Reallocate Storage (CEECZST) API

Required Parameter Group:

1	address	I/O	POINTER
2	new_size	Input	INT4

Omissible Parameter:

Output

FEEDBACK

  Service Program Name: QLEAWI

  Default Public Authority: *USE

  Threadsafe: Yes

The Reallocate Storage (CEECZST) API changes the size of a previously allocated storage block, preserving the contents.

None.

address (I/O): On input, this parameter contains an address returned by a previous CEEGTST call or a language intrinsic function. On output, the address of the first byte of the newly allocated storage is returned in this parameter.
In effect, reallocation of a storage block is accomplished by allocating a new storage block, of size new_size, and copying the contents of the old block to the new block.
new_size (input): The number of bytes of storage to be allocated for the new storage block. This value is rounded up to a multiple of the minimum boundary specified when the heap was created. The minimum boundary for the activation group default heap is 16 bytes.

A message severity of 10 or less represents success. If the severity is greater than 10:

CEE0000	The API completed successfully
Severity: 00
CEE0802	The storage headers are damaged
Severity: 40
CEE0808	Requested storage size is not valid
Severity: 30
CEE0810	The starting address for reallocation is not valid
Severity: 30
CEE0813	Insufficient storage available to satisfy the request
Severity: 30

The heap identifier is inferred from the address. The new storage block is allocated from the same heap that contained the old block. The reallocate operation may be issued from an activation group other than the one that owns the heap.
The contents of the old storage block are preserved in the following way:
- If new_size is greater than the old size, the entire contents of the old storage block are copied to the new block.
- If new_size is less than the old size, the contents of the old block are truncated to the size of the new block.
- If new_size is equal to the old size, the contents of the old storage block are copied to the new block.
Note: Because the new storage may be allocated at a different location than the existing allocation, any pointers that referred to the old storage are no longer valid. Continued use of such pointers will give unpredictable, or incorrect results.
Storage that is reallocated maintains the same mark and release status as the old storage block. If the old storage block was marked, the new storage block carries the same mark and is released by a release operation that specifies the mark.

API introduced: V2R3