/* * 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 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. * * 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 <stdio.h> # if !defined(MACOS) && !defined(MSWINCE) # include <signal.h> # include <sys/types.h> # endif /* * Separate free lists are maintained for different sized objects * up to MAXOBJSZ. * 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. */ int GC_full_freq = 19; /* Every 20th collection is a full */ /* collection, whether we need it */ /* or not. */ 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 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) 1999-2001 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." }; # include "version.h" #if defined(SAVE_CALL_CHAIN) && \ !(defined(REDIRECT_MALLOC) && defined(GC_HAVE_BUILTIN_BACKTRACE)) # define SAVE_CALL_CHAIN_IN_GC /* This is only safe if the call chain save mechanism won't end up */ /* calling GC_malloc. The GNU C library documentation suggests */ /* that backtrace doesn't use malloc, but at least the initial */ /* call in some versions does seem to invoke the dynamic linker, */ /* which uses malloc. */ #endif /* some more variables */ extern signed_word GC_mem_found; /* Number of reclaimed longwords */ /* after garbage collection */ GC_bool GC_dont_expand = 0; word GC_free_space_divisor = 3; extern GC_bool GC_collection_in_progress(); /* Collection is in progress, or was abandoned. */ int GC_never_stop_func GC_PROTO((void)) { return(0); } unsigned long GC_time_limit = TIME_LIMIT; CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */ /* used only in GC_timeout_stop_func. */ 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 int GC_timeout_stop_func GC_PROTO((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) { # ifdef CONDPRINT if (GC_print_stats) { GC_printf0("Abandoning stopped marking after "); GC_printf1("%lu msecs", (unsigned long)time_diff); GC_printf1("(attempt %ld)\n", (unsigned long) GC_n_attempts); } # endif 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_words_allocd() { # ifdef THREADS /* We punt, for now. */ register signed_word stack_size = 10000; # else int dummy; register 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 = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes + (GC_large_free_bytes >> 2) /* use a bit more of large empty heap */ + 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 words allocated, adjusted for explicit storage */ /* management, etc.. This number is used in deciding when to trigger */ /* collections. */ word GC_adj_words_allocd() { register signed_word result; register signed_word expl_managed = BYTES_TO_WORDS((long)GC_non_gc_bytes - (long)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_words_allocd - (signed_word)GC_mem_freed + (signed_word)GC_finalizer_mem_freed - expl_managed; if (result > (signed_word)GC_words_allocd) { result = GC_words_allocd; /* probably client bug or unfortunate scheduling */ } result += GC_words_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 ((GC_words_wasted >> 3) < result) result += GC_words_wasted; /* This doesn't reflect useful work. But if there is lots of */ /* new fragmentation, the same is probably true of the heap, */ /* and the collection will be correspondingly cheaper. */ if (result < (signed_word)(GC_words_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_words_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 garbade 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. */ void GC_clear_a_few_frames() { # define NWORDS 64 word frames[NWORDS]; /* Some compilers will warn that frames was set but never used. */ /* That's the whole idea ... */ register int i; for (i = 0; i < 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() { return(GC_adj_words_allocd() >= min_words_allocd() || GC_heapsize >= GC_collect_at_heapsize); } void GC_notify_full_gc() { if (GC_start_call_back != (void (*) GC_PROTO((void)))0) { (*GC_start_call_back)(); } } GC_bool GC_is_full_gc = FALSE; /* * Initiate a garbage collection if appropriate. * Choose judiciously * between partial, full, and stop-world collections. * Assumes lock held, signals disabled. */ void GC_maybe_gc() { static int n_partial_gcs = 0; if (GC_should_collect()) { if (!GC_incremental) { GC_gcollect_inner(); n_partial_gcs = 0; return; } else { # ifdef PARALLEL_MARK GC_wait_for_reclaim(); # endif if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) { # ifdef CONDPRINT if (GC_print_stats) { GC_printf2( "***>Full mark for collection %lu after %ld allocd bytes\n", (unsigned long) GC_gc_no+1, (long)WORDS_TO_BYTES(GC_words_allocd)); } # endif 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_IN_GC 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, signals disabled. * 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(stop_func) GC_stop_func stop_func; { # ifdef CONDPRINT CLOCK_TYPE start_time, current_time; # endif if (GC_dont_gc) return FALSE; if (GC_incremental && GC_collection_in_progress()) { # ifdef CONDPRINT if (GC_print_stats) { GC_printf0( "GC_try_to_collect_inner: finishing collection in progress\n"); } # endif /* CONDPRINT */ /* 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(); # ifdef CONDPRINT if (GC_print_stats) { if (GC_print_stats) GET_TIME(start_time); GC_printf2( "Initiating full world-stop collection %lu after %ld allocd bytes\n", (unsigned long) GC_gc_no+1, (long)WORDS_TO_BYTES(GC_words_allocd)); } # 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 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_IN_GC 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(); # if defined(CONDPRINT) if (GC_print_stats) { GET_TIME(current_time); GC_printf1("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 needa 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. */ # define GC_RATE 10 # define MAX_PRIOR_ATTEMPTS 1 /* 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. */ int GC_deficit = 0; /* The number of extra calls to GC_mark_some */ /* that we have made. */ void GC_collect_a_little_inner(n) int n; { register 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_IN_GC GC_save_callers(GC_last_stack); # endif # ifdef PARALLEL_MARK GC_wait_for_reclaim(); # endif if (GC_n_attempts < MAX_PRIOR_ATTEMPTS && GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); 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(); } } int GC_collect_a_little GC_PROTO(()) { int result; DCL_LOCK_STATE; DISABLE_SIGNALS(); LOCK(); GC_collect_a_little_inner(1); result = (int)GC_collection_in_progress(); UNLOCK(); ENABLE_SIGNALS(); if (!result && GC_debugging_started) GC_print_all_smashed(); return(result); } /* * Assumes lock is held, signals are disabled. * We stop the world. * If stop_func() ever returns TRUE, we may fail and return FALSE. * Increment GC_gc_no if we succeed. */ GC_bool GC_stopped_mark(stop_func) GC_stop_func stop_func; { register int i; int dummy; # if defined(PRINTTIMES) || defined(CONDPRINT) CLOCK_TYPE start_time, current_time; # endif # ifdef PRINTTIMES GET_TIME(start_time); # endif # if defined(CONDPRINT) && !defined(PRINTTIMES) if (GC_print_stats) GET_TIME(start_time); # endif # if defined(REGISTER_LIBRARIES_EARLY) GC_cond_register_dynamic_libraries(); # endif STOP_WORLD(); IF_THREADS(GC_world_stopped = TRUE); # ifdef CONDPRINT if (GC_print_stats) { GC_printf1("--> Marking for collection %lu ", (unsigned long) GC_gc_no + 1); GC_printf2("after %lu allocd bytes + %lu wasted bytes\n", (unsigned long) WORDS_TO_BYTES(GC_words_allocd), (unsigned long) WORDS_TO_BYTES(GC_words_wasted)); } # endif # 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)()) { # ifdef CONDPRINT if (GC_print_stats) { GC_printf0("Abandoned stopped marking after "); GC_printf1("%lu iterations\n", (unsigned long)i); } # endif 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++; # ifdef PRINTSTATS GC_printf2("Collection %lu reclaimed %ld bytes", (unsigned long) GC_gc_no - 1, (long)WORDS_TO_BYTES(GC_mem_found)); # else # ifdef CONDPRINT if (GC_print_stats) { GC_printf1("Collection %lu finished", (unsigned long) GC_gc_no - 1); } # endif # endif /* !PRINTSTATS */ # ifdef CONDPRINT if (GC_print_stats) { GC_printf1(" ---> heapsize = %lu bytes\n", (unsigned long) GC_heapsize); /* Printf arguments may be pushed in funny places. Clear the */ /* space. */ GC_printf0(""); } # endif /* CONDPRINT */ /* Check all debugged objects for consistency */ if (GC_debugging_started) { (*GC_check_heap)(); } IF_THREADS(GC_world_stopped = FALSE); START_WORLD(); # ifdef PRINTTIMES GET_TIME(current_time); GC_printf1("World-stopped marking took %lu msecs\n", MS_TIME_DIFF(current_time,start_time)); # else # ifdef CONDPRINT if (GC_print_stats) { GET_TIME(current_time); GC_printf1("World-stopped marking took %lu msecs\n", MS_TIME_DIFF(current_time,start_time)); } # endif # endif return(TRUE); } /* Set all mark bits for the free list whose first entry is q */ #ifdef __STDC__ void GC_set_fl_marks(ptr_t q) #else void GC_set_fl_marks(q) ptr_t q; #endif { ptr_t p; struct hblk * h, * last_h = 0; hdr *hhdr; int word_no; for (p = q; p != 0; p = obj_link(p)){ h = HBLKPTR(p); if (h != last_h) { last_h = h; hhdr = HDR(h); } word_no = (((word *)p) - ((word *)h)); set_mark_bit_from_hdr(hhdr, word_no); } } /* Clear all mark bits for the free list whose first entry is q */ /* Decrement GC_mem_found by number of words on free list. */ #ifdef __STDC__ void GC_clear_fl_marks(ptr_t q) #else void GC_clear_fl_marks(q) ptr_t q; #endif { ptr_t p; struct hblk * h, * last_h = 0; hdr *hhdr; int word_no; for (p = q; p != 0; p = obj_link(p)){ h = HBLKPTR(p); if (h != last_h) { last_h = h; hhdr = HDR(h); } word_no = (((word *)p) - ((word *)h)); clear_mark_bit_from_hdr(hhdr, word_no); # ifdef GATHERSTATS GC_mem_found -= hhdr -> hb_sz; # endif } } /* Finish up a collection. Assumes lock is held, signals are disabled, */ /* but the world is otherwise running. */ void GC_finish_collection() { # ifdef PRINTTIMES CLOCK_TYPE start_time; CLOCK_TYPE finalize_time; CLOCK_TYPE done_time; GET_TIME(start_time); finalize_time = start_time; # endif # ifdef GATHERSTATS GC_mem_found = 0; # endif # 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. */ { register word size; /* current object size */ int kind; ptr_t q; for (kind = 0; kind < GC_n_kinds; kind++) { for (size = 1; size <= MAXOBJSZ; 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 # ifdef PRINTTIMES GET_TIME(finalize_time); # endif if (GC_print_back_height) { # ifdef MAKE_BACK_GRAPH GC_traverse_back_graph(); # else # ifndef SMALL_CONFIG GC_err_printf0("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_mem_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. */ { register word size; /* current object size */ register ptr_t q; /* pointer to current object */ int kind; for (kind = 0; kind < GC_n_kinds; kind++) { for (size = 1; size <= MAXOBJSZ; size++) { q = GC_obj_kinds[kind].ok_freelist[size]; if (q != 0) GC_clear_fl_marks(q); } } } # ifdef PRINTSTATS GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n", (long)WORDS_TO_BYTES(GC_mem_found)); # endif /* Reconstruct free lists to contain everything not marked */ GC_start_reclaim(FALSE); if (GC_is_full_gc) { GC_used_heap_size_after_full = USED_HEAP_SIZE; GC_need_full_gc = FALSE; } else { GC_need_full_gc = BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full) > min_words_allocd(); } # ifdef PRINTSTATS GC_printf2( "Immediately reclaimed %ld bytes in heap of size %lu bytes", (long)WORDS_TO_BYTES(GC_mem_found), (unsigned long)GC_heapsize); # ifdef USE_MUNMAP GC_printf1("(%lu unmapped)", GC_unmapped_bytes); # endif GC_printf2( "\n%lu (atomic) + %lu (composite) collectable bytes in use\n", (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use), (unsigned long)WORDS_TO_BYTES(GC_composite_in_use)); # endif GC_n_attempts = 0; GC_is_full_gc = FALSE; /* Reset or increment counters for next cycle */ GC_words_allocd_before_gc += GC_words_allocd; GC_non_gc_bytes_at_gc = GC_non_gc_bytes; GC_words_allocd = 0; GC_words_wasted = 0; GC_mem_freed = 0; GC_finalizer_mem_freed = 0; # ifdef USE_MUNMAP GC_unmap_old(); # endif # ifdef PRINTTIMES GET_TIME(done_time); GC_printf2("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 */ # if defined(__STDC__) || defined(__cplusplus) int GC_try_to_collect(GC_stop_func stop_func) # else int GC_try_to_collect(stop_func) GC_stop_func stop_func; # endif { int result; DCL_LOCK_STATE; if (GC_debugging_started) GC_print_all_smashed(); GC_INVOKE_FINALIZERS(); DISABLE_SIGNALS(); LOCK(); ENTER_GC(); if (!GC_is_initialized) GC_init_inner(); /* 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(); ENABLE_SIGNALS(); if(result) { if (GC_debugging_started) GC_print_all_smashed(); GC_INVOKE_FINALIZERS(); } return(result); } void