diff --git a/automotive/vehicle/2.0/types.hal b/automotive/vehicle/2.0/types.hal
index 1355d9f..bc0b4d3 100644
--- a/automotive/vehicle/2.0/types.hal
+++ b/automotive/vehicle/2.0/types.hal
@@ -2569,6 +2569,11 @@
 
     /** AP can only shutdown with postponing allowed. */
     SHUTDOWN_ONLY = 3,
+
+    /**
+     * AP may enter deep sleep, but must either sleep or shut down immediately.
+     * Postponing is not allowed. */
+    SLEEP_IMMEDIATELY = 4,
 };
 
 enum VehicleApPowerStateReport : int32_t {
@@ -3581,4 +3586,3 @@
 enum VmsPublisherInformationIntegerValuesIndex : VmsBaseMessageIntegerValuesIndex {
     PUBLISHER_ID = 1,
 };
-
diff --git a/health/2.0/default/Android.bp b/health/2.0/default/Android.bp
index 1c455d3..3c5877e 100644
--- a/health/2.0/default/Android.bp
+++ b/health/2.0/default/Android.bp
@@ -31,7 +31,11 @@
     vendor_available: true,
     srcs: [
         "Health.cpp",
-        "healthd_common.cpp",
+        "healthd_common_adapter.cpp",
+    ],
+
+    whole_static_libs: [
+        "libhealthloop",
     ],
 
