/* (c) FSF 2002. */ #ifndef PRIVATE_GC #define PRIVATE_GC #include "_scm.h" /* {heap tuning parameters} * * These are parameters for controlling memory allocation. The heap * is the area out of which scm_cons, and object headers are allocated. * * Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a * 64 bit machine. The units of the _SIZE parameters are bytes. * Cons pairs and object headers occupy one heap cell. * * SCM_INIT_HEAP_SIZE is the initial size of heap. If this much heap is * allocated initially the heap will grow by half its current size * each subsequent time more heap is needed. * * If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE * will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more * heap is needed. SCM_HEAP_SEG_SIZE must fit into type size_t. This code * is in scm_init_storage() and alloc_some_heap() in sys.c * * If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by * SCM_EXPHEAP(scm_heap_size) when more heap is needed. * * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap * is needed. */ /* * Heap size 45000 and 40% min yield gives quick startup and no extra * heap allocation. Having higher values on min yield may lead to * large heaps, especially if code behaviour is varying its * maximum consumption between different freelists. */ /* These values used to be global C variables. However, they're also available through the environment, and having a double interface is confusing. Now they're #defines --hwn. */ #define SCM_DEFAULT_INIT_HEAP_SIZE_1 256*1024 #define SCM_DEFAULT_MIN_YIELD_1 40 #define SCM_DEFAULT_INIT_HEAP_SIZE_2 32*1024 /* The following value may seem large, but note that if we get to GC at * all, this means that we have a numerically intensive application */ #define SCM_DEFAULT_MIN_YIELD_2 40 #define SCM_DEFAULT_MAX_SEGMENT_SIZE 2097000L /* a little less (adm) than 2 Mb */ #define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD) #define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell)) #define SCM_DOUBLECELL_ALIGNED_P(x) (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0) #define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \ ((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS) #define SCM_GC_IN_CARD_HEADERP(x) \ (scm_t_cell *) (x) < SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS int scm_getenv_int (const char *var, int def); typedef enum { return_on_error, abort_on_error } policy_on_error; /* gc-freelist*/ /* FREELIST: A struct holding GC statistics on a particular type of cells. */ typedef struct scm_t_cell_type_statistics { /* heap segment where the last cell was allocated */ int heap_segment_idx; /* minimum yield on this list in order not to grow the heap */ long min_yield; /* defines min_yield as percent of total heap size */ int min_yield_fraction; /* number of cells per object on this list */ int span; /* number of collected cells during last GC */ unsigned long collected; /* number of collected cells during penultimate GC */ unsigned long collected_1; /* total number of cells in heap segments * belonging to this list. */ unsigned long heap_size; } scm_t_cell_type_statistics; extern scm_t_cell_type_statistics scm_i_master_freelist; extern scm_t_cell_type_statistics scm_i_master_freelist2; extern unsigned long scm_gc_cells_collected_1; void scm_i_adjust_min_yield (scm_t_cell_type_statistics *freelist); void scm_i_gc_sweep_freelist_reset (scm_t_cell_type_statistics *freelist); int scm_i_gc_grow_heap_p (scm_t_cell_type_statistics * freelist); #define SCM_HEAP_SIZE \ (scm_i_master_freelist.heap_size + scm_i_master_freelist2.heap_size) #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B)) #define SCM_MIN(A, B) ((A) < (B) ? (A) : (B)) #define CELL_P(x) (SCM_ITAG3 (x) == scm_tc3_cons) /* gc-mark */ void scm_mark_all (void); /* gc-segment: */ /* Cells are stored in a heap-segment: it is a contiguous chunk of memory, that associated with one freelist. */ typedef struct scm_t_heap_segment { /* {lower, upper} bounds of the segment The upper bound is also the start of the mark space. */ scm_t_cell *bounds[2]; /* If we ever decide to give it back, we could do it with this ptr. Note that giving back memory is not very useful; as long we don't touch a chunk of memory, the virtual memory system will keep it swapped out. We could simply forget about a block. (not that we do that, but anyway.) */ void* malloced; scm_t_cell * next_free_card; /* address of the head-of-freelist pointer for this segment's cells. All segments usually point to the same one, scm_i_freelist. */ scm_t_cell_type_statistics *freelist; /* number of cells per object in this segment */ int span; /* Is this the first time that the cells are accessed? */ int first_time; } scm_t_heap_segment; /* A table of segment records is kept that records the upper and lower extents of the segment; this is used during the conservative phase of gc to identify probably gc roots (because they point into valid segments at reasonable offsets). */ extern scm_t_heap_segment ** scm_i_heap_segment_table; extern size_t scm_i_heap_segment_table_size; int scm_i_init_card_freelist (scm_t_cell * card, SCM *free_list,scm_t_heap_segment*); int scm_i_sweep_card (scm_t_cell * card, SCM *free_list, scm_t_heap_segment*); int scm_i_initialize_heap_segment_data (scm_t_heap_segment * segment, size_t requested); int scm_i_segment_card_count (scm_t_heap_segment * seg); int scm_i_segment_cell_count (scm_t_heap_segment * seg); void scm_i_clear_segment_mark_space (scm_t_heap_segment *seg); scm_t_heap_segment * scm_i_make_empty_heap_segment (scm_t_cell_type_statistics*); SCM scm_i_sweep_some_cards (scm_t_heap_segment *seg); void scm_i_sweep_segment (scm_t_heap_segment * seg); int scm_i_insert_segment (scm_t_heap_segment * seg); long int scm_i_find_heap_segment_containing_object (SCM obj); int scm_i_get_new_heap_segment (scm_t_cell_type_statistics *, policy_on_error); void scm_i_clear_mark_space (void); void scm_i_sweep_segments (void); SCM scm_i_sweep_some_segments (scm_t_cell_type_statistics * fl); void scm_i_reset_segments (void); void scm_i_sweep_all_segments (char const *reason); void scm_i_make_initial_segment (int init_heap_size, scm_t_cell_type_statistics *freelist); extern long int scm_i_deprecated_memory_return; /* global init funcs. */ void scm_gc_init_malloc (void); void scm_gc_init_freelist (void); void scm_gc_init_segments (void); void scm_gc_init_mark (void); #endif