[bpt/guile.git] / libguile / private-gc.h

/*
  (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  (20*1024*1024L)


#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;


/* Sweep statistics.  */
typedef struct scm_sweep_statistics
{
  /* Number of cells "swept", i.e., visited during the sweep operation.  */
  unsigned swept;

  /* Number of cells collected during the sweep operation.  This number must
     alsways be lower than or equal to SWEPT.  */
  unsigned collected;
} scm_t_sweep_statistics;

#define scm_i_sweep_statistics_init(_stats)	\
  do						\
   {						\
     (_stats)->swept = (_stats)->collected = 0;	\
   }						\
  while (0)

#define scm_i_sweep_statistics_sum(_sum, _addition)	\
  do							\
   {							\
     (_sum)->swept += (_addition).swept;		\
     (_sum)->collected += (_addition).collected;	\
   }							\
  while (0)

\f
extern scm_t_cell_type_statistics scm_i_master_freelist;
extern scm_t_cell_type_statistics scm_i_master_freelist2;

void scm_i_adjust_min_yield (scm_t_cell_type_statistics *freelist,
			     scm_t_sweep_statistics sweep_stats,
			     scm_t_sweep_statistics sweep_stats_1);
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))

/* CELL_P checks a random word whether it has the right form for a
   pointer to a cell.  Use scm_i_find_heap_segment_containing_object
   to find out whether it actually points to a real cell.

   The right form for a cell pointer is this: the low three bits must
   be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the
   resulting pointer must be correctly aligned.
   scm_i_initialize_heap_segment_data guarantees that the test below
   works.
*/
#define CELL_P(x)  ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == 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*);
void scm_i_card_statistics (scm_t_cell *p, SCM hashtab, scm_t_heap_segment *seg);
char const *scm_i_tag_name (scm_t_bits tag); /* MOVEME */

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,
			    scm_t_sweep_statistics *sweep_stats);
void scm_i_sweep_segment (scm_t_heap_segment *seg,
			  scm_t_sweep_statistics *sweep_stats);

void scm_i_heap_segment_statistics (scm_t_heap_segment *seg, SCM tab);

