2 * stop and copy GC based on Cheney's algorithm
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
18 #include <sys/resource.h>
24 #include "gc-internal.h"
26 #include "interrupt.h"
30 #include "genesis/static-symbols.h"
31 #include "genesis/primitive-objects.h"
34 /* So you need to debug? */
37 #define DEBUG_SPACE_PREDICATES
38 #define DEBUG_SCAVENGE_VERBOSE
39 #define DEBUG_COPY_VERBOSE
44 lispobj *from_space_free_pointer;
47 lispobj *new_space_free_pointer;
49 static void scavenge_newspace(void);
50 static void scavenge_interrupt_contexts(void);
51 extern struct interrupt_data * global_interrupt_data;
53 extern unsigned long bytes_consed_between_gcs;
56 /* collecting garbage */
60 tv_diff(struct timeval *x, struct timeval *y)
62 return (((double) x->tv_sec + (double) x->tv_usec * 1.0e-6) -
63 ((double) y->tv_sec + (double) y->tv_usec * 1.0e-6));
67 #define BYTES_ZERO_BEFORE_END (1<<12)
69 /* FIXME do we need this? Doesn't it duplicate lisp code in
70 * scrub-control-stack? */
75 u32 *ptr = (u32 *)current_control_stack_pointer;
81 } while (((unsigned long)ptr) & (BYTES_ZERO_BEFORE_END-1));
86 } while (((unsigned long)ptr) & (BYTES_ZERO_BEFORE_END-1));
93 gc_general_alloc(int bytes, int unboxed_p, int quick_p) {
94 lispobj *new=new_space_free_pointer;
95 new_space_free_pointer+=(bytes/4);
99 lispobj copy_large_unboxed_object(lispobj object, int nwords) {
100 return copy_object(object,nwords);
102 lispobj copy_unboxed_object(lispobj object, int nwords) {
103 return copy_object(object,nwords);
105 lispobj copy_large_object(lispobj object, int nwords) {
106 return copy_object(object,nwords);
109 /* Note: The generic GC interface we're implementing passes us a
110 * last_generation argument. That's meaningless for us, since we're
111 * not a generational GC. So we ignore it. */
113 collect_garbage(unsigned ignore)
116 struct timeval start_tv, stop_tv;
117 struct rusage start_rusage, stop_rusage;
118 double real_time, system_time, user_time;
119 double percent_retained, gc_rate;
120 unsigned long size_discarded;
122 unsigned long size_retained;
123 lispobj *current_static_space_free_pointer;
124 unsigned long static_space_size;
125 unsigned long control_stack_size, binding_stack_size;
127 struct thread *th=arch_os_get_current_thread();
128 struct interrupt_data *data=
129 th ? th->interrupt_data : global_interrupt_data;
133 printf("[Collecting garbage ... \n");
135 getrusage(RUSAGE_SELF, &start_rusage);
136 gettimeofday(&start_tv, (struct timezone *) 0);
140 sigaddset_blockable(&tmp);
141 sigprocmask(SIG_BLOCK, &tmp, &old);
143 current_static_space_free_pointer =
144 (lispobj *) ((unsigned long)
145 SymbolValue(STATIC_SPACE_FREE_POINTER,0));
148 /* Set up from space and new space pointers. */
150 from_space = current_dynamic_space;
151 from_space_free_pointer = dynamic_space_free_pointer;
154 fprintf(stderr,"from_space = %lx\n",
155 (unsigned long) current_dynamic_space);
157 if (current_dynamic_space == (lispobj *) DYNAMIC_0_SPACE_START)
158 new_space = (lispobj *)DYNAMIC_1_SPACE_START;
159 else if (current_dynamic_space == (lispobj *) DYNAMIC_1_SPACE_START)
160 new_space = (lispobj *) DYNAMIC_0_SPACE_START;
162 lose("GC lossage. Current dynamic space is bogus!\n");
164 new_space_free_pointer = new_space;
166 /* Initialize the weak pointer list. */
167 weak_pointers = (struct weak_pointer *) NULL;
170 /* Scavenge all of the roots. */
172 printf("Scavenging interrupt contexts ...\n");
174 scavenge_interrupt_contexts();
177 printf("Scavenging interrupt handlers (%d bytes) ...\n",
178 (int)sizeof(interrupt_handlers));
180 scavenge((lispobj *) data->interrupt_handlers,
181 sizeof(data->interrupt_handlers) / sizeof(lispobj));
183 /* _size quantities are in units of sizeof(lispobj) - i.e. 4 */
