https://github.com/JuliaLang/julia
Tip revision: 13375f599deb73bad54616794a8f2c2a36eb927f authored by Keno Fischer on 19 October 2015, 23:13:43 UTC
Add back some code that was dropped during rebase
Add back some code that was dropped during rebase
Tip revision: 13375f5
gc.c
// This file is a part of Julia. License is MIT: http://julialang.org/license
/*
allocation and garbage collection
. non-moving, precise mark and sweep collector
. pool-allocates small objects, keeps big objects on a simple list
*/
// use mmap instead of malloc to allocate pages. default = off.
//#define USE_MMAP
// free pages as soon as they are empty. if not defined, then we
// will wait for the next GC, to allow the space to be reused more
// efficiently. default = on.
#define FREE_PAGES_EAGER
#include <stdlib.h>
#include <string.h>
#ifndef _MSC_VER
#include <strings.h>
#endif
#include <assert.h>
#include <inttypes.h>
#include "julia.h"
#include "julia_internal.h"
#ifndef _OS_WINDOWS_
#include <sys/mman.h>
#ifdef _OS_DARWIN_
#define MAP_ANONYMOUS MAP_ANON
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
// manipulating mark bits
#define GC_CLEAN 0 // freshly allocated
#define GC_MARKED 1 // reachable and old
#define GC_QUEUED 2 // if it is reachable it will be marked as old
#define GC_MARKED_NOESC (GC_MARKED | GC_QUEUED) // reachable and young
#define jl_valueof(v) (&((jl_taggedvalue_t*)(v))->value)
// This struct must be kept in sync with the Julia type of the same name in base/util.jl
typedef struct {
int64_t allocd;
int64_t freed;
uint64_t malloc;
uint64_t realloc;
uint64_t poolalloc;
uint64_t bigalloc;
uint64_t freecall;
uint64_t total_time;
uint64_t total_allocd;
uint64_t since_sweep;
size_t collect;
int pause;
int full_sweep;
} GC_Num;
static GC_Num gc_num = {0,0,0,0,0,0,0,0,0,0,0,0,0};
#define collect_interval gc_num.collect
#define n_pause gc_num.pause
#define n_full_sweep gc_num.full_sweep
#define allocd_bytes gc_num.allocd
#define freed_bytes gc_num.freed
#define total_gc_time gc_num.total_time
#define total_allocd_bytes gc_num.total_allocd
#define allocd_bytes_since_sweep gc_num.since_sweep
static size_t last_long_collect_interval;
typedef struct _buff_t {
union {
uintptr_t header;
struct _buff_t *next;
uptrint_t flags;
jl_value_t *type; // 16-bytes aligned
struct {
uintptr_t gc_bits:2;
uintptr_t pooled:1;
};
};
// Work around a bug affecting gcc up to (at least) version 4.4.7
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36839
#if !defined(_COMPILER_MICROSOFT_)
int _dummy[0];
#endif
char data[];
} buff_t;
typedef buff_t gcval_t;
// layout for big (>2k) objects
typedef struct _bigval_t {
struct _bigval_t *next;
struct _bigval_t **prev; // pointer to the next field of the prev entry
union {
size_t sz;
uptrint_t age : 2;
};
//struct buff_t <>;
union {
uptrint_t header;
uptrint_t flags;
uptrint_t gc_bits:2;
};
// Work around a bug affecting gcc up to (at least) version 4.4.7
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36839
#if !defined(_COMPILER_MICROSOFT_)
int _dummy[0];
#endif
// must be 16-aligned here, in 32 & 64b
char data[];
} bigval_t;
#define bigval_header(data) container_of((data), bigval_t, header)
// data structure for tracking malloc'd arrays.
typedef struct _mallocarray_t {
jl_array_t *a;
struct _mallocarray_t *next;
} mallocarray_t;
typedef struct _pool_t {
gcval_t *freelist; // root of list of free objects
gcval_t *newpages; // root of list of chunks of free objects
uint16_t end_offset; // stored to avoid computing it at each allocation
uint16_t osize; // size of objects in this pool
uint16_t nfree; // number of free objects in page pointed into by free_list
} pool_t;
// layout for small (<2k) objects
#define GC_PAGE_LG2 14 // log2(size of a page)
#define GC_PAGE_SZ (1 << GC_PAGE_LG2) // 16k
#define GC_PAGE_OFFSET (16 - (sizeof_jl_taggedvalue_t % 16))
// pool page metadata
typedef struct _gcpage_t {
struct {
uint16_t pool_n : 8; // index (into norm_pool) of pool that owns this page
uint16_t allocd : 1; // true if an allocation happened in this page since last sweep
uint16_t gc_bits : 2; // this is a bitwise | of all gc_bits in this page
};
uint16_t nfree; // number of free objects in this page.
// invalid if pool that owns this page is allocating objects from this page.
uint16_t osize; // size of each object in this page
uint16_t fl_begin_offset; // offset of first free object in this page
uint16_t fl_end_offset; // offset of last free object in this page
char *data;
uint8_t *ages;
} gcpage_t;
#define PAGE_PFL_BEG(p) ((gcval_t**)((p->data) + (p)->fl_begin_offset))
#define PAGE_PFL_END(p) ((gcval_t**)((p->data) + (p)->fl_end_offset))
// round an address inside a gcpage's data to its beginning
#define GC_PAGE_DATA(x) ((char*)((uintptr_t)(x) >> GC_PAGE_LG2 << GC_PAGE_LG2))
// A region is contiguous storage for up to REGION_PG_COUNT naturally aligned GC_PAGE_SZ pages
// It uses a very naive allocator (see malloc_page & free_page)
#if defined(_P64) && !defined(_COMPILER_MICROSOFT_)
#define REGION_PG_COUNT 16*8*4096 // 8G because virtual memory is cheap
#else
#define REGION_PG_COUNT 8*4096 // 512M
#endif
#define REGION_COUNT 8
typedef struct {
// Page layout:
// Padding: GC_PAGE_OFFSET
// Blocks: osize * n
// Tag: sizeof_jl_taggedvalue_t
// Data: <= osize - sizeof_jl_taggedvalue_t
char pages[REGION_PG_COUNT][GC_PAGE_SZ]; // must be first, to preserve page alignment
uint32_t freemap[REGION_PG_COUNT/32];
gcpage_t meta[REGION_PG_COUNT];
} region_t
#ifndef _COMPILER_MICROSOFT_
__attribute__((aligned(GC_PAGE_SZ)))
#endif
;
static region_t *regions[REGION_COUNT] = {NULL};
// store a lower bound of the first free page in each region
static int regions_lb[REGION_COUNT] = {0};
// an upper bound of the last non-free page
static int regions_ub[REGION_COUNT] = {REGION_PG_COUNT/32-1};
// Variables that become fields of a thread-local struct in the thread-safe
// version.
