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/* //device/libs/android_runtime/android_server_AlarmManagerService.cpp
**
** Copyright 2006, 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 "AlarmManagerService"
#include <nativehelper/JNIHelp.h>
#include "jni.h"
#include <utils/Log.h>
#include <utils/misc.h>
#include <utils/String8.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/timerfd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <linux/ioctl.h>
#include <linux/rtc.h>
#include <array>
#include <memory>
namespace android {
static constexpr int ANDROID_ALARM_TIME_CHANGE_MASK = 1 << 16;
/**
* The AlarmManager alarm constants:
*
* RTC_WAKEUP
* RTC
* REALTIME_WAKEUP
* REALTIME
* SYSTEMTIME (only defined in old alarm driver header, possibly unused?)
*
* We also need an extra CLOCK_REALTIME fd which exists specifically to be
* canceled on RTC changes.
*/
static const size_t ANDROID_ALARM_TYPE_COUNT = 5;
static const size_t N_ANDROID_TIMERFDS = ANDROID_ALARM_TYPE_COUNT + 1;
static const clockid_t android_alarm_to_clockid[N_ANDROID_TIMERFDS] = {
CLOCK_REALTIME_ALARM,
CLOCK_REALTIME,
CLOCK_BOOTTIME_ALARM,
CLOCK_BOOTTIME,
CLOCK_MONOTONIC,
CLOCK_REALTIME,
};
typedef std::array<int, N_ANDROID_TIMERFDS> TimerFds;
class AlarmImpl
{
public:
AlarmImpl(const TimerFds &fds, int epollfd, int rtc_id) :
fds{fds}, epollfd{epollfd}, rtc_id{rtc_id} { }
~AlarmImpl();
int set(int type, struct timespec *ts);
int setTime(struct timeval *tv);
int waitForAlarm();
private:
const TimerFds fds;
const int epollfd;
const int rtc_id;
};
AlarmImpl::~AlarmImpl()
{
for (auto fd : fds) {
epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, nullptr);
close(fd);
}
close(epollfd);
}
int AlarmImpl::set(int type, struct timespec *ts)
{
if (static_cast<size_t>(type) > ANDROID_ALARM_TYPE_COUNT) {
errno = EINVAL;
return -1;
}
if (!ts->tv_nsec && !ts->tv_sec) {
ts->tv_nsec = 1;
}
/* timerfd interprets 0 = disarm, so replace with a practically
equivalent deadline of 1 ns */
struct itimerspec spec;
memset(&spec, 0, sizeof(spec));
memcpy(&spec.it_value, ts, sizeof(spec.it_value));
return timerfd_settime(fds[type], TFD_TIMER_ABSTIME, &spec, NULL);
}
int AlarmImpl::setTime(struct timeval *tv)
{
struct rtc_time rtc;
struct tm tm, *gmtime_res;
int fd;
int res;
res = settimeofday(tv, NULL);
if (res < 0) {
ALOGV("settimeofday() failed: %s\n", strerror(errno));
return -1;
}
if (rtc_id < 0) {
ALOGV("Not setting RTC because wall clock RTC was not found");
errno = ENODEV;
return -1;
}
android::String8 rtc_dev = String8::format("/dev/rtc%d", rtc_id);
fd = open(rtc_dev.string(), O_RDWR);
if (fd < 0) {
ALOGV("Unable to open %s: %s\n", rtc_dev.string(), strerror(errno));
return res;
}
gmtime_res = gmtime_r(&tv->tv_sec, &tm);
if (!gmtime_res) {
ALOGV("gmtime_r() failed: %s\n", strerror(errno));
res = -1;
goto done;
}
memset(&rtc, 0, sizeof(rtc));
rtc.tm_sec = tm.tm_sec;
rtc.tm_min = tm.tm_min;
rtc.tm_hour = tm.tm_hour;
rtc.tm_mday = tm.tm_mday;
rtc.tm_mon = tm.tm_mon;
rtc.tm_year = tm.tm_year;
rtc.tm_wday = tm.tm_wday;
rtc.tm_yday = tm.tm_yday;
rtc.tm_isdst = tm.tm_isdst;
res = ioctl(fd, RTC_SET_TIME, &rtc);
if (res < 0)
ALOGV("RTC_SET_TIME ioctl failed: %s\n", strerror(errno));
done:
close(fd);
return res;
}
int AlarmImpl::waitForAlarm()
{
