Fix deadlock on SensorService
If mLock is held by SensorService::threadLoop(), and a new call
from SensorEventConnection comes in to e.g. enable/disable a sensor,
this thread must wait for the mLock to be released. However, if this
thread holds mConnectionLock in SensorEventConnection, and SensorService
invokes SensorEventConnection.sendEvent, the system will come into a
deadlock because both threads are waiting for each other.
To avoid this situation unlock SensotEventConnection's mConnectionLock
while going out of scope.
Also create separate mutexes for modifying mSensorInfo and
mSensorInfoBackup for better separation.
Bug: 153188258
Test: 1) Run sensor logger and enable sensor, put app in background.
2) Open a_sns_test and start streaming sensor samples
3) Open app again and verify no system ANR, sensor samples
continue to be received on app.
Change-Id: If137f39918a8b1148dcc00f1b1d82b4454bb5c7b
diff --git a/services/sensorservice/SensorEventConnection.cpp b/services/sensorservice/SensorEventConnection.cpp
index 77d8c11..5be4ccd 100644
--- a/services/sensorservice/SensorEventConnection.cpp
+++ b/services/sensorservice/SensorEventConnection.cpp
@@ -70,17 +70,16 @@
}
bool SensorService::SensorEventConnection::needsWakeLock() {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
return !mDead && mWakeLockRefCount > 0;
}
void SensorService::SensorEventConnection::resetWakeLockRefCount() {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
mWakeLockRefCount = 0;
}
void SensorService::SensorEventConnection::dump(String8& result) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
result.appendFormat("\tOperating Mode: ");
if (!mService->isWhiteListedPackage(getPackageName())) {
result.append("RESTRICTED\n");
@@ -92,6 +91,8 @@
result.appendFormat("\t %s | WakeLockRefCount %d | uid %d | cache size %d | "
"max cache size %d\n", mPackageName.string(), mWakeLockRefCount, mUid, mCacheSize,
mMaxCacheSize);
+
+ std::lock_guard<std::mutex> _l(mConnectionLock);
for (auto& it : mSensorInfo) {
const FlushInfo& flushInfo = it.second.flushInfo;
result.appendFormat("\t %s 0x%08x | status: %s | pending flush events %d \n",
@@ -122,7 +123,7 @@
*/
void SensorService::SensorEventConnection::dump(util::ProtoOutputStream* proto) const {
using namespace service::SensorEventConnectionProto;
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (!mService->isWhiteListedPackage(getPackageName())) {
proto->write(OPERATING_MODE, OP_MODE_RESTRICTED);
@@ -160,7 +161,7 @@
bool SensorService::SensorEventConnection::addSensor(
int32_t handle, nsecs_t samplingPeriodNs, nsecs_t maxBatchReportLatencyNs, int reservedFlags) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
sp<SensorInterface> si = mService->getSensorInterfaceFromHandle(handle);
if (si == nullptr ||
!canAccessSensor(si->getSensor(), "Tried adding", mOpPackageName) ||
@@ -179,12 +180,12 @@
}
bool SensorService::SensorEventConnection::removeSensor(int32_t handle) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
return mSensorInfo.erase(handle) > 0;
}
std::vector<int32_t> SensorService::SensorEventConnection::getActiveSensorHandles() const {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
std::vector<int32_t> list;
for (auto& it : mSensorInfo) {
list.push_back(it.first);
@@ -193,17 +194,19 @@
}
bool SensorService::SensorEventConnection::hasSensor(int32_t handle) const {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::recursive_mutex> _backlock(mBackupLock);
+ std::lock_guard<std::mutex> _lock(mConnectionLock);
return mSensorInfo.count(handle) + mSensorInfoBackup.count(handle) > 0;
}
bool SensorService::SensorEventConnection::hasAnySensor() const {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::recursive_mutex> _backlock(mBackupLock);