#define HEAP_DECL static
// variable for tracking preserved values.
HEAP_DECL arraylist_t preserved_values;
// variable for tracking weak references
HEAP_DECL arraylist_t weak_refs;
// variables for tracking malloc'd arrays
HEAP_DECL mallocarray_t *mallocarrays;
HEAP_DECL mallocarray_t *mafreelist;
// variables for tracking big objects
HEAP_DECL bigval_t *big_objects;
// variables for tracking "remembered set"
HEAP_DECL arraylist_t rem_bindings;
HEAP_DECL arraylist_t _remset[2]; // contains jl_value_t*
// lower bound of the number of pointers inside remembered values
static int remset_nptr;
HEAP_DECL arraylist_t *remset;
HEAP_DECL arraylist_t *last_remset;
// variables for allocating objects from pools
#ifdef _P64
#define N_POOLS 41
#else
#define N_POOLS 43
#endif
HEAP_DECL pool_t norm_pools[N_POOLS];
// End of Variables that become fields of a thread-local struct in the thread-safe version.
// The following macros are used for accessing these variables.
// In the future multi-threaded version, they establish the desired thread context.
// In the single-threaded version, they are essentially noops, but nonetheless
// serve to check that the thread context macros are being used.
#define FOR_CURRENT_HEAP {void *current_heap=NULL;
#define END }
#define FOR_EACH_HEAP {void *current_heap=NULL;
/*}*/
#define HEAP(x) (*((void)current_heap,&(x)))
#define preserved_values HEAP(preserved_values)
#define weak_refs HEAP(weak_refs)
#define big_objects HEAP(big_objects)
#define mallocarrays HEAP(mallocarrays)
#define mafreelist HEAP(mafreelist)
#define remset HEAP(remset)
#define last_remset HEAP(last_remset)
#define rem_bindings HEAP(rem_bindings)
#define pools norm_pools
// List of marked big objects. Not per-thread. Accessed only by master thread.
static bigval_t *big_objects_marked = NULL;
// finalization
static arraylist_t finalizer_list;
static arraylist_t finalizer_list_marked;
static arraylist_t to_finalize;
static int check_timeout = 0;
#define should_timeout() 0
#define gc_bits(o) (((gcval_t*)(o))->gc_bits)
#define gc_marked(o) (((gcval_t*)(o))->gc_bits & GC_MARKED)
#define _gc_setmark(o, mark_mode) (((gcval_t*)(o))->gc_bits = mark_mode)
static gcpage_t *page_metadata(void *data);
static void pre_mark(void);
static void post_mark(arraylist_t *list, int dryrun);
static region_t *find_region(void *ptr, int maybe);
#define PAGE_INDEX(region, data) \
((GC_PAGE_DATA((data) - GC_PAGE_OFFSET) - \
&(region)->pages[0][0])/GC_PAGE_SZ)
NOINLINE static uintptr_t gc_get_stack_ptr()
{
void *dummy = NULL;
// The mask is to suppress the compiler warning about returning
// address of local variable
return (uintptr_t)&dummy & ~(uintptr_t)15;
}
#include "gc-debug.c"
int jl_in_gc; // referenced from switchto task.c
static int jl_gc_finalizers_inhibited; // don't run finalizers during codegen #11956
// malloc wrappers, aligned allocation
#if defined(_P64) || defined(__APPLE__)
#define malloc_a16(sz) malloc(sz)
#define realloc_a16(p, sz, oldsz) realloc((p), (sz))
#define free_a16(p) free(p)
#elif defined(_OS_WINDOWS_) /* 32-bit OS is implicit here. */
#define malloc_a16(sz) _aligned_malloc((sz)?(sz):1, 16)
#define realloc_a16(p, sz, oldsz) _aligned_realloc((p), (sz)?(sz):1, 16)
#define free_a16(p) _aligned_free(p)
#else
static inline void *malloc_a16(size_t sz)
{
void *ptr;
if (posix_memalign(&ptr, 16, sz))
return NULL;
return ptr;
}
static inline void *realloc_a16(void *d, size_t sz, size_t oldsz)
{
void *b = malloc_a16(sz);
if (b != NULL) {
memcpy(b, d, oldsz);
free(d);
}
return b;
}
#define free_a16(p) free(p)
#endif
static void schedule_finalization(void *o, void *f)
{
arraylist_push(&to_finalize, o);
arraylist_push(&to_finalize, f);
}
static void run_finalizer(jl_value_t *o, jl_value_t *ff)
{
jl_function_t *f = (jl_function_t*)ff;
assert(jl_is_function(f));
JL_TRY {
jl_apply(f, (jl_value_t**)&o, 1);
}
JL_CATCH {
jl_printf(JL_STDERR, "error in running finalizer: ");
jl_static_show(JL_STDERR, jl_exception_in_transit);
jl_printf(JL_STDERR, "\n");
}
}
static int finalize_object(jl_value_t *o)
{
int success = 0;
jl_value_t *f = NULL;
JL_GC_PUSH1(&f);
for(int i = 0; i < finalizer_list.len; i+=2) {
if (o == (jl_value_t*)finalizer_list.items[i]) {
f = (jl_value_t*)finalizer_list.items[i+1];
if (i < finalizer_list.len - 2) {
finalizer_list.items[i] = finalizer_list.items[finalizer_list.len-2];
finalizer_list.items[i+1] = finalizer_list.items[finalizer_list.len-1];
i -= 2;
}
finalizer_list.len -= 2;
run_finalizer(o, f);
success = 1;
}
}
JL_GC_POP();
return success;
}
static void run_finalizers(void)
{
void *o = NULL, *f = NULL;
JL_GC_PUSH2(&o, &f);
while (to_finalize.len > 0) {
f = arraylist_pop(&to_finalize);
o = arraylist_pop(&to_finalize);
run_finalizer((jl_value_t*)o, (jl_value_t*)f);
}
JL_GC_POP();
}
void jl_gc_inhibit_finalizers(int state)
{
if (jl_gc_finalizers_inhibited && !state && !jl_in_gc) {
jl_in_gc = 1;
run_finalizers();
jl_in_gc = 0;
}
jl_gc_finalizers_inhibited = state;
}
static void schedule_all_finalizers(arraylist_t* flist)
{
// Multi-thread version should steal the entire list while holding a lock.
