const int handle = mSensorInfo.keyAt(i);
1499        if (mService->getSensorFromHandle(handle).isWakeUpSensor()) {
1500            looper_flags |= ALOOPER_EVENT_INPUT;
1501            break;
1502        }
1503    }
1504    // If flags is still set to zero, we don't need to add this fd to the Looper, if
1505    // the fd has already been added, remove it. This is likely to happen when ALL the
1506    // events stored in the cache have been sent to the corresponding app.
1507    if (looper_flags == 0) {
1508        if (mHasLooperCallbacks) {
1509            ALOGD_IF(DEBUG_CONNECTIONS, "removeFd fd=%d", mChannel->getSendFd());
1510            looper->removeFd(mChannel->getSendFd());
1511            mHasLooperCallbacks = false;
1512        }
1513        return;
1514    }
1515    // Add the file descriptor to the Looper for receiving acknowledegments if the app has
1516    // registered for wake-up sensors OR for sending events in the cache.
1517    int ret = looper->addFd(mChannel->getSendFd(), 0, looper_flags, this, NULL);
1518    if (ret == 1) {
1519        ALOGD_IF(DEBUG_CONNECTIONS, "%p addFd fd=%d", this, mChannel->getSendFd());
1520        mHasLooperCallbacks = true;
1521    } else {
1522        ALOGE("Looper::addFd failed ret=%d fd=%d", ret, mChannel->getSendFd());
1523    }
1524}
1525
1526void SensorService::SensorEventConnection::incrementPendingFlushCount(int32_t handle) {
1527    Mutex::Autolock _l(mConnectionLock);
1528    ssize_t index = mSensorInfo.indexOfKey(handle);
1529    if (index >= 0) {
1530        FlushInfo& flushInfo = mSensorInfo.editValueAt(index);
1531        flushInfo.mPendingFlushEventsToSend++;
1532    }
1533}
1534
1535status_t SensorService::SensorEventConnection::sendEvents(
1536        sensors_event_t const* buffer, size_t numEvents,
1537        sensors_event_t* scratch,
1538        SensorEventConnection const * const * mapFlushEventsToConnections) {
1539    // filter out events not for this connection
1540    int count = 0;
1541    Mutex::Autolock _l(mConnectionLock);
1542    if (scratch) {
1543        size_t i=0;
1544        while (i<numEvents) {
1545            int32_t sensor_handle = buffer[i].sensor;
1546            if (buffer[i].type == SENSOR_TYPE_META_DATA) {
1547                ALOGD_IF(DEBUG_CONNECTIONS, "flush complete event sensor==%d ",
1548                        buffer[i].meta_data.sensor);
1549                // Setting sensor_handle to the correct sensor to ensure the sensor events per
1550                // connection are filtered correctly.  buffer[i].sensor is zero for meta_data
1551                // events.
1552                sensor_handle = buffer[i].meta_data.sensor;
1553            }
1554            ssize_t index = mSensorInfo.indexOfKey(sensor_handle);
1555            // Check if this connection has registered for this sensor. If not continue to the
1556            // next sensor_event.
1557            if (index < 0) {
1558                ++i;
1559                continue;
1560            }
1561
1562            FlushInfo& flushInfo = mSensorInfo.editValueAt(index);
1563            // Check if there is a pending flush_complete event for this sensor on this connection.
1564            if (buffer[i].type == SENSOR_TYPE_META_DATA && flushInfo.mFirstFlushPending == true &&
1565                    this == mapFlushEventsToConnections[i]) {
1566                flushInfo.mFirstFlushPending = false;
1567                ALOGD_IF(DEBUG_CONNECTIONS, "First flush event for sensor==%d ",
1568                        buffer[i].meta_data.sensor);
1569                ++i;
1570                continue;
1571            }
1572
1573            // If there is a pending flush complete event for this sensor on this connection,
1574            // ignore the event and proceed to the next.
1575            if (flushInfo.mFirstFlushPending) {
1576                ++i;
1577                continue;
1578            }
1579
1580            do {
1581                // Keep copying events into the scratch buffer as long as they are regular
1582                // sensor_events are from the same sensor_handle OR they are flush_complete_events
1583                // from the same sensor_handle AND the current connection is mapped to the
1584                // corresponding flush_complete_event.
1585                if (buffer[i].type == SENSOR_TYPE_META_DATA) {
1586                    if (this == mapFlushEventsToConnections[i]) {
1587                        scratch[count++] = buffer[i];
1588                    }
1589                    ++i;
1590                } else {
1591                    // Regular sensor event, just copy it to the scratch buffer.
