这个是
private void setLocked(int type, long when) {
if (mNativeData != 0) {
// The kernel never triggers alarms with negative wakeup times
// so we ensure they are positive.
long alarmSeconds, alarmNanoseconds;
if (when < 0) {
alarmSeconds = 0;
alarmNanoseconds = 0;
} else {
alarmSeconds = when / 1000;
alarmNanoseconds = (when % 1000) * 1000 * 1000;
}
set(mNativeData, type, alarmSeconds, alarmNanoseconds);
} else {
Message msg = Message.obtain();
msg.what = ALARM_EVENT;
mHandler.removeMessages(ALARM_EVENT);
mHandler.sendMessageAtTime(msg, when);
}
}
setLocked()内部会调用native函数set()：
- private native void set(int fd, int type, long seconds, long nanoseconds);
重新设置“实体闹钟”的激发时间。这个函数内部会调用ioctl()和底层打交道。具体代码可参考frameworks/base/services/jni/com_android_server_AlarmManagerService.cpp文件：
- static void android_server_AlarmManagerService_set(JNIEnv* env, jobject obj, jint fd,
- jint type, jlong seconds, jlong nanoseconds)
- {
- struct timespec ts;
- ts.tv_sec = seconds;
- ts.tv_nsec = nanoseconds;
- int result = ioctl(fd, ANDROID_ALARM_SET(type), &ts);
- if (result < )
- {
- ALOGE("Unable to set alarm to %lld.%09lld: %s\n", seconds, nanoseconds, strerror(errno));
- }
- }