src/object.m

   1 /*
   2  * Copyright (c) 2011-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 #include "internal.h"
  22
  23 #if USE_OBJC
  24
  25 #if _OS_OBJECT_OBJC_ARC
  26 #error "Cannot build with ARC"
  27 #endif
  28 #if defined(__OBJC_GC__)
  29 #error Objective C GC isn't supported anymore
  30 #endif
  31
  32 #include <objc/objc-internal.h>
  33 #include <objc/objc-exception.h>
  34 #include <Foundation/NSString.h>
  35
  36 #pragma mark -
  37 #pragma mark _os_object_t
  38
  39 static inline id
  40 _os_objc_alloc(Class cls, size_t size)
  41 {
  42         id obj;
  43         size -= sizeof(((struct _os_object_s *)NULL)->os_obj_isa);
  44         while (!fastpath(obj = class_createInstance(cls, size))) {
  45                 _dispatch_temporary_resource_shortage();
  46         }
  47         return obj;
  48 }
  49
  50 static void*
  51 _os_objc_destructInstance(id obj)
  52 {
  53         // noop if only Libystem is loaded
  54         return obj;
  55 }
  56
  57 #if DISPATCH_COCOA_COMPAT
  58 static bool _os_object_debug_missing_pools;
  59 #endif
  60
  61 void
  62 _os_object_init(void)
  63 {
  64         _objc_init();
  65         Block_callbacks_RR callbacks = {
  66                 sizeof(Block_callbacks_RR),
  67                 (void (*)(const void *))&objc_retain,
  68                 (void (*)(const void *))&objc_release,
  69                 (void (*)(const void *))&_os_objc_destructInstance
  70         };
  71         _Block_use_RR2(&callbacks);
  72 #if DISPATCH_COCOA_COMPAT
  73         const char *v = getenv("OBJC_DEBUG_MISSING_POOLS");
  74         _os_object_debug_missing_pools = v && !strcmp(v, "YES");
  75 #endif
  76 }
  77
  78 _os_object_t
  79 _os_object_alloc_realized(const void *cls, size_t size)
  80 {
  81         dispatch_assert(size >= sizeof(struct _os_object_s));
  82         return _os_objc_alloc(cls, size);
  83 }
  84
  85 _os_object_t
  86 _os_object_alloc(const void *_cls, size_t size)
  87 {
  88         dispatch_assert(size >= sizeof(struct _os_object_s));
  89         Class cls = _cls ? [(id)_cls class] : [OS_OBJECT_CLASS(object) class];
  90         return _os_objc_alloc(cls, size);
  91 }
  92
  93 void
  94 _os_object_dealloc(_os_object_t obj)
  95 {
  96         [obj dealloc];
  97 }
  98
  99 void
 100 _os_object_xref_dispose(_os_object_t obj)
 101 {
 102         struct _os_object_s *o = (struct _os_object_s *)obj;
 103         _os_object_xrefcnt_dispose_barrier(o);
 104         [obj _xref_dispose];
 105 }
 106
 107 void
 108 _os_object_dispose(_os_object_t obj)
 109 {
 110         struct _os_object_s *o = (struct _os_object_s *)obj;
 111         _os_object_refcnt_dispose_barrier(o);
 112         [obj _dispose];
 113 }
 114
 115 #undef os_retain
 116 void*
 117 os_retain(void *obj)
 118 {
 119         return objc_retain(obj);
 120 }
 121
 122 #undef os_release
 123 void
 124 os_release(void *obj)
 125 {
 126         return objc_release(obj);
 127 }
 128
 129 void
 130 _os_object_atfork_prepare(void)
 131 {
 132         return _objc_atfork_prepare();
 133 }
 134
 135 void
 136 _os_object_atfork_parent(void)
 137 {
 138         return _objc_atfork_parent();
