scheduler_msgs¶

Message types¶

• scheduler_msgs/CurrentStatus
• scheduler_msgs/Resource
• scheduler_msgs/KnownResources
• scheduler_msgs/SchedulerRequests
• scheduler_msgs/Request

scheduler_msgs/CurrentStatus¶

Field:	uri (string) – status (uint8) – owner (uuid_msgs/UniqueID) – priority (int16) – rapps[] (string) –
Constant:	AVAILABLE (uint8):0 – ALLOCATED (uint8):1 – MISSING (uint8):2 – GONE (uint8):3 –

## ROCON resource current status.

A ROCON scheduler uses this message to report the status of each resource it manages.

Resource Identification

A canonical ROCON Uniform Resource Identifier describing this resource, a fully-resolved character string in the form:

rocon:/platform/name/framework/os

### ROCON resource current status.
#
#   A ROCON scheduler uses this message to report the status of each
#   resource it manages.
#

##############################################################################
# Resource Identification
##############################################################################

#   A canonical ROCON Uniform Resource Identifier describing this
#   resource, a fully-resolved character string in the form:
#
#      rocon:/platform/name/framework/os
#
string uri

##############################################################################
# Status
##############################################################################

uint8 status            # Current status of this resource

#  Status value labels:
uint8 AVAILABLE   = 0   # Available for use
uint8 ALLOCATED   = 1   # Allocated to some ROCON request
uint8 MISSING     = 2   # Not currently responding
uint8 GONE        = 3   # Has left the concert (cleanly)

#   The owner is the unique identifier of the Request message to which
#   this resource is currently assigned, or a zero UUID if it is not
#   assigned.  An AVAILABLE resource never has an owner, but a MISSING
#   one might.
uuid_msgs/UniqueID owner

#   The priority of an ALLOCATED resource is the priority of its
#   owning request.  An AVAILABLE resource never has a non-zero
#   priority, but a MISSING one might.
int16 priority

#   List of ROCON application names currently available with this
#   resource. The name string is usually a ROS "package/node"
#   identifier, unique because ROS package names are unique.  The
#   contents of this list could change over time due to the device's
#   own activities.
string[] rapps

scheduler_msgs/Resource¶

Field:	rapp (string) – id (uuid_msgs/UniqueID) – uri (string) – remappings[] (rocon_std_msgs/Remapping) – parameters[] (rocon_std_msgs/KeyValue) –

## ROCON resource request or response.

A scheduler_msgs/Request message includes one Resource message for each desired resource. The scheduler responds using this same message to identify exactly what corresponding resource it has granted.

This is usually a uniquely identifying ros_package/rapp name identifier, which is unique because ros packages are unique.

### ROCON resource request or response.
#
#   A scheduler_msgs/Request message includes one Resource message for
#   each desired resource.  The scheduler responds using this same
#   message to identify exactly what corresponding resource it has
#   granted.

# This is usually a uniquely identifying ros_package/rapp name
# identifier, which is unique because ros packages are unique.
string rapp

# Unique identifier assigned by the requester to track resources
# assigned in the scheduler feedback.
uuid_msgs/UniqueID id

# Uniform Resource Identifier for the platform.  ROCON defines two
# kinds of URI strings:
#
# 1) A "resource description URI" is a canonical string for a specific
#    device.  All components are fully resolved to their most specific
#    values, like:
#
#      "rocon:/turtlebot/dude3/hydro/precise"
#
#    The scheduler provides fully resolved resource description URIs
#    in its feedback for requests that have been granted.
#
# 2) A "request URI" may provide a similar descriptive representation,
#    or may include patterns for matching multiple alternative
#    platforms.  Omitted or '*' patterns match any valid value:
#
#      ""                               # (empty string): any platform
#      "rocon:/turtlebot"               # any turtlebot
#      "rocon:/(turtlebot|segbot)"      # any robot of either type
#      "rocon:/*/dude3"                 # any device named dude3
#      "rocon:/*/*/ros/ubuntu"          # any ROS Ubuntu platform
#
string uri

# Remappings which get passed on for starting the rapps. Also potentially for
# more esoteric use cases such as checking whether an app is sharable.
rocon_std_msgs/Remapping[] remappings
rocon_std_msgs/KeyValue[] parameters

scheduler_msgs/KnownResources¶

Field:	header (std_msgs/Header) – resources[] (scheduler_msgs/CurrentStatus) –

## Known resources.

A ROCON scheduler uses this message to report the status of all the resources it knows about and manages.