     export_include_dirs: ["include"],
diff --git a/health/2.0/default/healthd_common.cpp b/health/2.0/default/healthd_common.cpp
deleted file mode 100644
index b5fdc8e..0000000
--- a/health/2.0/default/healthd_common.cpp
+++ /dev/null
@@ -1,273 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "android.hardware.health@2.0-impl"
-#define KLOG_LEVEL 6
-
-#include <healthd/BatteryMonitor.h>
-#include <healthd/healthd.h>
-
-#include <batteryservice/BatteryService.h>
-#include <cutils/klog.h>
-#include <cutils/uevent.h>
-#include <errno.h>
-#include <libgen.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/epoll.h>
-#include <sys/timerfd.h>
-#include <unistd.h>
-#include <utils/Errors.h>
-
-#include <health2/Health.h>
-
-using namespace android;
-
-// Periodic chores fast interval in seconds
-#define DEFAULT_PERIODIC_CHORES_INTERVAL_FAST (60 * 1)
-// Periodic chores fast interval in seconds
-#define DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW (60 * 10)
-
-static struct healthd_config healthd_config = {
-    .periodic_chores_interval_fast = DEFAULT_PERIODIC_CHORES_INTERVAL_FAST,
-    .periodic_chores_interval_slow = DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW,
-    .batteryStatusPath = String8(String8::kEmptyString),
-    .batteryHealthPath = String8(String8::kEmptyString),
-    .batteryPresentPath = String8(String8::kEmptyString),
-    .batteryCapacityPath = String8(String8::kEmptyString),
-    .batteryVoltagePath = String8(String8::kEmptyString),
-    .batteryTemperaturePath = String8(String8::kEmptyString),
-    .batteryTechnologyPath = String8(String8::kEmptyString),
-    .batteryCurrentNowPath = String8(String8::kEmptyString),
-    .batteryCurrentAvgPath = String8(String8::kEmptyString),
-    .batteryChargeCounterPath = String8(String8::kEmptyString),
-    .batteryFullChargePath = String8(String8::kEmptyString),
-    .batteryCycleCountPath = String8(String8::kEmptyString),
-    .energyCounter = NULL,
-    .boot_min_cap = 0,
-    .screen_on = NULL,
-};
-
-static int eventct;
-static int epollfd;
-
-#define POWER_SUPPLY_SUBSYSTEM "power_supply"
-
-static int uevent_fd;
-static int wakealarm_fd;
-
-// -1 for no epoll timeout
-static int awake_poll_interval = -1;
-
-static int wakealarm_wake_interval = DEFAULT_PERIODIC_CHORES_INTERVAL_FAST;
-
-using ::android::hardware::health::V2_0::implementation::Health;
-
-struct healthd_mode_ops* healthd_mode_ops = nullptr;
-
-int healthd_register_event(int fd, void (*handler)(uint32_t), EventWakeup wakeup) {
-    struct epoll_event ev;
-
-    ev.events = EPOLLIN;
-
-    if (wakeup == EVENT_WAKEUP_FD) ev.events |= EPOLLWAKEUP;
-
-    ev.data.ptr = (void*)handler;
-    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) == -1) {
-        KLOG_ERROR(LOG_TAG, "epoll_ctl failed; errno=%d\n", errno);
-        return -1;
-    }
-
-    eventct++;
-    return 0;
-}
-
-static void wakealarm_set_interval(int interval) {
-    struct itimerspec itval;
-
-    if (wakealarm_fd == -1) return;
-
-    wakealarm_wake_interval = interval;
-
-    if (interval == -1) interval = 0;
-
-    itval.it_interval.tv_sec = interval;
-    itval.it_interval.tv_nsec = 0;
-    itval.it_value.tv_sec = interval;
-    itval.it_value.tv_nsec = 0;
-
-    if (timerfd_settime(wakealarm_fd, 0, &itval, NULL) == -1)
-        KLOG_ERROR(LOG_TAG, "wakealarm_set_interval: timerfd_settime failed\n");
-}
-
-void healthd_battery_update_internal(bool charger_online) {
-    // Fast wake interval when on charger (watch for overheat);
-    // slow wake interval when on battery (watch for drained battery).
-
-    int new_wake_interval = charger_online ? healthd_config.periodic_chores_interval_fast
-                                           : healthd_config.periodic_chores_interval_slow;
-
-    if (new_wake_interval != wakealarm_wake_interval) wakealarm_set_interval(new_wake_interval);
-
-    // During awake periods poll at fast rate.  If wake alarm is set at fast
-    // rate then just use the alarm; if wake alarm is set at slow rate then
-    // poll at fast rate while awake and let alarm wake up at slow rate when
-    // asleep.
-
-    if (healthd_config.periodic_chores_interval_fast == -1)
-        awake_poll_interval = -1;
-    else
-        awake_poll_interval = new_wake_interval == healthd_config.periodic_chores_interval_fast
-                                  ? -1
-                                  : healthd_config.periodic_chores_interval_fast * 1000;
-}
-
-static void healthd_battery_update(void) {
-    Health::getImplementation()->update();
-}
-
-static void periodic_chores() {
-    healthd_battery_update();
-}
-
-#define UEVENT_MSG_LEN 2048
-static void uevent_event(uint32_t /*epevents*/) {
-    char msg[UEVENT_MSG_LEN + 2];
-    char* cp;
-    int n;
-
-    n = uevent_kernel_multicast_recv(uevent_fd, msg, UEVENT_MSG_LEN);
-    if (n <= 0) return;
-    if (n >= UEVENT_MSG_LEN) /* overflow -- discard */
-        return;
-
-    msg[n] = '\0';
-    msg[n + 1] = '\0';
-    cp = msg;
-
-    while (*cp) {
-        if (!strcmp(cp, "SUBSYSTEM=" POWER_SUPPLY_SUBSYSTEM)) {
-            healthd_battery_update();
-            break;
-        }
-
-        /* advance to after the next \0 */
-        while (*cp++)
-            ;
-    }
-}
-
-static void uevent_init(void) {
-    uevent_fd = uevent_open_socket(64 * 1024, true);
-
-    if (uevent_fd < 0) {
-        KLOG_ERROR(LOG_TAG, "uevent_init: uevent_open_socket failed\n");
-        return;
-    }
-
-    fcntl(uevent_fd, F_SETFL, O_NONBLOCK);
-    if (healthd_register_event(uevent_fd, uevent_event, EVENT_WAKEUP_FD))
-        KLOG_ERROR(LOG_TAG, "register for uevent events failed\n");
-}
-
-static void wakealarm_event(uint32_t /*epevents*/) {
-    unsigned long long wakeups;
-
-    if (read(wakealarm_fd, &wakeups, sizeof(wakeups)) == -1) {
-        KLOG_ERROR(LOG_TAG, "wakealarm_event: read wakealarm fd failed\n");
-        return;
-    }
-
-    periodic_chores();
-}
-
-static void wakealarm_init(void) {
-    wakealarm_fd = timerfd_create(CLOCK_BOOTTIME_ALARM, TFD_NONBLOCK);
-    if (wakealarm_fd == -1) {
-        KLOG_ERROR(LOG_TAG, "wakealarm_init: timerfd_create failed\n");
-        return;
-    }
-
-    if (healthd_register_event(wakealarm_fd, wakealarm_event, EVENT_WAKEUP_FD))
-        KLOG_ERROR(LOG_TAG, "Registration of wakealarm event failed\n");
