1 /**
2 * \file
3 * Simple generational GC.
4 *
5 * Copyright 2001-2003 Ximian, Inc
6 * Copyright 2003-2010 Novell, Inc.
7 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
8 * Copyright (C) 2012 Xamarin Inc
9 *
10 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
11 */
12 #ifndef __MONO_SGENGC_H__
13 #define __MONO_SGENGC_H__
14
15 /* pthread impl */
16 #include "config.h"
17
18 #ifdef HAVE_SGEN_GC
19
20 typedef struct _SgenThreadInfo SgenThreadInfo;
21 #undef THREAD_INFO_TYPE
22 #define THREAD_INFO_TYPE SgenThreadInfo
23
24 #include <glib.h>
25 #include <stdio.h>
26 #ifdef HAVE_PTHREAD_H
27 #include <pthread.h>
28 #endif
29 #include <stdint.h>
30 #include "mono/utils/mono-compiler.h"
31 #include "mono/utils/atomic.h"
32 #include "mono/utils/mono-os-mutex.h"
33 #include "mono/utils/mono-coop-mutex.h"
34 #include "mono/utils/ward.h"
35 #include "mono/sgen/sgen-conf.h"
36 #include "mono/sgen/sgen-hash-table.h"
37 #include "mono/sgen/sgen-protocol.h"
38 #include "mono/sgen/gc-internal-agnostic.h"
39 #include "mono/sgen/sgen-thread-pool.h"
40
41 /* The method used to clear the nursery */
42 /* Clearing at nursery collections is the safest, but has bad interactions with caches.
43 * Clearing at TLAB creation is much faster, but more complex and it might expose hard
44 * to find bugs.
45 */
46 typedef enum {
47 CLEAR_AT_GC,
48 CLEAR_AT_TLAB_CREATION,
49 CLEAR_AT_TLAB_CREATION_DEBUG
50 } NurseryClearPolicy;
51
52 NurseryClearPolicy sgen_get_nursery_clear_policy (void);
53
54 #if !defined(__MACH__) && !MONO_MACH_ARCH_SUPPORTED && defined(HAVE_PTHREAD_KILL)
55 #define SGEN_POSIX_STW 1
56 #endif
57
58 /*
59 * The nursery section uses this struct.
60 */
61 typedef struct _GCMemSection GCMemSection;
62 struct _GCMemSection {
63 char *data;
64 char *end_data;
65 /*
66 * scan starts is an array of pointers to objects equally spaced in the allocation area
67 * They let use quickly find pinned objects from pinning pointers.
68 */
69 char **scan_starts;
70 /* in major collections indexes in the pin_queue for objects that pin this section */
71 size_t pin_queue_first_entry;
72 size_t pin_queue_last_entry;
73 size_t num_scan_start;
74 };
75
76 /*
77 * Recursion is not allowed for the thread lock.
78 */
79 #define LOCK_DECLARE(name) mono_mutex_t name
80 /* if changing LOCK_INIT to something that isn't idempotent, look at
81 its use in mono_gc_base_init in sgen-gc.c */
82 #define LOCK_INIT(name) mono_os_mutex_init (&(name))
83 #define LOCK_GC do { sgen_gc_lock (); } while (0)
84 #define UNLOCK_GC do { sgen_gc_unlock (); } while (0)
85
86 extern MonoCoopMutex sgen_interruption_mutex;
87
88 #define LOCK_INTERRUPTION mono_coop_mutex_lock (&sgen_interruption_mutex)
89 #define UNLOCK_INTERRUPTION mono_coop_mutex_unlock (&sgen_interruption_mutex)
90
91 /* FIXME: Use mono_atomic_add_i32 & mono_atomic_add_i64 to reduce the CAS cost. */
92 #define SGEN_CAS mono_atomic_cas_i32
93 #define SGEN_CAS_PTR mono_atomic_cas_ptr
94 #define SGEN_ATOMIC_ADD(x,i) do { \
95 int __old_x; \
96 do { \
97 __old_x = (x); \
98 } while (mono_atomic_cas_i32 (&(x), __old_x + (i), __old_x) != __old_x); \
99 } while (0)
100 #define SGEN_ATOMIC_ADD_P(x,i) do { \
101 size_t __old_x; \
102 do { \
103 __old_x = (x); \
104 } while (mono_atomic_cas_ptr ((void**)&(x), (void*)(__old_x + (i)), (void*)__old_x) != (void*)__old_x); \
105 } while (0)
106
107 #ifdef HEAVY_STATISTICS
108 extern guint64 stat_objects_alloced_degraded;
109 extern guint64 stat_bytes_alloced_degraded;
110 extern guint64 stat_copy_object_called_major;
111 extern guint64 stat_objects_copied_major;
112 #endif
113
114 #define SGEN_ASSERT(level, a, ...) do { \
115 if (G_UNLIKELY ((level) <= SGEN_MAX_ASSERT_LEVEL && !(a))) { \
116 g_error (__VA_ARGS__); \
117 } } while (0)
118
119 #ifdef HAVE_LOCALTIME_R
120 # define LOG_TIMESTAMP \
121 do { \
122 time_t t; \
123 struct tm tod; \
124 time(&t); \
125 localtime_r(&t, &tod); \
126 strftime(logTime, sizeof(logTime), "%Y-%m-%d %H:%M:%S", &tod); \
127 } while (0)
128 #else
129 # define LOG_TIMESTAMP \
130 do { \
131 time_t t; \
132 struct tm *tod; \
133 time(&t); \
134 tod = localtime(&t); \
135 strftime(logTime, sizeof(logTime), "%F %T", tod); \
136 } while (0)
137 #endif
138
139 #define SGEN_LOG(level, format, ...) do { \
140 if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) { \
141 char logTime[80]; \
142 LOG_TIMESTAMP; \
143 mono_gc_printf (gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__); \
144 } } while (0)
145
146 #define SGEN_COND_LOG(level, cond, format, ...) do { \
147 if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) { \
148 if (cond) { \
149 char logTime[80]; \
150 LOG_TIMESTAMP; \
151 mono_gc_printf (gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__); \
152 } \
153 } } while (0)
154
155 extern int gc_debug_level;
156 extern FILE* gc_debug_file;
