Fix SEGV when JuliaWrapper is freed by Ruby GC

Author: mrkn

RbCall.jl/src/init.jl

@@ -7,6 +7,10 @@ function jlwrap_init()
  copy!(mJuliaBridge, rb_define_module_under(mJulia, "JuliaBridge"))
  copy!(cJuliaWrapper, rb_define_class_under(mJuliaBridge, "JuliaWrapper", rb_cObject))
 
+ jlwrap_free_cfunc = @cfunction(jlwrap_free, Cvoid, (Ptr{jlwrap_t},))
+ jlwrap_size_cfunc = @cfunction(jlwrap_size, Csize_t, (Ptr{jlwrap_t},))
+ jlwrap_data_type[] = rb_data_type_t(jlwrap_type_name; dfree=jlwrap_free_cfunc, dsize=jlwrap_size_cfunc)
+
  rb_define_method(cJuliaWrapper, "call", jlwrap_call, -1)
  rb_define_method(cJuliaWrapper, "inspect", jlwrap_inspect, 0)
 

RbCall.jl/src/jlwrap.jl

@@ -16,10 +16,6 @@ end
 
 const jlwrap_type_name = Base.unsafe_convert(Cstring, "julia.jlwrap")
 const jlwrap_data_type = Ref{rb_data_type_t}()
-const jlwrap_free_cfunc = @cfunction(jlwrap_free, Cvoid, (Ptr{jlwrap_t},))
-const jlwrap_size_cfunc = @cfunction(jlwrap_size, Csize_t, (Ptr{jlwrap_t},))
-
-jlwrap_data_type[] = rb_data_type_t(jlwrap_type_name; dfree=jlwrap_free_cfunc, dsize=jlwrap_size_cfunc)
 
 function is_jlwrap(ro::Union{RubyObject,RbPtr})
  Bool(ccall((@rbsym :rb_typeddata_is_kind_of), Cint, (RbPtr, Ptr{rb_data_type_t}), ro, jlwrap_data_type))