Copyright (C) 1993, Digital Equipment Corporation           

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RTHeap provides access to the layout of data on the heap. \index{heap} \index{storage allocator} \index{allocator}

Each referent on the heap, and the heap data record for each object, is represented as a contiguous sequence of ``data bytes''. Referents and data records may also contain other ``non-data'' bytes like headers, method suite pointers, or open array shapes.

See RTType for related operations on types.

INTERFACE RTHeap;

PROCEDURE GetDataAdr(r: REFANY): ADDRESS;

If r is a traced reference, returns the address of r^'s data bytes. If r is a traced object, returns the address of the bytes of r's data record. It is a checked runtime error if r is NIL. Note that the address can subsequently change unless object mobility is disabled using RTCollector.

PROCEDURE GetDataSize(r: REFANY): CARDINAL;

If r is a traced reference, returns the number of r^'s data bytes. If r is a traced object, returns the number of bytes of r's data record. It is a checked runtime error if r is NIL.

PROCEDURE GetArrayShape(r: REFANY; VAR s: ARRAY OF INTEGER);

If r is a traced reference to an open array, returns in s[0 .. n-1] the size of each dimension of the n-dimensional open array r^. If s is too large, the extra elements are ignored; if it's too small, the extra sizes are discarded. It is a checked runtime error if r is NIL. If r is not a reference to an open array, s is unchanged.

END RTHeap.