157
158 extern int current_collection_generation;
159
160 extern unsigned int sgen_global_stop_count;
161
162 #define SGEN_ALIGN_UP_TO(val,align) (((val) + (align - 1)) & ~(align - 1))
163 #define SGEN_ALIGN_DOWN_TO(val,align) ((val) & ~(align - 1))
164
165 #define SGEN_ALLOC_ALIGN 8
166 #define SGEN_ALLOC_ALIGN_BITS 3
167
168 /* s must be non-negative */
169 #define SGEN_CAN_ALIGN_UP(s) ((s) <= SIZE_MAX - (SGEN_ALLOC_ALIGN - 1))
170 #define SGEN_ALIGN_UP(s) SGEN_ALIGN_UP_TO(s, SGEN_ALLOC_ALIGN)
171 #define SGEN_ALIGN_DOWN(s) SGEN_ALIGN_DOWN_TO(s, SGEN_ALLOC_ALIGN)
172
173 #if SIZEOF_VOID_P == 4
174 #define ONE_P 1
175 #else
176 #define ONE_P 1ll
177 #endif
178
179 static inline guint
sgen_aligned_addr_hash(gconstpointer ptr)180 sgen_aligned_addr_hash (gconstpointer ptr)
181 {
182 return GPOINTER_TO_UINT (ptr) >> 3;
183 }
184
185 #define SGEN_PTR_IN_NURSERY(p,bits,start,end) (((mword)(p) & ~(((mword)1 << (bits)) - 1)) == (mword)(start))
186
187 extern size_t sgen_nursery_size;
188 extern size_t sgen_nursery_max_size;
189 extern int sgen_nursery_bits;
190
191 extern char *sgen_nursery_start;
192 extern char *sgen_nursery_end;
193
194 static inline MONO_ALWAYS_INLINE gboolean
sgen_ptr_in_nursery(void * p)195 sgen_ptr_in_nursery (void *p)
196 {
197 return SGEN_PTR_IN_NURSERY ((p), sgen_nursery_bits, sgen_nursery_start, sgen_nursery_end);
198 }
199
200 static inline MONO_ALWAYS_INLINE char*
sgen_get_nursery_start(void)201 sgen_get_nursery_start (void)
202 {
203 return sgen_nursery_start;
204 }
205
206 static inline MONO_ALWAYS_INLINE char*
sgen_get_nursery_end(void)207 sgen_get_nursery_end (void)
208 {
209 return sgen_nursery_end;
210 }
211
212 /*
213 * We use the lowest three bits in the vtable pointer of objects to tag whether they're
214 * forwarded, pinned, and/or cemented. These are the valid states:
215 *
216 * | State | bits |
217 * |------------------+------+
218 * | default | 000 |
219 * | forwarded | 001 |
220 * | pinned | 010 |
221 * | pinned, cemented | 110 |
222 *
223 * We store them in the vtable slot because the bits are used in the sync block for other
224 * purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
225 * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
226 * would be an invalid combination for the monitor and hash code).
227 */
228
229 #include "sgen-tagged-pointer.h"
230
231 #define SGEN_VTABLE_BITS_MASK SGEN_TAGGED_POINTER_MASK
232
233 #define SGEN_POINTER_IS_TAGGED_FORWARDED(p) SGEN_POINTER_IS_TAGGED_1((p))
234 #define SGEN_POINTER_TAG_FORWARDED(p) SGEN_POINTER_TAG_1((p))
235
236 #define SGEN_POINTER_IS_TAGGED_PINNED(p) SGEN_POINTER_IS_TAGGED_2((p))
237 #define SGEN_POINTER_TAG_PINNED(p) SGEN_POINTER_TAG_2((p))
238
239 #define SGEN_POINTER_IS_TAGGED_CEMENTED(p) SGEN_POINTER_IS_TAGGED_4((p))
240 #define SGEN_POINTER_TAG_CEMENTED(p) SGEN_POINTER_TAG_4((p))
241
242 #define SGEN_POINTER_UNTAG_VTABLE(p) SGEN_POINTER_UNTAG_ALL((p))
243
244 /* returns NULL if not forwarded, or the forwarded address */
245 #define SGEN_VTABLE_IS_FORWARDED(vtable) ((GCObject *)(SGEN_POINTER_IS_TAGGED_FORWARDED ((vtable)) ? SGEN_POINTER_UNTAG_VTABLE ((vtable)) : NULL))
246 #define SGEN_OBJECT_IS_FORWARDED(obj) ((GCObject *)SGEN_VTABLE_IS_FORWARDED (((mword*)(obj))[0]))
247
248 #define SGEN_VTABLE_IS_PINNED(vtable) SGEN_POINTER_IS_TAGGED_PINNED ((vtable))
249 #define SGEN_OBJECT_IS_PINNED(obj) (SGEN_VTABLE_IS_PINNED (((mword*)(obj))[0]))
250
251 #define SGEN_OBJECT_IS_CEMENTED(obj) (SGEN_POINTER_IS_TAGGED_CEMENTED (((mword*)(obj))[0]))
252
253 /* set the forwarded address fw_addr for object obj */
254 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do { \
255 *(void**)(obj) = SGEN_POINTER_TAG_FORWARDED ((fw_addr)); \
256 } while (0)
257 #define SGEN_FORWARD_OBJECT_PAR(obj,fw_addr,final_fw_addr) do { \
258 gpointer old_vtable_word = *(gpointer*)obj; \
259 gpointer new_vtable_word; \
260 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word); \
261 if (final_fw_addr) \
262 break; \
263 new_vtable_word = SGEN_POINTER_TAG_FORWARDED ((fw_addr)); \
264 old_vtable_word = mono_atomic_cas_ptr ((gpointer*)obj, new_vtable_word, old_vtable_word); \
265 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word); \
266 if (!final_fw_addr) \
267 final_fw_addr = (fw_addr); \
268 } while (0)
269 #define SGEN_PIN_OBJECT(obj) do { \
270 *(void**)(obj) = SGEN_POINTER_TAG_PINNED (*(void**)(obj)); \
271 } while (0)
272 #define SGEN_CEMENT_OBJECT(obj) do { \
273 *(void**)(obj) = SGEN_POINTER_TAG_CEMENTED (*(void**)(obj)); \
274 } while (0)
275 /* Unpins and uncements */
276 #define SGEN_UNPIN_OBJECT(obj) do { \
277 *(void**)(obj) = SGEN_POINTER_UNTAG_VTABLE (*(void**)(obj)); \
278 } while (0)
279
280 /*
281 * Since we set bits in the vtable, use the macro to load it from the pointer to
282 * an object that is potentially pinned.
