am eb0ca2b7: Merge "Add timerfd backend to AlarmManagerService"

* commit 'eb0ca2b7bfd70fbbf2bd730b1c431faac21d0416':
  Add timerfd backend to AlarmManagerService

2 files changed, 235 insertions, 28 deletions

diff --git a/services/java/com/android/server/AlarmManagerService.java b/services/java/com/android/server/AlarmManagerService.java
index 5ae9a6d..2e1b0af 100644
--- a/services/java/com/android/server/AlarmManagerService.java
+++ b/services/java/com/android/server/AlarmManagerService.java
@@ -99,7 +99,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
 
     private Object mLock = new Object();
 
-    private int mDescriptor;
+    private long mNativeData;
     private long mNextWakeup;
     private long mNextNonWakeup;
     private int mBroadcastRefCount = 0;
@@ -464,7 +464,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
     
     public AlarmManagerService(Context context) {
         mContext = context;
-        mDescriptor = init();
+        mNativeData = init();
         mNextWakeup = mNextNonWakeup = 0;
 
         // We have to set current TimeZone info to kernel
@@ -493,7 +493,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
         mClockReceiver.scheduleDateChangedEvent();
         mUninstallReceiver = new UninstallReceiver();
         
-        if (mDescriptor != -1) {
+        if (mNativeData != 0) {
             mWaitThread.start();
         } else {
             Slog.w(TAG, "Failed to open alarm driver. Falling back to a handler.");
@@ -502,7 +502,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
     
     protected void finalize() throws Throwable {
         try {
-            close(mDescriptor);
+            close(mNativeData);
         } finally {
             super.finalize();
         }
@@ -702,7 +702,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
                 // Update the kernel timezone information
                 // Kernel tracks time offsets as 'minutes west of GMT'
                 int gmtOffset = zone.getOffset(System.currentTimeMillis());
-                setKernelTimezone(mDescriptor, -(gmtOffset / 60000));
+                setKernelTimezone(mNativeData, -(gmtOffset / 60000));
             }
 
             TimeZone.setDefault(null);
@@ -796,7 +796,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
 
     private void setLocked(int type, long when)
     {
-        if (mDescriptor != -1)
+        if (mNativeData != 0)
         {
             // The kernel never triggers alarms with negative wakeup times
             // so we ensure they are positive.
@@ -809,7 +809,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
                 alarmNanoseconds = (when % 1000) * 1000 * 1000;
             }
             
-            set(mDescriptor, type, alarmSeconds, alarmNanoseconds);
+            set(mNativeData, type, alarmSeconds, alarmNanoseconds);
         }
         else
         {
@@ -1014,11 +1014,11 @@ class AlarmManagerService extends IAlarmManager.Stub {
         }
     }
 
-    private native int init();
-    private native void close(int fd);
-    private native void set(int fd, int type, long seconds, long nanoseconds);
-    private native int waitForAlarm(int fd);
-    private native int setKernelTimezone(int fd, int minuteswest);
+    private native long init();
+    private native void close(long nativeData);
+    private native void set(long nativeData, int type, long seconds, long nanoseconds);
+    private native int waitForAlarm(long nativeData);
+    private native int setKernelTimezone(long nativeData, int minuteswest);
 
     private void triggerAlarmsLocked(ArrayList<Alarm> triggerList, long nowELAPSED, long nowRTC) {
         // batches are temporally sorted, so we need only pull from the
@@ -1158,7 +1158,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
 
             while (true)
             {
-                int result = waitForAlarm(mDescriptor);
+                int result = waitForAlarm(mNativeData);
 
                 triggerList.clear();
 
