Class: FFI::Function

Inherits:
Pointer show all
Defined in:
lib/ffi/function.rb,
ext/ffi_c/Function.c

Constant Summary

Constants inherited from Pointer

Pointer::NULL, Pointer::SIZE

Instance Method Summary collapse

Methods inherited from Pointer

#+, #==, #address, #inspect, #null?, #order, #read, #read_array_of_type, #read_string, #read_string_length, #read_string_to_null, size, #slice, #to_ptr, #to_s, #type_size, #write, #write_array_of_type, #write_string, #write_string_length

Methods inherited from AbstractMemory

#[], #__copy_from__, #clear, #freeze, #get, #get_array_of_float32, #get_array_of_float64, #get_array_of_pointer, #get_array_of_string, #get_bytes, #get_float32, #get_float64, #get_pointer, #get_string, #put, #put_array_of_float32, #put_array_of_float64, #put_array_of_pointer, #put_bytes, #put_float32, #put_float64, #put_pointer, #put_string, #read_array_of_double, #read_array_of_float, #read_array_of_pointer, #read_array_of_string, #read_bytes, #read_double, #read_float, #read_pointer, #size_limit?, #total, #type_size, #write_array_of_double, #write_array_of_float, #write_array_of_pointer, #write_bytes, #write_double, #write_float, #write_pointer

Constructor Details

#initialize(return_type, param_types, options = {}) {|i| ... } ⇒ self #initialize(return_type, param_types, proc, options = {}) ⇒ self

A new Function instance.

Define a function from a Proc or a block.

Overloads:

  • #initialize(return_type, param_types, options = {}) {|i| ... } ⇒ self

    Yield Parameters:

    • i —

      parameters for the function

  • #initialize(return_type, param_types, proc, options = {}) ⇒ self

    Parameters:

    • proc (Proc)

Parameters:

  • return_type (Type, Symbol) —

    return type for the function

  • param_types (Array<Type, Symbol>) —

    array of parameters types

  • options (Hash) —

    see FFI::FunctionType for available options



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# File 'ext/ffi_c/Function.c', line 346

static VALUE
function_initialize(int argc, VALUE* argv, VALUE self)
{

    VALUE rbReturnType = Qnil, rbParamTypes = Qnil, rbProc = Qnil, rbOptions = Qnil;
    VALUE rbFunctionInfo = Qnil;
    VALUE infoArgv[3];
    int nargs;

    nargs = rb_scan_args(argc, argv, "22", &rbReturnType, &rbParamTypes, &rbProc, &rbOptions);

    /*
     * Callback with block,
     * e.g. Function.new(:int, [ :int ]) { |i| blah }
     * or   Function.new(:int, [ :int ], { :convention => :stdcall }) { |i| blah }
     */
    if (rb_block_given_p()) {
        if (nargs > 3) {
            rb_raise(rb_eArgError, "cannot create function with both proc/address and block");
        }
        rbOptions = rbProc;
        rbProc = rb_block_proc();
    } else {
        /* Callback with proc, or Function with address
         * e.g. Function.new(:int, [ :int ], Proc.new { |i| })
         *      Function.new(:int, [ :int ], Proc.new { |i| }, { :convention => :stdcall })
         *      Function.new(:int, [ :int ], addr)
         *      Function.new(:int, [ :int ], addr, { :convention => :stdcall })
         */
    }

    infoArgv[0] = rbReturnType;
    infoArgv[1] = rbParamTypes;
    infoArgv[2] = rbOptions;
    rbFunctionInfo = rb_class_new_instance(rbOptions != Qnil ? 3 : 2, infoArgv, rbffi_FunctionTypeClass);

    function_init(self, rbFunctionInfo, rbProc);

    return self;
}

Instance Method Details

#attach(m, name) ⇒ self

Attach a Function to the Module m as name.

Parameters:

  • m (Module)
  • name (String)

Returns:

  • (self) 


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# File 'lib/ffi/function.rb', line 56

def attach(mod, name)
  this = self
  body = proc do |*args, &block|
    this.call(*args, &block)
  end

  mod.define_method(name, body)
  mod.define_singleton_method(name, body)

  # Store function Proc's for re-definition as Ractor-shareable in Library#freeze
  funcs = mod.instance_variable_get("@ffi_function_procs")
  unless funcs
    funcs = {}
    mod.instance_variable_set("@ffi_function_procs", funcs)
  end
  funcs[name] = self

  self
end

#autorelease ⇒ Boolean

Get autorelease attribute. Synonymous for #autorelease?.

Returns:

  • (Boolean) 


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# File 'ext/ffi_c/Function.c', line 561

static VALUE
function_autorelease_p(VALUE self)
{
    Function* fn;

    TypedData_Get_Struct(self, Function, &function_data_type, fn);

    return fn->autorelease ? Qtrue : Qfalse;
}

#autorelease=(autorelease) ⇒ self

Set autorelease attribute (See Pointer).

Parameters:

  • autorelease (Boolean)

Returns:

  • (self) 


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# File 'ext/ffi_c/Function.c', line 548

static VALUE
function_set_autorelease(VALUE self, VALUE autorelease)
{
    Function* fn;

    rb_check_frozen(self);
    TypedData_Get_Struct(self, Function, &function_data_type, fn);

    fn->autorelease = RTEST(autorelease);

    return self;
}

#autorelease? ⇒ Boolean

Get autorelease attribute.

Returns:

  • (Boolean) —

    autorelease attribute



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# File 'ext/ffi_c/Function.c', line 561

static VALUE
function_autorelease_p(VALUE self)
{
    Function* fn;

    TypedData_Get_Struct(self, Function, &function_data_type, fn);

    return fn->autorelease ? Qtrue : Qfalse;
}

#call(*args) ⇒ FFI::Type

Call the function

Parameters:

  • args (Array) —

    function arguments

Returns:



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# File 'ext/ffi_c/Function.c', line 493

static VALUE
function_call(int argc, VALUE* argv, VALUE self)
{
    Function* fn;

    TypedData_Get_Struct(self, Function, &function_data_type, fn);

    return (*fn->info->invoke)(argc, argv, fn->base.memory.address, fn->info);
}

#free ⇒ self

Free memory allocated by Function.

Returns:

  • (self) 


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# File 'ext/ffi_c/Function.c', line 586

static VALUE
function_release(VALUE self)
{
    Function* fn;

    TypedData_Get_Struct(self, Function, &function_data_type, fn);

    if (fn->closure == NULL) {
        rb_raise(rb_eRuntimeError, "cannot free function which was not allocated");
    }

    rbffi_Closure_Free(fn->closure);
    fn->closure = NULL;

    return self;
}

#initialize_copy(other) ⇒ nil

DO NOT CALL THIS METHOD

Returns:

  • (nil) 


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# File 'ext/ffi_c/Function.c', line 392

static VALUE
function_initialize_copy(VALUE self, VALUE other)
{
    rb_raise(rb_eRuntimeError, "cannot duplicate function instances");
    return Qnil;
}

#param_types ⇒ Array<FFI::Type>

Retrieve Array of parameter types

This method returns an Array of FFI types accepted as function parameters.

Returns:



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# File 'lib/ffi/function.rb', line 49

def param_types
  type.param_types
end

#return_type ⇒ FFI::Type

Retrieve the return type of the function

This method returns FFI type returned by the function.

Returns:



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# File 'lib/ffi/function.rb', line 40

def return_type
  type.return_type
end