Store each FFI::Function in it's own instance variabe in the module to be attached

This allows to freeze the FFI::Function immediately, so that it is shareable by Ractor without the need to freeze the module explicit.
To make it shareable the typedef hash used for variadic functions is duplicated and made frozen.

This creates a small compatibility issue:
Only typedefs defined above the variadic function can be used by that function.
If a typedef is created after the definition of the variadic function, then this typedef can no longer be used as parameter to that variadic function.

Also fix the retrieval of simple (non-struct) global variables per #attached_variables.

Closes #975

1 files changed, 2 insertions, 3 deletions

diff --git a/lib/ffi/variadic.rb b/lib/ffi/variadic.rb
index 42c5549..800d121 100644
--- a/lib/ffi/variadic.rb
+++ b/lib/ffi/variadic.rb
@@ -55,11 +55,10 @@ module FFI
       params = "*args"
       call = "call"
       mod.module_eval <<-code
-        @ffi_functions = {} unless defined?(@ffi_functions)
-        @ffi_functions[#{mname.inspect}] = invoker
+        @ffi_function_#{mname} = invoker
 
         def self.#{mname}(#{params})
-          @ffi_functions[#{mname.inspect}].#{call}(#{params})
+          @ffi_function_#{mname}.#{call}(#{params})
         end
 
         define_method(#{mname.inspect}, &method(:#{mname}))