Class FFI::ManagedStruct
In: lib/ffi/managedstruct.rb
Parent: FFI::Struct

FFI::ManagedStruct allows custom garbage-collection of your FFI::Structs.

The typical use case would be when interacting with a library that has a nontrivial memory management design, such as a linked list or a binary tree.

When the {Struct} instance is garbage collected, FFI::ManagedStruct will invoke the class‘s release() method during object finalization.

@example Example usage:

 module MyLibrary
   ffi_lib "libmylibrary"
   attach_function :new_dlist, [], :pointer
   attach_function :destroy_dlist, [:pointer], :void
 end

 class DoublyLinkedList < FFI::ManagedStruct
   @@@
   struct do |s|
     s.name 'struct dlist'
     s.include 'dlist.h'
     s.field :head, :pointer
     s.field :tail, :pointer
   end
   @@@

   def self.release ptr
     MyLibrary.destroy_dlist(ptr)
   end
 end

 begin
   ptr = DoublyLinkedList.new(MyLibrary.new_dlist)
   #  do something with the list
 end
 # struct is out of scope, and will be GC'd using DoublyLinkedList#release

Methods

new  

Public Class methods

@overload initialize(pointer)

 @param [Pointer] pointer
 Create a new ManagedStruct which will invoke the class method #release on

@overload initialize A new instance of FFI::ManagedStruct.

[Validate]