Re: cvs head initdb hangs on unixware

ohp(at)pyrenet(dot)fr writes:
> the infinite loop occurs in fsm_search_avail when called for the 32nd
> time.

... which is the first time that the initial test doesn't make it fall
out immediately.

Would you add a couple more printouts, along the line of

nodeno = target;
while (nodeno > 0)
{
+ fprintf(stderr, "ascend at node %d value %d\n",
+ nodeno, fsmpage->fp_nodes[nodeno]);

if (fsmpage->fp_nodes[nodeno] >= minvalue)
break;

/*
* Move to the right, wrapping around on same level if necessary,
* then climb up.
*/
nodeno = parentof(rightneighbor(nodeno));
}

/*
* We're now at a node with enough free space, somewhere in the middle of
* the tree. Descend to the bottom, following a path with enough free
* space, preferring to move left if there's a choice.
*/
while (nodeno < NonLeafNodesPerPage)
{
int leftnodeno = leftchild(nodeno);
int rightnodeno = leftnodeno + 1;
bool leftok = (leftnodeno < NodesPerPage) &&
(fsmpage->fp_nodes[leftnodeno] >= minvalue);
bool rightok = (rightnodeno < NodesPerPage) &&
(fsmpage->fp_nodes[rightnodeno] >= minvalue);

+ fprintf(stderr, "descend at node %d value %d, leftnode %d value %d, rightnode %d value %d\n",
+ nodeno, fsmpage->fp_nodes[nodeno],
+ leftnodeno, fsmpage->fp_nodes[leftnodeno],
+ rightnodeno, fsmpage->fp_nodes[rightnodeno]);

if (leftok)
nodeno = leftnodeno;
else if (rightok)
nodeno = rightnodeno;
else

(I'm assuming we can print possibly-off-the-end array elements without dumping
core; which is bogus in general but I expect we can get away with it
for this purpose.)

Also, we don't really need 94MB of log to convince us it's an
infinite loop ;-)

regards, tom lane