for(size_t i=0; i < flist->len; i+=2) {
jl_value_t *f = (jl_value_t*)flist->items[i+1];
if (f != HT_NOTFOUND && !jl_is_cpointer(f)) {
schedule_finalization(flist->items[i], flist->items[i+1]);
}
}
flist->len = 0;
}
void jl_gc_run_all_finalizers(void)
{
schedule_all_finalizers(&finalizer_list);
schedule_all_finalizers(&finalizer_list_marked);
run_finalizers();
}
DLLEXPORT void jl_gc_add_finalizer(jl_value_t *v, jl_function_t *f)
{
arraylist_push(&finalizer_list, (void*)v);
arraylist_push(&finalizer_list, (void*)f);
}
void jl_finalize(jl_value_t *o)
{
(void)finalize_object(o);
}
static region_t *find_region(void *ptr, int maybe)
{
// on 64bit systems we could probably use a single region and remove this loop
for (int i = 0; i < REGION_COUNT && regions[i]; i++) {
char *begin = ®ions[i]->pages[0][0];
char *end = begin + sizeof(regions[i]->pages);
if ((char*)ptr >= begin && (char*)ptr <= end)
return regions[i];
}
(void)maybe;
assert(maybe && "find_region failed");
return NULL;
}
static gcpage_t *page_metadata(void *data)
{
region_t *r = find_region(data, 0);
int pg_idx = PAGE_INDEX(r, (char*)data);
return &r->meta[pg_idx];
}
static uint8_t *page_age(gcpage_t *pg)
{
return pg->ages;
}
#define GC_POOL_END_OFS(osize) ((((GC_PAGE_SZ - GC_PAGE_OFFSET)/(osize)) - 1)*(osize) + GC_PAGE_OFFSET)
// GC knobs and self-measurement variables
static int64_t last_gc_total_bytes = 0;
static int gc_inc_steps = 1;
#ifdef _P64
#define default_collect_interval (5600*1024*sizeof(void*))
static size_t max_collect_interval = 1250000000UL;
#else
#define default_collect_interval (3200*1024*sizeof(void*))
static size_t max_collect_interval = 500000000UL;
#endif
// global variables for GC stats
#define NS_TO_S(t) ((double)(t/1000)/(1000*1000))
#define NS2MS(t) ((double)(t/1000)/1000)
static int64_t live_bytes = 0;
static int64_t promoted_bytes = 0;
static size_t current_pg_count = 0;
static size_t max_pg_count = 0;
#ifdef OBJPROFILE
static htable_t obj_counts[3];
static htable_t obj_sizes[3];
#endif
DLLEXPORT size_t jl_gc_total_freed_bytes=0;
#ifdef GC_FINAL_STATS
static uint64_t max_pause = 0;
static uint64_t total_sweep_time = 0;
static uint64_t total_mark_time = 0;
static uint64_t total_fin_time = 0;
#endif
int sweeping = 0;
/*
* The state transition looks like :
*
* ([(quick)sweep] means either a sweep or a quicksweep)
*
* <-[(quick)sweep]-
* |
* ---> GC_QUEUED <--[(quick)sweep && age>promotion]--
* | | ^ |
* | [mark] | |
* [sweep] | [write barrier] |
* | v | |
* ----- GC_MARKED <-------- |
* | | |
* --[quicksweep]-- |
* |
* ========= above this line objects are old ========= |
* |
* ----[new]------> GC_CLEAN ------[mark]--------> GC_MARKED_NOESC
* | ^ |
* <-[(quick)sweep]--- | |
* --[(quick)sweep && age<=promotion]---
*/
// A quick sweep is a sweep where sweep_mask == GC_MARKED_NOESC.
// It means we won't touch GC_MARKED objects (old gen).
// When a reachable object has survived more than PROMOTE_AGE+1 collections
// it is tagged with GC_QUEUED during sweep and will be promoted on next mark
// because at that point we can know easily if it references young objects.
// Marked old objects that reference young ones are kept in the remset.
// When a write barrier triggers, the offending marked object is both queued,
// so as not to trigger the barrier again, and put in the remset.
#define PROMOTE_AGE 1
// this cannot be increased as is without changing :
// - sweep_page which is specialized for 1bit age
// - the size of the age storage in region_t
static int64_t scanned_bytes; // young bytes scanned while marking
static int64_t perm_scanned_bytes; // old bytes scanned while marking
static int prev_sweep_mask = GC_MARKED;
static size_t scanned_bytes_goal;
#ifdef OBJPROFILE
static void *BUFFTY = (void*)0xdeadb00f;
#endif
static void *MATY = (void*)0xdeadaa01;
static size_t array_nbytes(jl_array_t*);
static inline void objprofile_count(void* ty, int old, int sz)
{
#ifdef OBJPROFILE
#ifdef GC_VERIFY
if (verifying) return;
#endif
if ((intptr_t)ty <= 0x10)
ty = BUFFTY;
void **bp = ptrhash_bp(&obj_counts[old], ty);
if (*bp == HT_NOTFOUND)
*bp = (void*)2;
else
(*((ptrint_t*)bp))++;
bp = ptrhash_bp(&obj_sizes[old], ty);
if (*bp == HT_NOTFOUND)
*bp = (void*)(1 + sz);
else
*((ptrint_t*)bp) += sz;
#endif
}
//static inline void gc_setmark_other(jl_value_t *v, int mark_mode) // unused function
//{
// jl_taggedvalue_t *o = jl_astaggedvalue(v);
// _gc_setmark(o, mark_mode);
// verify_val(o);
//}
#define inc_sat(v,s) v = (v) >= s ? s : (v)+1
static inline int gc_setmark_big(void *o, int mark_mode)
{
#ifdef GC_VERIFY
if (verifying) {
_gc_setmark(o, mark_mode);
return 0;
}
#endif
bigval_t* hdr = bigval_header(o);
int bits = gc_bits(o);
if (bits == GC_QUEUED || bits == GC_MARKED)
mark_mode = GC_MARKED;
if ((mark_mode == GC_MARKED) & (bits != GC_MARKED)) {