-
-    wakealarm_set_interval(healthd_config.periodic_chores_interval_fast);
-}
-
-static void healthd_mainloop(void) {
-    int nevents = 0;
-    while (1) {
-        struct epoll_event events[eventct];
-        int timeout = awake_poll_interval;
-        int mode_timeout;
-
-        /* Don't wait for first timer timeout to run periodic chores */
-        if (!nevents) periodic_chores();
-
-        healthd_mode_ops->heartbeat();
-
-        mode_timeout = healthd_mode_ops->preparetowait();
-        if (timeout < 0 || (mode_timeout > 0 && mode_timeout < timeout)) timeout = mode_timeout;
-        nevents = epoll_wait(epollfd, events, eventct, timeout);
-        if (nevents == -1) {
-            if (errno == EINTR) continue;
-            KLOG_ERROR(LOG_TAG, "healthd_mainloop: epoll_wait failed\n");
-            break;
-        }
-
-        for (int n = 0; n < nevents; ++n) {
-            if (events[n].data.ptr) (*(void (*)(int))events[n].data.ptr)(events[n].events);
-        }
-    }
-
-    return;
-}
-
-static int healthd_init() {
-    epollfd = epoll_create1(EPOLL_CLOEXEC);
-    if (epollfd == -1) {
-        KLOG_ERROR(LOG_TAG, "epoll_create1 failed; errno=%d\n", errno);
-        return -1;
-    }
-
-    healthd_mode_ops->init(&healthd_config);
-    wakealarm_init();
-    uevent_init();
-
-    return 0;
-}
-
-int healthd_main() {
-    int ret;
-
-    klog_set_level(KLOG_LEVEL);
-
-    if (!healthd_mode_ops) {
-        KLOG_ERROR("healthd ops not set, exiting\n");
-        exit(1);
-    }
-
-    ret = healthd_init();
-    if (ret) {
-        KLOG_ERROR("Initialization failed, exiting\n");
-        exit(2);
-    }
-
-    healthd_mainloop();
-    KLOG_ERROR("Main loop terminated, exiting\n");
-    return 3;
-}
diff --git a/health/2.0/default/healthd_common_adapter.cpp b/health/2.0/default/healthd_common_adapter.cpp
new file mode 100644
index 0000000..8fc689d
--- /dev/null
+++ b/health/2.0/default/healthd_common_adapter.cpp
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Support legacy functions in healthd/healthd.h using healthd_mode_ops.
+// New code should use HealthLoop directly instead.
+
+#include <memory>
+
+#include <cutils/klog.h>
+#include <health/HealthLoop.h>
+#include <health2/Health.h>
+#include <healthd/healthd.h>
+
+using android::hardware::health::HealthLoop;
+using android::hardware::health::V2_0::implementation::Health;
+
+struct healthd_mode_ops* healthd_mode_ops = nullptr;
+
+// Adapter of HealthLoop to use legacy healthd_mode_ops.
+class HealthLoopAdapter : public HealthLoop {
+   public:
+    // Expose internal functions, assuming clients calls them in the same thread
+    // where StartLoop is called.
+    int RegisterEvent(int fd, BoundFunction func, EventWakeup wakeup) {
+        return HealthLoop::RegisterEvent(fd, func, wakeup);
+    }
+    void AdjustWakealarmPeriods(bool charger_online) {
+        return HealthLoop::AdjustWakealarmPeriods(charger_online);
+    }
+   protected:
+    void Init(healthd_config* config) override { healthd_mode_ops->init(config); }
+    void Heartbeat() override { healthd_mode_ops->heartbeat(); }
+    int PrepareToWait() override { return healthd_mode_ops->preparetowait(); }
+    void ScheduleBatteryUpdate() override { Health::getImplementation()->update(); }
+};
+static std::unique_ptr<HealthLoopAdapter> health_loop;
+
+int healthd_register_event(int fd, void (*handler)(uint32_t), EventWakeup wakeup) {
+    auto wrapped_handler = [handler](auto*, uint32_t epevents) { handler(epevents); };
+    return health_loop->RegisterEvent(fd, wrapped_handler, wakeup);
+}
+
+void healthd_battery_update_internal(bool charger_online) {
+    health_loop->AdjustWakealarmPeriods(charger_online);
+}
+
+int healthd_main() {
+    if (!healthd_mode_ops) {
+        KLOG_ERROR("healthd ops not set, exiting\n");
+        exit(1);
+    }
+
+    health_loop = std::make_unique<HealthLoopAdapter>();
+
+    int ret = health_loop->StartLoop();
+
+    // Should not reach here. The following will exit().
+    health_loop.reset();
+
+    return ret;
+}
diff --git a/health/utils/libhealthloop/Android.bp b/health/utils/libhealthloop/Android.bp
new file mode 100644
index 0000000..de0f24f
--- /dev/null
+++ b/health/utils/libhealthloop/Android.bp
@@ -0,0 +1,35 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+cc_library_static {
+    name: "libhealthloop",
+    vendor_available: true,
+    recovery_available: true,
+    srcs: [
+        "HealthLoop.cpp",
+        "utils.cpp",
+    ],
+    shared_libs: [
+        "libcutils",
+        "libbase",
+    ],
+    header_libs: [
+        "libbatteryservice_headers",
+        "libhealthd_headers",
+        "libutils_headers",
+    ],
+    export_include_dirs: [
+        "include",
+    ],
+}
diff --git a/health/utils/libhealthloop/HealthLoop.cpp b/health/utils/libhealthloop/HealthLoop.cpp
new file mode 100644
index 0000000..3f4b5bc
--- /dev/null
+++ b/health/utils/libhealthloop/HealthLoop.cpp
@@ -0,0 +1,267 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "HealthLoop"
+#define KLOG_LEVEL 6
+
+#include <health/HealthLoop.h>
+
+#include <errno.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/timerfd.h>
+#include <unistd.h>
+
+#include <android-base/logging.h>
+#include <batteryservice/BatteryService.h>
+#include <cutils/klog.h>
+#include <cutils/uevent.h>
+#include <healthd/healthd.h>
+#include <utils/Errors.h>
+
+#include <health/utils.h>
+
+using namespace android;
+using namespace std::chrono_literals;
+
+#define POWER_SUPPLY_SUBSYSTEM "power_supply"
+
+namespace android {
+namespace hardware {
+namespace health {
+
+HealthLoop::HealthLoop() {
+    InitHealthdConfig(&healthd_config_);
+    awake_poll_interval_ = -1;
+    wakealarm_wake_interval_ = healthd_config_.periodic_chores_interval_fast;
+}
+
+HealthLoop::~HealthLoop() {
+    LOG(FATAL) << "HealthLoop cannot be destroyed";
+}
+
+int HealthLoop::RegisterEvent(int fd, BoundFunction func, EventWakeup wakeup) {
+    CHECK(!reject_event_register_);
+
+    auto* event_handler =
+            event_handlers_
+                    .emplace_back(std::make_unique<EventHandler>(EventHandler{this, fd, func}))
+                    .get();
+
+    struct epoll_event ev;
+
+    ev.events = EPOLLIN;
+
+    if (wakeup == EVENT_WAKEUP_FD) ev.events |= EPOLLWAKEUP;
