class Fiddle::Closure

描述¶ ↑

用于处理回调的 FFI 闭包包装器。

示例¶ ↑

closure = Class.new(Fiddle::Closure) {
  def call
    10
  end
}.new(Fiddle::TYPE_INT, [])
   #=> #<#<Class:0x0000000150d308>:0x0000000150d240>
func = Fiddle::Function.new(closure, [], Fiddle::TYPE_INT)
   #=> #<Fiddle::Function:0x00000001516e58>
func.call
   #=> 10

属性

args[R]

FFI 闭包的参数

ctype[R]

FFI 闭包返回值的 C 类型

公共类方法

create(*args) { |closure| ... } 点击切换源码

创建一个新的闭包。如果给出了代码块，则在执行完给定代码块后，创建的闭包将自动释放。

所有给定的参数都会传递给 Fiddle::Closure.new。因此，不使用代码块调用此方法等同于调用 Fiddle::Closure.new。

示例¶ ↑

Fiddle::Closure.create(TYPE_INT, [TYPE_INT]) do |closure|
  # closure is freed automatically when this block is finished.
end

# File fiddle/lib/fiddle/closure.rb, line 16
def create(*args)
  if block_given?
    closure = new(*args)
    begin
      yield(closure)
    ensure
      closure.free
    end
  else
    new(*args)
  end
end

new(ret, args, abi = Fiddle::DEFAULT) 点击切换源码

构造一个新的 Closure 对象。

ret 是要返回的 C 类型
args 是传递给回调函数的参数数组
abi 是闭包的 ABI

如果在准备 ffi_cif 或 ffi_prep_closure 时发生错误，则会引发 RuntimeError。

static VALUE
initialize(int argc, VALUE *argv, VALUE self)
{
    initialize_data data;
    data.self = self;
    data.argc = argc;
    data.argv = argv;
    return rb_rescue(initialize_body, (VALUE)&data,
                     initialize_rescue, (VALUE)&data);
}

new(ret, args, abi = Function::DEFAULT) 点击切换源码

# File fiddle/lib/fiddle/ffi_backend.rb, line 181
def initialize(ret, args, abi = Function::DEFAULT)
  raise TypeError.new "invalid argument types" unless args.is_a?(Array)

  @ctype, @args = ret, args
  ffi_args = @args.map { |t| Fiddle::FFIBackend.to_ffi_type(t) }
  if ffi_args.size == 1 && ffi_args[0] == FFI::Type::Builtin::VOID
    ffi_args = []
  end
  return_type = Fiddle::FFIBackend.to_ffi_type(@ctype)
  raise "#{self.class} must implement #call" unless respond_to?(:call)
  callable = method(:call)
  @function = FFI::Function.new(return_type, ffi_args, callable, convention: abi)
  @freed = false
end

公共实例方法

free() 点击切换源码

显式释放此闭包。您不能再使用此闭包。

如果此闭包已被释放，则此操作不起任何作用。

static VALUE
closure_free(VALUE self)
{
    fiddle_closure *closure;
    TypedData_Get_Struct(self, fiddle_closure, &closure_data_type, closure);
    if (closure) {
        dealloc(closure);
        RTYPEDDATA_DATA(self) = NULL;
    }
    return RUBY_Qnil;
}

freed?() 点击切换源码

此闭包是否已被显式释放。

static VALUE
closure_freed_p(VALUE self)
{
    fiddle_closure *closure;
    TypedData_Get_Struct(self, fiddle_closure, &closure_data_type, closure);
    return closure ? RUBY_Qfalse : RUBY_Qtrue;
}

to_i() 点击切换源码

返回此闭包的内存地址。

static VALUE
to_i(VALUE self)
{
    fiddle_closure *closure = get_raw(self);
    return PTR2NUM(closure->code);
}

to_ptr() 点击切换源码

# File fiddle/lib/fiddle/ffi_backend.rb, line 196
def to_ptr
  @function
end