/Classes/task

Classes / task / index.html

A long-running asynchronous task

Fields

string uuid
Unique identifier/object reference
string name_label
a human-readable name
string name_description
a notes field containg human-readable description
Set[enum task_allowed_operations] allowed_operations
list of the operations allowed in this state. This list is advisory only and the server state may have changed by the time this field is read by a client.
Map[string,enum task_allowed_operations] current_operations
links each of the running tasks using this object (by reference) to a current_operation enum which describes the nature of the task.
datetime created
Time task was created
datetime finished
Time task finished (i.e. succeeded or failed). If task-status is pending, then the value of this field has no meaning
enum task_status_type status
current status of the task
session session
the session that created the task
host resident_on
the host on which the task is running
float progress
if the task is still pending, this field contains the estimated fraction complete (0.-1.). If task has completed (successfully or unsuccessfully) this should be 1.
int externalpid
If the task has spawned a program, the field record the PID of the process that the task is waiting on. (-1 if no waiting completion of an external program )
int stunnelpid
If the task has been forwarded, this field records the pid of the stunnel process spawned to manage the forwarding connection
bool forwarded
True if this task has been forwarded to a slave
host forwarded_to
The host to which the task has been forwarded
string type
if the task has completed successfully, this field contains the type of the encoded result (i.e. name of the class whose reference is in the result field). Undefined otherwise.
string result
if the task has completed successfully, this field contains the result value (either Void or an object reference). Undefined otherwise.
Set[string] error_info
if the task has failed, this field contains the set of associated error strings. Undefined otherwise.
Map[string,string] other_config
additional configuration
task subtask_of
Ref pointing to the task this is a substask of.
Set[task] subtasks
List pointing to all the substasks.

Implicit messages

Record[task] get_record (session session_id, task self)
Get a record containing the current state of the given task.
task get_by_uuid (session session_id, string uuid)
Get a reference to the task instance with the specified UUID.
Set[task] get_by_name_label (session session_id, string label)
Get all the task instances with the given label.
Set[task] get_all (session session_id)
Return a list of all the tasks known to the system.
Map[task,Record[task]] get_all_records (session session_id)
Return a map of task references to task records for all tasks known to the system.

Explicit messages

task create (session session_id, string label, string description)
Create a new task object which must be manually destroyed.
void destroy (session session_id, task self)
Destroy the task object
void cancel (session session_id, task task)
Request that a task be cancelled. Note that a task may fail to be cancelled and may complete or fail normally and note that, even when a task does cancel, it might take an arbitrary amount of time.