+
+    ev.data.ptr = reinterpret_cast<void*>(event_handler);
+
+    if (epoll_ctl(epollfd_, EPOLL_CTL_ADD, fd, &ev) == -1) {
+        KLOG_ERROR(LOG_TAG, "epoll_ctl failed; errno=%d\n", errno);
+        return -1;
+    }
+
+    return 0;
+}
+
+void HealthLoop::WakeAlarmSetInterval(int interval) {
+    struct itimerspec itval;
+
+    if (wakealarm_fd_ == -1) return;
+
+    wakealarm_wake_interval_ = interval;
+
+    if (interval == -1) interval = 0;
+
+    itval.it_interval.tv_sec = interval;
+    itval.it_interval.tv_nsec = 0;
+    itval.it_value.tv_sec = interval;
+    itval.it_value.tv_nsec = 0;
+
+    if (timerfd_settime(wakealarm_fd_, 0, &itval, NULL) == -1)
+        KLOG_ERROR(LOG_TAG, "wakealarm_set_interval: timerfd_settime failed\n");
+}
+
+void HealthLoop::AdjustWakealarmPeriods(bool charger_online) {
+    // Fast wake interval when on charger (watch for overheat);
+    // slow wake interval when on battery (watch for drained battery).
+
+    int new_wake_interval = charger_online ? healthd_config_.periodic_chores_interval_fast
+                                           : healthd_config_.periodic_chores_interval_slow;
+
+    if (new_wake_interval != wakealarm_wake_interval_) WakeAlarmSetInterval(new_wake_interval);
+
+    // During awake periods poll at fast rate.  If wake alarm is set at fast
+    // rate then just use the alarm; if wake alarm is set at slow rate then
+    // poll at fast rate while awake and let alarm wake up at slow rate when
+    // asleep.
+
+    if (healthd_config_.periodic_chores_interval_fast == -1)
+        awake_poll_interval_ = -1;
+    else
+        awake_poll_interval_ = new_wake_interval == healthd_config_.periodic_chores_interval_fast
+                                       ? -1
+                                       : healthd_config_.periodic_chores_interval_fast * 1000;
+}
+
+void HealthLoop::PeriodicChores() {
+    ScheduleBatteryUpdate();
+}
+
+// TODO(b/140330870): Use BPF instead.
+#define UEVENT_MSG_LEN 2048
+void HealthLoop::UeventEvent(uint32_t /*epevents*/) {
+    // No need to lock because uevent_fd_ is guaranteed to be initialized.
+
+    char msg[UEVENT_MSG_LEN + 2];
+    char* cp;
+    int n;
+
+    n = uevent_kernel_multicast_recv(uevent_fd_, msg, UEVENT_MSG_LEN);
+    if (n <= 0) return;
+    if (n >= UEVENT_MSG_LEN) /* overflow -- discard */
+        return;
+
+    msg[n] = '\0';
+    msg[n + 1] = '\0';
+    cp = msg;
+
+    while (*cp) {
+        if (!strcmp(cp, "SUBSYSTEM=" POWER_SUPPLY_SUBSYSTEM)) {
+            ScheduleBatteryUpdate();
+            break;
+        }
+
+        /* advance to after the next \0 */
+        while (*cp++)
+            ;
+    }
+}
+
+void HealthLoop::UeventInit(void) {
+    uevent_fd_.reset(uevent_open_socket(64 * 1024, true));
+
+    if (uevent_fd_ < 0) {
+        KLOG_ERROR(LOG_TAG, "uevent_init: uevent_open_socket failed\n");
+        return;
+    }
+
+    fcntl(uevent_fd_, F_SETFL, O_NONBLOCK);
+    if (RegisterEvent(uevent_fd_, &HealthLoop::UeventEvent, EVENT_WAKEUP_FD))
+        KLOG_ERROR(LOG_TAG, "register for uevent events failed\n");
+}
+
+void HealthLoop::WakeAlarmEvent(uint32_t /*epevents*/) {
+    // No need to lock because wakealarm_fd_ is guaranteed to be initialized.
+
+    unsigned long long wakeups;
+
+    if (read(wakealarm_fd_, &wakeups, sizeof(wakeups)) == -1) {
+        KLOG_ERROR(LOG_TAG, "wakealarm_event: read wakealarm fd failed\n");
+        return;
+    }
+
+    PeriodicChores();
+}
+
+void HealthLoop::WakeAlarmInit(void) {
+    wakealarm_fd_.reset(timerfd_create(CLOCK_BOOTTIME_ALARM, TFD_NONBLOCK));
+    if (wakealarm_fd_ == -1) {
+        KLOG_ERROR(LOG_TAG, "wakealarm_init: timerfd_create failed\n");
+        return;
+    }
+
+    if (RegisterEvent(wakealarm_fd_, &HealthLoop::WakeAlarmEvent, EVENT_WAKEUP_FD))
+        KLOG_ERROR(LOG_TAG, "Registration of wakealarm event failed\n");
+
+    WakeAlarmSetInterval(healthd_config_.periodic_chores_interval_fast);
+}
+
+void HealthLoop::MainLoop(void) {
+    int nevents = 0;
+    while (1) {
+        reject_event_register_ = true;
+        size_t eventct = event_handlers_.size();
+        struct epoll_event events[eventct];
+        int timeout = awake_poll_interval_;
+
+        int mode_timeout;
+
+        /* Don't wait for first timer timeout to run periodic chores */
+        if (!nevents) PeriodicChores();
+
+        Heartbeat();
+
+        mode_timeout = PrepareToWait();
+        if (timeout < 0 || (mode_timeout > 0 && mode_timeout < timeout)) timeout = mode_timeout;
+        nevents = epoll_wait(epollfd_, events, eventct, timeout);
+        if (nevents == -1) {
+            if (errno == EINTR) continue;
+            KLOG_ERROR(LOG_TAG, "healthd_mainloop: epoll_wait failed\n");
+            break;
+        }
+
+        for (int n = 0; n < nevents; ++n) {
+            if (events[n].data.ptr) {
+                auto* event_handler = reinterpret_cast<EventHandler*>(events[n].data.ptr);
+                event_handler->func(event_handler->object, events[n].events);
+            }
+        }
+    }
+
+    return;
+}
+
+int HealthLoop::InitInternal() {
+    epollfd_.reset(epoll_create1(EPOLL_CLOEXEC));
+    if (epollfd_ == -1) {
+        KLOG_ERROR(LOG_TAG, "epoll_create1 failed; errno=%d\n", errno);
+        return -1;
+    }
+
+    // Call subclass's init for any additional init steps.
+    // Note that healthd_config_ is initialized before wakealarm_fd_; see
+    // AdjustUeventWakealarmPeriods().
+    Init(&healthd_config_);
+
+    WakeAlarmInit();
+    UeventInit();
+
+    return 0;
+}
+
+int HealthLoop::StartLoop() {
+    int ret;
+
+    klog_set_level(KLOG_LEVEL);
+
+    ret = InitInternal();
+    if (ret) {
+        KLOG_ERROR(LOG_TAG, "Initialization failed, exiting\n");
+        return 2;
+    }
+
+    MainLoop();
+    KLOG_ERROR(LOG_TAG, "Main loop terminated, exiting\n");
+    return 3;
+}
+
+}  // namespace health
+}  // namespace hardware
+}  // namespace android
diff --git a/health/utils/libhealthloop/include/health/HealthLoop.h b/health/utils/libhealthloop/include/health/HealthLoop.h
new file mode 100644
index 0000000..693e6cb
--- /dev/null
+++ b/health/utils/libhealthloop/include/health/HealthLoop.h
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include <memory>
+#include <mutex>