epoll_event events[N_ANDROID_TIMERFDS];
int nevents = epoll_wait(epollfd, events, N_ANDROID_TIMERFDS, -1);
if (nevents < 0) {
return nevents;
}
int result = 0;
for (int i = 0; i < nevents; i++) {
uint32_t alarm_idx = events[i].data.u32;
uint64_t unused;
ssize_t err = read(fds[alarm_idx], &unused, sizeof(unused));
if (err < 0) {
if (alarm_idx == ANDROID_ALARM_TYPE_COUNT && errno == ECANCELED) {
result |= ANDROID_ALARM_TIME_CHANGE_MASK;
} else {
return err;
}
} else {
result |= (1 << alarm_idx);
}
}
return result;
}
static jint android_server_AlarmManagerService_setKernelTime(JNIEnv*, jobject, jlong nativeData, jlong millis)
{
AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
struct timeval tv;
int ret;
if (millis <= 0 || millis / 1000LL >= INT_MAX) {
return -1;
}
tv.tv_sec = (time_t) (millis / 1000LL);
tv.tv_usec = (suseconds_t) ((millis % 1000LL) * 1000LL);
ALOGD("Setting time of day to sec=%d\n", (int) tv.tv_sec);
ret = impl->setTime(&tv);
if(ret < 0) {
ALOGW("Unable to set rtc to %ld: %s\n", tv.tv_sec, strerror(errno));
ret = -1;
}
return ret;
}
static jint android_server_AlarmManagerService_setKernelTimezone(JNIEnv*, jobject, jlong, jint minswest)
{
struct timezone tz;
tz.tz_minuteswest = minswest;
tz.tz_dsttime = 0;
int result = settimeofday(NULL, &tz);
if (result < 0) {
ALOGE("Unable to set kernel timezone to %d: %s\n", minswest, strerror(errno));
return -1;
} else {
ALOGD("Kernel timezone updated to %d minutes west of GMT\n", minswest);
}
return 0;
}
static const char rtc_sysfs[] = "/sys/class/rtc";
static bool rtc_is_hctosys(unsigned int rtc_id)
{
android::String8 hctosys_path = String8::format("%s/rtc%u/hctosys",
rtc_sysfs, rtc_id);
FILE *file = fopen(hctosys_path.string(), "re");
if (!file) {
ALOGE("failed to open %s: %s", hctosys_path.string(), strerror(errno));
return false;
}
unsigned int hctosys;
bool ret = false;
int err = fscanf(file, "%u", &hctosys);
if (err == EOF)
ALOGE("failed to read from %s: %s", hctosys_path.string(),
strerror(errno));
else if (err == 0)
ALOGE("%s did not have expected contents", hctosys_path.string());
else
ret = hctosys;
fclose(file);
return ret;
}
static int wall_clock_rtc()
{
std::unique_ptr<DIR, int(*)(DIR*)> dir(opendir(rtc_sysfs), closedir);
if (!dir.get()) {
ALOGE("failed to open %s: %s", rtc_sysfs, strerror(errno));
return -1;
}
struct dirent *dirent;
while (errno = 0, dirent = readdir(dir.get())) {
unsigned int rtc_id;
int matched = sscanf(dirent->d_name, "rtc%u", &rtc_id);
if (matched < 0)
break;
else if (matched != 1)
continue;
if (rtc_is_hctosys(rtc_id)) {
ALOGV("found wall clock RTC %u", rtc_id);
return rtc_id;
}
}
if (errno == 0)
ALOGW("no wall clock RTC found");
else
ALOGE("failed to enumerate RTCs: %s", strerror(errno));
return -1;
}
static void log_timerfd_create_error(clockid_t id)
{
if (errno == EINVAL) {
switch (id) {
case CLOCK_REALTIME_ALARM:
case CLOCK_BOOTTIME_ALARM:
ALOGE("kernel missing required commits:");
ALOGE("https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6cffe00f7d4e24679eae6b7aae4caaf915288256");
ALOGE("https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=11ffa9d6065f344a9bd769a2452f26f2f671e5f8");
LOG_ALWAYS_FATAL("kernel does not support timerfd_create() with alarm timers");
break;
case CLOCK_BOOTTIME:
