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<concept xml:lang="en" id="GUID-DA68ED44-4BF4-54EF-8090-821F73F7904D"><title>System-wide Properties</title><prolog><metadata><keywords/></metadata></prolog><conbody><p>System-wide properties are attributes of a device that have system-wide significance. It allows components to be aware of the state of the device. They are defined by system-wide property policies within a SSM plug-in that can be customised by licensees. These policies determine the set of properties, their permissible values and transitions, and the tasks that are performed when each value changes. </p> <p>A component with appropriate platform security capabilities can request a change to a system-wide property value. The SSM distributes notifications of the changing of system-wide property values to components that have requested notifications. A reference plug-in implements policies for the system-wide properties defined by Symbian. </p> <section><title>Symbian defined system-wide property transition</title> <p>The system-wide property is indicated to interested parties using the P&amp;S mechanism. When a new value for a system-wide property is indicated to <filepath>SysStateMgr</filepath>, depending on the policy associated with that transition, a <codeph>commandList</codeph> is run (by <filepath>SysCLE.exe</filepath>). </p> <p>System-wide property transitions are queued, accepted or rejected. If accepted, then they are put in a First In First Out (FIFO) queue. If a system-wide property transition is requested when an existing transition is in progress, the SSM calls <codeph>TransitionAllowed()</codeph> as if there was no existing transition in progress. </p> </section> <section><title>Differences between system state and system-wide property</title> <p>The differences between system state and system-wide properties are listed in the following table: </p> <table id="GUID-02030B6B-0493-50E0-AFDE-F2799440BF48"><tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/><thead><row><entry>System state</entry> <entry>System-wide property</entry> </row> </thead> <tbody><row><entry><p>A device can only be in one state. </p> </entry> <entry><p>A device can have multiple system-wide properties. </p> </entry> </row> <row><entry><p>The state and different properties can be combined with the policy to generate new status indications and actions. </p> </entry> <entry><p>The value of any system-wide properties is normally independent of the system state. </p> </entry> </row> </tbody> </tgroup> </table> </section> </conbody></concept>