+#include <vector>
+
+#include <android-base/unique_fd.h>
+#include <healthd/healthd.h>
+
+namespace android {
+namespace hardware {
+namespace health {
+
+class HealthLoop {
+  public:
+    HealthLoop();
+
+    // Client is responsible for holding this forever. Process will exit
+    // when this is destroyed.
+    virtual ~HealthLoop();
+
+    // Initialize and start the main loop. This function does not exit unless
+    // the process is interrupted.
+    // Once the loop is started, event handlers are no longer allowed to be
+    // registered.
+    int StartLoop();
+
+  protected:
+    // healthd_mode_ops overrides. Note that healthd_mode_ops->battery_update
+    // is missing because it is only used by BatteryMonitor.
+    // Init is called right after epollfd_ is initialized (so RegisterEvent
+    // is allowed) but before other things are initialized (so SetChargerOnline
+    // is not allowed.)
+    virtual void Init(healthd_config* config) = 0;
+    virtual void Heartbeat() = 0;
+    virtual int PrepareToWait() = 0;
+
+    // Note that this is NOT healthd_mode_ops->battery_update(BatteryProperties*),
+    // which is called by BatteryMonitor after values are fetched. This is the
+    // implementation of healthd_battery_update(), which calls
+    // the correct IHealth::update(),
+    // which calls BatteryMonitor::update(), which calls
+    // healthd_mode_ops->battery_update(BatteryProperties*).
+    virtual void ScheduleBatteryUpdate() = 0;
+
+    // Register an epoll event. When there is an event, |func| will be
+    // called with |this| as the first argument and |epevents| as the second.
+    // This may be called in a different thread from where StartLoop is called
+    // (for obvious reasons; StartLoop never ends).
+    // Once the loop is started, event handlers are no longer allowed to be
+    // registered.
+    using BoundFunction = std::function<void(HealthLoop*, uint32_t /* epevents */)>;
+    int RegisterEvent(int fd, BoundFunction func, EventWakeup wakeup);
+
+    // Helper for implementing ScheduleBatteryUpdate(). An implementation of
+    // ScheduleBatteryUpdate should get charger_online from BatteryMonitor::update(),
+    // then reset wake alarm interval by calling AdjustWakealarmPeriods.
+    void AdjustWakealarmPeriods(bool charger_online);
+
+  private:
+    struct EventHandler {
+        HealthLoop* object = nullptr;
+        int fd;
+        BoundFunction func;
+    };
+
+    int InitInternal();
+    void MainLoop();
+    void WakeAlarmInit();
+    void WakeAlarmEvent(uint32_t);
+    void UeventInit();
+    void UeventEvent(uint32_t);
+    void WakeAlarmSetInterval(int interval);
+    void PeriodicChores();
+
+    // These are fixed after InitInternal() is called.
+    struct healthd_config healthd_config_;
+    android::base::unique_fd wakealarm_fd_;
+    android::base::unique_fd uevent_fd_;
+
+    android::base::unique_fd epollfd_;
+    std::vector<std::unique_ptr<EventHandler>> event_handlers_;
+    int awake_poll_interval_;  // -1 for no epoll timeout
+    int wakealarm_wake_interval_;
+
+    // If set to true, future RegisterEvent() will be rejected. This is to ensure all
+    // events are registered before StartLoop().
+    bool reject_event_register_ = false;
+};
+
+}  // namespace health
+}  // namespace hardware
+}  // namespace android
diff --git a/health/utils/libhealthloop/include/health/utils.h b/health/utils/libhealthloop/include/health/utils.h
new file mode 100644
index 0000000..e46771c
--- /dev/null
+++ b/health/utils/libhealthloop/include/health/utils.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include <healthd/healthd.h>
+
+namespace android {
+namespace hardware {
+namespace health {
+
+void InitHealthdConfig(struct healthd_config* healthd_config);
+
+}  // namespace health
+}  // namespace hardware
+}  // namespace android
diff --git a/health/utils/libhealthloop/utils.cpp b/health/utils/libhealthloop/utils.cpp
new file mode 100644
index 0000000..b0d153f
--- /dev/null
+++ b/health/utils/libhealthloop/utils.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <health/utils.h>
+namespace android {
+namespace hardware {
+namespace health {
+
+// Periodic chores fast interval in seconds
+#define DEFAULT_PERIODIC_CHORES_INTERVAL_FAST (60 * 1)
+// Periodic chores fast interval in seconds
+#define DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW (60 * 10)
+
+void InitHealthdConfig(struct healthd_config* healthd_config) {
+    *healthd_config = {
+            .periodic_chores_interval_fast = DEFAULT_PERIODIC_CHORES_INTERVAL_FAST,
+            .periodic_chores_interval_slow = DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW,
+            .batteryStatusPath = String8(String8::kEmptyString),
+            .batteryHealthPath = String8(String8::kEmptyString),
+            .batteryPresentPath = String8(String8::kEmptyString),
+            .batteryCapacityPath = String8(String8::kEmptyString),
+            .batteryVoltagePath = String8(String8::kEmptyString),
+            .batteryTemperaturePath = String8(String8::kEmptyString),
+            .batteryTechnologyPath = String8(String8::kEmptyString),
+            .batteryCurrentNowPath = String8(String8::kEmptyString),
+            .batteryCurrentAvgPath = String8(String8::kEmptyString),
+            .batteryChargeCounterPath = String8(String8::kEmptyString),
+            .batteryFullChargePath = String8(String8::kEmptyString),
+            .batteryCycleCountPath = String8(String8::kEmptyString),
+            .energyCounter = NULL,
+            .boot_min_cap = 0,
+            .screen_on = NULL,
+    };
+}
+
+}  // namespace health
+}  // namespace hardware
+}  // namespace android
diff --git a/sensors/2.0/multihal/Android.bp b/sensors/2.0/multihal/Android.bp
index 5c67676..c13eaf2 100644
--- a/sensors/2.0/multihal/Android.bp
+++ b/sensors/2.0/multihal/Android.bp
@@ -21,6 +21,7 @@
     shared_libs: [
         "android.hardware.sensors@1.0",
         "android.hardware.sensors@2.0",
+        "libbase",
         "libcutils",
         "libfmq",
         "libhidlbase",
diff --git a/sensors/2.0/multihal/HalProxy.cpp b/sensors/2.0/multihal/HalProxy.cpp
index fe2b98b..b78806a 100644
--- a/sensors/2.0/multihal/HalProxy.cpp
+++ b/sensors/2.0/multihal/HalProxy.cpp
@@ -20,11 +20,13 @@
 