@@ -1340,7 +1340,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
                 // daylight savings information.
                 TimeZone zone = TimeZone.getTimeZone(SystemProperties.get(TIMEZONE_PROPERTY));
                 int gmtOffset = zone.getOffset(System.currentTimeMillis());
-                setKernelTimezone(mDescriptor, -(gmtOffset / 60000));
+                setKernelTimezone(mNativeData, -(gmtOffset / 60000));
                 scheduleDateChangedEvent();
             }
         }
diff --git a/services/jni/com_android_server_AlarmManagerService.cpp b/services/jni/com_android_server_AlarmManagerService.cpp
index 8da143d..342515b 100644
--- a/services/jni/com_android_server_AlarmManagerService.cpp
+++ b/services/jni/com_android_server_AlarmManagerService.cpp
@@ -25,6 +25,8 @@
 #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>
@@ -37,7 +39,136 @@
 
 namespace android {
 
-static jint android_server_AlarmManagerService_setKernelTimezone(JNIEnv*, jobject, jint, jint minswest)
+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,
+};
+/* to match the legacy alarm driver implementation, we need an extra
+   CLOCK_REALTIME fd which exists specifically to be canceled on RTC changes */
+
+class AlarmImpl
+{
+public:
+    AlarmImpl(int *fds, size_t n_fds);
+    virtual ~AlarmImpl();
+
+    virtual int set(int type, struct timespec *ts) = 0;
+    virtual int waitForAlarm() = 0;
+
+protected:
+    int *fds;
+    size_t n_fds;
+};
+
+class AlarmImplAlarmDriver : public AlarmImpl
+{
+public:
+    AlarmImplAlarmDriver(int fd) : AlarmImpl(&fd, 1) { }
+
+    int set(int type, struct timespec *ts);
+    int waitForAlarm();
+};
+
+class AlarmImplTimerFd : public AlarmImpl
+{
+public:
+    AlarmImplTimerFd(int fds[N_ANDROID_TIMERFDS], int epollfd) :
+        AlarmImpl(fds, N_ANDROID_TIMERFDS), epollfd(epollfd) { }
+    ~AlarmImplTimerFd();
+
+    int set(int type, struct timespec *ts);
+    int waitForAlarm();
+
+private:
+    int epollfd;
+};
+
+AlarmImpl::AlarmImpl(int *fds_, size_t n_fds) : fds(new int[n_fds]),
+        n_fds(n_fds)
+{
+    memcpy(fds, fds_, n_fds * sizeof(fds[0]));
+}
+
+AlarmImpl::~AlarmImpl()
+{
+    for (size_t i = 0; i < n_fds; i++) {
+        close(fds[i]);
+    }
+    delete [] fds;
+}
+
+int AlarmImplAlarmDriver::set(int type, struct timespec *ts)
+{
+    return ioctl(fds[0], ANDROID_ALARM_SET(type), ts);
+}
+
+int AlarmImplAlarmDriver::waitForAlarm()
+{
+    return ioctl(fds[0], ANDROID_ALARM_WAIT);
+}
+
+AlarmImplTimerFd::~AlarmImplTimerFd()
+{
+    for (size_t i = 0; i < N_ANDROID_TIMERFDS; i++) {
+        epoll_ctl(epollfd, EPOLL_CTL_DEL, fds[i], NULL);
+    }
+    close(epollfd);
+}
+
+int AlarmImplTimerFd::set(int type, struct timespec *ts)
+{
+    if (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 AlarmImplTimerFd::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_setKernelTimezone(JNIEnv*, jobject, jlong, jint minswest)
 {
     struct timezone tz;
 
@@ -55,36 +186,112 @@ static jint android_server_AlarmManagerService_setKernelTimezone(JNIEnv*, jobjec
     return 0;
 }
 