1592                    scratch[count++] = buffer[i++];
1593                }
1594            } while ((i<numEvents) && ((buffer[i].sensor == sensor_handle &&
1595                                        buffer[i].type != SENSOR_TYPE_META_DATA) ||
1596                                       (buffer[i].type == SENSOR_TYPE_META_DATA  &&
1597                                        buffer[i].meta_data.sensor == sensor_handle)));
1598        }
1599    } else {
1600        scratch = const_cast<sensors_event_t *>(buffer);
1601        count = numEvents;
1602    }
1603
1604    sendPendingFlushEventsLocked();
1605    // Early return if there are no events for this connection.
1606    if (count == 0) {
1607        return status_t(NO_ERROR);
1608    }
1609
1610#if DEBUG_CONNECTIONS
1611     mEventsReceived += count;
1612#endif
1613    if (mCacheSize != 0) {
1614        // There are some events in the cache which need to be sent first. Copy this buffer to
1615        // the end of cache.
1616        if (mCacheSize + count <= mMaxCacheSize) {
1617            memcpy(&mEventCache[mCacheSize], scratch, count * sizeof(sensors_event_t));
1618            mCacheSize += count;
1619        } else {
1620            // Check if any new sensors have registered on this connection which may have increased
1621            // the max cache size that is desired.
1622            if (mCacheSize + count < computeMaxCacheSizeLocked()) {
1623                reAllocateCacheLocked(scratch, count);
1624                return status_t(NO_ERROR);
1625            }
1626            // Some events need to be dropped.
1627            int remaningCacheSize = mMaxCacheSize - mCacheSize;
1628            if (remaningCacheSize != 0) {
1629                memcpy(&mEventCache[mCacheSize], scratch,
1630                                                remaningCacheSize * sizeof(sensors_event_t));
1631            }
1632            int numEventsDropped = count - remaningCacheSize;
1633            countFlushCompleteEventsLocked(mEventCache, numEventsDropped);
1634            // Drop the first "numEventsDropped" in the cache.
1635            memmove(mEventCache, &mEventCache[numEventsDropped],
1636                    (mCacheSize - numEventsDropped) * sizeof(sensors_event_t));
1637
1638            // Copy the remainingEvents in scratch buffer to the end of cache.
1639            memcpy(&mEventCache[mCacheSize - numEventsDropped], scratch + remaningCacheSize,
1640                                            numEventsDropped * sizeof(sensors_event_t));
1641        }
1642        return status_t(NO_ERROR);
1643    }
1644
1645    int index_wake_up_event = findWakeUpSensorEventLocked(scratch, count);
1646    if (index_wake_up_event >= 0) {
1647        scratch[index_wake_up_event].flags |= WAKE_UP_SENSOR_EVENT_NEEDS_ACK;
1648        ++mWakeLockRefCount;
1649#if DEBUG_CONNECTIONS
1650        ++mTotalAcksNeeded;
1651#endif
1652    }
1653
1654    // NOTE: ASensorEvent and sensors_event_t are the same type.
1655    ssize_t size = SensorEventQueue::write(mChannel,
1656                                    reinterpret_cast<ASensorEvent const*>(scratch), count);
1657    if (size < 0) {
1658        // Write error, copy events to local cache.
1659        if (index_wake_up_event >= 0) {
1660            // If there was a wake_up sensor_event, reset the flag.
1661            scratch[index_wake_up_event].flags &= ~WAKE_UP_SENSOR_EVENT_NEEDS_ACK;
1662            if (mWakeLockRefCount > 0) {
1663                --mWakeLockRefCount;
1664            }
1665#if DEBUG_CONNECTIONS
1666            --mTotalAcksNeeded;
1667#endif
1668        }
1669        if (mEventCache == NULL) {
1670            mMaxCacheSize = computeMaxCacheSizeLocked();
1671            mEventCache = new sensors_event_t[mMaxCacheSize];
1672            mCacheSize = 0;
1673        }
1674        memcpy(&mEventCache[mCacheSize], scratch, count * sizeof(sensors_event_t));
1675        mCacheSize += count;
1676
1677        // Add this file descriptor to the looper to get a callback when this fd is available for
1678        // writing.
1679        updateLooperRegistrationLocked(mService->getLooper());
1680        return size;
1681    }
1682
1683#if DEBUG_CONNECTIONS
1684    if (size > 0) {
1685        mEventsSent += count;
1686    }
1687#endif
1688
1689    return size < 0 ? status_t(size) : status_t(NO_ERROR);
1690}
1691
1692void SensorService::SensorEventConnection::reAllocateCacheLocked(sensors_event_t const* scratch,
1693                                                                 int count) {
1694    sensors_event_t *eventCache_new;
1695    const int new_cache_size = computeMaxCacheSizeLocked();
1696    // Allocate new cache, copy over events from the old cache & scratch, free up memory.