283 */
284 #define SGEN_LOAD_VTABLE(obj) ((GCVTable)(SGEN_POINTER_UNTAG_ALL (SGEN_LOAD_VTABLE_UNCHECKED ((GCObject *)(obj)))))
285
286 /*
287 List of what each bit on of the vtable gc bits means.
288 */
289 enum {
290 // When the Java bridge has determined an object is "bridged", it uses these two bits to cache that information.
291 SGEN_GC_BIT_BRIDGE_OBJECT = 1,
292 SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT = 2,
293 SGEN_GC_BIT_FINALIZER_AWARE = 4,
294 };
295
296 void sgen_gc_init (void)
297 MONO_PERMIT (need (sgen_lock_gc));
298
299 void sgen_os_init (void);
300
301 void sgen_update_heap_boundaries (mword low, mword high);
302
303 void sgen_check_section_scan_starts (GCMemSection *section);
304
305 void sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type);
306
307 gboolean sgen_gc_initialized (void);
308
309 /* Keep in sync with description_for_type() in sgen-internal.c! */
310 enum {
311 INTERNAL_MEM_PIN_QUEUE,
312 INTERNAL_MEM_FRAGMENT,
313 INTERNAL_MEM_SECTION,
314 INTERNAL_MEM_SCAN_STARTS,
315 INTERNAL_MEM_FIN_TABLE,
316 INTERNAL_MEM_FINALIZE_ENTRY,
317 INTERNAL_MEM_FINALIZE_READY,
318 INTERNAL_MEM_DISLINK_TABLE,
319 INTERNAL_MEM_DISLINK,
320 INTERNAL_MEM_ROOTS_TABLE,
321 INTERNAL_MEM_ROOT_RECORD,
322 INTERNAL_MEM_STATISTICS,
323 INTERNAL_MEM_STAT_PINNED_CLASS,
324 INTERNAL_MEM_STAT_REMSET_CLASS,
325 INTERNAL_MEM_GRAY_QUEUE,
326 INTERNAL_MEM_MS_TABLES,
327 INTERNAL_MEM_MS_BLOCK_INFO,
328 INTERNAL_MEM_MS_BLOCK_INFO_SORT,
329 INTERNAL_MEM_WORKER_DATA,
330 INTERNAL_MEM_THREAD_POOL_JOB,
331 INTERNAL_MEM_BRIDGE_DATA,
332 INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE,
333 INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE_ENTRY,
334 INTERNAL_MEM_BRIDGE_HASH_TABLE,
335 INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
336 INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
337 INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
338 INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE,
339 INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE_ENTRY,
340 INTERNAL_MEM_TARJAN_OBJ_BUCKET,
341 INTERNAL_MEM_BRIDGE_DEBUG,
342 INTERNAL_MEM_TOGGLEREF_DATA,
343 INTERNAL_MEM_CARDTABLE_MOD_UNION,
344 INTERNAL_MEM_BINARY_PROTOCOL,
345 INTERNAL_MEM_TEMPORARY,
346 INTERNAL_MEM_LOG_ENTRY,
347 INTERNAL_MEM_COMPLEX_DESCRIPTORS,
348 INTERNAL_MEM_FIRST_CLIENT
349 };
350
351 enum {
352 GENERATION_NURSERY,
353 GENERATION_OLD,
354 GENERATION_MAX
355 };
356
357 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
358 #define BINARY_PROTOCOL_ARG(x) ,x
359 #else
360 #define BINARY_PROTOCOL_ARG(x)
361 #endif
362
363 void sgen_init_internal_allocator (void);
364
365 #define SGEN_DEFINE_OBJECT_VTABLE
366 #ifdef SGEN_CLIENT_HEADER
367 #include SGEN_CLIENT_HEADER
368 #else
369 #include "metadata/sgen-client-mono.h"
370 #endif
371 #undef SGEN_DEFINE_OBJECT_VTABLE
372
373 #include "mono/sgen/sgen-descriptor.h"
374 #include "mono/sgen/sgen-gray.h"
375
376 /* the runtime can register areas of memory as roots: we keep two lists of roots,
377 * a pinned root set for conservatively scanned roots and a normal one for
378 * precisely scanned roots (currently implemented as a single list).
379 */
380 typedef struct _RootRecord RootRecord;
381 struct _RootRecord {
382 char *end_root;
383 SgenDescriptor root_desc;
384 int source;
385 const char *msg;
386 };
387
388 enum {
389 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
390 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
391 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
392 ROOT_TYPE_NUM
393 };
394
395 extern SgenHashTable roots_hash [ROOT_TYPE_NUM];
396
397 int sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg)
398 MONO_PERMIT (need (sgen_lock_gc));
399 void sgen_deregister_root (char* addr)
400 MONO_PERMIT (need (sgen_lock_gc));
401
402 typedef void (*IterateObjectCallbackFunc) (GCObject*, size_t, void*);
403
404 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries);
405
406 /* eventually share with MonoThread? */
407 /*
408 * This structure extends the MonoThreadInfo structure.