-static jint android_server_AlarmManagerService_init(JNIEnv*, jobject)
+static jlong init_alarm_driver()
+{
+    int fd = open("/dev/alarm", O_RDWR);
+    if (fd < 0) {
+        ALOGV("opening alarm driver failed: %s", strerror(errno));
+        return 0;
+    }
+
+    AlarmImpl *ret = new AlarmImplAlarmDriver(fd);
+    return reinterpret_cast<jlong>(ret);
+}
+
+static jlong init_timerfd()
 {
-    return open("/dev/alarm", O_RDWR);
+    int epollfd;
+    int fds[N_ANDROID_TIMERFDS];
+
+    epollfd = epoll_create(N_ANDROID_TIMERFDS);
+    if (epollfd < 0) {
+        ALOGV("epoll_create(%u) failed: %s", N_ANDROID_TIMERFDS,
+                strerror(errno));
+        return 0;
+    }
+
+    for (size_t i = 0; i < N_ANDROID_TIMERFDS; i++) {
+        fds[i] = timerfd_create(android_alarm_to_clockid[i], 0);
+        if (fds[i] < 0) {
+            ALOGV("timerfd_create(%u) failed: %s",  android_alarm_to_clockid[i],
+                    strerror(errno));
+            close(epollfd);
+            for (size_t j = 0; j < i; j++) {
+                close(fds[j]);
+            }
+            return 0;
+        }
+    }
+
+    AlarmImpl *ret = new AlarmImplTimerFd(fds, epollfd);
+
+    for (size_t i = 0; i < N_ANDROID_TIMERFDS; 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) {
+            ALOGV("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) {
+        ALOGV("timerfd_settime() failed: %s", strerror(errno));
+        delete ret;
+        return 0;
+    }
+
+    return reinterpret_cast<jlong>(ret);
+}
+
+static jlong android_server_AlarmManagerService_init(JNIEnv*, jobject)
+{
+    jlong ret = init_alarm_driver();
+    if (ret) {
+        return ret;
+    }
+
+    return init_timerfd();
 }
 
-static void android_server_AlarmManagerService_close(JNIEnv*, jobject, jint fd)
+static void android_server_AlarmManagerService_close(JNIEnv*, jobject, jlong nativeData)
 {
-    close(fd);
+    AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
+    delete impl;
 }
 
-static void android_server_AlarmManagerService_set(JNIEnv*, jobject, jint fd, jint type, jlong seconds, jlong nanoseconds)
+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 = ioctl(fd, ANDROID_ALARM_SET(type), &ts);
+    int result = impl->set(type, &ts);
     if (result < 0)
     {
         ALOGE("Unable to set alarm to %lld.%09lld: %s\n", seconds, nanoseconds, strerror(errno));
     }
 }
 
-static jint android_server_AlarmManagerService_waitForAlarm(JNIEnv*, jobject, jint fd)
+static jint android_server_AlarmManagerService_waitForAlarm(JNIEnv*, jobject, jlong nativeData)
 {
+    AlarmImpl *impl = reinterpret_cast<AlarmImpl *>(nativeData);
     int result = 0;
 
     do
     {
-        result = ioctl(fd, ANDROID_ALARM_WAIT);
+        result = impl->waitForAlarm();
     } while (result < 0 && errno == EINTR);
 
     if (result < 0)
@@ -98,11 +305,11 @@ static jint android_server_AlarmManagerService_waitForAlarm(JNIEnv*, jobject, ji
 
 static JNINativeMethod sMethods[] = {
      /* name, signature, funcPtr */
-    {"init", "()I", (void*)android_server_AlarmManagerService_init},
-    {"close", "(I)V", (void*)android_server_AlarmManagerService_close},
-    {"set", "(IIJJ)V", (void*)android_server_AlarmManagerService_set},
-    {"waitForAlarm", "(I)I", (void*)android_server_AlarmManagerService_waitForAlarm},
-    {"setKernelTimezone", "(II)I", (void*)android_server_AlarmManagerService_setKernelTimezone},
+    {"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},
+    {"setKernelTimezone", "(JI)I", (void*)android_server_AlarmManagerService_setKernelTimezone},
 };
 
 int register_android_server_AlarmManagerService(JNIEnv* env)