(* Library module defined by the International Standard
   Information technology - programming languages
   BS ISO/IEC 10514-1:1996E Part 1: Modula-2, Base Language.

   Copyright ISO/IEC (International Organization for Standardization
   and International Electrotechnical Commission) 1996-2021.

   It may be freely copied for the purpose of implementation (see page
   707 of the Information technology - Programming languages Part 1:
   Modula-2, Base Language.  BS ISO/IEC 10514-1:1996).  *)

DEFINITION MODULE Storage;

  (* Facilities for dynamically allocating and deallocating storage *)

IMPORT SYSTEM;

PROCEDURE ALLOCATE (VAR addr: SYSTEM.ADDRESS; amount: CARDINAL);
  (* Allocates storage for a variable of size amount and assigns
     the address of this variable to addr. If there is insufficient
     unallocated storage to do this, the value NIL is assigned to addr.
  *)

PROCEDURE DEALLOCATE (VAR addr: SYSTEM.ADDRESS; amount: CARDINAL);
  (* Deallocates amount locations allocated by ALLOCATE for
     the storage of the variable addressed by addr and assigns
     the value NIL to addr.
  *)

PROCEDURE REALLOCATE (VAR addr: SYSTEM.ADDRESS; amount: CARDINAL);
  (* Attempts to reallocate, amount of storage.  Effectively it
     calls ALLOCATE, copies the amount of data pointed to by
     addr into the new space and DEALLOCATES the addr.
     This procedure is a GNU extension.
  *)

TYPE
  StorageExceptions = (
    nilDeallocation,             (* first argument to DEALLOCATE is NIL *)
    pointerToUnallocatedStorage, (* storage to deallocate not allocated by ALLOCATE *)
    wrongStorageToUnallocate     (* amount to deallocate is not amount allocated *)
  );

PROCEDURE IsStorageException (): BOOLEAN;
  (* Returns TRUE if the current coroutine is in the exceptional
     execution state because of the raising of an exception from
     StorageExceptions; otherwise returns FALSE.
  *)

PROCEDURE StorageException (): StorageExceptions;
  (* If the current coroutine is in the exceptional execution
     state because of the raising of an exception from
     StorageExceptions, returns the corresponding
     enumeration value, and otherwise raises an exception.
  *)

END Storage.