Fiddle::Closure

Parent:Object

描述

一个FFI封闭包装器，用于处理回调。

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

argsR

FFI关闭的论点

ctypeR

FFI封闭返回的C类型

公共类方法

new(ret, args, abi = Fiddle::DEFAULT) Show source

构建一个新的Closure对象。

• ret 是要返回的C类型

• args 是一个传递给回调函数的参数数组

• abi 是关闭的abi

如果在准备ffi_cif或ffi_prep_closure时出错，则会引发RuntimeError。

static VALUE
initialize(int rbargc, VALUE argv[], VALUE self)
{
    VALUE ret;
    VALUE args;
    VALUE abi;
    fiddle_closure * cl;
    ffi_cif * cif;
    ffi_closure *pcl;
    ffi_status result;
    int i, argc;

    if (2 == rb_scan_args(rbargc, argv, "21", &ret, &args, &abi))
        abi = INT2NUM(FFI_DEFAULT_ABI);

    Check_Type(args, T_ARRAY);

    argc = RARRAY_LENINT(args);

    TypedData_Get_Struct(self, fiddle_closure, &closure_data_type, cl);

    cl->argv = (ffi_type **)xcalloc(argc + 1, sizeof(ffi_type *));

    for (i = 0; i < argc; i++) {
        int type = NUM2INT(RARRAY_AREF(args, i));
        cl->argv[i] = INT2FFI_TYPE(type);
    }
    cl->argv[argc] = NULL;

    rb_iv_set(self, "@ctype", ret);
    rb_iv_set(self, "@args", args);

    cif = &cl->cif;
    pcl = cl->pcl;

    result = ffi_prep_cif(cif, NUM2INT(abi), argc,
                INT2FFI_TYPE(NUM2INT(ret)),
                cl->argv);

    if (FFI_OK != result)
        rb_raise(rb_eRuntimeError, "error prepping CIF %d", result);

#if USE_FFI_CLOSURE_ALLOC
    result = ffi_prep_closure_loc(pcl, cif, callback,
                (void *)self, cl->code);
#else
    result = ffi_prep_closure(pcl, cif, callback, (void *)self);
    cl->code = (void *)pcl;
    i = mprotect(pcl, sizeof(*pcl), PROT_READ | PROT_EXEC);
    if (i) {
        rb_sys_fail("mprotect");
    }
#endif

    if (FFI_OK != result)
        rb_raise(rb_eRuntimeError, "error prepping closure %d", result);

    return self;
}

公共实例方法

to_i() Show source

返回此闭包的内存地址

static VALUE
to_i(VALUE self)
{
    fiddle_closure * cl;
    void *code;

    TypedData_Get_Struct(self, fiddle_closure, &closure_data_type, cl);

    code = cl->code;

    return PTR2NUM(code);
}