409 */
410 struct _SgenThreadInfo {
411 SgenClientThreadInfo client_info;
412
413 char *tlab_start;
414 char *tlab_next;
415 char *tlab_temp_end;
416 char *tlab_real_end;
417 };
418
419 gboolean sgen_is_worker_thread (MonoNativeThreadId thread);
420
421 typedef void (*CopyOrMarkObjectFunc) (GCObject**, SgenGrayQueue*);
422 typedef void (*ScanObjectFunc) (GCObject *obj, SgenDescriptor desc, SgenGrayQueue*);
423 typedef void (*ScanVTypeFunc) (GCObject *full_object, char *start, SgenDescriptor desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
424 typedef void (*ScanPtrFieldFunc) (GCObject *obj, GCObject **ptr, SgenGrayQueue* queue);
425 typedef gboolean (*DrainGrayStackFunc) (SgenGrayQueue *queue);
426
427 typedef struct {
428 CopyOrMarkObjectFunc copy_or_mark_object;
429 ScanObjectFunc scan_object;
430 ScanVTypeFunc scan_vtype;
431 ScanPtrFieldFunc scan_ptr_field;
432 /* Drain stack optimized for the above functions */
433 DrainGrayStackFunc drain_gray_stack;
434 /*FIXME add allocation function? */
435 } SgenObjectOperations;
436
437 typedef struct
438 {
439 SgenObjectOperations *ops;
440 SgenGrayQueue *queue;
441 } ScanCopyContext;
442
443 #define CONTEXT_FROM_OBJECT_OPERATIONS(ops, queue) ((ScanCopyContext) { (ops), (queue) })
444
445 void sgen_report_internal_mem_usage (void);
446 void sgen_dump_internal_mem_usage (FILE *heap_dump_file);
447 void sgen_dump_section (GCMemSection *section, const char *type);
448 void sgen_dump_occupied (char *start, char *end, char *section_start);
449
450 void sgen_register_fixed_internal_mem_type (int type, size_t size);
451
452 void* sgen_alloc_internal (int type);
453 void sgen_free_internal (void *addr, int type);
454
455 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure);
456 void sgen_free_internal_dynamic (void *addr, size_t size, int type);
457
458 void sgen_pin_stats_enable (void);
459 void sgen_pin_stats_register_object (GCObject *obj, int generation);
460 void sgen_pin_stats_register_global_remset (GCObject *obj);
461 void sgen_pin_stats_report (void);
462
463 void sgen_sort_addresses (void **array, size_t size);
464 void sgen_add_to_global_remset (gpointer ptr, GCObject *obj);
465
466 int sgen_get_current_collection_generation (void);
467 gboolean sgen_collection_is_concurrent (void);
468 gboolean sgen_concurrent_collection_in_progress (void);
469
470 typedef struct _SgenFragment SgenFragment;
471
472 struct _SgenFragment {
473 SgenFragment *next;
474 char *fragment_start;
475 char *fragment_next; /* the current soft limit for allocation */
476 char *fragment_end;
477 SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
478 };
479
480 typedef struct {
481 SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
482 SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
483 } SgenFragmentAllocator;
484
485 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end);
486 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator);
487 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size);
488 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
489 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
490 SgenFragment* sgen_fragment_allocator_alloc (void);
491 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator);
492 void sgen_clear_range (char *start, char *end);
493
494
495 /*
496 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
497 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
498 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
499
500 Experimental results on how much space we waste with a 4Mb nursery:
501
502 Note that the wastage applies to the half nursery, or 2Mb:
503
504 Test 1 (compiling corlib):
505 9: avg: 3.1k
506 8: avg: 1.6k
507
508 */
509 #define SGEN_TO_SPACE_GRANULE_BITS 9
510 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
511
512 extern char *sgen_space_bitmap;
513 extern size_t sgen_space_bitmap_size;
514
515 static inline gboolean
sgen_nursery_is_to_space(void * object)516 sgen_nursery_is_to_space (void *object)
517 {
518 size_t idx = ((char*)object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
519 size_t byte = idx >> 3;
520 size_t bit = idx & 0x7;
521
522 SGEN_ASSERT (4, sgen_ptr_in_nursery (object), "object %p is not in nursery [%p - %p]", object, sgen_get_nursery_start (), sgen_get_nursery_end ());
523 SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %zd out of range (%zd)", byte, sgen_space_bitmap_size);
524
525 return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
526 }
527
528 static inline gboolean
sgen_nursery_is_from_space(void * object)529 sgen_nursery_is_from_space (void *object)
530 {
531 return !sgen_nursery_is_to_space (object);
532 }
533
534 static inline gboolean
sgen_nursery_is_object_alive(GCObject * obj)535 sgen_nursery_is_object_alive (GCObject *obj)
536 {
537 /* FIXME put this asserts under a non default level */
538 g_assert (sgen_ptr_in_nursery (obj));
539
540 if (sgen_nursery_is_to_space (obj))
541 return TRUE;
542
543 if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
544 return TRUE;
545
546 return FALSE;
547 }
548
549 typedef struct {
550 gboolean is_split;
551 gboolean is_parallel;
552
553 GCObject* (*alloc_for_promotion) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
554 GCObject* (*alloc_for_promotion_par) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
555
556 SgenObjectOperations serial_ops;
557 SgenObjectOperations serial_ops_with_concurrent_major;
558 SgenObjectOperations parallel_ops;
559 SgenObjectOperations parallel_ops_with_concurrent_major;
560
561 void (*prepare_to_space) (char *to_space_bitmap, size_t space_bitmap_size);
562 void (*clear_fragments) (void);
563 SgenFragment* (*build_fragments_get_exclude_head) (void);
564 void (*build_fragments_release_exclude_head) (void);
565 void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
566 void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
567
568 gboolean (*handle_gc_param) (const char *opt); /* Optional */
569 void (*print_gc_param_usage) (void); /* Optional */
570 } SgenMinorCollector;
571
572 extern SgenMinorCollector sgen_minor_collector;
573
574 void sgen_simple_nursery_init (SgenMinorCollector *collector, gboolean parallel);
575 void sgen_split_nursery_init (SgenMinorCollector *collector);
576
577 /* Updating references */
578
579 #ifdef SGEN_CHECK_UPDATE_REFERENCE
580 gboolean sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread);
581
582 static inline void
sgen_update_reference(GCObject ** p,GCObject * o,gboolean allow_null)583 sgen_update_reference (GCObject **p, GCObject *o, gboolean allow_null)
584 {
585 if (!allow_null)
586 SGEN_ASSERT (0, o, "Cannot update a reference with a NULL pointer");
587 SGEN_ASSERT (0, !sgen_workers_is_worker_thread (mono_native_thread_id_get ()), "Can't update a reference in the worker thread");
588 *p = o;
589 }
590
591 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o) sgen_update_reference ((GCObject**)(p), (GCObject*)(o), TRUE)