// Move hdr from big_objects list to big_objects_marked list
*hdr->prev = hdr->next;
if (hdr->next)
hdr->next->prev = hdr->prev;
hdr->next = big_objects_marked;
hdr->prev = &big_objects_marked;
if (big_objects_marked)
big_objects_marked->prev = &hdr->next;
big_objects_marked = hdr;
}
if (!(bits & GC_MARKED)) {
if (mark_mode == GC_MARKED)
perm_scanned_bytes += hdr->sz&~3;
else
scanned_bytes += hdr->sz&~3;
#ifdef OBJPROFILE
objprofile_count(jl_typeof(o), mark_mode == GC_MARKED, hdr->sz&~3);
#endif
}
_gc_setmark(o, mark_mode);
verify_val(jl_valueof(o));
return mark_mode;
}
static inline int gc_setmark_pool(void *o, int mark_mode)
{
#ifdef GC_VERIFY
if (verifying) {
_gc_setmark(o, mark_mode);
return mark_mode;
}
#endif
gcpage_t* page = page_metadata(o);
int bits = gc_bits(o);
if (bits == GC_QUEUED || bits == GC_MARKED) {
mark_mode = GC_MARKED;
}
if (!(bits & GC_MARKED)) {
if (mark_mode == GC_MARKED)
perm_scanned_bytes += page->osize;
else
scanned_bytes += page->osize;
#ifdef OBJPROFILE
objprofile_count(jl_typeof(o), mark_mode == GC_MARKED, page->osize);
#endif
}
_gc_setmark(o, mark_mode);
page->gc_bits |= mark_mode;
verify_val(jl_valueof(o));
return mark_mode;
}
static inline int gc_setmark(jl_value_t *v, int sz, int mark_mode)
{
jl_taggedvalue_t *o = jl_astaggedvalue(v);
sz += sizeof_jl_taggedvalue_t;
#ifdef MEMDEBUG
return gc_setmark_big(o, mark_mode);
#endif
if (sz <= GC_MAX_SZCLASS + sizeof(buff_t))
return gc_setmark_pool(o, mark_mode);
else
return gc_setmark_big(o, mark_mode);
}
#define gc_typeof(v) jl_typeof(v)
#define gc_val_buf(o) ((buff_t*)(((void**)(o))-1))
inline void gc_setmark_buf(void *o, int mark_mode)
{
buff_t *buf = gc_val_buf(o);
#ifdef MEMDEBUG
gc_setmark_big(buf, mark_mode);
return;
#endif
if (buf->pooled)
gc_setmark_pool(buf, mark_mode);
else
gc_setmark_big(buf, mark_mode);
}
static NOINLINE void *malloc_page(void)
{
void *ptr = (void*)0;
int i;
region_t* region;
int region_i = 0;
while(region_i < REGION_COUNT) {
region = regions[region_i];
if (region == NULL) {
size_t alloc_size = sizeof(region_t);
#ifdef _OS_WINDOWS_
char* mem = (char*)VirtualAlloc(NULL, sizeof(region_t) + GC_PAGE_SZ, MEM_RESERVE, PAGE_READWRITE);
#else
if (GC_PAGE_SZ > jl_page_size)
alloc_size += GC_PAGE_SZ;
char* mem = (char*)mmap(0, alloc_size, PROT_READ | PROT_WRITE, MAP_NORESERVE | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
mem = mem == MAP_FAILED ? NULL : mem;
#endif
if (mem == NULL) {
jl_printf(JL_STDERR, "could not allocate pools\n");
abort();
}
if (GC_PAGE_SZ > jl_page_size) {
// round data pointer up to the nearest GC_PAGE_DATA-aligned boundary
// if mmap didn't already do so
alloc_size += GC_PAGE_SZ;
region = (region_t*)((char*)GC_PAGE_DATA(mem + GC_PAGE_SZ - 1));
}
else {
region = (region_t*)mem;
}
#ifdef _OS_WINDOWS_
VirtualAlloc(region->freemap, REGION_PG_COUNT/8, MEM_COMMIT, PAGE_READWRITE);
VirtualAlloc(region->meta, REGION_PG_COUNT*sizeof(gcpage_t), MEM_COMMIT, PAGE_READWRITE);
#endif
memset(region->freemap, 0xff, REGION_PG_COUNT/8);
regions[region_i] = region;
}
for(i = regions_lb[region_i]; i < REGION_PG_COUNT/32; i++) {
if (region->freemap[i]) break;
}
if (i == REGION_PG_COUNT/32) {
// region full
region_i++;
continue;
}
break;
}
if (region_i >= REGION_COUNT) {
jl_printf(JL_STDERR, "increase REGION_COUNT or allocate less memory\n");
abort();
}
if (regions_lb[region_i] < i)
regions_lb[region_i] = i;
if (regions_ub[region_i] < i)
regions_ub[region_i] = i;
#if defined(_COMPILER_MINGW_)
int j = __builtin_ffs(region->freemap[i]) - 1;
#elif defined(_COMPILER_MICROSOFT_)
unsigned long j;
_BitScanForward(&j, region->freemap[i]);
#else
int j = ffs(region->freemap[i]) - 1;
#endif
region->freemap[i] &= ~(uint32_t)(1 << j);
ptr = region->pages[i*32 + j];
#ifdef _OS_WINDOWS_
VirtualAlloc(ptr, GC_PAGE_SZ, MEM_COMMIT, PAGE_READWRITE);
#endif
current_pg_count++;
max_pg_count = max_pg_count < current_pg_count ? current_pg_count : max_pg_count;
return ptr;
}
static void free_page(void *p)
{
int pg_idx = -1;
int i;
for(i = 0; i < REGION_COUNT && regions[i] != NULL; i++) {
pg_idx = PAGE_INDEX(regions[i], (char*)p+GC_PAGE_OFFSET);
if (pg_idx >= 0 && pg_idx < REGION_PG_COUNT) break;
}
assert(i < REGION_COUNT && regions[i] != NULL);
region_t *region = regions[i];
uint32_t msk = (uint32_t)(1 << (pg_idx % 32));
assert(!(region->freemap[pg_idx/32] & msk));
region->freemap[pg_idx/32] ^= msk;
free(region->meta[pg_idx].ages);
// tell the OS we don't need these pages right now
size_t decommit_size = GC_PAGE_SZ;
if (GC_PAGE_SZ < jl_page_size) {
// ensure so we don't release more memory than intended
size_t n_pages = (GC_PAGE_SZ + jl_page_size - 1) / GC_PAGE_SZ;
decommit_size = jl_page_size;
p = (void*)((uintptr_t)®ion->pages[pg_idx][0] & ~(jl_page_size - 1)); // round down to the nearest page
pg_idx = PAGE_INDEX(region, (char*)p+GC_PAGE_OFFSET);
