3.14 Work List

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3.14 Work List
IOC Core Channel Access
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Changes to IOC Core

• Online add/delete of record instances
• Tool to support online add/delete
• OS independent layer to support port of IOC Core
• Revisit time stamp library
• Redundancy
• Standard set of statistics available through
  pseudo-channels
• Log writes to database fields
• Use priority in scan tasks differently
• Frequency-based monitor notification
• Port database to the portable server
• Improve array handling capabilities
• ANSI-fy src/drv/old - drivers
• Put off until later..
• Extensible link type definition - 4.0
• Adding record, device, driver support

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Changes to IOC Core - Online Add/Delete

• Changeable links was the first part of the task
  and was completed in 3.13
• dynamic lockset computation taken from IOC init
  and done dynamically
• Downloading record instances during operation
  will need to be supported
• IOC initialization has to be broken up and called
  at any time
• record initialization must be possible at any
  time during operation
• device initialization and driver initialization
  must be possible at any time
• modifications may need to be made for all device
  and driver support

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Changes to IOC Core - tools to support add/delete

• Is the request to load new records initiated in
  the host or the target?
• Will we use dbLoadRecords or a network protocol
  to accomplish this?
• How closely integrated will this be with the
  existing configuration tools?
• CAPFAST
• GDCT
• DCT
• Relational and OO databases
• ASCII (AWK/PERL/VI)

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Changes to IOC Core - OS independent layer

• Operating system services needing a compatibility
  layer
• SymFindByName
• Semaphores
• Task Create
• Interrupt Services
• Timer management
• Bus to local addresses
• Sockets
• Create list of services needed - partial list
  above
• Put the existing ones in the source release
  control for common use
• Document the compatibility layer

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Changes to IOC Core - Revisit Time Stamp Library

• Use UNIX time stamp format
• Use the standard UNIX routines for time in place
  of the existing time stamp library
• Verify the year 2000 is no problem
• Resolve a newly discovered time stamp issue at
  TJNAF

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Changes to IOC Core - Redundancy

• All database record types?
• State notation language
• Which drivers can handle redundant hardware?
• How do you mix redundant and non-redundant
  hardware capability
• Recreate it - merge Tate changes
• Is this required by anyone?

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Changes to IOC Core - Statistics from IOC

• CPU utilization
• Memory utilization
• Stack usage
• Critical task state of health
• running/suspended/etc
• periodicity of scan tasks - do they start on time
• number of records processed by each scan task
• CPU utilization per task

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Changes to IOC Core - Logging Database Writes

• Uses of write logging
• discover unexpected access to a record
• use the log as a playback script complete with
  delay/value information
• Logging done at the channel access write level
• Ability to log writes to a database enabled on a
  record by record basis
• Integrate the logging into a tool that allows
  callable access

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Changes to IOC Core - Task Priorities

• Currently scan tasks are given tasks priorities
• ioevent high, ioevent med, ioevent low, .1 sec
  high, .1secmed. .10 sec low, channel acc.
• New scheme would allow setting the relative
  priorities of scan tasks amongst themselves and
  in relationship with the channel access server.
• NOTE channel access buffering is a side affect
  of having a lower priority than scanning
• Several priorities will be reserved above channel
  access to continue the current relationship
  between scan tasks and channel access.
• Several priorities will be reserved where the
  channel access client and the scan tasks can be
  interleaved to provide more suitable environment
  for closed-loop control over the network and a
  more controlled degradation mode.

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Changes to IOC Core - Frequency Based Monitors

• Add two notification methods minimum interval
  and regular interval
• Minimum interval would check only when the record
  is being processed. Notification is sent when
  the specified time has expired - this is inline
  code for record processing.
• Regular interval monitors would send values
  regardless of record processing
• a new thread would be needed to service these
• synchronizing with record processing is important
  for time stamp alignment

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Channel Access Modifications - V3 w/Old Server

• 1 dimensional big arrays supported
• name caching / alternate name services in the
  client
• coalesce multiple requests for a single channel
  to one request to the IOC
• use a common data object for the gateway and CDEV
• (merge the functionality of CDEV Data and GDD)

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Channel Access Modifications - V3 w/Portable
Server (3.14 or later)

• Put the new server in the IOC
• Revise CA buffering so that 32K is not used - it
  becomes configurable
• Control over monitor engine - rate limit, queue
  length limit, independent deadband, trigger from
  an alternate channel
• JAVA client
• Multipriority client connections to the server
• Export transaction semantics to the client
• Client conversions in the client
• Special server library for exporting C variables
  (no database needed)
• Pseudo channels to make server statistics
  available
• Hooks to log all writes (specified in access
  control)
• C API for client - review interface to CDEV as
  part of design
• Review portable server docs

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Channel Access Modifications - V4

• Compress the protocol - header, data, alignment
• Multi-dimensional array support
• User defined containers exported to the client
  API
• User defined application types to the client API
• User defined event types to the client API