592 #define SGEN_UPDATE_REFERENCE(p,o) sgen_update_reference ((GCObject**)(p), (GCObject*)(o), FALSE)
593 #else
594 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o) (*(GCObject**)(p) = (GCObject*)(o))
595 #define SGEN_UPDATE_REFERENCE(p,o) SGEN_UPDATE_REFERENCE_ALLOW_NULL ((p), (o))
596 #endif
597
598 /* Major collector */
599
600 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
601 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
602 void sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback);
603
604 typedef enum {
605 ITERATE_OBJECTS_SWEEP = 1,
606 ITERATE_OBJECTS_NON_PINNED = 2,
607 ITERATE_OBJECTS_PINNED = 4,
608 ITERATE_OBJECTS_SWEEP_NON_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED,
609 ITERATE_OBJECTS_SWEEP_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_PINNED,
610 ITERATE_OBJECTS_SWEEP_ALL = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED
611 } IterateObjectsFlags;
612
613 typedef struct
614 {
615 size_t num_scanned_objects;
616 size_t num_unique_scanned_objects;
617 } ScannedObjectCounts;
618
619 typedef enum {
620 CARDTABLE_SCAN_GLOBAL = 0,
621 CARDTABLE_SCAN_MOD_UNION = 1,
622 CARDTABLE_SCAN_MOD_UNION_PRECLEAN = CARDTABLE_SCAN_MOD_UNION | 2,
623 } CardTableScanType;
624
625 typedef struct _SgenMajorCollector SgenMajorCollector;
626 struct _SgenMajorCollector {
627 size_t section_size;
628 gboolean is_concurrent;
629 gboolean is_parallel;
630 gboolean supports_cardtable;
631 gboolean sweeps_lazily;
632
633 void* (*alloc_heap) (mword nursery_size, mword nursery_align);
634 gboolean (*is_object_live) (GCObject *obj);
635 GCObject* (*alloc_small_pinned_obj) (GCVTable vtable, size_t size, gboolean has_references);
636 GCObject* (*alloc_degraded) (GCVTable vtable, size_t size);
637
638 SgenObjectOperations major_ops_serial;
639 SgenObjectOperations major_ops_concurrent_start;
640 SgenObjectOperations major_ops_concurrent_finish;
641 SgenObjectOperations major_ops_conc_par_start;
642 SgenObjectOperations major_ops_conc_par_finish;
643
644 GCObject* (*alloc_object) (GCVTable vtable, size_t size, gboolean has_references);
645 GCObject* (*alloc_object_par) (GCVTable vtable, size_t size, gboolean has_references);
646 void (*free_pinned_object) (GCObject *obj, size_t size);
647
648 /*
649 * This is used for domain unloading, heap walking from the logging profiler, and
650 * debugging. Can assume the world is stopped.
651 */
652 void (*iterate_objects) (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data);
653
654 void (*free_non_pinned_object) (GCObject *obj, size_t size);
655 void (*pin_objects) (SgenGrayQueue *queue);
656 void (*pin_major_object) (GCObject *obj, SgenGrayQueue *queue);
657 void (*scan_card_table) (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count, int block_count);
658 void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
659 void (*iterate_block_ranges) (sgen_cardtable_block_callback callback);
660 void (*update_cardtable_mod_union) (void);
661 void (*init_to_space) (void);
662 void (*sweep) (void);
663 gboolean (*have_swept) (void);
664 void (*finish_sweeping) (void);
665 void (*free_swept_blocks) (size_t section_reserve);
666 void (*check_scan_starts) (void);
667 void (*dump_heap) (FILE *heap_dump_file);
668 gint64 (*get_used_size) (void);
669 void (*start_nursery_collection) (void);
670 void (*finish_nursery_collection) (void);
671 void (*start_major_collection) (void);
672 void (*finish_major_collection) (ScannedObjectCounts *counts);
673 gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
674 gboolean (*ptr_is_from_pinned_alloc) (char *ptr);
675 void (*report_pinned_memory_usage) (void);
676 size_t (*get_num_major_sections) (void);
677 size_t (*get_bytes_survived_last_sweep) (void);
678 gboolean (*handle_gc_param) (const char *opt);
679 void (*print_gc_param_usage) (void);
680 void (*post_param_init) (SgenMajorCollector *collector);
681 gboolean (*is_valid_object) (char *ptr);
682 GCVTable (*describe_pointer) (char *pointer);
683 guint8* (*get_cardtable_mod_union_for_reference) (char *object);
684 long long (*get_and_reset_num_major_objects_marked) (void);
685 void (*count_cards) (long long *num_total_cards, long long *num_marked_cards);
686 void (*init_block_free_lists) (gpointer *list_p);
687 };
688
689 extern SgenMajorCollector major_collector;
690
691 void sgen_marksweep_init (SgenMajorCollector *collector);
692 void sgen_marksweep_conc_init (SgenMajorCollector *collector);
693 void sgen_marksweep_conc_par_init (SgenMajorCollector *collector);
694 SgenMajorCollector* sgen_get_major_collector (void);
695 SgenMinorCollector* sgen_get_minor_collector (void);
696
697
698 typedef struct _SgenRememberedSet {
699 void (*wbarrier_set_field) (GCObject *obj, gpointer field_ptr, GCObject* value);
700 void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gpointer src_ptr, int count);
701 void (*wbarrier_value_copy) (gpointer dest, gpointer src, int count, size_t element_size);
702 void (*wbarrier_object_copy) (GCObject* obj, GCObject *src);
703 void (*wbarrier_generic_nostore) (gpointer ptr);
704 void (*record_pointer) (gpointer ptr);
705 void (*wbarrier_range_copy) (gpointer dest, gpointer src, int count);
706
707 void (*start_scan_remsets) (void);
708
709 void (*clear_cards) (void);
710
711 gboolean (*find_address) (char *addr);
712 gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
713 } SgenRememberedSet;
714
715 SgenRememberedSet *sgen_get_remset (void);
716
717 /*
718 * These must be kept in sync with object.h. They're here for using SGen independently of
719 * Mono.
720 */
721 void mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count);
722 void mono_gc_wbarrier_generic_nostore (gpointer ptr);
723 void mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value);
724 void mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value);
725
726 void sgen_wbarrier_range_copy (gpointer _dest, gpointer _src, int size);
727
728 static inline SgenDescriptor
sgen_obj_get_descriptor(GCObject * obj)729 sgen_obj_get_descriptor (GCObject *obj)
730 {
731 GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
732 SGEN_ASSERT (9, !SGEN_POINTER_IS_TAGGED_ANY (vtable), "Object can't be tagged");
733 return sgen_vtable_get_descriptor (vtable);
734 }
735
736 static inline SgenDescriptor
sgen_obj_get_descriptor_safe(GCObject * obj)737 sgen_obj_get_descriptor_safe (GCObject *obj)
738 {
739 GCVTable vtable = SGEN_LOAD_VTABLE (obj);
740 return sgen_vtable_get_descriptor (vtable);
741 }
742
743 static mword sgen_client_par_object_get_size (GCVTable vtable, GCObject* o);
744 static mword sgen_client_slow_object_get_size (GCVTable vtable, GCObject* o);
745
746 static inline mword
sgen_safe_object_get_size(GCObject * obj)747 sgen_safe_object_get_size (GCObject *obj)
748 {
749 GCObject *forwarded;
750 GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
751
752 /*
753 * Once we load the vtable, we must always use it, in case we are in parallel case.
