libalarm Documentation

Author:: Simo Piiroinen <simo.piiroinen@nokia.com>

Copyright

Contact: Simo Piiroinen <simo.piiroinen@nokia.com>

Alarmd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License version 2.1 as published by the Free Software Foundation.

Alarmd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with Alarmd; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Introduction

Alarm service is a subsysten that consists of two parts:

alarmd - daemon process that keeps track of current alarms
libalarm - client library for accessing the alarm data

Architecture

Simplified view to system utilizing alarm service:

Alarm daemon supports any number of clients
Application code includes libalarm.h
Application binary is linked against libalarm.so
Libalarm utilizes D-Bus to communicate with the server
Alarm daemon accepts request on dbus
Alarm data is stored to a file
HW RTC can be used to boot up the device
Triggered alarms are send to system ui dialog service
System ui sends user response back to alarmd
Snooze / Execute / D-Bus action is performed by alarm daemon

ASCII art diagram of the above:

   +----------+  +-------+  +-------+
   |          |  |       |  |       |
   | calendar |  | clock |  | app X |
   |          |  |       |  |       |
 ======================================  libalarm.h
               |          |
               | libalarm |
               |          |
               +----------+
                    ^
                    |
                  ==z=== D-Bus
                    |
                    v
               +---------+
               |         |            +---------+
               |         |<-----------| snooze  |
               |         |            +---------+
               | alarmd  |                  ^
               |         |                  |
  +-------+    |         |            +------------------+
  | alarm |<-->|         |----------->|  alarm action    |
  | queue |    +---------+            +------------------+
  | file  |     ^     | ^                   |          |
  +-------+     |     | |            exec ==z==      ==z== D-Bus
                |     | |                   |          |
                |     | |                   v          v
       ioctl ===z== ==z=z=== D-Bus    +---------+ +-------------+
                |     | |             |         | | dbus signal |
                v     v |             | command | | or method   |
      +----------+  +----------+      |         | | call        |
      |          |  | systemui |      +---------+ +-------------+
      | /dev/rtc |  | dialog   |
      |          |  | service  |
      +----------+  +----------+
                        ^
                        |
                      ==z=== Touchscreen
                        |
                        v
                    +----------+
                    | response |
                    | from the |
                    | user     |
                    +----------+

SVN

All source code is stored in subversion repository dms, subdirectory alarmd.