/* * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved. * Copyright (c) 1998 by Silicon Graphics. All rights reserved. * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P. * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. * * Permission is hereby granted to use or copy this program * for any purpose, provided the above notices are retained on all copies. * Permission to modify the code and to distribute modified code is granted, * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. * */ # include "private/gc_priv.h" # include # if !defined(MACOS) && !defined(MSWINCE) # include # include # endif /* * Separate free lists are maintained for different sized objects * up to MAXOBJBYTES. * The call GC_allocobj(i,k) ensures that the freelist for * kind k objects of size i points to a non-empty * free list. It returns a pointer to the first entry on the free list. * In a single-threaded world, GC_allocobj may be called to allocate * an object of (small) size i as follows: * * opp = &(GC_objfreelist[i]); * if (*opp == 0) GC_allocobj(i, NORMAL); * ptr = *opp; * *opp = obj_link(ptr); * * Note that this is very fast if the free list is non-empty; it should * only involve the execution of 4 or 5 simple instructions. * All composite objects on freelists are cleared, except for * their first word. */ /* * The allocator uses GC_allochblk to allocate large chunks of objects. * These chunks all start on addresses which are multiples of * HBLKSZ. Each allocated chunk has an associated header, * which can be located quickly based on the address of the chunk. * (See headers.c for details.) * This makes it possible to check quickly whether an * arbitrary address corresponds to an object administered by the * allocator. */ word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */ word GC_gc_no = 0; #ifndef SMALL_CONFIG int GC_incremental = 0; /* By default, stop the world. */ #endif int GC_parallel = FALSE; /* By default, parallel GC is off. */ #ifndef GC_FULL_FREQ # define GC_FULL_FREQ 19 /* Every 20th collection is a full */ /* collection, whether we need it */ /* or not. */ #endif int GC_full_freq = GC_FULL_FREQ; STATIC GC_bool GC_need_full_gc = FALSE; /* Need full GC do to heap growth. */ #ifdef THREADS GC_bool GC_world_stopped = FALSE; # define IF_THREADS(x) x #else # define IF_THREADS(x) #endif STATIC word GC_used_heap_size_after_full = 0; char * GC_copyright[] = {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ", "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ", "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ", "Copyright (c) 1999-2009 by Hewlett-Packard Company. All rights reserved. ", "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY", " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.", "See source code for details." }; /* Version macros are now defined in gc_version.h, which is included by */ /* gc.h, which is included by gc_priv.h". */ #ifndef GC_NO_VERSION_VAR unsigned GC_version = ((GC_VERSION_MAJOR << 16) | (GC_VERSION_MINOR << 8) | GC_TMP_ALPHA_VERSION); #endif /* GC_NO_VERSION_VAR */ /* some more variables */ extern signed_word GC_bytes_found; /* Number of reclaimed bytes */ /* after garbage collection */ #ifdef GC_DONT_EXPAND GC_bool GC_dont_expand = TRUE; #else GC_bool GC_dont_expand = FALSE; #endif #ifndef GC_FREE_SPACE_DIVISOR # define GC_FREE_SPACE_DIVISOR 3 /* must be > 0 */ #endif word GC_free_space_divisor = GC_FREE_SPACE_DIVISOR; extern GC_bool GC_collection_in_progress(void); /* Collection is in progress, or was abandoned. */ int GC_CALLBACK GC_never_stop_func (void) { return(0); } #ifndef GC_TIME_LIMIT # define GC_TIME_LIMIT 50 /* We try to keep pause times from exceeding */ /* this by much. In milliseconds. */ #endif unsigned long GC_time_limit = GC_TIME_LIMIT; #ifndef NO_CLOCK STATIC CLOCK_TYPE GC_start_time;/* Time at which