754 * Otherwise the object might get forwarded in the meantime and we would read an
755 * invalid vtable. An object cannot be forwarded for a second time during same GC.
756 */
757 if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable)))
758 return sgen_client_par_object_get_size (SGEN_LOAD_VTABLE (forwarded), obj);
759 else
760 return sgen_client_par_object_get_size ((GCVTable)SGEN_POINTER_UNTAG_ALL (vtable), obj);
761 }
762
763 static inline gboolean
sgen_safe_object_is_small(GCObject * obj,int type)764 sgen_safe_object_is_small (GCObject *obj, int type)
765 {
766 if (type <= DESC_TYPE_MAX_SMALL_OBJ)
767 return TRUE;
768 return SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE;
769 }
770
771 /*
772 * This variant guarantees to return the exact size of the object
773 * before alignment. Needed for canary support.
774 */
775 static inline guint
sgen_safe_object_get_size_unaligned(GCObject * obj)776 sgen_safe_object_get_size_unaligned (GCObject *obj)
777 {
778 GCObject *forwarded;
779
780 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
781 obj = (GCObject*)forwarded;
782 }
783
784 return sgen_client_slow_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
785 }
786
787 #ifdef SGEN_CLIENT_HEADER
788 #include SGEN_CLIENT_HEADER
789 #else
790 #include "metadata/sgen-client-mono.h"
791 #endif
792
793 gboolean sgen_object_is_live (GCObject *obj);
794
795 void sgen_init_fin_weak_hash (void);
796
797 void sgen_register_obj_with_weak_fields (GCObject *obj);
798
799 /* FIXME: move the toggleref stuff out of here */
800 void sgen_mark_togglerefs (char *start, char *end, ScanCopyContext ctx);
801 void sgen_clear_togglerefs (char *start, char *end, ScanCopyContext ctx);
802
803 void sgen_process_togglerefs (void);
804 void sgen_register_test_toggleref_callback (void);
805
806 void sgen_mark_bridge_object (GCObject *obj)
807 MONO_PERMIT (need (sgen_gc_locked));
808 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx)
809 MONO_PERMIT (need (sgen_gc_locked));
810
811 typedef gboolean (*SgenObjectPredicateFunc) (GCObject *obj, void *user_data);
812
813 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track)
814 MONO_PERMIT (need (sgen_gc_locked, sgen_world_stopped));
815
816 gboolean sgen_gc_is_object_ready_for_finalization (GCObject *object);
817 void sgen_gc_lock (void) MONO_PERMIT (use (sgen_lock_gc), grant (sgen_gc_locked), revoke (sgen_lock_gc));
818 void sgen_gc_unlock (void) MONO_PERMIT (use (sgen_gc_locked), revoke (sgen_gc_locked), grant (sgen_lock_gc));
819
820 void sgen_queue_finalization_entry (GCObject *obj);
821 const char* sgen_generation_name (int generation);
822
823 void sgen_finalize_in_range (int generation, ScanCopyContext ctx)
824 MONO_PERMIT (need (sgen_gc_locked));
825 void sgen_null_link_in_range (int generation, ScanCopyContext ctx, gboolean track)
826 MONO_PERMIT (need (sgen_gc_locked, sgen_world_stopped));
827 void sgen_process_fin_stage_entries (void)
828 MONO_PERMIT (need (sgen_gc_locked));
829 gboolean sgen_have_pending_finalizers (void);
830 void sgen_object_register_for_finalization (GCObject *obj, void *user_data)
831 MONO_PERMIT (need (sgen_lock_gc));
832
833 void sgen_finalize_if (SgenObjectPredicateFunc predicate, void *user_data)
834 MONO_PERMIT (need (sgen_lock_gc));
835 void sgen_remove_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, int generation);
836 void sgen_set_suspend_finalizers (void);
837
838 void sgen_wbroots_iterate_live_block_ranges (sgen_cardtable_block_callback cb);
839 void sgen_wbroots_scan_card_table (ScanCopyContext ctx);
840
841 void sgen_register_disappearing_link (GCObject *obj, void **link, gboolean track, gboolean in_gc);
842
843 GCObject* sgen_weak_link_get (void **link_addr);
844
845 gboolean sgen_drain_gray_stack (ScanCopyContext ctx);
846
847 enum {
848 SPACE_NURSERY,
849 SPACE_MAJOR,
850 SPACE_LOS
851 };
852
853 void sgen_pin_object (GCObject *object, SgenGrayQueue *queue);
854 void sgen_set_pinned_from_failed_allocation (mword objsize);
855
856 void sgen_ensure_free_space (size_t size, int generation)
857 MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
858 void sgen_gc_collect (int generation)
859 MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
860 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw)
861 MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
862
863 int sgen_gc_collection_count (int generation);
864 /* FIXME: what exactly does this return? */
865 size_t sgen_gc_get_used_size (void)
866 MONO_PERMIT (need (sgen_lock_gc));
867 size_t sgen_gc_get_total_heap_allocation (void);
868
869 /* STW */
870
871 void sgen_stop_world (int generation)
872 MONO_PERMIT (need (sgen_gc_locked), use (sgen_stop_world), grant (sgen_world_stopped), revoke (sgen_stop_world));
873 void sgen_restart_world (int generation)
874 MONO_PERMIT (need (sgen_gc_locked), use (sgen_world_stopped), revoke (sgen_world_stopped), grant (sgen_stop_world));
875 gboolean sgen_is_world_stopped (void);
876
877 gboolean sgen_set_allow_synchronous_major (gboolean flag);
878
879 /* LOS */
880
881 typedef struct _LOSObject LOSObject;
882 struct _LOSObject {
883 LOSObject *next;
884 mword size; /* this is the object size, lowest bit used for pin/mark */
885 guint8 * volatile cardtable_mod_union; /* only used by the concurrent collector */
886 #if SIZEOF_VOID_P < 8
887 mword dummy; /* to align object to sizeof (double) */
888 #endif
889 GCObject data [MONO_ZERO_LEN_ARRAY];
890 };
