GCD and rpmalloc_thread_initialize

[vitorhugomagalhaes]

Hi,

I'm trying to include rpmalloc into my ios project however, since we use GCD I'm not sure where to call rpmalloc_thread_initialize.

Without this call the app crashes in all the callers that are not performed in the main thread where rpmalloc_initialize was called.

Thanksm

[mjansson]

Are you using the malloc wrappers in malloc.c? The idea is that the pthread create calls should be intercepted and threads automagically initialized.

[vitorhugomagalhaes]

I tried the malloc wrappers and the code crashes. I'm not sure that intercepting the pthread_create actually solves the issue when using GCD. Are you sure GCD threads are created with pthread library ?

[mjansson]

Can you share a minimal reproduction case for this?

[victorstewart]

hey I also was really interested in using rpmalloc in my iOS app (Objective C++), but I also use GCD to dispatch work at will... thus can't (if the malloc wrappers are insufficient as described above). I use a lot of static queues to synchronize memory access... but all object creation happens on random queues aka dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0).

I haven't tested any of this though, just exploring the idea right now.

Theoretically I could and would use known/static queues to do all allocations on, if that's necessary to use rpmalloc.. once the more general problem of "will it work with GCD" is sorted out.

[dcouture2]

You could try it out with this branch

https://github.com/dcou/rpmalloc-greedy/tree/greedy_unmap

[victorstewart]

@dcouture2 what’s the difference? i don’t see it in the readme

[dcou]

Just added a section to document the changes
https://github.com/dcou/rpmalloc-greedy/blob/master/README.md#greedy-unmap-fork-enhancements

[mjansson]

Related #63

[mjansson]

Any chance you could provide a minimal reproduction of this issue?

[mjansson]

Ping @vitorhugomagalhaes and @victorstewart on providing more info or a reproduction case

[mjansson]

This should work now in latest develop branch if ENABLE_PRELOAD is set to 1 (in which case each thread will self-init when needed)