1697    eventCache_new = new sensors_event_t[new_cache_size];
1698    memcpy(eventCache_new, mEventCache, mCacheSize * sizeof(sensors_event_t));
1699    memcpy(&eventCache_new[mCacheSize], scratch, count * sizeof(sensors_event_t));
1700
1701    ALOGD_IF(DEBUG_CONNECTIONS, "reAllocateCacheLocked maxCacheSize=%d %d", mMaxCacheSize,
1702            new_cache_size);
1703
1704    delete mEventCache;
1705    mEventCache = eventCache_new;
1706    mCacheSize += count;
1707    mMaxCacheSize = new_cache_size;
1708}
1709
1710void SensorService::SensorEventConnection::sendPendingFlushEventsLocked() {
1711    ASensorEvent flushCompleteEvent;
1712    memset(&flushCompleteEvent, 0, sizeof(flushCompleteEvent));
1713    flushCompleteEvent.type = SENSOR_TYPE_META_DATA;
1714    // Loop through all the sensors for this connection and check if there are any pending
1715    // flush complete events to be sent.
1716    for (size_t i = 0; i < mSensorInfo.size(); ++i) {
1717        FlushInfo& flushInfo = mSensorInfo.editValueAt(i);
1718        while (flushInfo.mPendingFlushEventsToSend > 0) {
1719            const int sensor_handle = mSensorInfo.keyAt(i);
1720            flushCompleteEvent.meta_data.sensor = sensor_handle;
1721            bool wakeUpSensor = mService->getSensorFromHandle(sensor_handle).isWakeUpSensor();
1722            if (wakeUpSensor) {
1723               ++mWakeLockRefCount;
1724               flushCompleteEvent.flags |= WAKE_UP_SENSOR_EVENT_NEEDS_ACK;
1725            }
1726            ssize_t size = SensorEventQueue::write(mChannel, &flushCompleteEvent, 1);
1727            if (size < 0) {
1728                if (wakeUpSensor) --mWakeLockRefCount;
1729                return;
1730            }
1731            ALOGD_IF(DEBUG_CONNECTIONS, "sent dropped flush complete event==%d ",
1732                    flushCompleteEvent.meta_data.sensor);
1733            flushInfo.mPendingFlushEventsToSend--;
1734        }
1735    }
1736}
1737
1738void SensorService::SensorEventConnection::writeToSocketFromCache() {
1739    // At a time write at most half the size of the receiver buffer in SensorEventQueue OR
1740    // half the size of the socket buffer allocated in BitTube whichever is smaller.
1741    const int maxWriteSize = helpers::min(SensorEventQueue::MAX_RECEIVE_BUFFER_EVENT_COUNT/2,
1742            int(mService->mSocketBufferSize/(sizeof(sensors_event_t)*2)));
1743    Mutex::Autolock _l(mConnectionLock);
1744    // Send pending flush complete events (if any)
1745    sendPendingFlushEventsLocked();
1746    for (int numEventsSent = 0; numEventsSent < mCacheSize;) {
1747        const int numEventsToWrite = helpers::min(mCacheSize - numEventsSent, maxWriteSize);
1748        int index_wake_up_event =
1749                  findWakeUpSensorEventLocked(mEventCache + numEventsSent, numEventsToWrite);
1750        if (index_wake_up_event >= 0) {
1751            mEventCache[index_wake_up_event + numEventsSent].flags |=
1752                    WAKE_UP_SENSOR_EVENT_NEEDS_ACK;
1753            ++mWakeLockRefCount;
1754#if DEBUG_CONNECTIONS
1755            ++mTotalAcksNeeded;
1756#endif
1757        }
1758
1759        ssize_t size = SensorEventQueue::write(mChannel,
1760                          reinterpret_cast<ASensorEvent const*>(mEventCache + numEventsSent),
1761                          numEventsToWrite);
1762        if (size < 0) {
1763            if (index_wake_up_event >= 0) {
1764                // If there was a wake_up sensor_event, reset the flag.