 139 }
 140
 141 void
 142 _os_object_atfork_child(void)
 143 {
 144         return _objc_atfork_child();
 145 }
 146
 147 #pragma mark -
 148 #pragma mark _os_object
 149
 150 @implementation OS_OBJECT_CLASS(object)
 151 DISPATCH_UNAVAILABLE_INIT()
 152
 153 -(id)retain {
 154         return _os_object_retain(self);
 155 }
 156
 157 -(oneway void)release {
 158         return _os_object_release(self);
 159 }
 160
 161 -(NSUInteger)retainCount {
 162         return _os_object_retain_count(self);
 163 }
 164
 165 -(BOOL)retainWeakReference {
 166         return _os_object_retain_weak(self);
 167 }
 168
 169 -(BOOL)allowsWeakReference {
 170         return _os_object_allows_weak_reference(self);
 171 }
 172
 173 - (void)_xref_dispose {
 174         return _os_object_release_internal(self);
 175 }
 176
 177 - (void)_dispose {
 178         return _os_object_dealloc(self);
 179 }
 180
 181 @end
 182
 183 #pragma mark -
 184 #pragma mark _dispatch_objc
 185 #if OS_OBJECT_HAVE_OBJC2
 186
 187 id
 188 _dispatch_objc_alloc(Class cls, size_t size)
 189 {
 190         return _os_objc_alloc(cls, size);
 191 }
 192
 193 void
 194 _dispatch_objc_retain(dispatch_object_t dou)
 195 {
 196         return (void)os_retain(dou);
 197 }
 198
 199 void
 200 _dispatch_objc_release(dispatch_object_t dou)
 201 {
 202         return os_release(dou);
 203 }
 204
 205 void
 206 _dispatch_objc_set_context(dispatch_object_t dou, void *context)
 207 {
 208         return [dou _setContext:context];
 209 }
 210
 211 void *
 212 _dispatch_objc_get_context(dispatch_object_t dou)
 213 {
 214         return [dou _getContext];
 215 }
 216
 217 void
 218 _dispatch_objc_set_finalizer_f(dispatch_object_t dou,
 219                 dispatch_function_t finalizer)
 220 {
 221         return [dou _setFinalizer:finalizer];
 222 }
 223
 224 void
 225 _dispatch_objc_set_target_queue(dispatch_object_t dou, dispatch_queue_t queue)
 226 {
 227         return [dou _setTargetQueue:queue];
 228 }
 229
 230 void
 231 _dispatch_objc_suspend(dispatch_object_t dou)
 232 {
 233         return [dou _suspend];
 234 }
 235
 236 void
 237 _dispatch_objc_resume(dispatch_object_t dou)
 238 {
 239         return [dou _resume];
 240 }
 241
 242 void
 243 _dispatch_objc_activate(dispatch_object_t dou)
 244 {
 245         return [dou _activate];
 246 }
 247
 248 size_t
 249 _dispatch_objc_debug(dispatch_object_t dou, char* buf, size_t bufsiz)
 250 {
 251         NSUInteger offset = 0;
 252         NSString *desc = [dou debugDescription];
 253         [desc getBytes:buf maxLength:bufsiz-1 usedLength:&offset
 254                         encoding:NSUTF8StringEncoding options:0
 255                         range:NSMakeRange(0, [desc length]) remainingRange:NULL];
 256         if (offset) buf[offset] = 0;
 257         return offset;
 258 }
 259
 260 #endif
 261 #pragma mark -
 262 #pragma mark _dispatch_object
 263
 264 // Force non-lazy class realization rdar://10640168
 265 #define DISPATCH_OBJC_LOAD() + (void)load {}
 266
 267 @implementation DISPATCH_CLASS(object)
 268 DISPATCH_UNAVAILABLE_INIT()
 269
 270 - (void)_dispose {
 271         return _dispatch_dispose(self); // calls _os_object_dealloc()