### Known resources.
#
#   A ROCON scheduler uses this message to report the status of all
#   the resources it knows about and manages.
#
Header header                   # Time of this status, frame_id irrelevant
CurrentStatus[] resources       # Status of every currently-known resource

scheduler_msgs/SchedulerRequests¶

Field:	header (std_msgs/Header) – requester (uuid_msgs/UniqueID) – requests[] (scheduler_msgs/Request) –

## Scheduler Requests

Rocon services send this message on the scheduler’s input topic to make or update their resource requests. All resources they currently have or desire should be included.

If not all of the requested resources are immediately available, the scheduler will queue those requests and provide feedback using a message of the same type. The requester should wait until feedback indicates the associated resources are available. It may cancel some requests at any time via an new allocation message.

### Scheduler Requests
#
#   Rocon services send this message on the scheduler's input topic to
#   make or update their resource requests.  All resources they
#   currently have or desire should be included.
#
#   If not all of the requested resources are immediately available,
#   the scheduler will queue those requests and provide feedback using
#   a message of the same type.  The requester should wait until
#   feedback indicates the associated resources are available.  It may
#   cancel some requests at any time via an new allocation message.
#
Header header                   # Time of this status, frame_id irrelevant
uuid_msgs/UniqueID requester    # Requester identifier
Request[] requests              # Status of every currently-known request

scheduler_msgs/Request¶

Field:

id (uuid_msgs/UniqueID) – resources[] (scheduler_msgs/Resource) – status (uint8) – reason (uint8) – problem (string) – availability (time) – hold_time (duration) – priority (int16) –

Constant:

NEW (uint8):0 – RESERVED (uint8):1 – WAITING (uint8):2 – GRANTED (uint8):3 – PREEMPTING (uint8):4 – CANCELING (uint8):5 – CLOSED (uint8):6 – NONE (uint8):0 – PREEMPTED (uint8):1 – BUSY (uint8):2 – UNAVAILABLE (uint8):3 – TIMEOUT (uint8):4 – INVALID (uint8):5 – BACKGROUND_PRIORITY (int16):-20000 – LOW_PRIORITY (int16):-10000 – DEFAULT_PRIORITY (int16):0 – HIGH_PRIORITY (int16):10000 – CRITICAL_PRIORITY (int16):20000 –

## Resource request description

This tracks the progress of a single requested resource group. All these resources will be granted, preempted or canceled together as a unit.

Resource Identification

### Resource request description
#
#   This tracks the progress of a single requested resource group.
#   All these resources will be granted, preempted or canceled
#   together as a unit.

##############################################################################
# Resource Identification
##############################################################################

uuid_msgs/UniqueID id   # Requester-assigned universally unique identifier
Resource[] resources    # List of requested rapps and platforms

##############################################################################
# State
##############################################################################

uint8 status            # Current status of this request
uint8 reason            # Reason for this status
string problem          # Convenience message for introspecting on the reason 

#  Status value labels:
uint8 NEW         = 0   # New request for the scheduler
uint8 RESERVED    = 1   # Request for a reservation at some future time
uint8 WAITING     = 2   # Request has been queued by the scheduler
uint8 GRANTED     = 3   # Request was granted by the scheduler
uint8 PREEMPTING  = 4   # The scheduler wants to preempt this
                        #   previously-granted request, but the
                        #   requester has not yet canceled it
uint8 CANCELING   = 5   # The requester wishes to cancel this
                        #   request, but the scheduler has not yet
                        #   confirmed that it is closed
uint8 CLOSED      = 6   # Request is now closed (terminal state)

# Reason labels:
uint8 NONE        = 0   # No reason provided
uint8 PREEMPTED   = 1   # Preempted for higher-priority task
uint8 BUSY        = 2   # Requested resource busy elsewhere
uint8 UNAVAILABLE = 3   # Requested resource not available
uint8 TIMEOUT     = 4   # Lost contact with requester
uint8 INVALID     = 5   # Ill-formed request: see problem string for details

##############################################################################
# Scheduling Variables
##############################################################################

time     availability   # Estimated time of availability (zero if unknown)
duration hold_time      # Estimated hold time once allocated (zero if unknown)
int16    priority       # Current priority of this request

# Priority labels:
int16 BACKGROUND_PRIORITY = -20000      # When nothing else to do
int16 LOW_PRIORITY = -10000             # Low-priority task
int16 DEFAULT_PRIORITY = 0              # Sane default priority
int16 HIGH_PRIORITY = 10000             # High-priority task
int16 CRITICAL_PRIORITY = 20000         # Mission-critical task