     
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 *,
				scm_t_sweep_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,
			       scm_t_sweep_statistics *sweep_stats);
void scm_i_reset_segments (void);
void scm_i_sweep_all_segments (char const *reason,
			       scm_t_sweep_statistics *sweep_stats);
SCM scm_i_all_segments_statistics (SCM hashtab);
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
Commit	Line	Data
c7743d02 HWN	1	/*
	2	(c) FSF 2002.
	3	*/
	4
	5
	6	#ifndef PRIVATE_GC
	7	#define PRIVATE_GC
	8
	9	#include "_scm.h"
	10
	11	/* {heap tuning parameters}
	12	*
	13	* These are parameters for controlling memory allocation. The heap
	14	* is the area out of which scm_cons, and object headers are allocated.
	15	*
	16	* Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a
	17	* 64 bit machine. The units of the _SIZE parameters are bytes.
	18	* Cons pairs and object headers occupy one heap cell.
	19	*
	20	* SCM_INIT_HEAP_SIZE is the initial size of heap. If this much heap is
	21	* allocated initially the heap will grow by half its current size
	22	* each subsequent time more heap is needed.
	23	*
	24	* If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE
	25	* will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more
	26	* heap is needed. SCM_HEAP_SEG_SIZE must fit into type size_t. This code
	27	* is in scm_init_storage() and alloc_some_heap() in sys.c
	28	*
	29	* If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by
	30	* SCM_EXPHEAP(scm_heap_size) when more heap is needed.
	31	*
	32	* SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap
	33	* is needed.
	34	*/
	35
	36
	37	/*
	38	* Heap size 45000 and 40% min yield gives quick startup and no extra
	39	* heap allocation. Having higher values on min yield may lead to
	40	* large heaps, especially if code behaviour is varying its
	41	* maximum consumption between different freelists.
	42	*/
	43
	44	/*
	45	These values used to be global C variables. However, they're also
	46	available through the environment, and having a double interface is
	47	confusing. Now they're #defines --hwn.
	48	*/
	49
	50	#define SCM_DEFAULT_INIT_HEAP_SIZE_1 256*1024
	51	#define SCM_DEFAULT_MIN_YIELD_1 40
	52	#define SCM_DEFAULT_INIT_HEAP_SIZE_2 32*1024
	53
	54	/* The following value may seem large, but note that if we get to GC at
	55	* all, this means that we have a numerically intensive application
	56	*/
	57	#define SCM_DEFAULT_MIN_YIELD_2 40
322a2bf7 MV	58
322a2bf7 MV	59	#define SCM_DEFAULT_MAX_SEGMENT_SIZE (2010241024L)
c7743d02 HWN	60
	61
	62
	63	#define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD)
	64	#define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell))
	65
	66
1383773b	67	#define SCM_DOUBLECELL_ALIGNED_P(x) (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0)
c7743d02 HWN	68
c7743d02 HWN	69
1383773b HWN	70	#define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \
	71	((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS)
	72	#define SCM_GC_IN_CARD_HEADERP(x) \
	73	(scm_t_cell *) (x) < SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS
c7743d02 HWN	74
	75
	76	int scm_getenv_int (const char *var, int def);
	77
	78
	79	typedef enum { return_on_error, abort_on_error } policy_on_error;
	80
	81	/* gc-freelist*/
	82
	83	/*
	84	FREELIST:
	85
	86	A struct holding GC statistics on a particular type of cells.
	87	*/
	88	typedef struct scm_t_cell_type_statistics {
	89
	90	/*
	91	heap segment where the last cell was allocated
	92	*/
	93	int heap_segment_idx;
	94
	95	/* minimum yield on this list in order not to grow the heap
	96	*/
	97	long min_yield;
	98
	99	/* defines min_yield as percent of total heap size
	100	*/
	101	int min_yield_fraction;
	102
	103	/* number of cells per object on this list */
	104	int span;
	105
	106	/* number of collected cells during last GC */
	107	unsigned long collected;
	108
	109	/* number of collected cells during penultimate GC */
	110	unsigned long collected_1;
	111
	112	/* total number of cells in heap segments
	113	* belonging to this list.
	114	*/
	115	unsigned long heap_size;
	116
c2cbcc57	117
c7743d02 HWN	118	} scm_t_cell_type_statistics;
	119
	120
4c7016dc HWN	121	/* Sweep statistics. */
	122	typedef struct scm_sweep_statistics
	123	{
	124	/* Number of cells "swept", i.e., visited during the sweep operation. */
	125	unsigned swept;
	126
	127	/* Number of cells collected during the sweep operation. This number must
	128	alsways be lower than or equal to SWEPT. */
	129	unsigned collected;
	130	} scm_t_sweep_statistics;
	131
	132	#define scm_i_sweep_statistics_init(_stats) \
	133	do \
	134	{ \
	135	(_stats)->swept = (_stats)->collected = 0; \
	136	} \
	137	while (0)
	138
	139	#define scm_i_sweep_statistics_sum(_sum, _addition) \
	140	do \
	141	{ \
	142	(_sum)->swept += (_addition).swept; \
	143	(_sum)->collected += (_addition).collected; \
	144	} \
	145	while (0)
	146
4c7016dc	147	\f
c7743d02 HWN	148	extern scm_t_cell_type_statistics scm_i_master_freelist;
c7743d02 HWN	149	extern scm_t_cell_type_statistics scm_i_master_freelist2;
c7743d02	150
4c7016dc	151	void scm_i_adjust_min_yield (scm_t_cell_type_statistics *freelist,