 272 }
 273
 274 - (NSString *)debugDescription {
 275         Class nsstring = objc_lookUpClass("NSString");
 276         if (!nsstring) return nil;
 277         char buf[2048];
 278         struct dispatch_object_s *obj = (struct dispatch_object_s *)self;
 279         if (dx_vtable(obj)->do_debug) {
 280                 dx_debug(obj, buf, sizeof(buf));
 281         } else {
 282                 strlcpy(buf, dx_kind(obj), sizeof(buf));
 283         }
 284         return [nsstring stringWithFormat:
 285                         [nsstring stringWithUTF8String:"<%s: %s>"],
 286                         class_getName([self class]), buf];
 287 }
 288
 289 @end
 290
 291 @implementation DISPATCH_CLASS(queue)
 292 DISPATCH_OBJC_LOAD()
 293 DISPATCH_UNAVAILABLE_INIT()
 294
 295 - (NSString *)description {
 296         Class nsstring = objc_lookUpClass("NSString");
 297         if (!nsstring) return nil;
 298         return [nsstring stringWithFormat:
 299                         [nsstring stringWithUTF8String:"<%s: %s[%p]>"],
 300                         class_getName([self class]), dispatch_queue_get_label(self), self];
 301 }
 302
 303 - (void)_xref_dispose {
 304         _dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 305         [super _xref_dispose];
 306 }
 307
 308 @end
 309
 310 @implementation DISPATCH_CLASS(source)
 311 DISPATCH_OBJC_LOAD()
 312 DISPATCH_UNAVAILABLE_INIT()
 313
 314 - (void)_xref_dispose {
 315         _dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 316         _dispatch_source_xref_dispose(self);
 317         [super _xref_dispose];
 318 }
 319
 320 @end
 321
 322 @implementation DISPATCH_CLASS(mach)
 323 DISPATCH_OBJC_LOAD()
 324 DISPATCH_UNAVAILABLE_INIT()
 325
 326 - (void)_xref_dispose {
 327         _dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 328         [super _xref_dispose];
 329 }
 330
 331 @end
 332
 333 @implementation DISPATCH_CLASS(queue_runloop)
 334 DISPATCH_OBJC_LOAD()
 335 DISPATCH_UNAVAILABLE_INIT()
 336
 337 - (void)_xref_dispose {
 338         _dispatch_queue_xref_dispose((struct dispatch_queue_s *)self);
 339         _dispatch_runloop_queue_xref_dispose(self);
 340         [super _xref_dispose];
 341 }
 342
 343 @end
 344
 345 #define DISPATCH_CLASS_IMPL(name) \
 346                 @implementation DISPATCH_CLASS(name) \
 347                 DISPATCH_OBJC_LOAD() \
 348                 DISPATCH_UNAVAILABLE_INIT() \
 349                 @end
 350
 351 #if !DISPATCH_DATA_IS_BRIDGED_TO_NSDATA
 352 DISPATCH_CLASS_IMPL(data)
 353 #endif
 354 DISPATCH_CLASS_IMPL(semaphore)
 355 DISPATCH_CLASS_IMPL(group)
 356 DISPATCH_CLASS_IMPL(queue_serial)
 357 DISPATCH_CLASS_IMPL(queue_concurrent)
 358 DISPATCH_CLASS_IMPL(queue_main)
 359 DISPATCH_CLASS_IMPL(queue_root)
 360 DISPATCH_CLASS_IMPL(queue_mgr)
 361 DISPATCH_CLASS_IMPL(queue_specific_queue)
 362 DISPATCH_CLASS_IMPL(queue_attr)
 363 DISPATCH_CLASS_IMPL(mach_msg)
 364 DISPATCH_CLASS_IMPL(io)
 365 DISPATCH_CLASS_IMPL(operation)
 366 DISPATCH_CLASS_IMPL(disk)
 367
 368 @implementation OS_OBJECT_CLASS(voucher)
 369 DISPATCH_UNAVAILABLE_INIT()
 370 DISPATCH_OBJC_LOAD()
 371
 372 - (void)_xref_dispose {
