I guess I could try using std::remove() followed by jl_array_del_end() to remove entries.
Cheers, Kit On Wednesday, August 10, 2016 at 9:45:55 PM UTC+12, Kit Adams wrote: > > Thank you for those links, they are a great help. > > Is there an "unprotect_from_gc(T* val)"? > > I am looking for a smart pointer a bit like v8's UniquePersistent<>. > > I guess I could make one that searched through the array for the value in > order to remove it (in the smart pointer's dtor). > > Thanks, > Kit > > > On Wednesday, August 10, 2016 at 8:10:34 PM UTC+12, Bart Janssens wrote: >> >> >> >> On Wed, Aug 10, 2016 at 9:11 AM Yichao Yu <yyc...@gmail.com> wrote: >> >>> On Wed, Aug 10, 2016 at 2:17 PM, Kit Adams <kit....@gmail.com> wrote: >>> >>>> I am investigating the feasibility of embedding Julia in a C++ >>>> real-time signal processing framework, using Julia-0.4.6 (BTW, the >>>> performance is looking amazing). >>>> >>>> However, for this usage I need to retain Julia state variables across >>>> c++ function calls, so the stack based JL_GC_PUSH() and JL_GC_POP() are >>>> not >>>> sufficient. >>>> When I injected some jl_gc_collect() calls for testing purposes, to >>>> simulate having multiple Julia scripts running (from the same thread), I >>>> got crashes, which I was able to fix using e.g. jl_gc_preserve(mMyState); >>>> and appropriate matching jl_gc_unpreserve() calls. >>>> >>>> I see these functions have been removed from the latest Julia version. >>>> >>>> Is there an alternative that allows Julia values to be retained in a >>>> C++ app across gc calls? >>>> >>> >>> Copy from my reply on github >>> >>> > This never works in the way you think it did. For keeping a value >>> live, put it in a rooted global array. >>> >>> >>> >> I'm not saying this is the best way to implement Yichao's suggestion, but >> here is how it's done in CxxWrap.jl: >> >> https://github.com/barche/CxxWrap.jl/blob/master/deps/src/cxx_wrap/type_conversion.hpp#L27-L38 >> >> The array is allocated and rooted using jl_set_const here: >> >> https://github.com/barche/CxxWrap.jl/blob/master/deps/src/cxx_wrap/cxx_wrap.cpp#L14-L28 >> >> Cheers, >> >> Bart >> >