if (pg_idx + n_pages > REGION_PG_COUNT) goto no_decommit;
for (; n_pages--; pg_idx++) {
msk = (uint32_t)(1 << ((pg_idx % 32)));
if (!(region->freemap[pg_idx/32] & msk)) goto no_decommit;
}
}
#ifdef _OS_WINDOWS_
VirtualFree(p, decommit_size, MEM_DECOMMIT);
#else
madvise(p, decommit_size, MADV_DONTNEED);
#endif
no_decommit:
if (regions_lb[i] > pg_idx/32) regions_lb[i] = pg_idx/32;
current_pg_count--;
}
#define should_collect() (__unlikely(allocd_bytes>0))
static inline int maybe_collect(void)
{
if (should_collect() || gc_debug_check_other()) {
jl_gc_collect(0);
return 1;
}
return 0;
}
// preserved values
DLLEXPORT int jl_gc_n_preserved_values(void)
{
FOR_CURRENT_HEAP
return preserved_values.len;
END
}
DLLEXPORT void jl_gc_preserve(jl_value_t *v)
{
FOR_CURRENT_HEAP
arraylist_push(&preserved_values, (void*)v);
END
}
DLLEXPORT void jl_gc_unpreserve(void)
{
FOR_CURRENT_HEAP
(void)arraylist_pop(&preserved_values);
END
}
// weak references
DLLEXPORT jl_weakref_t *jl_gc_new_weakref(jl_value_t *value)
{
jl_weakref_t *wr = (jl_weakref_t*)jl_gc_alloc_1w();
jl_set_typeof(wr, jl_weakref_type);
wr->value = value;
FOR_CURRENT_HEAP
arraylist_push(&weak_refs, wr);
END
return wr;
}
static void sweep_weak_refs(void)
{
FOR_EACH_HEAP
size_t n=0, ndel=0, l=weak_refs.len;
jl_weakref_t *wr;
void **lst = weak_refs.items;
void *tmp;
#define SWAP_wr(a,b) (tmp=a,a=b,b=tmp,1)
if (l == 0)
return;
do {
wr = (jl_weakref_t*)lst[n];
if (gc_marked(jl_astaggedvalue(wr))) {
// weakref itself is alive
if (!gc_marked(jl_astaggedvalue(wr->value)))
wr->value = (jl_value_t*)jl_nothing;
n++;
}
else {
ndel++;
}
} while ((n < l-ndel) && SWAP_wr(lst[n],lst[n+ndel]));
weak_refs.len -= ndel;
END
}
// big value list
static NOINLINE void *alloc_big(size_t sz)
{
maybe_collect();
size_t offs = offsetof(bigval_t, header);
size_t allocsz = LLT_ALIGN(sz + offs, 16);
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
bigval_t *v = (bigval_t*)malloc_a16(allocsz);
if (v == NULL)
jl_throw(jl_memory_exception);
allocd_bytes += allocsz;
gc_num.bigalloc++;
#ifdef MEMDEBUG
memset(v, 0xee, allocsz);
#endif
v->sz = allocsz;
v->flags = 0;
v->age = 0;
FOR_CURRENT_HEAP
v->next = big_objects;
v->prev = &big_objects;
if (v->next)
v->next->prev = &v->next;
big_objects = v;
END
return (void*)&v->header;
}
static int big_total;
static int big_freed;
static int big_reset;
// Sweep list rooted at *pv, removing and freeing any unmarked objects.
// Return pointer to last `next` field in the culled list.
static bigval_t** sweep_big_list(int sweep_mask, bigval_t** pv)
{
bigval_t *v = *pv;
while (v != NULL) {
bigval_t *nxt = v->next;
if (gc_marked(&v->header)) {
pv = &v->next;
int age = v->age;
int bits = gc_bits(&v->header);
if (age >= PROMOTE_AGE) {
if (sweep_mask == GC_MARKED || bits == GC_MARKED_NOESC) {
bits = GC_QUEUED;
}
}
else {
inc_sat(age, PROMOTE_AGE);
v->age = age;
if ((sweep_mask & bits) == sweep_mask) {
bits = GC_CLEAN;
big_reset++;
}
}
gc_bits(&v->header) = bits;
}
else {
// Remove v from list and free it
*pv = nxt;
if (nxt)
nxt->prev = pv;
freed_bytes += v->sz&~3;
#ifdef MEMDEBUG
memset(v, 0xbb, v->sz&~3);
#endif
free_a16(v);
big_freed++;
}
big_total++;
v = nxt;
}
return pv;
}
static void sweep_big(int sweep_mask)
{
FOR_EACH_HEAP
sweep_big_list(sweep_mask, &big_objects);
END
if (sweep_mask == GC_MARKED) {
bigval_t** last_next = sweep_big_list(sweep_mask, &big_objects_marked);
// Move all survivors from big_objects_marked list to big_objects list.
FOR_CURRENT_HEAP
if (big_objects)
big_objects->prev = last_next;
*last_next = big_objects;
big_objects = big_objects_marked;
if (big_objects)
big_objects->prev = &big_objects;
END
big_objects_marked = NULL;
}
}
// tracking Arrays with malloc'd storage
void jl_gc_track_malloced_array(jl_array_t *a)
{
FOR_CURRENT_HEAP
mallocarray_t *ma;
if (mafreelist == NULL) {
ma = (mallocarray_t*)malloc(sizeof(mallocarray_t));
}
else {
ma = mafreelist;
mafreelist = ma->next;
}
ma->a = a;
ma->next = mallocarrays;
mallocarrays = ma;
END
}
void jl_gc_count_allocd(size_t sz)
{
allocd_bytes += sz;
}
static size_t array_nbytes(jl_array_t *a)
{
size_t sz = 0;
if (jl_array_ndims(a)==1)
sz = a->elsize * a->maxsize + (a->elsize == 1 ? 1 : 0);
else
sz = a->elsize * jl_array_len(a);
return sz;
}
void jl_gc_free_array(jl_array_t *a)
{
if (a->how == 2) {
char *d = (char*)a->data - a->offset*a->elsize;
if (a->isaligned)
free_a16(d);
else
free(d);
freed_bytes += array_nbytes(a);
}
}
static int mallocd_array_total;
static int mallocd_array_freed;
static void sweep_malloced_arrays(void)
{
FOR_EACH_HEAP
mallocarray_t *ma = mallocarrays;
mallocarray_t **pma = &mallocarrays;
while (ma != NULL) {
mallocarray_t *nxt = ma->next;
if (gc_marked(jl_astaggedvalue(ma->a))) {
pma = &ma->next;
}
else {
*pma = nxt;
assert(ma->a->how == 2);
jl_gc_free_array(ma->a);
ma->next = mafreelist;
mafreelist = ma;
