Hello,
while debugging resource leaks in my code I found that I used ohash
incorrectly. I came here to ask what is the best way of doing what I
need to do.
The task is simple: remove all elements that satisfy some property.
Naively, I wrote:
for (el = ohash_first(map, &it); el; el = ohash_next(map, &it))
if (condition(el))
ohash_remove(el->key);
This fails, because the hash map may be resized in the middle of the
loop. If that happens, some elements that meet the condition can be
moved to a position before the iterator and skipped. It seems to me that
in order to do a proper deletion, I should either:
* do 2 passes; collect keys to delete in the first and remove them in
the second, or
* add another layer of looping and keep iterating as long as a pass over
the map deleted at least one element.
Neither seems to be a good way of doing such a trivial task.
Please note that man is totally unhelpful:
"Those functions are safe to use even while entries are added to/removed
from the table, but in such a case they don't guarantee that new entries
will be returned. As a special case, they can safely be used to free
elements in the table."
In my opinion, the man entry should be clarified.
Regards,
--
Maciej Adamczyk