ALOGE("kernel missing required commit:");
ALOGE("https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4a2378a943f09907fb1ae35c15de917f60289c14");
LOG_ALWAYS_FATAL("kernel does not support timerfd_create(CLOCK_BOOTTIME)");
break;
default:
break;
}
}
ALOGE("timerfd_create(%u) failed: %s", id, strerror(errno));
}
static jlong android_server_AlarmManagerService_init(JNIEnv*, jobject)
{
int epollfd;
TimerFds fds;
epollfd = epoll_create(fds.size());
if (epollfd < 0) {
ALOGE("epoll_create(%zu) failed: %s", fds.size(),
strerror(errno));
return 0;
}
for (size_t i = 0; i < fds.size(); i++) {
fds[i] = timerfd_create(android_alarm_to_clockid[i], 0);
if (fds[i] < 0) {
log_timerfd_create_error(android_alarm_to_clockid[i]);
close(epollfd);
for (size_t j = 0; j < i; j++) {
close(fds[j]);
}
return 0;
}
}
AlarmImpl *ret = new AlarmImpl(fds, epollfd, wall_clock_rtc());
for (size_t i = 0; i < fds.size(); i++) {
epoll_event event;
event.events = EPOLLIN | EPOLLWAKEUP;
event.data.u32 = i;
int err = epoll_ctl(epollfd, EPOLL_CTL_ADD, fds[i], &event);
if (err < 0) {
ALOGE("epoll_ctl(EPOLL_CTL_ADD) failed: %s", strerror(errno));
delete ret;
return 0;
}
}
struct itimerspec spec;
memset(&spec, 0, sizeof(spec));
/* 0 = disarmed; the timerfd doesn't need to be armed to get
RTC change notifications, just set up as cancelable */
int err = timerfd_settime(fds[ANDROID_ALARM_TYPE_COUNT],
TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET, &spec, NULL);
if (err < 0) {
ALOGE("timerfd_settime() failed: %s", strerror(errno));
delete ret;
return 0;
}
return reinterpret_cast<jlong>(ret);
}
static void android_server_AlarmManagerService_close(JNIEnv*, jobject, jlong nativeData)
{
AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
delete impl;
}
static void android_server_AlarmManagerService_set(JNIEnv*, jobject, jlong nativeData, jint type, jlong seconds, jlong nanoseconds)
{
AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
struct timespec ts;
ts.tv_sec = seconds;
ts.tv_nsec = nanoseconds;
int result = impl->set(type, &ts);
if (result < 0)
{
ALOGE("Unable to set alarm to %lld.%09lld: %s\n",
static_cast<long long>(seconds),
static_cast<long long>(nanoseconds), strerror(errno));
}
}
static jint android_server_AlarmManagerService_waitForAlarm(JNIEnv*, jobject, jlong nativeData)
{
AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
int result = 0;
do
{
result = impl->waitForAlarm();
} while (result < 0 && errno == EINTR);
if (result < 0)
{
ALOGE("Unable to wait on alarm: %s\n", strerror(errno));
return 0;
}
return result;
}
static const JNINativeMethod sMethods[] = {
/* name, signature, funcPtr */
{"init", "()J", (void*)android_server_AlarmManagerService_init},
{"close", "(J)V", (void*)android_server_AlarmManagerService_close},
{"set", "(JIJJ)V", (void*)android_server_AlarmManagerService_set},
{"waitForAlarm", "(J)I", (void*)android_server_AlarmManagerService_waitForAlarm},
{"setKernelTime", "(JJ)I", (void*)android_server_AlarmManagerService_setKernelTime},
{"setKernelTimezone", "(JI)I", (void*)android_server_AlarmManagerService_setKernelTimezone},
};
int register_android_server_AlarmManagerService(JNIEnv* env)
{
return jniRegisterNativeMethods(env, "com/android/server/AlarmManagerService",
sMethods, NELEM(sMethods));
}
} /* namespace android */