1765                mEventCache[index_wake_up_event + numEventsSent].flags  &=
1766                        ~WAKE_UP_SENSOR_EVENT_NEEDS_ACK;
1767                if (mWakeLockRefCount > 0) {
1768                    --mWakeLockRefCount;
1769                }
1770#if DEBUG_CONNECTIONS
1771                --mTotalAcksNeeded;
1772#endif
1773            }
1774            memmove(mEventCache, &mEventCache[numEventsSent],
1775                                 (mCacheSize - numEventsSent) * sizeof(sensors_event_t));
1776            ALOGD_IF(DEBUG_CONNECTIONS, "wrote %d events from cache size==%d ",
1777                    numEventsSent, mCacheSize);
1778            mCacheSize -= numEventsSent;
1779            return;
1780        }
1781        numEventsSent += numEventsToWrite;
1782#if DEBUG_CONNECTIONS
1783        mEventsSentFromCache += numEventsToWrite;
1784#endif
1785    }
1786    ALOGD_IF(DEBUG_CONNECTIONS, "wrote all events from cache size=%d ", mCacheSize);
1787    // All events from the cache have been sent. Reset cache size to zero.
1788    mCacheSize = 0;
1789    // There are no more events in the cache. We don't need to poll for write on the fd.
1790    // Update Looper registration.
1791    updateLooperRegistrationLocked(mService->getLooper());
1792}
1793
1794void SensorService::SensorEventConnection::countFlushCompleteEventsLocked(
1795                sensors_event_t const* scratch, const int numEventsDropped) {
1796    ALOGD_IF(DEBUG_CONNECTIONS, "dropping %d events ", numEventsDropped);
1797    // Count flushComplete events in the events that are about to the dropped. These will be sent
1798    // separately before the next batch of events.
1799    for (int j = 0; j < numEventsDropped; ++j) {
1800        if (scratch[j].type == SENSOR_TYPE_META_DATA) {
1801            FlushInfo& flushInfo = mSensorInfo.editValueFor(scratch[j].meta_data.sensor);
1802            flushInfo.mPendingFlushEventsToSend++;
1803            ALOGD_IF(DEBUG_CONNECTIONS, "increment pendingFlushCount %d",
1804                     flushInfo.mPendingFlushEventsToSend);
1805        }
1806    }
1807    return;
1808}
1809
1810int SensorService::SensorEventConnection::findWakeUpSensorEventLocked(
1811                       sensors_event_t const* scratch, const int count) {
1812    for (int i = 0; i < count; ++i) {
1813        if (mService->isWakeUpSensorEvent(scratch[i])) {
1814            return i;
1815        }
1816    }
1817    return -1;
1818}
1819
1820sp<BitTube> SensorService::SensorEventConnection::getSensorChannel() const
1821{
1822    return mChannel;
1823}
1824
1825status_t SensorService::SensorEventConnection::enableDisable(
1826        int handle, bool enabled, nsecs_t samplingPeriodNs, nsecs_t maxBatchReportLatencyNs,
1827        int reservedFlags)
1828{
1829    status_t err;
1830    if (enabled) {
1831        err = mService->enable(this, handle, samplingPeriodNs, maxBatchReportLatencyNs,
1832                               reservedFlags, mOpPackageName);
1833
1834    } else {
1835        err = mService->disable(this, handle);
1836    }
1837    return err;
1838}
1839
1840status_t SensorService::SensorEventConnection::setEventRate(
1841        int handle, nsecs_t samplingPeriodNs)
1842{
1843    return mService->setEventRate(this, handle, samplingPeriodNs, mOpPackageName);
1844}
1845
1846status_t  SensorService::SensorEventConnection::flush() {
1847    return  mService->flushSensor(this, mOpPackageName);
1848}
1849
1850int SensorService::SensorEventConnection::handleEvent(int fd, int events, void* /*data*/) {
1851    if (events & ALOOPER_EVENT_HANGUP || events & ALOOPER_EVENT_ERROR) {
1852        {
1853            // If the Looper encounters some error, set the flag mDead, reset mWakeLockRefCount,
1854            // and remove the fd from Looper. Call checkWakeLockState to know if SensorService
1855            // can release the wake-lock.
1856            ALOGD_IF(DEBUG_CONNECTIONS, "%p Looper error %d", this, fd);
1857            Mutex::Autolock _l(mConnectionLock);
1858            mDead = true;
1859            mWakeLockRefCount = 0;
1860            updateLooperRegistrationLocked(mService->getLooper());
1861        }
1862        mService->checkWakeLockState();
1863        if (mDataInjectionMode) {
1864            // If the Looper has encountered some error in data injection mode, reset SensorService
1865            // back to normal mode.