891
892 extern LOSObject *los_object_list;
893 extern mword los_memory_usage;
894 extern mword los_memory_usage_total;
895
896 void sgen_los_free_object (LOSObject *obj);
897 void* sgen_los_alloc_large_inner (GCVTable vtable, size_t size)
898 MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
899 void sgen_los_sweep (void);
900 gboolean sgen_ptr_is_in_los (char *ptr, char **start);
901 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data);
902 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
903 void sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
904 void sgen_los_update_cardtable_mod_union (void);
905 void sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards);
906 gboolean sgen_los_is_valid_object (char *object);
907 gboolean mono_sgen_los_describe_pointer (char *ptr);
908 LOSObject* sgen_los_header_for_object (GCObject *data);
909 mword sgen_los_object_size (LOSObject *obj);
910 void sgen_los_pin_object (GCObject *obj);
911 gboolean sgen_los_pin_object_par (GCObject *obj);
912 gboolean sgen_los_object_is_pinned (GCObject *obj);
913 void sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr);
914
915
916 /* nursery allocator */
917
918 void sgen_clear_nursery_fragments (void);
919 void sgen_nursery_allocator_prepare_for_pinning (void);
920 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, size_t min_size, size_t max_size);
921 void sgen_resize_nursery (gboolean need_shrink);
922 mword sgen_build_nursery_fragments (GCMemSection *nursery_section, SgenGrayQueue *unpin_queue);
923 void sgen_init_nursery_allocator (void);
924 void sgen_nursery_allocator_init_heavy_stats (void);
925 void sgen_init_allocator (void);
926 void* sgen_nursery_alloc (size_t size);
927 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size);
928 gboolean sgen_can_alloc_size (size_t size);
929 void sgen_nursery_retire_region (void *address, ptrdiff_t size);
930
931 void sgen_nursery_alloc_prepare_for_minor (void);
932 void sgen_nursery_alloc_prepare_for_major (void);
933
934 GCObject* sgen_alloc_for_promotion (GCObject *obj, size_t objsize, gboolean has_references);
935
936 GCObject* sgen_alloc_obj_nolock (GCVTable vtable, size_t size)
937 MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
938 GCObject* sgen_try_alloc_obj_nolock (GCVTable vtable, size_t size);
939
940 /* Threads */
941
942 void* sgen_thread_attach (SgenThreadInfo* info);
943 void sgen_thread_detach_with_lock (SgenThreadInfo *p);
944
945 /* Finalization/ephemeron support */
946
947 static inline gboolean
sgen_major_is_object_alive(GCObject * object)948 sgen_major_is_object_alive (GCObject *object)
949 {
950 mword objsize;
951
952 /* Oldgen objects can be pinned and forwarded too */
953 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
954 return TRUE;
955
956 /*
957 * FIXME: major_collector.is_object_live() also calculates the
958 * size. Avoid the double calculation.
959 */
960 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (object));
961 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
962 return sgen_los_object_is_pinned (object);
963
964 return major_collector.is_object_live (object);
965 }
966
967
968 /*
969 * If the object has been forwarded it means it's still referenced from a root.
970 * If it is pinned it's still alive as well.
971 * A LOS object is only alive if we have pinned it.
972 * Return TRUE if @obj is ready to be finalized.
973 */
974 static inline gboolean
sgen_is_object_alive(GCObject * object)975 sgen_is_object_alive (GCObject *object)
976 {
977 if (sgen_ptr_in_nursery (object))
978 return sgen_nursery_is_object_alive (object);
979
980 return sgen_major_is_object_alive (object);
981 }
982
983
984 /*
985 * This function returns true if @object is either alive or it belongs to the old gen
986 * and we're currently doing a minor collection.
987 */
988 static inline int
sgen_is_object_alive_for_current_gen(GCObject * object)989 sgen_is_object_alive_for_current_gen (GCObject *object)
990 {
991 if (sgen_ptr_in_nursery (object))
992 return sgen_nursery_is_object_alive (object);
993
994 if (current_collection_generation == GENERATION_NURSERY)
995 return TRUE;
996
997 return sgen_major_is_object_alive (object);
998 }
999
1000 int sgen_gc_invoke_finalizers (void)
1001 MONO_PERMIT (need (sgen_lock_gc));
1002
1003 /* GC handles */
1004
1005 void sgen_init_gchandles (void);
1006
1007 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track)
1008 MONO_PERMIT (need (sgen_gc_locked));
1009
1010 typedef gpointer (*SgenGCHandleIterateCallback) (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user);
1011
1012 guint32 sgen_gchandle_new (GCObject *obj, gboolean pinned);
1013 guint32 sgen_gchandle_new_weakref (GCObject *obj, gboolean track_resurrection);
1014 void sgen_gchandle_iterate (GCHandleType handle_type, int max_generation, SgenGCHandleIterateCallback callback, gpointer user)
1015 MONO_PERMIT (need (sgen_world_stopped));
1016 void sgen_gchandle_set_target (guint32 gchandle, GCObject *obj);
1017 void sgen_mark_normal_gc_handles (void *addr, SgenUserMarkFunc mark_func, void *gc_data)
1018 MONO_PERMIT (need (sgen_world_stopped));
1019 gpointer sgen_gchandle_get_metadata (guint32 gchandle);
1020 GCObject *sgen_gchandle_get_target (guint32 gchandle);
1021 void sgen_gchandle_free (guint32 gchandle);
1022
1023 /* Other globals */
1024
1025 extern GCMemSection *nursery_section;
1026 extern guint32 collect_before_allocs;
1027 extern guint32 verify_before_allocs;