185 current_control_stack_pointer-
186 (lispobj *)th->control_stack_start;
188 printf("Scavenging the control stack at %p (%ld words) ...\n",
189 ((lispobj *)th->control_stack_start),
192 scavenge(((lispobj *)th->control_stack_start), control_stack_size);
196 current_binding_stack_pointer -
197 (lispobj *)th->binding_stack_start;
199 printf("Scavenging the binding stack %x - %x (%d words) ...\n",
200 th->binding_stack_start,current_binding_stack_pointer,
201 (int)(binding_stack_size));
203 scavenge(((lispobj *)th->binding_stack_start), binding_stack_size);
206 current_static_space_free_pointer - (lispobj *) STATIC_SPACE_START;
208 printf("Scavenging static space %x - %x (%d words) ...\n",
209 STATIC_SPACE_START,current_static_space_free_pointer,
210 (int)(static_space_size));
212 scavenge(((lispobj *)STATIC_SPACE_START), static_space_size);
214 /* Scavenge newspace. */
216 printf("Scavenging new space (%d bytes) ...\n",
217 (int)((new_space_free_pointer - new_space) * sizeof(lispobj)));
222 #if defined(DEBUG_PRINT_GARBAGE)
223 print_garbage(from_space, from_space_free_pointer);
226 /* Scan the weak pointers. */
228 printf("Scanning weak pointers ...\n");
230 scan_weak_pointers();
235 printf("Flipping spaces ...\n");
238 os_zero((os_vm_address_t) current_dynamic_space,
239 (os_vm_size_t) DYNAMIC_SPACE_SIZE);
241 current_dynamic_space = new_space;
242 dynamic_space_free_pointer = new_space_free_pointer;
245 size_discarded = (from_space_free_pointer - from_space) * sizeof(lispobj);
247 size_retained = (new_space_free_pointer - new_space) * sizeof(lispobj);
251 printf("Zeroing empty part of control stack ...\n");
254 set_auto_gc_trigger(size_retained+bytes_consed_between_gcs);
255 sigprocmask(SIG_SETMASK, &old, 0);
259 gettimeofday(&stop_tv, (struct timezone *) 0);
260 getrusage(RUSAGE_SELF, &stop_rusage);
264 percent_retained = (((float) size_retained) /
265 ((float) size_discarded)) * 100.0;
267 printf("Total of %ld bytes out of %ld bytes retained (%3.2f%%).\n",
268 size_retained, size_discarded, percent_retained);
270 real_time = tv_diff(&stop_tv, &start_tv);
271 user_time = tv_diff(&stop_rusage.ru_utime, &start_rusage.ru_utime);
272 system_time = tv_diff(&stop_rusage.ru_stime, &start_rusage.ru_stime);
275 printf("Statistics:\n");
276 printf("%10.2f sec of real time\n", real_time);
277 printf("%10.2f sec of user time,\n", user_time);
278 printf("%10.2f sec of system time.\n", system_time);
280 printf("Statistics: %10.2fs real, %10.2fs user, %10.2fs system.\n",
281 real_time, user_time, system_time);
284 gc_rate = ((float) size_retained / (float) (1<<20)) / real_time;
286 printf("%10.2f M bytes/sec collected.\n", gc_rate);
288 /* os_flush_icache((os_vm_address_t) 0, sizeof(unsigned long)); */
289 /* Maybe FIXME: it's possible that we could significantly reduce
290 * RSS by zeroing the from_space or madvise(MADV_DONTNEED) or
291 * similar os-dependent tricks here */
298 scavenge_newspace(void)
300 lispobj *here, *next;
303 while (here < new_space_free_pointer) {
304 /* printf("here=%lx, new_space_free_pointer=%lx\n",
305 here,new_space_free_pointer); */
306 next = new_space_free_pointer;
307 scavenge(here, next - here);
310 /* printf("done with newspace\n"); */
313 /* scavenging interrupt contexts */
315 static int boxed_registers[] = BOXED_REGISTERS;
318 scavenge_interrupt_context(os_context_t *context)
323 unsigned long lip_offset;
324 int lip_register_pair;
326 unsigned long pc_code_offset;
327 #ifdef ARCH_HAS_LINK_REGISTER
328 unsigned long lr_code_offset;
330 #ifdef ARCH_HAS_NPC_REGISTER
331 unsigned long npc_code_offset;
333 #ifdef DEBUG_SCAVENGE_VERBOSE
334 fprintf(stderr, "Scavenging interrupt context at 0x%x\n",context);