d9f71a07 LC	152	scm_t_sweep_statistics sweep_stats,
d9f71a07 LC	153	scm_t_sweep_statistics sweep_stats_1);
c7743d02 HWN	154	void scm_i_gc_sweep_freelist_reset (scm_t_cell_type_statistics *freelist);
c7743d02 HWN	155	int scm_i_gc_grow_heap_p (scm_t_cell_type_statistics * freelist);
dac04e9f HWN	156
dac04e9f HWN	157
c7743d02 HWN	158	#define SCM_HEAP_SIZE \
	159	(scm_i_master_freelist.heap_size + scm_i_master_freelist2.heap_size)
	160
	161
	162	#define SCM_MAX(A, B) ((A) > (B) ? (A) : (B))
	163	#define SCM_MIN(A, B) ((A) < (B) ? (A) : (B))
	164
d3774e2c MV	165	/* CELL_P checks a random word whether it has the right form for a
	166	pointer to a cell. Use scm_i_find_heap_segment_containing_object
	167	to find out whether it actually points to a real cell.
	168
	169	The right form for a cell pointer is this: the low three bits must
	170	be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the
	171	resulting pointer must be correctly aligned.
	172	scm_i_initialize_heap_segment_data guarantees that the test below
	173	works.
	174	*/
	175	#define CELL_P(x) ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == scm_tc3_cons)
c7743d02 HWN	176
	177	/*
	178	gc-mark
	179	*/
	180
	181
	182	void scm_mark_all (void);
	183
	184
	185
	186	/*
	187	gc-segment:
	188	*/
	189
	190
	191
	192
	193	/*
	194
	195	Cells are stored in a heap-segment: it is a contiguous chunk of
	196	memory, that associated with one freelist.
	197	*/
	198
	199	typedef struct scm_t_heap_segment
	200	{
	201	/*
	202	{lower, upper} bounds of the segment
	203
	204	The upper bound is also the start of the mark space.
	205	*/
	206	scm_t_cell *bounds[2];
	207
	208	/*
	209	If we ever decide to give it back, we could do it with this ptr.
	210
	211	Note that giving back memory is not very useful; as long we don't
	212	touch a chunk of memory, the virtual memory system will keep it
	213	swapped out. We could simply forget about a block.
	214
	215	(not that we do that, but anyway.)
	216	*/
	217
	218	void* malloced;
	219
	220	scm_t_cell * next_free_card;
	221
	222	/* address of the head-of-freelist pointer for this segment's cells.
	223	All segments usually point to the same one, scm_i_freelist. */
	224	scm_t_cell_type_statistics *freelist;
	225
	226	/* number of cells per object in this segment */
	227	int span;
	228
	229
	230	/*
	231	Is this the first time that the cells are accessed?
	232	*/
	233	int first_time;
	234
	235	} scm_t_heap_segment;
	236
	237
	238
	239	/*
240
241	A table of segment records is kept that records the upper and
242	lower extents of the segment; this is used during the conservative
243	phase of gc to identify probably gc roots (because they point
244	into valid segments at reasonable offsets).
245
246	*/
247	extern scm_t_heap_segment ** scm_i_heap_segment_table;
248	extern size_t scm_i_heap_segment_table_size;
249
250
1383773b HWN	251	int scm_i_init_card_freelist (scm_t_cell * card, SCM free_list,scm_t_heap_segment);
1383773b HWN	252	int scm_i_sweep_card (scm_t_cell * card, SCM free_list, scm_t_heap_segment);
1367aa5e HWN	253	void scm_i_card_statistics (scm_t_cell p, SCM hashtab, scm_t_heap_segment seg);
	254	char const scm_i_tag_name (scm_t_bits tag); / MOVEME */
	255
c7743d02 HWN	256	int scm_i_initialize_heap_segment_data (scm_t_heap_segment * segment, size_t requested);
	257	int scm_i_segment_card_count (scm_t_heap_segment * seg);
	258	int scm_i_segment_cell_count (scm_t_heap_segment * seg);
	259
	260	void scm_i_clear_segment_mark_space (scm_t_heap_segment *seg);
	261	scm_t_heap_segment * scm_i_make_empty_heap_segment (scm_t_cell_type_statistics*);
4c7016dc HWN	262	SCM scm_i_sweep_some_cards (scm_t_heap_segment *seg,
	263	scm_t_sweep_statistics *sweep_stats);
	264	void scm_i_sweep_segment (scm_t_heap_segment *seg,
	265	scm_t_sweep_statistics *sweep_stats);
c7743d02	266
1367aa5e HWN	267	void scm_i_heap_segment_statistics (scm_t_heap_segment *seg, SCM tab);
1367aa5e HWN	268
c7743d02 HWN	269
	270	int scm_i_insert_segment (scm_t_heap_segment * seg);
	271	long int scm_i_find_heap_segment_containing_object (SCM obj);
d9f71a07 LC	272	int scm_i_get_new_heap_segment (scm_t_cell_type_statistics *,
	273	scm_t_sweep_statistics,
	274	policy_on_error);
c7743d02 HWN	275	void scm_i_clear_mark_space (void);
c7743d02 HWN	276	void scm_i_sweep_segments (void);
4c7016dc HWN	277	SCM scm_i_sweep_some_segments (scm_t_cell_type_statistics *fl,
4c7016dc HWN	278	scm_t_sweep_statistics *sweep_stats);
c7743d02	279	void scm_i_reset_segments (void);
4c7016dc HWN	280	void scm_i_sweep_all_segments (char const *reason,
4c7016dc HWN	281	scm_t_sweep_statistics *sweep_stats);
1367aa5e	282	SCM scm_i_all_segments_statistics (SCM hashtab);
dac04e9f	283	void scm_i_make_initial_segment (int init_heap_size, scm_t_cell_type_statistics *freelist);
c7743d02 HWN	284
	285	extern long int scm_i_deprecated_memory_return;
	286
	287
	288	/*
	289	global init funcs.
	290	*/
	291	void scm_gc_init_malloc (void);
	292	void scm_gc_init_freelist (void);
	293	void scm_gc_init_segments (void);
	294	void scm_gc_init_mark (void);
eab1b259 HWN	295
eab1b259 HWN	296
c7743d02	297	#endif