 #include <android/hardware/sensors/2.0/types.h>
 
+#include <android-base/file.h>
 #include "hardware_legacy/power.h"
 
 #include <dlfcn.h>
 
 #include <cinttypes>
+#include <cmath>
 #include <fstream>
 #include <functional>
 #include <thread>
@@ -42,6 +44,8 @@
 
 typedef ISensorsSubHal*(SensorsHalGetSubHalFunc)(uint32_t*);
 
+static constexpr int32_t kBitsAfterSubHalIndex = 24;
+
 /**
  * Set the subhal index as first byte of sensor handle and return this modified version.
  *
@@ -50,8 +54,31 @@
  *
  * @return The modified sensor handle.
  */
-uint32_t setSubHalIndex(uint32_t sensorHandle, size_t subHalIndex) {
-    return sensorHandle | (subHalIndex << 24);
+int32_t setSubHalIndex(int32_t sensorHandle, size_t subHalIndex) {
+    return sensorHandle | (static_cast<int32_t>(subHalIndex) << kBitsAfterSubHalIndex);
+}
+
+/**
+ * Extract the subHalIndex from sensorHandle.
+ *
+ * @param sensorHandle The sensorHandle to extract from.
+ *
+ * @return The subhal index.
+ */
+size_t extractSubHalIndex(int32_t sensorHandle) {
+    return static_cast<size_t>(sensorHandle >> kBitsAfterSubHalIndex);
+}
+
+/**
+ * Convert nanoseconds to milliseconds.
+ *
+ * @param nanos The nanoseconds input.
+ *
+ * @return The milliseconds count.
+ */
+int64_t msFromNs(int64_t nanos) {
+    constexpr int64_t nanosecondsInAMillsecond = 1000000;
+    return nanos / nanosecondsInAMillsecond;
 }
 
 HalProxy::HalProxy() {
@@ -101,6 +128,9 @@
 }
 
 Return<Result> HalProxy::activate(int32_t sensorHandle, bool enabled) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
     return getSubHalForSensorHandle(sensorHandle)
             ->activate(clearSubHalIndex(sensorHandle), enabled);
 }
@@ -174,11 +204,17 @@
 
 Return<Result> HalProxy::batch(int32_t sensorHandle, int64_t samplingPeriodNs,
                                int64_t maxReportLatencyNs) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
     return getSubHalForSensorHandle(sensorHandle)
             ->batch(clearSubHalIndex(sensorHandle), samplingPeriodNs, maxReportLatencyNs);
 }
 
 Return<Result> HalProxy::flush(int32_t sensorHandle) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
     return getSubHalForSensorHandle(sensorHandle)->flush(clearSubHalIndex(sensorHandle));
 }
 
@@ -192,6 +228,9 @@
     }
     if (result == Result::OK) {
         Event subHalEvent = event;
+        if (!isSubHalIndexValid(event.sensorHandle)) {
+            return Result::BAD_VALUE;
+        }
         subHalEvent.sensorHandle = clearSubHalIndex(event.sensorHandle);
         result = getSubHalForSensorHandle(event.sensorHandle)->injectSensorData(subHalEvent);
     }
@@ -229,8 +268,43 @@
     return Return<void>();
 }
 