336 /* Find the LIP's register pair and calculate its offset */
337 /* before we scavenge the context. */
339 lip = *os_context_register_addr(context, reg_LIP);
340 /* 0x7FFFFFFF or 0x7FFFFFFFFFFFFFFF ? */
341 lip_offset = 0x7FFFFFFF;
342 lip_register_pair = -1;
343 for (i = 0; i < (sizeof(boxed_registers) / sizeof(int)); i++) {
348 index = boxed_registers[i];
349 reg = *os_context_register_addr(context, index);
350 /* would be using PTR if not for integer length issues */
351 if ((reg & ~((1L<<N_LOWTAG_BITS)-1)) <= lip) {
353 if (offset < lip_offset) {
355 lip_register_pair = index;
361 /* Compute the PC's offset from the start of the CODE */
364 *os_context_pc_addr(context) -
365 *os_context_register_addr(context, reg_CODE);
366 #ifdef ARCH_HAS_NPC_REGISTER
368 *os_context_npc_addr(context) -
369 *os_context_register_addr(context, reg_CODE);
371 #ifdef ARCH_HAS_LINK_REGISTER
373 *os_context_lr_addr(context) -
374 *os_context_register_addr(context, reg_CODE);
377 /* Scavenge all boxed registers in the context. */
378 for (i = 0; i < (sizeof(boxed_registers) / sizeof(int)); i++) {
382 index = boxed_registers[i];
383 foo = *os_context_register_addr(context,index);
384 scavenge((lispobj *) &foo, 1);
385 *os_context_register_addr(context,index) = foo;
387 /* this is unlikely to work as intended on bigendian
388 * 64 bit platforms */
391 os_context_register_addr(context, index), 1);
396 *os_context_register_addr(context, reg_LIP) =
397 *os_context_register_addr(context, lip_register_pair) + lip_offset;
400 /* Fix the PC if it was in from space */
401 if (from_space_p(*os_context_pc_addr(context)))
402 *os_context_pc_addr(context) =
403 *os_context_register_addr(context, reg_CODE) + pc_code_offset;
404 #ifdef ARCH_HAS_LINK_REGISTER
405 /* Fix the LR ditto; important if we're being called from
406 * an assembly routine that expects to return using blr, otherwise
408 if (from_space_p(*os_context_lr_addr(context)))
409 *os_context_lr_addr(context) =
410 *os_context_register_addr(context, reg_CODE) + lr_code_offset;
413 #ifdef ARCH_HAS_NPC_REGISTER
414 if (from_space_p(*os_context_npc_addr(context)))
415 *os_context_npc_addr(context) =
416 *os_context_register_addr(context, reg_CODE) + npc_code_offset;
420 void scavenge_interrupt_contexts(void)
423 os_context_t *context;
425 struct thread *th=arch_os_get_current_thread();
426 struct interrupt_data *data=
427 th ? th->interrupt_data : global_interrupt_data;
429 index = fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,0));
432 #ifdef DEBUG_SCAVENGE_VERBOSE
433 fprintf(stderr, "%d interrupt contexts to scan\n",index);
435 for (i = 0; i < index; i++) {
436 context = th->interrupt_contexts[i];
437 scavenge_interrupt_context(context);
445 print_garbage(lispobj *from_space, lispobj *from_space_free_pointer)
448 int total_words_not_copied;
450 printf("Scanning from space ...\n");
452 total_words_not_copied = 0;
454 while (start < from_space_free_pointer) {
456 int forwardp, type, nwords;
460 forwardp = is_lisp_pointer(object) && new_space_p(object);
466 tag = lowtag_of(object);
469 case LIST_POINTER_LOWTAG:
472 case INSTANCE_POINTER_LOWTAG:
473 printf("Don't know about instances yet!\n");
476 case FUN_POINTER_LOWTAG:
479 case OTHER_POINTER_LOWTAG:
480 pointer = (lispobj *) native_pointer(object);
482 type = widetag_of(header);
483 nwords = (sizetab[type])(pointer);
485 default: nwords=1; /* shut yer whinging, gcc */
488 type = widetag_of(object);
489 nwords = (sizetab[type])(start);
490 total_words_not_copied += nwords;
491 printf("%4d words not copied at 0x%16lx; ",
492 nwords, (unsigned long) start);
493 printf("Header word is 0x%08x\n",
494 (unsigned int) object);
498 printf("%d total words not copied.\n", total_words_not_copied);
