Free Activation Group-Based Heap Space Storage (FREHSS)

Built-in number for FREHSS is 114.
FREHSS (
        space_allocation   : address
)

Note: The term "heap space" in this instruction refers to an "activation group-based heap space".

Description:   The heap space storage allocation beginning at the byte addressed by operand 1 is de-allocated from the heap space which supplied the allocation. De-allocation makes the storage available for reuse by subsequent Allocate Activation Group-Based Heap Space Storage (ALCHSS) instructions. The entire space allocation is de-allocated; partial de-allocation is not supported. A free of heap space storage can be performed without regard to the activation group in which it was allocated, as long as the allocation was done by a thread in the same process.

Operand 1 must be exactly equal to the space pointer that was returned by some previous Allocate Activation Group-Based Heap Space Storage (ALCHSS) or Reallocate Activation Group-Based Heap Space Storage (REALCHSS) instruction. If it is not, an invalid request  (hex 4502) exception will be signaled.

Subsequent references to space allocations which have been freed cause unpredictable results.

FREHSS will signal an object domain or hardware storage protection violation  (hex 4401) exception if a program running user state attempts to de-allocate heap space storage in a heap space with a domain of system.

Operand 1 is not modified by the instruction.

Authorization Required

• None

Lock Enforcement

• None

Exceptions

06 Addressing

• 0601 Space Addressing Violation
• 0602 Boundary Alignment
• 0603 Range

08 Argument/Parameter

• 0801 Parameter Reference Violation

10 Damage Encountered

• 1004 System Object Damage State
• 1005 Authority Verification Terminated Due to Damaged Object
• 1044 Partial System Object Damage

1C Machine-Dependent

• 1C03 Machine Storage Limit Exceeded

20 Machine Support

• 2002 Machine Check
• 2003 Function Check

24 Pointer Specification

• 2401 Pointer Does Not Exist
• 2402 Pointer Type Invalid
• 2403 Pointer Addressing Invalid Object Type

44 Protection Violation

• 4401 Object Domain or Hardware Storage Protection Violation

45 Heap Space

• 4502 Invalid Request
• 4505 Heap Space Destroyed
• 4506 Invalid Heap Space Condition