1028 extern gboolean has_per_allocation_action;
1029 extern size_t degraded_mode;
1030 extern int default_nursery_size;
1031 extern guint32 tlab_size;
1032 extern NurseryClearPolicy nursery_clear_policy;
1033 extern gboolean sgen_try_free_some_memory;
1034 extern mword total_promoted_size;
1035 extern mword total_allocated_major;
1036 extern volatile gboolean sgen_suspend_finalizers;
1037 extern MonoCoopMutex gc_mutex;
1038 extern volatile gboolean concurrent_collection_in_progress;
1039
1040 /* Nursery helpers. */
1041
1042 static inline void
sgen_set_nursery_scan_start(char * p)1043 sgen_set_nursery_scan_start (char *p)
1044 {
1045 size_t idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
1046 char *old = nursery_section->scan_starts [idx];
1047 if (!old || old > p)
1048 nursery_section->scan_starts [idx] = p;
1049 }
1050
1051
1052 /* Object Allocation */
1053
1054 typedef enum {
1055 ATYPE_NORMAL,
1056 ATYPE_VECTOR,
1057 ATYPE_SMALL,
1058 ATYPE_STRING,
1059 ATYPE_NUM
1060 } SgenAllocatorType;
1061
1062 void sgen_clear_tlabs (void);
1063
1064 GCObject* sgen_alloc_obj (GCVTable vtable, size_t size)
1065 MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1066 GCObject* sgen_alloc_obj_pinned (GCVTable vtable, size_t size)
1067 MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1068 GCObject* sgen_alloc_obj_mature (GCVTable vtable, size_t size)
1069 MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1070
1071 /* Debug support */
1072
1073 void sgen_check_remset_consistency (void);
1074 void sgen_check_mod_union_consistency (void);
1075 void sgen_check_major_refs (void);
1076 void sgen_check_whole_heap (gboolean allow_missing_pinning);
1077 void sgen_check_whole_heap_stw (void)
1078 MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
1079 void sgen_check_objref (char *obj);
1080 void sgen_check_heap_marked (gboolean nursery_must_be_pinned);
1081 void sgen_check_nursery_objects_pinned (gboolean pinned);
1082 void sgen_check_for_xdomain_refs (void);
1083 GCObject* sgen_find_object_for_ptr (char *ptr);
1084
1085 void mono_gc_scan_for_specific_ref (GCObject *key, gboolean precise);
1086
1087 void sgen_debug_enable_heap_dump (const char *filename);
1088 void sgen_debug_dump_heap (const char *type, int num, const char *reason);
1089
1090 void sgen_debug_verify_nursery (gboolean do_dump_nursery_content);
1091 void sgen_debug_check_nursery_is_clean (void);
1092
1093 /* Environment variable parsing */
1094
1095 #define MONO_GC_PARAMS_NAME "MONO_GC_PARAMS"
1096 #define MONO_GC_DEBUG_NAME "MONO_GC_DEBUG"
1097
1098 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...);
1099
1100 /* Utilities */
1101
1102 void sgen_qsort (void *array, size_t count, size_t element_size, int (*compare) (const void*, const void*));
1103 gint64 sgen_timestamp (void);
1104
1105 /*
1106 * Canary (guard word) support
1107 * Notes:
1108 * - CANARY_SIZE must be multiple of word size in bytes
1109 * - Canary space is not included on checks against SGEN_MAX_SMALL_OBJ_SIZE
1110 */
1111
1112 gboolean nursery_canaries_enabled (void);
1113
1114 #define CANARY_SIZE 8
1115 #define CANARY_STRING "koupepia"
1116
1117 #define CANARIFY_SIZE(size) if (nursery_canaries_enabled ()) { \
1118 size = size + CANARY_SIZE; \
1119 }
1120
1121 #define CANARIFY_ALLOC(addr,size) if (nursery_canaries_enabled ()) { \
1122 memcpy ((char*) (addr) + (size), CANARY_STRING, CANARY_SIZE); \
1123 }
1124
1125 #define CANARY_VALID(addr) (strncmp ((char*) (addr), CANARY_STRING, CANARY_SIZE) == 0)
1126
1127 #define CHECK_CANARY_FOR_OBJECT(addr,fail) if (nursery_canaries_enabled ()) { \
1128 guint size = sgen_safe_object_get_size_unaligned ((GCObject *) (addr)); \
1129 char* canary_ptr = (char*) (addr) + size; \
1130 if (!CANARY_VALID(canary_ptr)) { \
1131 char *window_start, *window_end; \
1132 window_start = (char*)(addr) - 128; \
1133 if (!sgen_ptr_in_nursery (window_start)) \
1134 window_start = sgen_get_nursery_start (); \
1135 window_end = (char*)(addr) + 128; \
1136 if (!sgen_ptr_in_nursery (window_end)) \
1137 window_end = sgen_get_nursery_end (); \
1138 fprintf (stderr, "\nCANARY ERROR - Type:%s Size:%d Address:%p Data:\n", sgen_client_vtable_get_name (SGEN_LOAD_VTABLE ((addr))), size, (char*) addr); \
1139 fwrite (addr, sizeof (char), size, stderr); \
1140 fprintf (stderr, "\nCanary zone (next 12 chars):\n"); \
1141 fwrite (canary_ptr, sizeof (char), 12, stderr); \
1142 fprintf (stderr, "\nOriginal canary string:\n"); \
1143 fwrite (CANARY_STRING, sizeof (char), 8, stderr); \
1144 for (int x = -8; x <= 8; x++) { \
1145 if (canary_ptr + x < (char*) addr); \
1146 continue; \
1147 if (CANARY_VALID(canary_ptr +x)) \
1148 fprintf (stderr, "\nCANARY ERROR - canary found at offset %d\n", x); \
1149 } \
1150 fprintf (stderr, "\nSurrounding nursery (%p - %p):\n", window_start, window_end); \
1151 fwrite (window_start, sizeof (char), window_end - window_start, stderr); \
1152 } }
1153
1154 /*
1155 * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1156 */
1157 static inline void
sgen_dummy_use(gpointer v)1158 sgen_dummy_use (gpointer v)
1159 {
1160 #if defined(_MSC_VER) || defined(HOST_WASM)
1161 static volatile gpointer ptr;
1162 ptr = v;
1163 #elif defined(__GNUC__)
1164 __asm__ volatile ("" : "=r"(v) : "r"(v));
1165 #else
1166 #error "Implement sgen_dummy_use for your compiler"
1167 #endif
1168 }
1169
1170 #endif /* HAVE_SGEN_GC */
1171
1172 #endif /* __MONO_SGENGC_H__ */
1173