502 /* code and code-related objects */
504 /* FIXME (1) this could probably be defined using something like
505 * sizeof(lispobj)*floor(sizeof(struct simple_fun)/sizeof(lispobj))
506 * - FUN_POINTER_LOWTAG
507 * as I'm reasonably sure that simple_fun->code must always be the
508 * last slot in the object
510 * FIXME (2) it also appears in purify.c, and it has a different value
511 * for SPARC users in that bit
514 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
516 /* Note: on the sparc we don't have to do anything special for fdefns, */
517 /* 'cause the raw-addr has a function lowtag. */
518 #ifndef LISP_FEATURE_SPARC
520 scav_fdefn(lispobj *where, lispobj object)
524 fdefn = (struct fdefn *)where;
526 if ((char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET)
527 == (char *)((unsigned long)(fdefn->raw_addr))) {
528 scavenge(where + 1, sizeof(struct fdefn)/sizeof(lispobj) - 1);
530 (u32) ((char *) LOW_WORD(fdefn->fun)) + FUN_RAW_ADDR_OFFSET;
531 return sizeof(struct fdefn) / sizeof(lispobj);
540 /* vector-like objects */
542 /* #define NWORDS(x,y) (CEILING((x),(y)) / (y)) */
545 scav_vector(lispobj *where, lispobj object)
547 if (HeaderValue(object) == subtype_VectorValidHashing) {
549 (subtype_VectorMustRehash<<N_WIDETAG_BITS) | SIMPLE_VECTOR_WIDETAG;
558 #define WEAK_POINTER_NWORDS \
559 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
562 scav_weak_pointer(lispobj *where, lispobj object)
564 /* Do not let GC scavenge the value slot of the weak pointer */
565 /* (that is why it is a weak pointer). Note: we could use */
566 /* the scav_unboxed method here. */
568 return WEAK_POINTER_NWORDS;
572 /* initialization. if gc_init can be moved to after core load, we could
573 * combine these two functions */
579 scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
580 scavtab[WEAK_POINTER_WIDETAG] = scav_weak_pointer;
584 gc_initialize_pointers(void)
586 /* FIXME: We do nothing here. We (briefly) misguidedly attempted
587 to set current_dynamic_space to DYNAMIC_0_SPACE_START here,
588 forgetting that (a) actually it could be the other and (b) it's
589 set in coreparse.c anyway. There's a FIXME note left here to
590 note that current_dynamic_space is a violation of OAOO: we can
591 tell which dynamic space we're currently in by looking at
592 dynamic_space_free_pointer. -- CSR, 2002-08-09 */
598 /* noise to manipulate the gc trigger stuff */
600 /* Functions that substantially change the dynamic space free pointer
601 * (collect_garbage, purify) are responsible also for resettting the
603 void set_auto_gc_trigger(os_vm_size_t dynamic_usage)
605 os_vm_address_t addr=(os_vm_address_t)current_dynamic_space
607 long length = DYNAMIC_SPACE_SIZE - dynamic_usage;
609 if (addr < (os_vm_address_t)dynamic_space_free_pointer) {
611 "set_auto_gc_trigger: tried to set gc trigger too low! (%d < %p)\n",
612 (unsigned int)dynamic_usage,
613 (os_vm_address_t)dynamic_space_free_pointer
614 - (os_vm_address_t)current_dynamic_space);
617 else if (length < 0) {
619 "set_auto_gc_trigger: tried to set gc trigger too high! (%p)\n",
624 addr=os_round_up_to_page(addr);
625 length=os_trunc_size_to_page(length);
627 #if defined(SUNOS) || defined(SOLARIS)
628 os_invalidate(addr,length);
630 os_protect(addr, length, 0);
633 current_auto_gc_trigger = (lispobj *)addr;
636 void clear_auto_gc_trigger(void)
638 if (current_auto_gc_trigger!=NULL){
639 #if defined(SUNOS) || defined(SOLARIS)/* don't want to force whole space into swapping mode... */
640 os_vm_address_t addr=(os_vm_address_t)current_auto_gc_trigger;
642 DYNAMIC_SPACE_SIZE + (os_vm_address_t)current_dynamic_space - addr;
644 os_validate(addr,length);
646 os_protect((os_vm_address_t)current_dynamic_space,
651 current_auto_gc_trigger = NULL;