-Return<void> HalProxy::debug(const hidl_handle& /* fd */, const hidl_vec<hidl_string>& /* args */) {
-    // TODO: output debug information
+Return<void> HalProxy::debug(const hidl_handle& fd, const hidl_vec<hidl_string>& /*args*/) {
+    if (fd.getNativeHandle() == nullptr || fd->numFds < 1) {
+        ALOGE("%s: missing fd for writing", __FUNCTION__);
+        return Void();
+    }
+
+    android::base::borrowed_fd writeFd = dup(fd->data[0]);
+
+    std::ostringstream stream;
+    stream << "===HalProxy===" << std::endl;
+    stream << "Internal values:" << std::endl;
+    stream << "  Threads are running: " << (mThreadsRun.load() ? "true" : "false") << std::endl;
+    int64_t now = getTimeNow();
+    stream << "  Wakelock timeout start time: " << msFromNs(now - mWakelockTimeoutStartTime)
+           << " ms ago" << std::endl;
+    stream << "  Wakelock timeout reset time: " << msFromNs(now - mWakelockTimeoutResetTime)
+           << " ms ago" << std::endl;
+    // TODO(b/142969448): Add logging for history of wakelock acquisition per subhal.
+    stream << "  Wakelock ref count: " << mWakelockRefCount << std::endl;
+    stream << "  Size of pending write events queue: " << mPendingWriteEventsQueue.size()
+           << std::endl;
+    if (!mPendingWriteEventsQueue.empty()) {
+        stream << "  Size of events list on front of pending writes queue: "
+               << mPendingWriteEventsQueue.front().first.size() << std::endl;
+    }
+    stream << "  # of non-dynamic sensors across all subhals: " << mSensors.size() << std::endl;
+    stream << "  # of dynamic sensors across all subhals: " << mDynamicSensors.size() << std::endl;
+    stream << "SubHals (" << mSubHalList.size() << "):" << std::endl;
+    for (ISensorsSubHal* subHal : mSubHalList) {
+        stream << "  Name: " << subHal->getName() << std::endl;
+        stream << "  Debug dump: " << std::endl;
+        android::base::WriteStringToFd(stream.str(), writeFd);
+        subHal->debug(fd, {});
+        stream.str("");
+        stream << std::endl;
+    }
+    android::base::WriteStringToFd(stream.str(), writeFd);
     return Return<void>();
 }
 
@@ -326,7 +400,7 @@
                     ALOGE("SubHal sensorHandle's first byte was not 0");
                 } else {
                     ALOGV("Loaded sensor: %s", sensor.name.c_str());
-                    sensor.sensorHandle |= (subHalIndex << 24);
+                    sensor.sensorHandle = setSubHalIndex(sensor.sensorHandle, subHalIndex);
                     setDirectChannelFlags(&sensor, subHal);
                     mSensors[sensor.sensorHandle] = sensor;
                 }
@@ -539,8 +613,12 @@
     }
 }
 
-ISensorsSubHal* HalProxy::getSubHalForSensorHandle(uint32_t sensorHandle) {
-    return mSubHalList[static_cast<size_t>(sensorHandle >> 24)];
+ISensorsSubHal* HalProxy::getSubHalForSensorHandle(int32_t sensorHandle) {
+    return mSubHalList[extractSubHalIndex(sensorHandle)];
+}
+
+bool HalProxy::isSubHalIndexValid(int32_t sensorHandle) {
+    return extractSubHalIndex(sensorHandle) < mSubHalList.size();
 }
 
 size_t HalProxy::countNumWakeupEvents(const std::vector<Event>& events, size_t n) {
@@ -554,11 +632,11 @@
     return numWakeupEvents;
 }
 
-uint32_t HalProxy::clearSubHalIndex(uint32_t sensorHandle) {
+int32_t HalProxy::clearSubHalIndex(int32_t sensorHandle) {
     return sensorHandle & (~kSensorHandleSubHalIndexMask);
 }
 
-bool HalProxy::subHalIndexIsClear(uint32_t sensorHandle) {
+bool HalProxy::subHalIndexIsClear(int32_t sensorHandle) {
     return (sensorHandle & kSensorHandleSubHalIndexMask) == 0;
 }
 
diff --git a/sensors/2.0/multihal/include/HalProxy.h b/sensors/2.0/multihal/include/HalProxy.h
index 26bc644..b1dd737 100644
--- a/sensors/2.0/multihal/include/HalProxy.h
+++ b/sensors/2.0/multihal/include/HalProxy.h
@@ -124,7 +124,7 @@
      *
      * @return The sensor info object in the mapping.
      */
-    const SensorInfo& getSensorInfo(uint32_t sensorHandle) { return mSensors[sensorHandle]; }
+    const SensorInfo& getSensorInfo(int32_t sensorHandle) { return mSensors[sensorHandle]; }
 
     bool areThreadsRunning() { return mThreadsRun.load(); }
 
@@ -177,10 +177,10 @@
      * The subhal index is encoded in the first byte of the sensor handle and the remaining
      * bytes are generated by the subhal to identify the sensor.
      */
-    std::map<uint32_t, SensorInfo> mSensors;
+    std::map<int32_t, SensorInfo> mSensors;
 
     //! Map of the dynamic sensors that have been added to halproxy.
-    std::map<uint32_t, SensorInfo> mDynamicSensors;
+    std::map<int32_t, SensorInfo> mDynamicSensors;
 