 373         return _voucher_xref_dispose(self); // calls _os_object_release_internal()
 374 }
 375
 376 - (void)_dispose {
 377         return _voucher_dispose(self); // calls _os_object_dealloc()
 378 }
 379
 380 - (NSString *)debugDescription {
 381         Class nsstring = objc_lookUpClass("NSString");
 382         if (!nsstring) return nil;
 383         char buf[2048];
 384         _voucher_debug(self, buf, sizeof(buf));
 385         return [nsstring stringWithFormat:
 386                         [nsstring stringWithUTF8String:"<%s: %s>"],
 387                         class_getName([self class]), buf];
 388 }
 389
 390 @end
 391
 392 #if VOUCHER_ENABLE_RECIPE_OBJECTS
 393 @implementation OS_OBJECT_CLASS(voucher_recipe)
 394 DISPATCH_UNAVAILABLE_INIT()
 395 DISPATCH_OBJC_LOAD()
 396
 397 - (void)_dispose {
 398
 399 }
 400
 401 - (NSString *)debugDescription {
 402         return nil; // TODO: voucher_recipe debugDescription
 403 }
 404
 405 @end
 406 #endif
 407
 408
 409 #pragma mark -
 410 #pragma mark dispatch_last_resort_autorelease_pool
 411
 412 #if DISPATCH_COCOA_COMPAT
 413
 414 void *
 415 _dispatch_last_resort_autorelease_pool_push(void)
 416 {
 417         if (!slowpath(_os_object_debug_missing_pools)) {
 418                 return _dispatch_autorelease_pool_push();
 419         }
 420         return NULL;
 421 }
 422
 423 void
 424 _dispatch_last_resort_autorelease_pool_pop(void *context)
 425 {
 426         if (!slowpath(_os_object_debug_missing_pools)) {
 427                 return _dispatch_autorelease_pool_pop(context);
 428         }
 429 }
 430
 431 #endif // DISPATCH_COCOA_COMPAT
 432
 433 #pragma mark -
 434 #pragma mark dispatch_client_callout
 435
 436 // Abort on uncaught exceptions thrown from client callouts rdar://8577499
 437 #if DISPATCH_USE_CLIENT_CALLOUT && !__USING_SJLJ_EXCEPTIONS__ && \
 438                 OS_OBJECT_HAVE_OBJC2
 439 // On platforms with zero-cost exceptions, use a compiler-generated catch-all
 440 // exception handler.
 441
 442 DISPATCH_NORETURN extern void objc_terminate(void);
 443
 444 #undef _dispatch_client_callout
 445 void
 446 _dispatch_client_callout(void *ctxt, dispatch_function_t f)
 447 {
 448         @try {
 449                 return f(ctxt);
 450         }
 451         @catch (...) {
 452                 objc_terminate();
 453         }
 454 }
 455
 456 #undef _dispatch_client_callout2
 457 void
 458 _dispatch_client_callout2(void *ctxt, size_t i, void (*f)(void *, size_t))
 459 {
 460         @try {
 461                 return f(ctxt, i);
 462         }
 463         @catch (...) {
 464                 objc_terminate();
 465         }
 466 }
 467
 468 #if HAVE_MACH
 469 #undef _dispatch_client_callout4
 470 void
 471 _dispatch_client_callout4(void *ctxt, dispatch_mach_reason_t reason,
 472                 dispatch_mach_msg_t dmsg, mach_error_t error,
 473                 dispatch_mach_handler_function_t f)
 474 {
 475         @try {
 476                 return f(ctxt, reason, dmsg, error);
 477         }
 478         @catch (...) {
 479                 objc_terminate();
 480         }
 481 }
 482 #endif // HAVE_MACH
 483
 484 #endif // DISPATCH_USE_CLIENT_CALLOUT
 485
 486 #endif // USE_OBJC