SNIP_CLASSIC_OS_SECTION_7_4_2_3_Performing_Synchronization

7.4.2.3 Performing Synchronization The Operating System module uses the synchronization count to support (re- )synchronization of a ScheduleTable at each expiry point by calculating an adjustment to the delay to the next expiry point. This provides faster re-synchronization of the ScheduleTable than doing the action on the final expiry point. [SWS_Os_00206] Upstream requirements: SRS_Os_11002 ⌈When a new synchronization count is provided, the Operating System module shall calculate the current deviation between the explicitly synchronized scheduled table and the synchronization count.⌋ It is meaningless to try and synchronize an explicitly synchronized ScheduleTable before a synchronization count is provided. [SWS_Os_00417] Upstream requirements: SRS_Os_11002 ⌈The Operating System module shall start to synchronize an explicitly synchronized ScheduleTable after a synchronization count is provided AND shall continue to adjust expiry points until synchronized.⌋ [SWS_Os_00418] Upstream requirements: SRS_Os_11002 ⌈The Operating System module shall set the state of an explicitly synchronized ScheduleTable to "running and synchronous" if the deviation is less than or equal to the configured OsScheduleTblExplicitPrecision threshold.⌋ [SWS_Os_00419] Upstream requirements: SRS_Os_11002 ⌈The Operating System module shall set the state of an explicitly synchronized ScheduleTable to "running" if the deviation is greater than the configured OsScheduleTblExplicitPrecision threshold.⌋ [SWS_Os_00420] Upstream requirements: SRS_Os_11002 ⌈IF the deviation is non-zero AND the next expiry point is adjustable AND the table is behind the sync Counter (TableTicksAheadOfSyncCounter <= TableTicksBehindOf SyncCounter) THEN the OS shall set the next EP to expire delay - min(MaxShorten, Deviation) ticks from the current expiry.⌋ [SWS_Os_00421] Upstream requirements: SRS_Os_11002 ⌈IF the deviation is non-zero AND the next expiry point is adjustable AND the table is ahead of the sync Counter (TableTicksAheadOfSyncCounter > TableTicksBehindOf SyncCounter) THEN the OS shall set the next EP to expire delay + min(MaxLengthen, Deviation) ticks from the current expiry.⌋ Figure 7.8 shows explicit synchronization of a ScheduleTable. It assumes the following: • EP1-3 have OsScheduleTableMaxLengthen=2 • EP1-3 have OsScheduleTableMaxShorten =1 Figure 7.8: Explicit ScheduleTable Synchronization The Operating System module provides the service SetScheduleTableAsync (see [SWS_Os_00422]) to cancel synchronization being performed at adjustable expiry points on a ScheduleTable. The Operating System module provides the service GetScheduleTableStatus (see [SWS_Os_00227]) to query the state of a ScheduleTable also with respect to synchronization.