closure.c
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#include <fiddle.h>
VALUE cFiddleClosure;
typedef struct {
void * code;
ffi_closure *pcl;
ffi_cif cif;
int argc;
ffi_type **argv;
} fiddle_closure;
#if defined(MACOSX) || defined(__linux) || defined(__OpenBSD__)
#define DONT_USE_FFI_CLOSURE_ALLOC
#endif
static void
dealloc(void * ptr)
{
fiddle_closure * cls = (fiddle_closure *)ptr;
#ifndef DONT_USE_FFI_CLOSURE_ALLOC
ffi_closure_free(cls->pcl);
#else
munmap(cls->pcl, sizeof(cls->pcl));
#endif
if (cls->argv) xfree(cls->argv);
xfree(cls);
}
static size_t
closure_memsize(const void * ptr)
{
fiddle_closure * cls = (fiddle_closure *)ptr;
size_t size = 0;
if (ptr) {
size += sizeof(*cls);
#if !defined(FFI_NO_RAW_API) || !FFI_NO_RAW_API
size += ffi_raw_size(&cls->cif);
#endif
size += sizeof(*cls->argv);
size += sizeof(ffi_closure);
}
return size;
}
const rb_data_type_t closure_data_type = {
"fiddle/closure",
{0, dealloc, closure_memsize,},
};
void
callback(ffi_cif *cif, void *resp, void **args, void *ctx)
{
VALUE self = (VALUE)ctx;
VALUE rbargs = rb_iv_get(self, "@args");
VALUE ctype = rb_iv_get(self, "@ctype");
int argc = RARRAY_LENINT(rbargs);
VALUE params = rb_ary_tmp_new(argc);
VALUE ret;
VALUE cPointer;
int i, type;
cPointer = rb_const_get(mFiddle, rb_intern("Pointer"));
for (i = 0; i < argc; i++) {
type = NUM2INT(RARRAY_PTR(rbargs)[i]);
switch (type) {
case TYPE_VOID:
argc = 0;
break;
case TYPE_INT:
rb_ary_push(params, INT2NUM(*(int *)args[i]));
break;
case -TYPE_INT:
rb_ary_push(params, UINT2NUM(*(unsigned int *)args[i]));
break;
case TYPE_VOIDP:
rb_ary_push(params,
rb_funcall(cPointer, rb_intern("[]"), 1,
PTR2NUM(*(void **)args[i])));
break;
case TYPE_LONG:
rb_ary_push(params, LONG2NUM(*(long *)args[i]));
break;
case -TYPE_LONG:
rb_ary_push(params, ULONG2NUM(*(unsigned long *)args[i]));
break;
case TYPE_CHAR:
rb_ary_push(params, INT2NUM(*(signed char *)args[i]));
break;
case -TYPE_CHAR:
rb_ary_push(params, UINT2NUM(*(unsigned char *)args[i]));
break;
case TYPE_SHORT:
rb_ary_push(params, INT2NUM(*(signed short *)args[i]));
break;
case -TYPE_SHORT:
rb_ary_push(params, UINT2NUM(*(unsigned short *)args[i]));
break;
case TYPE_DOUBLE:
rb_ary_push(params, rb_float_new(*(double *)args[i]));
break;
case TYPE_FLOAT:
rb_ary_push(params, rb_float_new(*(float *)args[i]));
break;
#if HAVE_LONG_LONG
case TYPE_LONG_LONG:
rb_ary_push(params, LL2NUM(*(LONG_LONG *)args[i]));
break;
case -TYPE_LONG_LONG:
rb_ary_push(params, ULL2NUM(*(unsigned LONG_LONG *)args[i]));
break;
#endif
default:
rb_raise(rb_eRuntimeError, "closure args: %d", type);
}
}
ret = rb_funcall2(self, rb_intern("call"), argc, RARRAY_PTR(params));
RB_GC_GUARD(params);
type = NUM2INT(ctype);
switch (type) {
case TYPE_VOID:
break;
case TYPE_LONG:
*(long *)resp = NUM2LONG(ret);
break;
case -TYPE_LONG:
*(unsigned long *)resp = NUM2ULONG(ret);
break;
case TYPE_CHAR:
case TYPE_SHORT:
case TYPE_INT:
*(ffi_sarg *)resp = NUM2INT(ret);
break;
case -TYPE_CHAR:
case -TYPE_SHORT:
case -TYPE_INT:
*(ffi_arg *)resp = NUM2UINT(ret);
break;
case TYPE_VOIDP:
*(void **)resp = NUM2PTR(ret);
break;
case TYPE_DOUBLE:
*(double *)resp = NUM2DBL(ret);
break;
case TYPE_FLOAT:
*(float *)resp = (float)NUM2DBL(ret);
break;
#if HAVE_LONG_LONG
case TYPE_LONG_LONG:
*(LONG_LONG *)resp = NUM2LL(ret);
break;
case -TYPE_LONG_LONG:
*(unsigned LONG_LONG *)resp = NUM2ULL(ret);
break;
#endif
default:
rb_raise(rb_eRuntimeError, "closure retval: %d", type);
}
}
static VALUE
allocate(VALUE klass)
{
fiddle_closure * closure;
VALUE i = TypedData_Make_Struct(klass, fiddle_closure,
&closure_data_type, closure);
#ifndef DONT_USE_FFI_CLOSURE_ALLOC
closure->pcl = ffi_closure_alloc(sizeof(ffi_closure), &closure->code);
#else
closure->pcl = mmap(NULL, sizeof(ffi_closure), PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
#endif
return i;
}
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_PTR(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);
#ifndef DONT_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;
mprotect(pcl, sizeof(pcl), PROT_READ | PROT_EXEC);
#endif
if (FFI_OK != result)
rb_raise(rb_eRuntimeError, "error prepping closure %d", result);
return self;
}
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);
}
void
Init_fiddle_closure()
{
#if 0
mFiddle = rb_define_module("Fiddle"); /* let rdoc know about mFiddle */
#endif
/*
* Document-class: Fiddle::Closure
*
* == Description
*
* An FFI closure wrapper, for handling callbacks.
*
* == Example
*
* 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
*/
cFiddleClosure = rb_define_class_under(mFiddle, "Closure", rb_cObject);
rb_define_alloc_func(cFiddleClosure, allocate);
/*
* Document-method: new
*
* call-seq: new(ret, *args, abi = Fiddle::DEFAULT)
*
* Construct a new Closure object.
*
* * +ret+ is the C type to be returned
* * +args+ are passed the callback
* * +abi+ is the abi of the closure
*
* If there is an error in preparing the ffi_cif or ffi_prep_closure,
* then a RuntimeError will be raised.
*/
rb_define_method(cFiddleClosure, "initialize", initialize, -1);
/*
* Document-method: to_i
*
* Returns the memory address for this closure
*/
rb_define_method(cFiddleClosure, "to_i", to_i, 0);
}
/* vim: set noet sw=4 sts=4 */