we stopped world. */ /* used only in GC_timeout_stop_func. */ #endif STATIC int GC_n_attempts = 0; /* Number of attempts at finishing */ /* collection within GC_time_limit. */ #if defined(SMALL_CONFIG) || defined(NO_CLOCK) # define GC_timeout_stop_func GC_never_stop_func #else STATIC int GC_CALLBACK GC_timeout_stop_func (void) { CLOCK_TYPE current_time; static unsigned count = 0; unsigned long time_diff; if ((count++ & 3) != 0) return(0); GET_TIME(current_time); time_diff = MS_TIME_DIFF(current_time,GC_start_time); if (time_diff >= GC_time_limit) { if (GC_print_stats) { GC_log_printf( "Abandoning stopped marking after %lu msecs (attempt %d)\n", time_diff, GC_n_attempts); } return(1); } return(0); } #endif /* !SMALL_CONFIG */ /* Return the minimum number of words that must be allocated between */ /* collections to amortize the collection cost. */ static word min_bytes_allocd(void) { # ifdef THREADS /* We punt, for now. */ signed_word stack_size = 10000; # else int dummy; signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom; # endif word total_root_size; /* includes double stack size, */ /* since the stack is expensive */ /* to scan. */ word scan_size; /* Estimate of memory to be scanned */ /* during normal GC. */ if (stack_size < 0) stack_size = -stack_size; total_root_size = 2 * stack_size + GC_root_size; scan_size = 2 * GC_composite_in_use + GC_atomic_in_use/4 + total_root_size; if (TRUE_INCREMENTAL) { return scan_size / (2 * GC_free_space_divisor); } else { return scan_size / GC_free_space_divisor; } } /* Return the number of bytes allocated, adjusted for explicit storage */ /* management, etc.. This number is used in deciding when to trigger */ /* collections. */ STATIC word GC_adj_bytes_allocd(void) { signed_word result; signed_word expl_managed = (signed_word)GC_non_gc_bytes - (signed_word)GC_non_gc_bytes_at_gc; /* Don't count what was explicitly freed, or newly allocated for */ /* explicit management. Note that deallocating an explicitly */ /* managed object should not alter result, assuming the client */ /* is playing by the rules. */ result = (signed_word)GC_bytes_allocd + (signed_word)GC_bytes_dropped - (signed_word)GC_bytes_freed + (signed_word)GC_finalizer_bytes_freed - expl_managed; if (result > (signed_word)GC_bytes_allocd) { result = GC_bytes_allocd; /* probably client bug or unfortunate scheduling */ } result += GC_bytes_finalized; /* We count objects enqueued for finalization as though they */ /* had been reallocated this round. Finalization is user */ /* visible progress. And if we don't count this, we have */ /* stability problems for programs that finalize all objects. */ if (result < (signed_word)(GC_bytes_allocd >> 3)) { /* Always count at least 1/8 of the allocations. We don't want */ /* to collect too infrequently, since that would inhibit */ /* coalescing of free storage blocks. */ /* This also makes us partially robust against client bugs. */ return(GC_bytes_allocd >> 3); } else { return(result); } } /* Clear up a few frames worth of garbage left at the top of the stack. */ /* This is used to prevent us from accidentally treating garbage left */ /* on the stack by other parts of the collector as roots. This */ /* differs from the code in misc.c, which actually tries to keep the */ /* stack clear of long-lived, client-generated garbage. */ STATIC void GC_clear_a_few_frames(void) { # ifndef CLEAR_NWORDS # define CLEAR_NWORDS 64 # endif volatile word frames[CLEAR_NWORDS]; int i; for (i = 0; i < CLEAR_NWORDS; i++) frames[i] = 0; } /* Heap size at which we need a collection to avoid expanding past */ /* limits used by blacklisting. */ static word GC_collect_at_heapsize = (word)(-1); /* Have we allocated enough to amortize a collection? */ GC_bool GC_should_collect(void) { static word last_min_bytes_allocd; static word last_gc_no; if (last_gc_no != GC_gc_no) { last_gc_no = GC_gc_no; last_min_bytes_allocd = min_bytes_allocd(); } return(GC_adj_bytes_allocd() >= last_min_bytes_allocd || GC_heapsize >= GC_collect_at_heapsize); } STATIC void GC_notify_full_gc(void) { if (GC_start_call_back != (void (*) (void))0) { (*GC_start_call_back)(); } } STATIC GC_bool GC_is_full_gc = FALSE; STATIC GC_bool GC_stopped_mark(GC_stop_func stop_func); STATIC void GC_finish_collection(void); /* * Initiate a garbage collection if appropriate. * Choose judiciously * between partial, full, and stop-world collections. */ STATIC void GC_maybe_gc(void) { static int n_partial_gcs = 0; GC_ASSERT(I_HOLD_LOCK()); if (GC_should_collect()) { if (!GC_incremental) { GC_gcollect_inner(); n_partial_gcs = 0; return; } else { # ifdef PARALLEL_MARK if (GC_parallel) GC_wait_for_reclaim(); # endif if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) { if (GC_print_stats) { GC_log_printf( "***>Full mark for collection %lu after %ld allocd bytes\n", (unsigned long)GC_gc_no+1, (long)GC_bytes_allocd); } GC_promote_black_lists(); (void)GC_reclaim_all((GC_stop_func)0, TRUE); GC_clear_marks(); n_partial_gcs = 0; GC_notify_full_gc(); GC_is_full_gc = TRUE; } else { n_partial_gcs++; } } /* We try to mark with the world stopped. */ /* If we run out of time, this turns into */ /* incremental marking. */ # ifndef NO_CLOCK if (GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); } # endif if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED? GC_never_stop_func : GC_timeout_stop_func)) { # ifdef SAVE_CALL_CHAIN GC_save_callers(GC_last_stack); # endif GC_finish_collection(); } else { if (!GC_is_full_gc) { /* Count this as the first attempt */ GC_n_attempts++; } } } } /* * Stop the world garbage collection. Assumes lock held. If stop_func is * not GC_never_stop_func then abort if stop_func returns TRUE. * Return TRUE if we successfully completed the collection. */ GC_bool GC_try_to_collect_inner(GC_stop_func stop_func) { # ifndef SMALL_CONFIG CLOCK_TYPE start_time = 0; /* initialized to prevent warning. */ CLOCK_TYPE current_time; # endif if (GC_dont_gc) return FALSE; if (GC_incremental && GC_collection_in_progress()) { if (GC_print_stats) { GC_log_printf( "GC_try_to_collect_inner: finishing collection in progress\n"); } /* Just finish collection already in progress. */ while(GC_collection_in_progress()) { if (stop_func()) return(FALSE); GC_collect_a_little_inner(1); } } if (stop_func == GC_never_stop_func) GC_notify_full_gc(); # ifndef SMALL_CONFIG if (GC_print_stats) { GET_TIME(start_time); GC_log_printf("Initiating full world-stop collection!\n"); } # endif GC_promote_black_lists(); /* Make sure all blocks have been reclaimed, so sweep routines */ /* don't see cleared mark bits. */ /* If we're guaranteed to finish, then this is unnecessary. */ /* In the find_leak case, we have to finish to guarantee that */ /* previously unmarked objects are not reported as leaks. */ # ifdef PARALLEL_MARK if (GC_parallel) GC_wait_for_reclaim(); # endif if ((GC_find_leak || stop_func != GC_never_stop_func) && !GC_reclaim_all(stop_func, FALSE)) { /* Aborted. So far everything is still consistent. */ return(FALSE); } GC_invalidate_mark_state(); /* Flush mark stack. */ GC_clear_marks(); # ifdef SAVE_CALL_CHAIN GC_save_callers(GC_last_stack); # endif GC_is_full_gc = TRUE; if (!GC_stopped_mark(stop_func)) { if (!GC_incremental) { /* We're partially done and have no way to complete or use */ /* current work. Reestablish invariants as cheaply as */ /* possible. */ GC_invalidate_mark_state(); GC_unpromote_black_lists(); } /* else we claim the world is already still consistent. We'll */ /* finish incrementally. */ return(FALSE); } GC_finish_collection(); # ifndef SMALL_CONFIG if (GC_print_stats) { GET_TIME(current_time); GC_log_printf("Complete collection took %lu msecs\n", MS_TIME_DIFF(current_time,start_time)); } # endif