D.7 Tasking Restrictions

All (nonenvironment) tasks depend directly on the environment task of the partition.

Objects of a type that needs finalization (see 7.6) and access types that designate a type that needs finalization shall be declared only at library level. 

There are no abort_statements, and there are no calls on Task_Identification.Abort_Task.

There are no selective_accepts with terminate_alternatives.

There are no allocators for task types or types containing task subcomponents.

There are no operations that implicitly require heap storage allocation to be performed by the implementation. The operations that implicitly require heap storage allocation are implementation defined. 

There are no semantic dependences on the package Dynamic_Priorities, and no occurrences of the attribute Priority.

There is no call to any of the operations defined in package Interrupts (Is_Reserved, Is_Attached, Current_Handler, Attach_Handler, Exchange_Handler, Detach_Handler, and Reference).

Protected objects shall be declared only at library level.

Timing_Events shall be declared only at library level.

There are no allocators for protected types or types containing protected type subcomponents.

There are no delay_relative_statements.

There are no requeue_statements.

There are no select_statements.

There are no calls to the Set_Specific_Handler and Specific_Handler subprograms in Task_Termination.

The Boolean expression in an entry barrier shall be either a static Boolean expression or a Boolean component of the enclosing protected object.

Specifies the maximum number of alternatives in a selective_accept.

Specifies the maximum number of entries per task. The bounds of every entry family of a task unit shall be static, or shall be defined by a discriminant of a subtype whose corresponding bound is static. A value of zero indicates that no rendezvous are possible.

Specifies the maximum number of entries per protected type. The bounds of every entry family of a protected unit shall be static, or shall be defined by a discriminant of a subtype whose corresponding bound is static.

All tasks are non-terminating. It is implementation-defined what happens if a task attempts to terminate. If there is a fall-back handler (see C.7.3) set for the partition it should be called when the first task attempts to terminate. 

Specifies the maximum portion (in storage elements) of a task's Storage_Size that can be retained by a blocked task. If an implementation chooses to detect a violation of this restriction, Storage_Error should be raised; otherwise, the behavior is implementation defined. 

Specifies the maximum dynamic nesting level of asynchronous_selects. A value of zero prevents the use of any asynchronous_select and, if a program contains an asynchronous_select, it is illegal. If an implementation chooses to detect a violation of this restriction for values other than zero, Storage_Error should be raised; otherwise, the behavior is implementation defined. 

Specifies the maximum number of task creations that may be executed over the lifetime of a partition, not counting the creation of the environment task. A value of zero prevents any task creation and, if a program contains a task creation, it is illegal. If an implementation chooses to detect a violation of this restriction, Storage_Error should be raised; otherwise, the behavior is implementation defined. 

Max_Entry_Queue_Length defines the maximum number of calls that are queued on an entry. Violation of this restriction results in the raising of Program_Error at the point of the call or requeue.