1866            mService->resetToNormalMode();
1867            mDataInjectionMode = false;
1868        }
1869        return 1;
1870    }
1871
1872    if (events & ALOOPER_EVENT_INPUT) {
1873        unsigned char buf[sizeof(sensors_event_t)];
1874        ssize_t numBytesRead = ::recv(fd, buf, sizeof(buf), MSG_DONTWAIT);
1875        {
1876           Mutex::Autolock _l(mConnectionLock);
1877           if (numBytesRead == sizeof(sensors_event_t)) {
1878               if (!mDataInjectionMode) {
1879                   ALOGE("Data injected in normal mode, dropping event"
1880                         "package=%s uid=%d", mPackageName.string(), mUid);
1881                   // Unregister call backs.
1882                   return 0;
1883               }
1884               SensorDevice& dev(SensorDevice::getInstance());
1885               sensors_event_t sensor_event;
1886               memset(&sensor_event, 0, sizeof(sensor_event));
1887               memcpy(&sensor_event, buf, sizeof(sensors_event_t));
1888               Sensor sensor = mService->getSensorFromHandle(sensor_event.sensor);
1889               sensor_event.type = sensor.getType();
1890               dev.injectSensorData(&sensor_event);
1891#if DEBUG_CONNECTIONS
1892               ++mEventsReceived;
1893#endif
1894           } else if (numBytesRead == sizeof(uint32_t)) {
1895               uint32_t numAcks = 0;
1896               memcpy(&numAcks, buf, numBytesRead);
1897               // Sanity check to ensure  there are no read errors in recv, numAcks is always
1898               // within the range and not zero. If any of the above don't hold reset
1899               // mWakeLockRefCount to zero.
1900               if (numAcks > 0 && numAcks < mWakeLockRefCount) {
1901                   mWakeLockRefCount -= numAcks;
1902               } else {
1903                   mWakeLockRefCount = 0;
1904               }
1905#if DEBUG_CONNECTIONS
1906               mTotalAcksReceived += numAcks;
1907#endif
1908           } else {
1909               // Read error, reset wakelock refcount.
1910               mWakeLockRefCount = 0;
1911           }
1912        }
1913        // Check if wakelock can be released by sensorservice. mConnectionLock needs to be released
1914        // here as checkWakeLockState() will need it.
1915        if (mWakeLockRefCount == 0) {
1916            mService->checkWakeLockState();
1917        }
1918        // continue getting callbacks.
1919        return 1;
1920    }
1921
1922    if (events & ALOOPER_EVENT_OUTPUT) {
1923        // send sensor data that is stored in mEventCache for this connection.
1924        mService->sendEventsFromCache(this);
1925    }
1926    return 1;
1927}
1928
1929int SensorService::SensorEventConnection::computeMaxCacheSizeLocked() const {
1930    size_t fifoWakeUpSensors = 0;
1931    size_t fifoNonWakeUpSensors = 0;
1932    for (size_t i = 0; i < mSensorInfo.size(); ++i) {
1933        const Sensor& sensor = mService->getSensorFromHandle(mSensorInfo.keyAt(i));
1934        if (sensor.getFifoReservedEventCount() == sensor.getFifoMaxEventCount()) {
1935            // Each sensor has a reserved fifo. Sum up the fifo sizes for all wake up sensors and
1936            // non wake_up sensors.
1937            if (sensor.isWakeUpSensor()) {
1938                fifoWakeUpSensors += sensor.getFifoReservedEventCount();
1939            } else {
1940                fifoNonWakeUpSensors += sensor.getFifoReservedEventCount();
1941            }
1942        } else {
1943            // Shared fifo. Compute the max of the fifo sizes for wake_up and non_wake up sensors.
1944            if (sensor.isWakeUpSensor()) {
1945                fifoWakeUpSensors = fifoWakeUpSensors > sensor.getFifoMaxEventCount() ?
1946                                          fifoWakeUpSensors : sensor.getFifoMaxEventCount();
1947
1948            } else {
1949                fifoNonWakeUpSensors = fifoNonWakeUpSensors > sensor.getFifoMaxEventCount() ?
1950                                          fifoNonWakeUpSensors : sensor.getFifoMaxEventCount();
1951
1952            }
1953        }
1954   }
1955   if (fifoWakeUpSensors + fifoNonWakeUpSensors == 0) {
1956       // It is extremely unlikely that there is a write failure in non batch mode. Return a cache
1957       // size that is equal to that of the batch mode.
1958       // ALOGW("Write failure in non-batch mode");
1959       return MAX_SOCKET_BUFFER_SIZE_BATCHED/sizeof(sensors_event_t);
1960   }
1961   return fifoWakeUpSensors + fifoNonWakeUpSensors;
1962}
1963
1964// ---------------------------------------------------------------------------
1965}; // namespace android
1966
1967