return(TRUE); } /* * Perform n units of garbage collection work. A unit is intended to touch * roughly GC_RATE pages. Every once in a while, we do more than that. * This needs to be a fairly large number with our current incremental * GC strategy, since otherwise we allocate too much during GC, and the * cleanup gets expensive. */ #ifndef GC_RATE # define GC_RATE 10 #endif #ifndef MAX_PRIOR_ATTEMPTS # define MAX_PRIOR_ATTEMPTS 1 #endif /* Maximum number of prior attempts at world stop marking */ /* A value of 1 means that we finish the second time, no matter */ /* how long it takes. Doesn't count the initial root scan */ /* for a full GC. */ STATIC int GC_deficit = 0;/* The number of extra calls to GC_mark_some */ /* that we have made. */ void GC_collect_a_little_inner(int n) { int i; if (GC_dont_gc) return; if (GC_incremental && GC_collection_in_progress()) { for (i = GC_deficit; i < GC_RATE*n; i++) { if (GC_mark_some((ptr_t)0)) { /* Need to finish a collection */ # ifdef SAVE_CALL_CHAIN GC_save_callers(GC_last_stack); # endif # ifdef PARALLEL_MARK if (GC_parallel) GC_wait_for_reclaim(); # endif if (GC_n_attempts < MAX_PRIOR_ATTEMPTS && GC_time_limit != GC_TIME_UNLIMITED) { # ifndef NO_CLOCK GET_TIME(GC_start_time); # endif if (!GC_stopped_mark(GC_timeout_stop_func)) { GC_n_attempts++; break; } } else { (void)GC_stopped_mark(GC_never_stop_func); } GC_finish_collection(); break; } } if (GC_deficit > 0) GC_deficit -= GC_RATE*n; if (GC_deficit < 0) GC_deficit = 0; } else { GC_maybe_gc(); } } GC_API int GC_CALL GC_collect_a_little(void) { int result; DCL_LOCK_STATE; LOCK(); GC_collect_a_little_inner(1); result = (int)GC_collection_in_progress(); UNLOCK(); if (!result && GC_debugging_started) GC_print_all_smashed(); return(result); } # if !defined(REDIRECT_MALLOC) && (defined(MSWIN32) || defined(MSWINCE)) void GC_add_current_malloc_heap(void); # endif #ifdef MAKE_BACK_GRAPH void GC_build_back_graph(void); #endif #ifndef SMALL_CONFIG /* Variables for world-stop average delay time statistic computation. */ /* "divisor" is incremented every world-stop and halved when reached */ /* its maximum (or upon "total_time" oveflow). */ STATIC unsigned world_stopped_total_time = 0; STATIC unsigned world_stopped_total_divisor = 0; # ifndef MAX_TOTAL_TIME_DIVISOR /* We shall not use big values here (so "outdated" delay time */ /* values would have less impact on "average" delay time value than */ /* newer ones). */ # define MAX_TOTAL_TIME_DIVISOR 1000 # endif #endif /* * Assumes lock is held. We stop the world and mark from all roots. * If stop_func() ever returns TRUE, we may fail and return FALSE. * Increment GC_gc_no if we succeed. */ STATIC GC_bool GC_stopped_mark(GC_stop_func stop_func) { unsigned i; int dummy; # ifndef SMALL_CONFIG CLOCK_TYPE start_time = 0; /* initialized to prevent warning. */ CLOCK_TYPE current_time; # endif # if !defined(REDIRECT_MALLOC) && (defined(MSWIN32) || defined(MSWINCE)) GC_add_current_malloc_heap(); # endif # if defined(REGISTER_LIBRARIES_EARLY) GC_cond_register_dynamic_libraries(); # endif # ifndef SMALL_CONFIG if (GC_print_stats) GET_TIME(start_time); # endif STOP_WORLD(); IF_THREADS(GC_world_stopped = TRUE); if (GC_print_stats) { /* Output blank line for convenience here */ GC_log_printf( "\n--> Marking for collection %lu after %lu allocated bytes\n", (unsigned long)GC_gc_no + 1, (unsigned long) GC_bytes_allocd); } # ifdef MAKE_BACK_GRAPH if (GC_print_back_height) { GC_build_back_graph(); } # endif /* Mark from all roots. */ /* Minimize junk left in my registers and on the stack */ GC_clear_a_few_frames(); GC_noop(0,0,0,0,0,0); GC_initiate_gc(); for(i = 0;;i++) { if ((*stop_func)()) { if (GC_print_stats) { GC_log_printf("Abandoned stopped marking after " "%u iterations\n", i); } GC_deficit = i; /* Give the mutator a chance. */ IF_THREADS(GC_world_stopped = FALSE); START_WORLD(); return(FALSE); } if (GC_mark_some((ptr_t)(&dummy))) break; } GC_gc_no++; if (GC_print_stats) { GC_log_printf( "Collection %lu reclaimed %ld bytes ---> heapsize = %lu bytes\n", (unsigned long)(GC_gc_no - 1), (long)GC_bytes_found, (unsigned long)GC_heapsize); /* Printf arguments may be pushed in funny places. Clear the */ /* space. */ GC_log_printf(""); } /* Check all debugged objects for consistency */ if (GC_debugging_started) { (*GC_check_heap)(); } IF_THREADS(GC_world_stopped = FALSE); START_WORLD(); # ifndef SMALL_CONFIG if (GC_print_stats) { unsigned long time_diff; unsigned total_time, divisor; GET_TIME(current_time); time_diff = MS_TIME_DIFF(current_time,start_time); /* Compute new world-stop delay total time */ total_time = world_stopped_total_time; divisor = world_stopped_total_divisor; if ((int)total_time < 0 || divisor >= MAX_TOTAL_TIME_DIVISOR) { /* Halve values if overflow occurs */ total_time >>= 1; divisor >>= 1; } total_time += time_diff < (((unsigned)-1) >> 1) ? (unsigned)time_diff : ((unsigned)-1) >> 1; /* Update old world_stopped_total_time and its divisor */ world_stopped_total_time = total_time; world_stopped_total_divisor = ++divisor; GC_ASSERT(divisor != 0); GC_log_printf( "World-stopped marking took %lu msecs (%lu in average)\n", time_diff, total_time / divisor); } # endif return(TRUE); } /* Set all mark bits for the free list whose first entry is q */ void GC_set_fl_marks(ptr_t q) { ptr_t p; struct hblk * h, * last_h = 0; hdr *hhdr; /* gcc "might be uninitialized" warning is bogus. */ IF_PER_OBJ(size_t sz;) unsigned bit_no; for (p = q; p != 0; p = obj_link(p)){ h = HBLKPTR(p); if (h != last_h) { last_h = h; hhdr = HDR(h); IF_PER_OBJ(sz = hhdr->hb_sz;) } bit_no = MARK_BIT_NO((ptr_t)p - (ptr_t)h, sz); if (!mark_bit_from_hdr(hhdr, bit_no)) { set_mark_bit_from_hdr(hhdr, bit_no); ++hhdr -> hb_n_marks; } } } #ifdef GC_ASSERTIONS /* Check that all mark bits for the free list whose first entry is q */ /* are set. */ void GC_check_fl_marks(ptr_t q) { ptr_t p; for (p = q; p != 0; p = obj_link(p)){ if (!GC_is_marked(p)) { GC_err_printf("Unmarked object %p on list %p\n", p, q); ABORT("Unmarked local free list entry."); } } } #endif /* Clear all mark bits for the free list whose first entry is q */ /* Decrement GC_bytes_found by number of bytes on free list. */ STATIC void GC_clear_fl_marks(ptr_t q) { ptr_t p; struct hblk * h, * last_h = 0; hdr *hhdr; size_t sz; unsigned bit_no; for (p = q; p != 0; p = obj_link(p)){ h = HBLKPTR(p); if (h != last_h) { last_h = h; hhdr = HDR(h); sz = hhdr->hb_sz; /* Normally set only once. */ } bit_no = MARK_BIT_NO((ptr_t)p - (ptr_t)h, sz); if (mark_bit_from_hdr(hhdr, bit_no)) { size_t n_marks = hhdr -> hb_n_marks - 1; clear_mark_bit_from_hdr(hhdr, bit_no); # ifdef PARALLEL_MARK /* Appr. count, don't decrement to zero! */ if (0 != n_marks || !GC_parallel) { hhdr -> hb_n_marks = n_marks; } # else hhdr -> hb_n_marks = n_marks; # endif } GC_bytes_found -= sz; } } #if defined(GC_ASSERTIONS) && defined(THREADS) && defined(THREAD_LOCAL_ALLOC) extern void GC_check_tls(void); #endif #ifdef MAKE_BACK_GRAPH void GC_traverse_back_graph(void); #endif /* Finish up a collection. Assumes mark bits are consistent, lock is */ /* held, but the world is otherwise running. */ STATIC void GC_finish_collection(void) { # ifndef SMALL_CONFIG CLOCK_TYPE start_time = 0; /* initialized to prevent warning. */ CLOCK_TYPE finalize_time = 0; CLOCK_TYPE done_time; # endif # if defined(GC_ASSERTIONS) && defined(THREADS) \ && defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL) /* Check that we marked some of our own data. */ /* FIXME: Add more checks. */ GC_check_tls(); # endif # ifndef SMALL_CONFIG if (GC_print_stats) GET_TIME(start_time); # endif GC_bytes_found = 0; # if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG) if (getenv("GC_PRINT_ADDRESS_MAP") != 0) { GC_print_address_map(); } # endif COND_DUMP; if (GC_find_leak) { /* Mark all objects on the free list. All objects should be */ /* marked when we're done. */ { word size; /* current object size */ unsigned kind; ptr_t q; for (kind = 0; kind < GC_n_kinds; kind++) { for (size = 1; size <= MAXOBJGRANULES; size++) { q = GC_obj_kinds[kind].ok_freelist[size]; if (q != 0) GC_set_fl_marks(q); } } } GC_start_reclaim(TRUE); /* The above just checks; it doesn't really reclaim anything. */ } GC_finalize(); # ifdef STUBBORN_ALLOC GC_clean_changing_list(); # endif # ifndef SMALL_CONFIG if (GC_print_stats) GET_TIME(finalize_time); # endif if (GC_print_back_height) { # ifdef MAKE_BACK_GRAPH GC_traverse_back_graph(); # else # ifndef SMALL_CONFIG GC_err_printf("Back height not available: " "Rebuild collector with -DMAKE_BACK_GRAPH\n"); # endif # endif } /* Clear free list mark bits, in case they got accidentally marked */ /* (or GC_find_leak is set and they were intentionally marked). */ /* Also subtract memory remaining from GC_bytes_found count. */ /* Note that composite objects on free list are cleared. */ /* Thus accidentally marking a free list is not a problem; only */ /* objects on the list itself will be marked, and that's fixed here. */ { word size; /* current object size */ ptr_t q; /* pointer to current object */ unsigned kind; for (kind = 0; kind < GC_n_kinds; kind++) { for (size = 1; size <= MAXOBJGRANULES; size++) { q = GC_obj_kinds[kind].ok_freelist[size]; if (q != 0) GC_clear_fl_marks(q); } } } if (GC_print_stats == VERBOSE) GC_log_printf("Bytes recovered before sweep - f.l. count = %ld\n", (long)GC_bytes_found); /* Reconstruct free lists to contain everything not marked */ GC_start_reclaim(FALSE); if (GC_print_stats) { GC_log_printf("Heap contains %lu pointer-containing " "+ %lu pointer-free reachable bytes\n", (unsigned long)GC_composite_in_use, (unsigned long)GC_atomic_in_use); } if (GC_is_full_gc) { GC_used_heap_size_after_full = USED_HEAP_SIZE; GC_need_full_gc = FALSE; } else { GC_need_full_gc = USED_HEAP_SIZE - GC_used_heap_size_after_full > min_bytes_allocd(); } if (GC_print_stats == VERBOSE) { # ifdef USE_MUNMAP GC_log_printf("Immediately reclaimed %ld bytes in heap" " of size %lu bytes (%lu unmapped)\n", (long)GC_bytes_found, (unsigned long)GC_heapsize, (unsigned long)GC_unmapped_bytes); # else GC_log_printf("Immediately reclaimed %ld bytes in heap" " of size %lu bytes\n", (long)GC_bytes_found, (unsigned long)GC_heapsize); # endif } /* Reset or increment counters for next cycle */ GC_n_attempts = 0; GC_is_full_gc = FALSE; GC_bytes_allocd_before_gc += GC_bytes_allocd; GC_non_gc_bytes_at_gc = GC_non_gc_bytes; GC_bytes_allocd = 0; GC_bytes_dropped = 0; GC_bytes_freed = 0; GC_finalizer_bytes_freed = 0; # ifdef USE_MUNMAP GC_unmap_old(); # endif # ifndef SMALL_CONFIG if (GC_print_stats) { GET_TIME(done_time); GC_log_printf("Finalize + initiate sweep took %lu + %lu msecs\n", MS_TIME_DIFF(finalize_time,start_time), MS_TIME_DIFF(done_time,finalize_time)); } # endif } /* Externally callable routine to invoke full, stop-world collection */ GC_API int GC_CALL GC_try_to_collect(GC_stop_func stop_func) { int result; DCL_LOCK_STATE; if (!GC_is_initialized) GC_init(); GC_ASSERT(stop_func != 0); if (GC_debugging_started) GC_print_all_smashed(); GC_INVOKE_FINALIZERS(); LOCK(); ENTER_GC(); /* Minimize junk left in my registers */ GC_noop(0,0,0,0,0,0); result = (int)GC_try_to_collect_inner(stop_func); EXIT_GC(); UNLOCK(); if(result) { if (GC_debugging_started) GC_print_all_smashed(); GC_INVOKE_FINALIZERS(); } return(result); } GC_API void GC_CALL GC_gcollect(void) { (void)GC_try_to_collect(GC_never_stop_func); if (GC_have_errors) GC_print_all_errors(); } word GC_n_heap_sects = 0; /* Number of sections currently in heap. */ #ifdef