GC_gcollect GC_PROTO(()) { (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. */ /* * 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(p, bytes) struct hblk *p; word bytes; { word words; hdr * phdr; if (GC_n_heap_sects >= MAX_HEAP_SECTS) { ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS"); } 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_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++; words = BYTES_TO_WORDS(bytes); phdr -> hb_sz = words; phdr -> hb_map = (unsigned char *)1; /* A value != GC_invalid_map */ 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 = (GC_PTR)((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 = (GC_PTR)((ptr_t)p + bytes); } } # if !defined(NO_DEBUGGING) void GC_print_heap_sects() { register unsigned i; GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize); for (i = 0; i < GC_n_heap_sects; i++) { unsigned long start = (unsigned long) GC_heap_sects[i].hs_start; unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes; struct hblk *h; unsigned nbl = 0; GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i, start, (unsigned long)(start + len)); for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) { if (GC_is_black_listed(h, HBLKSIZE)) nbl++; } GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl, (unsigned long)(len/HBLKSIZE)); } } # endif GC_PTR GC_least_plausible_heap_addr = (GC_PTR)ONES; GC_PTR GC_greatest_plausible_heap_addr = 0; ptr_t GC_max(x,y) ptr_t x, y; { return(x > y? x : y); } ptr_t GC_min(x,y) ptr_t x, y; { return(x < y? x : y); } # if defined(__STDC__) || defined(__cplusplus) void GC_set_max_heap_size(GC_word n) # else void GC_set_max_heap_size(n) GC_word n; # endif { 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(n) 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); if( space == 0 ) { # ifdef CONDPRINT if (GC_print_stats) { GC_printf1("Failed to expand heap by %ld bytes\n", (unsigned long)bytes); } # endif return(FALSE); } # ifdef CONDPRINT if (GC_print_stats) { GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n", (unsigned long)bytes, (unsigned long)WORDS_TO_BYTES(GC_words_allocd)); # ifdef UNDEFINED GC_printf1("Root size = %lu\n", GC_root_size); GC_print_block_list(); GC_print_hblkfreelist(); GC_printf0("\n"); # endif } # endif expansion_slop = WORDS_TO_BYTES(min_words_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 */ GC_greatest_plausible_heap_addr = (GC_PTR)GC_max((ptr_t)GC_greatest_plausible_heap_addr, (ptr_t)space + bytes + expansion_slop); } else { /* Heap is growing down */ GC_least_plausible_heap_addr = (GC_PTR)GC_min((ptr_t)GC_least_plausible_heap_addr, (ptr_t)space - expansion_slop); } # if defined(LARGE_CONFIG) if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space) && GC_heapsize > 0) { /* GC_add_to_heap will fix this, but ... */ WARN("Too close to address space limit: blacklisting ineffective\n", 0); } # endif 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. */ # if defined(__STDC__) || defined(__cplusplus) int GC_expand_hp(size_t bytes) # else int GC_expand_hp(bytes) size_t bytes; # endif { int result; DCL_LOCK_STATE; DISABLE_SIGNALS(); LOCK(); if (!GC_is_initialized) GC_init_inner(); result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes)); if (result) GC_requested_heapsize += bytes; UNLOCK(); ENABLE_SIGNALS(); return(result); } unsigned GC_fail_count = 0; /* How many consecutive GC/expansion failures? */ /* Reset by GC_allochblk. */ GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page) word needed_blocks; GC_bool ignore_off_page; { if (!GC_incremental && !GC_dont_gc && ((GC_dont_expand && GC_words_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 { # ifdef CONDPRINT if (GC_fail_count && GC_print_stats) { GC_printf0("Memory available again ...\n"); } # endif } } return(TRUE); } /* * Make sure the object free list for sz 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 and signals are disabled. * */ ptr_t GC_allocobj(sz, kind) word sz; int kind; { ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]); GC_bool tried_minor = FALSE; if (sz == 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(sz, kind); EXIT_GC(); if (*flh == 0) { GC_new_hblk(sz, 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); }