DCMT VARY ACTIVE TASK Usage

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DCMT VARY ACTIVE TASK Usage

Initial Maximum Task Count

The maximum task count initially established at runtime is the sum of:

The values specified in the MAXIMUM TASKS and MAXIMUM ERUS parameters of the SYSTEM statement
The number of system tasks. This includes:
- Communication line drivers
- Run unit service drivers
- Other specialized tasks
The number of system tasks vary depending on several parameters. For more information, see Task Resource Usage in the System Generation Guide.

Initial Dispatching Priority

The dispatching priority initially established at system generation time equals the sum of:

The priority for the user (USER statement)
Plus the priority for the logical terminal (LTERM statement) on which the task is executing
Plus the priority for the executing task (TASK statement)

For a system task, the priority of a task thread cannot exceed 255. If the sum of the above values exceeds 255, the task is assigned a priority of 255.

For a user task, the priority of a task thread cannot exceed 240. If the sum of the above values exceeds 240, the task is assigned a priority of 240.

Resource Limits for Task Threads

The following table describes the resource limits for each type of task thread:

Task thread	Description
Storage	The amount of storage that the task can hold at one time The limit (expressed in K bytes) must be an integerin the range 1 through 16383
Lock	The number of database-key locks that the task can holdat one time The limit must be an integer in the range 1 through 2,147,483,647
Call	The number of system service calls (for example, #GETSTG, #LOAD, orOBTAIN CALC) that the task can issue The limit must be an integer in the range 1 through 2,147,483,647
DBIO	The number of database I/O operations (that is, READs and WRITEs)that can be performed for the task The limit must be an integer in the range 1 through 2,147,483,647

Task Thread Task ID or Logical Terminal ID

To obtain the task ID or logical terminal ID for a task thread, use DCMT DISPLAY ACTIVE TASKS command.

Initial Resource Limits for a Task

Resource limits for a task are initially established at DC/UCF system generation time by the LIMIT parameter of the SYSTEM or TASK statement.

More Information

For more information about displaying information about active tasks, see the section DCMT DISPLAY ACTIVE TASKS.
For more information about defining a task to the system at runtime, see DCMT VARY DYNAMIC TASK.
For more information about resource limits and system run units, see the System Generation Guide and the System Operations Guide.
For more information about watching an active task dynamically, see the section OPER WATCH ACTIVE TASKS.