mallocd_array_freed++;
}
mallocd_array_total++;
ma = nxt;
}
END
}
// pool allocation
static inline gcval_t *reset_page(pool_t *p, gcpage_t *pg, gcval_t *fl)
{
pg->gc_bits = 0;
pg->nfree = (GC_PAGE_SZ - GC_PAGE_OFFSET) / p->osize;
pg->pool_n = p - norm_pools;
memset(page_age(pg), 0, LLT_ALIGN(GC_PAGE_SZ / p->osize, 8));
gcval_t *beg = (gcval_t*)(pg->data + GC_PAGE_OFFSET);
gcval_t *end = (gcval_t*)((char*)beg + (pg->nfree - 1)*p->osize);
end->next = fl;
pg->allocd = 0;
pg->fl_begin_offset = GC_PAGE_OFFSET;
pg->fl_end_offset = (char*)end - (char*)beg + GC_PAGE_OFFSET;
return beg;
}
static NOINLINE void add_page(pool_t *p)
{
char *data = (char*)malloc_page();
if (data == NULL)
jl_throw(jl_memory_exception);
gcpage_t *pg = page_metadata(data + GC_PAGE_OFFSET);
pg->data = data;
pg->osize = p->osize;
pg->ages = (uint8_t*)malloc(LLT_ALIGN(GC_PAGE_SZ / p->osize, 8));
gcval_t *fl = reset_page(p, pg, p->newpages);
p->newpages = fl;
}
static inline void *__pool_alloc(pool_t* p, int osize, int end_offset)
{
gcval_t *v, *end;
if (__unlikely((allocd_bytes += osize) >= 0) || gc_debug_check_pool()) {
//allocd_bytes -= osize;
jl_gc_collect(0);
//allocd_bytes += osize;
}
gc_num.poolalloc++;
// first try to use the freelist
v = p->freelist;
if (v) {
gcval_t* next = v->next;
v->flags = 0;
p->nfree--;
p->freelist = next;
if (__unlikely(GC_PAGE_DATA(v) != GC_PAGE_DATA(next))) {
// we only update pg's fields when the freelist changes page
// since pg's metadata is likely not in cache
gcpage_t* pg = page_metadata(v);
assert(pg->osize == p->osize);
pg->nfree = 0;
pg->allocd = 1;
if (next)
p->nfree = page_metadata(next)->nfree;
}
return v;
}
// if the freelist is empty we reuse empty but not freed pages
v = p->newpages;
if (__unlikely(!v)) {
add_page(p);
v = p->newpages;
}
end = (gcval_t*)&(GC_PAGE_DATA(v)[end_offset]);
if (__likely(v != end)) {
p->newpages = (gcval_t*)((char*)v + osize);
}
else {
// like the freelist case, but only update the page metadata when it is full
gcpage_t* pg = page_metadata(v);
assert(pg->osize == p->osize);
pg->nfree = 0;
pg->allocd = 1;
p->newpages = v->next;
}
v->flags = 0;
return v;
}
// use this variant when osize is statically known
// and is definitely in sizeclasses
// GC_POOL_END_OFS uses an integer division
static inline void *_pool_alloc(pool_t *p, int osize)
{
return __pool_alloc(p, osize, GC_POOL_END_OFS(osize));
}
static inline void *pool_alloc(pool_t *p)
{
return __pool_alloc(p, p->osize, p->end_offset);
}
// pools are 16376 bytes large (GC_POOL_SZ - GC_PAGE_OFFSET)
static const int sizeclasses[N_POOLS] = {
#ifdef _P64
8,
#else
4, 8, 12,
#endif
// 16 pools at 16-byte spacing
16, 32, 48, 64, 80, 96, 112, 128,
144, 160, 176, 192, 208, 224, 240, 256,
// the following tables are computed for maximum packing efficiency via the formula:
// sz=(div(2^14-8,rng)÷16)*16; hcat(sz, (2^14-8)÷sz, 2^14-(2^14-8)÷sz.*sz)'
// rng = 60:-4:32 (8 pools)
272, 288, 304, 336, 368, 400, 448, 496,
// 60, 56, 53, 48, 44, 40, 36, 33, /pool
// 64, 256, 272, 256, 192, 384, 256, 16, bytes lost
// rng = 30:-2:16 (8 pools)
544, 576, 624, 672, 736, 816, 896, 1008,
// 30, 28, 26, 24, 22, 20, 18, 16, /pool
// 64, 256, 160, 256, 192, 64, 256, 256, bytes lost
// rng = 15:-1:8 (8 pools)
1088, 1168, 1248, 1360, 1488, 1632, 1808, 2032
// 15, 14, 13, 12, 11, 10, 9, 8, /pool
// 64, 32, 160, 64, 16, 64, 112, 128, bytes lost
};
static inline int szclass(size_t sz)
{
#ifdef _P64
if (sz <= 8)
return 0;
const int N = 0;
#else
if (sz <= 12)
return (sz + 3) / 4 - 1;
const int N = 2;
#endif
if (sz <= 256)
return (sz + 15) / 16 + N;
if (sz <= 496)
return 16 - 16376 / 4 / LLT_ALIGN(sz, 16 * 4) + 16 + N;
if (sz <= 1008)
return 16 - 16376 / 2 / LLT_ALIGN(sz, 16 * 2) + 24 + N;
assert(sz <= GC_MAX_SZCLASS + sizeof(buff_t) && sizeclasses[N_POOLS-1] == GC_MAX_SZCLASS + sizeof(buff_t));
return 16 - 16376 / 1 / LLT_ALIGN(sz, 16 * 1) + 32 + N;
}
// sweep phase
static int skipped_pages = 0;
static int total_pages = 0;
static int freed_pages = 0;
static int lazy_freed_pages = 0;
static int page_done = 0;
static gcval_t** sweep_page(pool_t* p, gcpage_t* pg, gcval_t **pfl,int,int);
static void sweep_pool_region(gcval_t **pfl[N_POOLS], int region_i, int sweep_mask)
{
region_t* region = regions[region_i];
// the actual sweeping
int ub = 0;
int lb = regions_lb[region_i];
for (int pg_i = 0; pg_i <= regions_ub[region_i]; pg_i++) {
uint32_t line = region->freemap[pg_i];
if (!!~line) {
ub = pg_i;
for (int j = 0; j < 32; j++) {
if (!((line >> j) & 1)) {
gcpage_t *pg = ®ion->meta[pg_i*32 + j];
int p_n = pg->pool_n;
pool_t *p = &norm_pools[p_n];
int osize = pg->osize;
pfl[p_n] = sweep_page(p, pg, pfl[p_n], sweep_mask, osize);
}
}
}
else if (pg_i < lb) {
lb = pg_i;
}
}
regions_ub[region_i] = ub;
regions_lb[region_i] = lb;
}
// Returns pointer to terminal pointer of list rooted at *pfl.
