William,

Libuv does not allocate or destroy anything, except `uv_loop_new` function
(which is going to be removed one day).

Every request, be it write/shutdown/queue_work is allocated by user and
must be kept alive.

Cheers,
Fedor.

On Thu, Dec 18, 2014 at 9:38 AM, William Ehlhardt <[email protected]
> wrote:
>
> I thought about this some more. Obviously in (2), user code has to be
> responsible for deletion, since uv_queue_work takes a pointer that could be
> to a stack-allocated uv_work_t. So the question remains: when is it safe to
> delete the uv_work_t?
>
> On Wednesday, December 17, 2014 8:31:20 PM UTC-6, William Ehlhardt wrote:
>
>> Hi folks,
>>
>> In the attached file, I delete a uv_work_t after running uv_queue_work,
>> which causes a use-after-free crash. This is somewhat surprising behavior.
>>
>> 1. The documentation does not make it clear that the uv_work_t passed to
>> uv_queue_work needs to remain alive until (presumably?) the callbacks have
>> all completed, which leads to:
>>
>> 2. Since uv_queue_work spins off another thread to do the work, and since
>> this may happen in a context where you're spinning many uv_work_t tasks off
>> to run simultaneously, it's not clear where the uv_work_t should be
>> deleted. Declaring it on the stack of the caller of uv_run isn't a very
>> good solution because you can't stack-declare arbitrary numbers of
>> uv_work_t, which you need to do if you're potentially queuing lots of
>> background work at once. Allocating it on the heap, meanwhile, brings up
>> the question of (A) is user code responsible for deleting the uv_work_t, or
>> is libuv? and (B) if user code is responsible, when is it safe to delete
>> the work_t? During the "done" callback?
>>
>> -William
>>
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