SVs are in two parts: the head, which is fixed size and is 12 bytes on a typical 32-bit processor, and which may contain a pointer to the body, which is variable sized depending on the type (integer, string, reference, hash, etc). The address of the head is what is displayed by ref() etc. SV heads are allocated from arenas: malloc'd chunks of memory approx 1K in size. Within arenas, the addresses of SVs will be offset from neighbours by 12 bytes (again, only for a typical 32-bit system), but you can't make any assumptions about SVs allocated from different arenas.

Of course this might change completely in a future release of perl.

Dave.

In reply to Re: Circular reference testing. by dave_the_m
in thread Circular reference testing. by BrowserUk

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