static gcval_t** sweep_page(pool_t* p, gcpage_t* pg, gcval_t **pfl, int sweep_mask, int osize)
{
#ifdef FREE_PAGES_EAGER
int freedall;
#else
int empty;
#endif
gcval_t **prev_pfl = pfl;
gcval_t *v;
size_t old_nfree = 0, nfree = 0;
int pg_freedall = 0, pg_total = 0, pg_skpd = 0;
int obj_per_page = (GC_PAGE_SZ - GC_PAGE_OFFSET)/osize;
char *data = pg->data;
uint8_t *ages = page_age(pg);
v = (gcval_t*)(data + GC_PAGE_OFFSET);
char *lim = (char*)v + GC_PAGE_SZ - GC_PAGE_OFFSET - osize;
freedall = 1;
old_nfree += pg->nfree;
if (pg->gc_bits == GC_MARKED) {
// this page only contains GC_MARKED and free cells
// if we are doing a quick sweep and nothing has been allocated inside since last sweep
// we can skip it
if (sweep_mask == GC_MARKED_NOESC && !pg->allocd) {
// the position of the freelist begin/end in this page is stored in its metadata
if (pg->fl_begin_offset != (uint16_t)-1) {
*pfl = (gcval_t*)PAGE_PFL_BEG(pg);
pfl = prev_pfl = PAGE_PFL_END(pg);
}
pg_skpd++;
freedall = 0;
goto free_page;
}
}
else if (pg->gc_bits == GC_CLEAN) {
goto free_page;
}
{ // scope to avoid clang goto errors
int pg_nfree = 0;
gcval_t **pfl_begin = NULL;
uint8_t msk = 1; // mask for the age bit in the current age byte
while ((char*)v <= lim) {
int bits = gc_bits(v);
if (!(bits & GC_MARKED)) {
*pfl = v;
pfl = &v->next;
pfl_begin = pfl_begin ? pfl_begin : pfl;
pg_nfree++;
*ages &= ~msk;
}
else { // marked young or old
if (*ages & msk) { // old enough
if (sweep_mask == GC_MARKED || bits == GC_MARKED_NOESC) {
gc_bits(v) = GC_QUEUED; // promote
}
}
else if ((sweep_mask & bits) == sweep_mask) {
gc_bits(v) = GC_CLEAN; // unmark
}
*ages |= msk;
freedall = 0;
}
v = (gcval_t*)((char*)v + osize);
msk <<= 1;
if (!msk) {
msk = 1;
ages++;
}
}
pg->fl_begin_offset = pfl_begin ? (char*)pfl_begin - data : (uint16_t)-1;
pg->fl_end_offset = pfl_begin ? (char*)pfl - data : (uint16_t)-1;
pg->nfree = pg_nfree;
page_done++;
pg->allocd = 0;
}
free_page:
pg_freedall += freedall;
// lazy version: (empty) if the whole page was already unused, free it
// eager version: (freedall) free page as soon as possible
// the eager one uses less memory.
pg_total++;
if (freedall) {
// on quick sweeps, keep a few pages empty but allocated for performance
if (sweep_mask == GC_MARKED_NOESC && lazy_freed_pages <= default_collect_interval/GC_PAGE_SZ) {
gcval_t *begin = reset_page(p, pg, 0);
gcval_t** pend = (gcval_t**)((char*)begin + ((int)pg->nfree - 1)*osize);
gcval_t* npg = p->newpages;
*pend = npg;
p->newpages = begin;
begin->next = (gcval_t*)0;
lazy_freed_pages++;
pfl = prev_pfl;
}
else {
pfl = prev_pfl;
#ifdef MEMDEBUG
memset(pg->data, 0xbb, GC_PAGE_SZ);
#endif
free_page(data);
#ifdef MEMDEBUG
memset(pg, 0xbb, sizeof(gcpage_t));
#endif
}
freed_pages++;
nfree += obj_per_page;
}
else {
if (sweep_mask == GC_MARKED)
pg->gc_bits = GC_CLEAN;
if (sweep_mask == GC_MARKED_NOESC)
pg->gc_bits = GC_MARKED;
nfree += pg->nfree;
}
skipped_pages += pg_skpd;
total_pages += pg_total;
freed_bytes += (nfree - old_nfree)*osize;
return pfl;
}
static void gc_sweep_once(int sweep_mask)
{
#ifdef GC_TIME
double t0 = clock_now();
mallocd_array_total = 0;
mallocd_array_freed = 0;
#endif
sweep_malloced_arrays();
#ifdef GC_TIME
jl_printf(JL_STDOUT, "GC sweep arrays %.2f (freed %d/%d)\n", (clock_now() - t0)*1000, mallocd_array_freed, mallocd_array_total);
t0 = clock_now();
big_total = 0;
big_freed = 0;
big_reset = 0;
#endif
sweep_big(sweep_mask);
#ifdef GC_TIME
jl_printf(JL_STDOUT, "GC sweep big %.2f (freed %d/%d with %d rst)\n", (clock_now() - t0)*1000, big_freed, big_total, big_reset);
#endif
}
// returns 0 if not finished
static int gc_sweep_inc(int sweep_mask)
{
#ifdef GC_TIME
double t0 = clock_now();
#endif
skipped_pages = 0;
total_pages = 0;
freed_pages = 0;
lazy_freed_pages = 0;
page_done = 0;
int finished = 1;
gcval_t **pfl[N_POOLS];
// update metadata of pages that were pointed to by freelist or newpages from a pool
// i.e. pages being the current allocation target
FOR_EACH_HEAP
for (int i = 0; i < N_POOLS; i++) {
pool_t* p = &HEAP(norm_pools)[i];
gcval_t* last = p->freelist;
if (last) {
gcpage_t* pg = page_metadata(last);
pg->allocd = 1;
pg->nfree = p->nfree;
}
p->freelist = NULL;
pfl[i] = &p->freelist;
last = p->newpages;
if (last) {
gcpage_t* pg = page_metadata(last);
pg->nfree = (GC_PAGE_SZ - ((char*)last - GC_PAGE_DATA(last))) / p->osize;
pg->allocd = 1;
}
p->newpages = NULL;
}
END
for (int i = 0; i < REGION_COUNT; i++) {
if (regions[i])
/*finished &= */sweep_pool_region(pfl, i, sweep_mask);
}
// null out terminal pointers of free lists and cache back pg->nfree in the pool_t
FOR_EACH_HEAP
for (int i = 0; i < N_POOLS; i++) {
pool_t* p = &HEAP(norm_pools)[i];
*pfl[i] = NULL;
if (p->freelist) {
p->nfree = page_metadata(p->freelist)->nfree;
}
}
END
#ifdef GC_TIME
double sweep_pool_sec = clock_now() - t0;
double sweep_speed = ((((double)total_pages)*GC_PAGE_SZ)/(1024*1024*1024))/sweep_pool_sec;
