79 lines
1.8 KiB
Plaintext
79 lines
1.8 KiB
Plaintext
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(* Version 1.10, Nov 1984 *)
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DEFINITION MODULE Storage;
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(*
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Standard dynamic storage management
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Storage management for dynamic variables. Calls to the
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Modula-2 standard procedures NEW and DISPOSE are
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translated into calls to ALLOCATE and DEALLOCATE. The
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standard way to provide these two procedures is to
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import them from this module 'Storage'.
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Derived from the Lilith Modula-2 system developed by the
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group of Prof. N. Wirth at ETH Zurich, Switzerland.
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*)
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FROM SYSTEM IMPORT ADDRESS;
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EXPORT QUALIFIED
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ALLOCATE, DEALLOCATE, Available,
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InstallHeap, RemoveHeap;
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PROCEDURE ALLOCATE (VAR a: ADDRESS; size: CARDINAL);
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(*
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- Allocate some dynamic storage (contiguous memory area).
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in: size number of bytes to allocate,
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out: a ADDRESS of allocated storage.
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The actual number of bytes allocated may be slightly
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greater than 'size', due to administrative overhead.
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Errors: If not enough space is available, or when
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attempting to allocate more than 65520 (0FFF0H)
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bytes at once, then the calling program is terminated
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with the status 'heapovf'.
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*)
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PROCEDURE DEALLOCATE (VAR a: ADDRESS; size: CARDINAL);
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(*
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- Release some dynamic storage (contiguous memory area).
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in: a ADDRESS of the area to release,
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size number of bytes to be released,
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out: a set to NIL.
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The storage area released is made available for subsequent
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calls to ALLOCATE.
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*)
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PROCEDURE Available (size: CARDINAL) : BOOLEAN;
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(*
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- Test whether some number of bytes could be allocated.
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in: size number of bytes
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out: TRUE if ALLOCATE (p, size) would succeed.
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*)
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PROCEDURE InstallHeap;
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(*
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- Used internally by the loader
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*)
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PROCEDURE RemoveHeap;
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(*
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- Used internally by the loader
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*)
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END Storage.
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