     //! The current operation mode for all subhals.
     OperationMode mCurrentOperationMode = OperationMode::NORMAL;
@@ -192,7 +192,7 @@
     static const int64_t kPendingWriteTimeoutNs = 5 * INT64_C(1000000000) /* 5 seconds */;
 
     //! The bit mask used to get the subhal index from a sensor handle.
-    static constexpr uint32_t kSensorHandleSubHalIndexMask = 0xFF000000;
+    static constexpr int32_t kSensorHandleSubHalIndexMask = 0xFF000000;
 
     /**
      * A FIFO queue of pairs of vector of events and the number of wakeup events in that vector
@@ -233,7 +233,7 @@
 
     int64_t mWakelockTimeoutResetTime = getTimeNow();
 
-    const char* kWakelockName = "SensorsMultiHal";
+    const char* kWakelockName = "SensorsHAL_WAKEUP";
 
     /**
      * Initialize the list of SubHal objects in mSubHalList by reading from dynamic libraries
@@ -319,7 +319,16 @@
      *
      * @param sensorHandle The handle used to identify a sensor in one of the subhals.
      */
-    ISensorsSubHal* getSubHalForSensorHandle(uint32_t sensorHandle);
+    ISensorsSubHal* getSubHalForSensorHandle(int32_t sensorHandle);
+
+    /**
+     * Checks that sensorHandle's subhal index byte is within bounds of mSubHalList.
+     *
+     * @param sensorHandle The sensor handle to check.
+     *
+     * @return true if sensorHandles's subhal index byte is valid.
+     */
+    bool isSubHalIndexValid(int32_t sensorHandle);
 
     /**
      * Count the number of wakeup events in the first n events of the vector.
@@ -338,14 +347,14 @@
      *
      * @return The modified version of the sensor handle.
      */
-    static uint32_t clearSubHalIndex(uint32_t sensorHandle);
+    static int32_t clearSubHalIndex(int32_t sensorHandle);
 
     /**
      * @param sensorHandle The sensor handle to modify.
      *
      * @return true if subHalIndex byte of sensorHandle is zeroed.
      */
-    static bool subHalIndexIsClear(uint32_t sensorHandle);
+    static bool subHalIndexIsClear(int32_t sensorHandle);
 };
 
 /**
diff --git a/sensors/2.0/multihal/tests/Android.bp b/sensors/2.0/multihal/tests/Android.bp
index e3a4af1..50a55f9 100644
--- a/sensors/2.0/multihal/tests/Android.bp
+++ b/sensors/2.0/multihal/tests/Android.bp
@@ -82,6 +82,7 @@
     shared_libs: [
         "android.hardware.sensors@1.0",
         "android.hardware.sensors@2.0",
+        "libbase",
         "libcutils",
         "libfmq",
         "libhidlbase",
diff --git a/sensors/2.0/multihal/tests/HalProxy_test.cpp b/sensors/2.0/multihal/tests/HalProxy_test.cpp
index 040e8c2..75a4c22 100644
--- a/sensors/2.0/multihal/tests/HalProxy_test.cpp
+++ b/sensors/2.0/multihal/tests/HalProxy_test.cpp
@@ -663,6 +663,35 @@
     }
 }
 
+TEST(HalProxyTest, InvalidSensorHandleSubHalIndexProxyCalls) {
+    constexpr size_t kNumSubHals = 3;
+    constexpr size_t kQueueSize = 5;
+    int32_t kNumSubHalsInt32 = static_cast<int32_t>(kNumSubHals);
+    std::vector<AllSensorsSubHal> subHalObjs(kNumSubHals);
+    std::vector<ISensorsSubHal*> subHals;
+    for (const auto& subHal : subHalObjs) {
+        subHals.push_back((ISensorsSubHal*)(&subHal));
+    }
+
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    // Initialize for the injectSensorData call so callback postEvents is valid
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    // For testing proxy.injectSensorData properly
+    proxy.setOperationMode(OperationMode::DATA_INJECTION);
+
+    // kNumSubHalsInt32 index is one off the end of mSubHalList in proxy object
+    EXPECT_EQ(proxy.activate(0x00000001 | (kNumSubHalsInt32 << 24), true), Result::BAD_VALUE);
+    EXPECT_EQ(proxy.batch(0x00000001 | (kNumSubHalsInt32 << 24), 0, 0), Result::BAD_VALUE);
+    EXPECT_EQ(proxy.flush(0x00000001 | (kNumSubHalsInt32 << 24)), Result::BAD_VALUE);
+    Event event;
+    event.sensorHandle = 0x00000001 | (kNumSubHalsInt32 << 24);
+    EXPECT_EQ(proxy.injectSensorData(event), Result::BAD_VALUE);
+}
+
 // Helper implementations follow
 void testSensorsListFromProxyAndSubHal(const std::vector<SensorInfo>& proxySensorsList,
                                        const std::vector<SensorInfo>& subHalSensorsList) {
diff --git a/vibrator/1.4/vts/functional/Android.bp b/vibrator/1.4/vts/functional/Android.bp
index 4cdf3b6..202a824 100644
--- a/vibrator/1.4/vts/functional/Android.bp
+++ b/vibrator/1.4/vts/functional/Android.bp
@@ -25,6 +25,9 @@
         "android.hardware.vibrator@1.3",
         "android.hardware.vibrator@1.4",
     ],
-    test_suites: ["general-tests"],
+    test_suites: [
+        "general-tests",
+        "vts-core",
+    ],
 }