healthd: refactor healthd code to split into 'charger' and 'healthd'

This splits healthd code into 2 pieces as described below.

charger - statically linked executable in /sbin
 - responsible for charger-mode UI
 - battery/charger  monitoring in recovery/charger-mode.

healthd - dynamically linked (*mostly*) executable in /system/bin
 - responsible for battery / charger monitoring in Android
 - runs 'batteryproperties' service.

Both currently use libhealthd STATIC HALs. However, this now paves
way for the healthd (android) HAL to be a shared library that can
be trebelized.

   text    data     bss     dec     hex filename
 733356   15312   33864  782532   bf0c4 root/sbin/charger
  55943   10392     192   66527   103df system/bin/healthd
 789299   25704   34056  849059   cf4a3 (TOTALS)

Test: Tested recovery, charge-only and android boot with new binaries
with and without STATIC HAL.

Change-Id: I80f94948dda44d466f172d234b3fcc9064ef2476
Signed-off-by: Sandeep Patil <sspatil@google.com>
diff --git a/healthd/healthd_common.cpp b/healthd/healthd_common.cpp
new file mode 100644
index 0000000..6599919
--- /dev/null
+++ b/healthd/healthd_common.cpp
@@ -0,0 +1,304 @@
+/*
+ * 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 "healthd-common"
+#define KLOG_LEVEL 6
+
+#include <healthd/healthd.h>
+#include <healthd/BatteryMonitor.h>
+
+#include <errno.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <batteryservice/BatteryService.h>
+#include <cutils/klog.h>
+#include <cutils/uevent.h>
+#include <sys/epoll.h>
+#include <sys/timerfd.h>
+#include <utils/Errors.h>
+
+using namespace android;
+
+#ifndef BOARD_PERIODIC_CHORES_INTERVAL_FAST
+  // Periodic chores fast interval in seconds
+  #define DEFAULT_PERIODIC_CHORES_INTERVAL_FAST (60 * 1)
+#else
+  #define DEFAULT_PERIODIC_CHORES_INTERVAL_FAST (BOARD_PERIODIC_CHORES_INTERVAL_FAST)
+#endif
+
+#ifndef BOARD_PERIODIC_CHORES_INTERVAL_SLOW
+  // Periodic chores fast interval in seconds
+  #define DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW (60 * 10)
+#else
+  #define DEFAULT_PERIODIC_CHORES_INTERVAL_SLOW (BOARD_PERIODIC_CHORES_INTERVAL_SLOW)
+#endif
+
+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"
+
+// epoll_create() parameter is actually unused
+#define MAX_EPOLL_EVENTS 40
+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;
+
+static BatteryMonitor* gBatteryMonitor;
+
+struct healthd_mode_ops *healthd_mode_ops;
+
+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");
+}
+
+status_t healthd_get_property(int id, struct BatteryProperty *val) {
+    return gBatteryMonitor->getProperty(id, val);
+}
+
+void healthd_battery_update(void) {
+    // Fast wake interval when on charger (watch for overheat);
+    // slow wake interval when on battery (watch for drained battery).
+
+   int new_wake_interval = gBatteryMonitor->update() ?
+       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;
+}
+
+void healthd_dump_battery_state(int fd) {
+    gBatteryMonitor->dumpState(fd);
+    fsync(fd);
+}
+
+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_create(MAX_EPOLL_EVENTS);
+    if (epollfd == -1) {
+        KLOG_ERROR(LOG_TAG,
+                   "epoll_create failed; errno=%d\n",
+                   errno);
+        return -1;
+    }
+
+    healthd_board_init(&healthd_config);
+    healthd_mode_ops->init(&healthd_config);
+    wakealarm_init();
+    uevent_init();
+    gBatteryMonitor = new BatteryMonitor();
+    gBatteryMonitor->init(&healthd_config);
+    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;
+}