summaryrefslogtreecommitdiff
path: root/ext/fiddle/closure.c
blob: cb0c462a08097a7f9cfcd7ca785ee93def1bd82a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
#include <fiddle.h>

VALUE cFiddleClosure;

typedef struct {
    void * code;
    ffi_closure *pcl;
    ffi_cif cif;
    int argc;
    ffi_type **argv;
} fiddle_closure;

#if defined(USE_FFI_CLOSURE_ALLOC)
#elif defined(__OpenBSD__) || defined(__APPLE__) || defined(__linux__)
# define USE_FFI_CLOSURE_ALLOC 0
#elif defined(RUBY_LIBFFI_MODVERSION) && RUBY_LIBFFI_MODVERSION < 3000005 && \
	(defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_AMD64))
# define USE_FFI_CLOSURE_ALLOC 0
#else
# define USE_FFI_CLOSURE_ALLOC 1
#endif

static void
dealloc(void * ptr)
{
    fiddle_closure * cls = (fiddle_closure *)ptr;
#if 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);

#if 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);

#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;
}

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+ is an Array of arguments, passed to the callback function
     * * +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 */