USE_PROC_FOR_LIBRARIES word GC_n_memory = 0; /* Number of GET_MEM allocated memory */ /* sections. */ #endif #ifdef USE_PROC_FOR_LIBRARIES /* Add HBLKSIZE aligned, GET_MEM-generated block to GC_our_memory. */ /* Defined to do nothing if USE_PROC_FOR_LIBRARIES not set. */ void GC_add_to_our_memory(ptr_t p, size_t bytes) { if (0 == p) return; GC_our_memory[GC_n_memory].hs_start = p; GC_our_memory[GC_n_memory].hs_bytes = bytes; GC_n_memory++; } #endif /* * Use the chunk of memory starting at p of size bytes as part of the heap. * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE. */ void GC_add_to_heap(struct hblk *p, size_t bytes) { hdr * phdr; word endp; if (GC_n_heap_sects >= MAX_HEAP_SECTS) { ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS"); } while ((word)p <= HBLKSIZE) { /* Can't handle memory near address zero. */ ++p; bytes -= HBLKSIZE; if (0 == bytes) return; } endp = (word)p + bytes; if (endp <= (word)p) { /* Address wrapped. */ bytes -= HBLKSIZE; if (0 == bytes) return; endp -= HBLKSIZE; } phdr = GC_install_header(p); if (0 == phdr) { /* This is extremely unlikely. Can't add it. This will */ /* almost certainly result in a 0 return from the allocator, */ /* which is entirely appropriate. */ return; } GC_ASSERT(endp > (word)p && endp == (word)p + bytes); GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p; GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes; GC_n_heap_sects++; phdr -> hb_sz = bytes; phdr -> hb_flags = 0; GC_freehblk(p); GC_heapsize += bytes; if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr || GC_least_plausible_heap_addr == 0) { GC_least_plausible_heap_addr = (void *)((ptr_t)p - sizeof(word)); /* Making it a little smaller than necessary prevents */ /* us from getting a false hit from the variable */ /* itself. There's some unintentional reflection */ /* here. */ } if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) { GC_greatest_plausible_heap_addr = (void *)endp; } } # if !defined(NO_DEBUGGING) void GC_print_heap_sects(void) { unsigned i; GC_printf("Total heap size: %lu\n", (unsigned long) GC_heapsize); for (i = 0; i < GC_n_heap_sects; i++) { ptr_t start = GC_heap_sects[i].hs_start; size_t len = GC_heap_sects[i].hs_bytes; struct hblk *h; unsigned nbl = 0; for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) { if (GC_is_black_listed(h, HBLKSIZE)) nbl++; } GC_printf("Section %d from %p to %p %lu/%lu blacklisted\n", i, start, start + len, (unsigned long)nbl, (unsigned long)(len/HBLKSIZE)); } } # endif void * GC_least_plausible_heap_addr = (void *)ONES; void * GC_greatest_plausible_heap_addr = 0; static INLINE word GC_max(word x, word y) { return(x > y? x : y); } static INLINE word GC_min(word x, word y) { return(x < y? x : y); } GC_API void GC_CALL GC_set_max_heap_size(GC_word n) { GC_max_heapsize = n; } GC_word GC_max_retries = 0; /* * this explicitly increases the size of the heap. It is used * internally, but may also be invoked from GC_expand_hp by the user. * The argument is in units of HBLKSIZE. * Tiny values of n are rounded up. * Returns FALSE on failure. */ GC_bool GC_expand_hp_inner(word n) { word bytes; struct hblk * space; word expansion_slop; /* Number of bytes by which we expect the */ /* heap to expand soon. */ if (n < MINHINCR) n = MINHINCR; bytes = n * HBLKSIZE; /* Make sure bytes is a multiple of GC_page_size */ { word mask = GC_page_size - 1; bytes += mask; bytes &= ~mask; } if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) { /* Exceeded self-imposed limit */ return(FALSE); } space = GET_MEM(bytes); GC_add_to_our_memory((ptr_t)space, bytes); if( space == 0 ) { if (GC_print_stats) { GC_log_printf("Failed to expand heap by %ld bytes\n", (unsigned long)bytes); } return(FALSE); } if (GC_print_stats) { GC_log_printf("Increasing heap size by %lu after %lu allocated bytes\n", (unsigned long)bytes, (unsigned long)GC_bytes_allocd); } /* Adjust heap limits generously for blacklisting to work better. */ /* GC_add_to_heap performs minimal adjustment needed for */ /* correctness. */ expansion_slop = min_bytes_allocd() + 4*MAXHINCR*HBLKSIZE; if ((GC_last_heap_addr == 0 && !