+ std::lock_guard<std::mutex> _lock(mConnectionLock);
return mSensorInfo.size() + mSensorInfoBackup.size() ? true : false;
}
bool SensorService::SensorEventConnection::hasOneShotSensors() const {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
for (auto &it : mSensorInfo) {
const int handle = it.first;
sp<SensorInterface> si = mService->getSensorInterfaceFromHandle(handle);
@@ -220,7 +223,7 @@
void SensorService::SensorEventConnection::setFirstFlushPending(int32_t handle,
bool value) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (mSensorInfo.count(handle) > 0) {
FlushInfo& flushInfo = mSensorInfo[handle].flushInfo;
flushInfo.mFirstFlushPending = value;
@@ -228,7 +231,7 @@
}
void SensorService::SensorEventConnection::updateLooperRegistration(const sp<Looper>& looper) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
updateLooperRegistrationLocked(looper);
}
@@ -279,7 +282,7 @@
}
void SensorService::SensorEventConnection::incrementPendingFlushCount(int32_t handle) {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (mSensorInfo.count(handle) > 0) {
FlushInfo& flushInfo = mSensorInfo[handle].flushInfo;
flushInfo.mPendingFlushEventsToSend++;
@@ -295,7 +298,7 @@
std::unique_ptr<sensors_event_t[]> sanitizedBuffer;
int count = 0;
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (scratch) {
size_t i=0;
while (i<numEvents) {
@@ -453,11 +456,18 @@
}
void SensorService::SensorEventConnection::stopAll() {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
- if (!mSensorInfo.empty()) {
- mSensorInfoBackup = mSensorInfo;
- mSensorInfo.clear();
+ bool backupPerformed = false;
+ std::lock_guard<std::recursive_mutex> _backlock(mBackupLock);
+ {
+ std::lock_guard<std::mutex> _lock(mConnectionLock);
+ if (!mSensorInfo.empty()) {
+ mSensorInfoBackup = mSensorInfo;
+ mSensorInfo.clear();
+ backupPerformed = true;
+ }
+ }
+ if (backupPerformed) {
for (auto& it : mSensorInfoBackup) {
int32_t handle = it.first;
@@ -471,7 +481,7 @@
}
void SensorService::SensorEventConnection::recoverAll() {
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::recursive_mutex> _l(mBackupLock);
for (auto& it : mSensorInfoBackup) {
int32_t handle = it.first;
SensorRequest &request = it.second;
@@ -612,7 +622,7 @@
// half the size of the socket buffer allocated in BitTube whichever is smaller.
const int maxWriteSize = helpers::min(SensorEventQueue::MAX_RECEIVE_BUFFER_EVENT_COUNT/2,
int(mService->mSocketBufferSize/(sizeof(sensors_event_t)*2)));
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
// Send pending flush complete events (if any)
sendPendingFlushEventsLocked();
for (int numEventsSent = 0; numEventsSent < mCacheSize;) {
@@ -724,7 +734,7 @@
{
status_t err = mService->setEventRate(this, handle, samplingPeriodNs, mOpPackageName);
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (err == NO_ERROR && mSensorInfo.count(handle) > 0) {
mSensorInfo[handle].samplingPeriodNs = samplingPeriodNs;
}
@@ -750,7 +760,7 @@
// and remove the fd from Looper. Call checkWakeLockState to know if SensorService
// can release the wake-lock.
ALOGD_IF(DEBUG_CONNECTIONS, "%p Looper error %d", this, fd);
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
mDead = true;
mWakeLockRefCount = 0;
updateLooperRegistrationLocked(mService->getLooper());
@@ -769,7 +779,7 @@
unsigned char buf[sizeof(sensors_event_t)];
ssize_t numBytesRead = ::recv(fd, buf, sizeof(buf), MSG_DONTWAIT);
{
- std::lock_guard<std::recursive_mutex> _l(mConnectionLock);
+ std::lock_guard<std::mutex> _l(mConnectionLock);
if (numBytesRead == sizeof(sensors_event_t)) {
if (!mDataInjectionMode) {
ALOGE("Data injected in normal mode, dropping event"