<< Previous | Next >>

pxprev

long pxprev( Pool_t * p, long e );

Description

Get the previous allocated element in an xmem pool. The pool MUST be set to being a linked pool using pool_link(p, <non-zero>); otherwise the results are undefined.

You can easily iterate through all of the allocated elements of an xmem pool using the following construct:

   

long e;
Pool_t * p;
for (e = pxlast(p); e; e = pxprev(p, e)) {
   ...
}

Parameters

p

Pool handle structure, as previously passed to pool_xinit().

e

Previous element address, obtained by e.g., pxlast(). This must be an allocated element in the given pool; otherwise, the results are undefined. Be careful when iterating through a list and deleting elements using pxfree(): once the element is deleted, it is no longer valid to pass its address to this function. If this parameter is zero, then the result is the same as pxlast(). This ensures the invariant

pxlast(p, pxnext(p, e)) == e

Return value

 0: There are no more elements
!0: Points to previously allocated element

Library

POOL.LIB

See Also

pool_xinit, pool_link, pxalloc, pxfree, pxlast, pxnext