((word)space & SIGNB)) || (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) { /* Assume the heap is growing up */ word new_limit = (word)space + bytes + expansion_slop; if (new_limit > (word)space) { GC_greatest_plausible_heap_addr = (void *)GC_max((word)GC_greatest_plausible_heap_addr, (word)new_limit); } } else { /* Heap is growing down */ word new_limit = (word)space - expansion_slop; if (new_limit < (word)space) { GC_least_plausible_heap_addr = (void *)GC_min((word)GC_least_plausible_heap_addr, (word)space - expansion_slop); } } GC_prev_heap_addr = GC_last_heap_addr; GC_last_heap_addr = (ptr_t)space; GC_add_to_heap(space, bytes); /* Force GC before we are likely to allocate past expansion_slop */ GC_collect_at_heapsize = GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE; # if defined(LARGE_CONFIG) if (GC_collect_at_heapsize < GC_heapsize /* wrapped */) GC_collect_at_heapsize = (word)(-1); # endif return(TRUE); } /* Really returns a bool, but it's externally visible, so that's clumsy. */ /* Arguments is in bytes. */ GC_API int GC_CALL GC_expand_hp(size_t bytes) { int result; DCL_LOCK_STATE; LOCK(); if (!GC_is_initialized) GC_init_inner(); result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes)); if (result) GC_requested_heapsize += bytes; UNLOCK(); return(result); } unsigned GC_fail_count = 0; /* How many consecutive GC/expansion failures? */ /* Reset by GC_allochblk. */ GC_bool GC_collect_or_expand(word needed_blocks, GC_bool ignore_off_page) { if (!GC_incremental && !GC_dont_gc && ((GC_dont_expand && GC_bytes_allocd > 0) || GC_should_collect())) { GC_gcollect_inner(); } else { word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor) + needed_blocks; if (blocks_to_get > MAXHINCR) { word slop; /* Get the minimum required to make it likely that we */ /* can satisfy the current request in the presence of black- */ /* listing. This will probably be more than MAXHINCR. */ if (ignore_off_page) { slop = 4; } else { slop = 2*divHBLKSZ(BL_LIMIT); if (slop > needed_blocks) slop = needed_blocks; } if (needed_blocks + slop > MAXHINCR) { blocks_to_get = needed_blocks + slop; } else { blocks_to_get = MAXHINCR; } } if (!GC_expand_hp_inner(blocks_to_get) && !GC_expand_hp_inner(needed_blocks)) { if (GC_fail_count++ < GC_max_retries) { WARN("Out of Memory! Trying to continue ...\n", 0); GC_gcollect_inner(); } else { # if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC) WARN("Out of Memory! Returning NIL!\n", 0); # endif return(FALSE); } } else { if (GC_fail_count && GC_print_stats) { GC_printf("Memory available again ...\n"); } } } return(TRUE); } /* * Make sure the object free list for size gran (in granules) is not empty. * Return a pointer to the first object on the free list. * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER. * Assumes we hold the allocator lock. */ ptr_t GC_allocobj(size_t gran, int kind) { void ** flh = &(GC_obj_kinds[kind].ok_freelist[gran]); GC_bool tried_minor = FALSE; if (gran == 0) return(0); while (*flh == 0) { ENTER_GC(); /* Do our share of marking work */ if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1); /* Sweep blocks for objects of this size */ GC_continue_reclaim(gran, kind); EXIT_GC(); if (*flh == 0) { GC_new_hblk(gran, kind); } if (*flh == 0) { ENTER_GC(); if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED && ! tried_minor ) { GC_collect_a_little_inner(1); tried_minor = TRUE; } else { if (!GC_collect_or_expand((word)1,FALSE)) { EXIT_GC(); return(0); } } EXIT_GC(); } } /* Successful allocation; reset failure count. */ GC_fail_count = 0; return(*flh); }