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Re: [PATCH 3/3] Refactor atfork handlers
On 02/08/2018 01:50 PM, Adhemerval Zanella wrote:
+static struct fork_handler *
+fork_handler_list_find_if (struct fork_handler_list *fork_handlers,
+ void *dso_handle)
Should be called _find, not find_if (no callback is involved).
+ struct fork_handler *first = fork_handler_list_find_if (&fork_handlers,
+ dso_handle);
+ /* Removing is done by shifting the elements in the way the elements
+ that are not to be removed appear in the beginning in dynarray.
+ This avoid the quadradic run-time if a naive strategy to remove and
+ shift one element at time. */
+ if (first != NULL)
+ {
+ struct fork_handler *result = first;
result should probably be called new_end or something like that.
+ first++;
+ for (; first != fork_handler_list_end (&fork_handlers); ++first)
+ {
+ if (first->dso_handle != dso_handle)
+ {
+ memcpy (result, first, sizeof (struct fork_handler));
Wouldn't a simple struct assignment work here?
I think this patch is a step in the right direction, so it should go in
with these changes.
However, I think we should make a few improvements in follow-up fixes:
Reduce RSS usage for the common case that no atfork handlers are ever
registered. This will be the case once we remove the bogus
__reclaim_stacks function.
Make a temporary copy of the handler array during fork. This has two
benefits: We can run the handlers without acquiring the handler lock (to
avoid application deadlocks). We also make sure that a handler does not
run in a child process which did not run in the parent process. I think
the old implementation had both properties.
Thanks,
Florian