jl_printf(JL_STDOUT, "GC sweep pools %s %.2f at %.1f GB/s (skipped %d%% of %d, done %d pgs, %d freed with %d lazily) mask %d\n", finished ? "end" : "inc", sweep_pool_sec*1000, sweep_speed, total_pages ? (skipped_pages*100)/total_pages : 0, total_pages, page_done, freed_pages, lazy_freed_pages, sweep_mask);
#endif
return finished;
}
// mark phase
static jl_value_t **mark_stack = NULL;
static jl_value_t **mark_stack_base = NULL;
static size_t mark_stack_size = 0;
static size_t mark_sp = 0;
static void grow_mark_stack(void)
{
size_t newsz = mark_stack_size>0 ? mark_stack_size*2 : 32000;
size_t offset = mark_stack - mark_stack_base;
mark_stack_base = (jl_value_t**)realloc(mark_stack_base, newsz*sizeof(void*));
if (mark_stack_base == NULL) {
jl_printf(JL_STDERR, "Couldn't grow mark stack to : %" PRIuPTR "\n",
(uintptr_t)newsz);
exit(1);
}
mark_stack = mark_stack_base + offset;
mark_stack_size = newsz;
}
static int max_msp = 0;
static void reset_remset(void)
{
FOR_EACH_HEAP
arraylist_t *tmp = remset;
remset = last_remset;
last_remset = tmp;
remset->len = 0;
remset_nptr = 0;
END
}
DLLEXPORT void jl_gc_queue_root(jl_value_t *ptr)
{
FOR_CURRENT_HEAP
jl_taggedvalue_t *o = jl_astaggedvalue(ptr);
assert(gc_bits(o) != GC_QUEUED);
gc_bits(o) = GC_QUEUED;
arraylist_push(remset, ptr);
remset_nptr++; // conservative
END
}
void gc_queue_binding(jl_binding_t *bnd)
{
FOR_CURRENT_HEAP
buff_t *buf = gc_val_buf(bnd);
assert(gc_bits(buf) != GC_QUEUED);
gc_bits(buf) = GC_QUEUED;
arraylist_push(&rem_bindings, bnd);
END
}
static int push_root(jl_value_t *v, int d, int);
#ifdef JL_DEBUG_BUILD
static void *volatile gc_findval; // for usage from gdb, for finding the gc-root for a value
#endif
static inline int gc_push_root(void *v, int d) // v isa jl_value_t*
{
#ifdef JL_DEBUG_BUILD
if (v == gc_findval)
jl_raise_debugger();
#endif
assert(v != NULL);
jl_taggedvalue_t* o = jl_astaggedvalue(v);
verify_val(v);
int bits = gc_bits(o);
if (!gc_marked(o)) {
return push_root((jl_value_t*)v, d, bits);
}
return bits;
}
void jl_gc_setmark(jl_value_t *v) // TODO rename this as it is misleading now
{
// int64_t s = perm_scanned_bytes;
jl_taggedvalue_t *o = jl_astaggedvalue(v);
if (!gc_marked(o)) {
// objprofile_count(jl_typeof(v), 1, 16);
#ifdef MEMDEBUG
gc_setmark_big(o, GC_MARKED_NOESC);
#else
gc_setmark_pool(o, GC_MARKED_NOESC);
#endif
}
// perm_scanned_bytes = s;
}
static void gc_mark_stack(jl_value_t* ta, jl_gcframe_t *s, ptrint_t offset, int d)
{
while (s != NULL) {
s = (jl_gcframe_t*)((char*)s + offset);
jl_value_t ***rts = (jl_value_t***)(((void**)s)+2);
size_t nr = s->nroots>>1;
if (s->nroots & 1) {
for(size_t i=0; i < nr; i++) {
jl_value_t **ptr = (jl_value_t**)((char*)rts[i] + offset);
if (*ptr != NULL)
gc_push_root(*ptr, d);
}
}
else {
for(size_t i=0; i < nr; i++) {
if (rts[i] != NULL) {
verify_parent2("task", ta, &rts[i], "stack(%d)", (int)i);
gc_push_root(rts[i], d);
}
}
}
s = s->prev;
}
}
NOINLINE static int gc_mark_module(jl_module_t *m, int d)
{
size_t i;
int refyoung = 0;
void **table = m->bindings.table;
for(i=1; i < m->bindings.size; i+=2) {
if (table[i] != HT_NOTFOUND) {
jl_binding_t *b = (jl_binding_t*)table[i];
gc_setmark_buf(b, gc_bits(jl_astaggedvalue(m)));
#ifdef GC_VERIFY
void* vb = gc_val_buf(b);
verify_parent1("module", m, &vb, "binding_buff");
#endif
if (b->value != NULL) {
verify_parent2("module", m, &b->value, "binding(%s)", b->name->name);
refyoung |= gc_push_root(b->value, d);
}
if (b->globalref != NULL)
refyoung |= gc_push_root(b->globalref, d);
}
}
// this is only necessary because bindings for "using" modules
// are added only when accessed. therefore if a module is replaced
// after "using" it but before accessing it, this array might
// contain the only reference.
for(i=0; i < m->usings.len; i++) {
refyoung |= gc_push_root(m->usings.items[i], d);
}
if (m->constant_table) {
verify_parent1("module", m, &m->constant_table, "constant_table");
refyoung |= gc_push_root(m->constant_table, d);
}
if (m->parent) {
refyoung |= gc_push_root(m->parent, d);
}
return refyoung;
}
static void gc_mark_task_stack(jl_task_t *ta, int d)
{
if (ta->stkbuf != NULL || ta == jl_current_task) {
if (ta->stkbuf != NULL) {
gc_setmark_buf(ta->stkbuf, gc_bits(jl_astaggedvalue(ta)));
}
#ifdef COPY_STACKS
ptrint_t offset;
if (ta == jl_current_task) {
offset = 0;
gc_mark_stack((jl_value_t*)ta, jl_pgcstack, offset, d);
}
else {
offset = (char *)ta->stkbuf - ((char *)jl_stackbase - ta->ssize);
gc_mark_stack((jl_value_t*)ta, ta->gcstack, offset, d);
}
#else
gc_mark_stack((jl_value_t*)ta, ta->gcstack, 0, d);
#endif
}
}
NOINLINE static void gc_mark_task(jl_task_t *ta, int d)
{
if (ta->parent) gc_push_root(ta->parent, d);
if (ta->last) gc_push_root(ta->last, d);
gc_push_root(ta->tls, d);
gc_push_root(ta->consumers, d);
gc_push_root(ta->donenotify, d);
gc_push_root(ta->exception, d);
if (ta->backtrace) gc_push_root(ta->backtrace, d);
if (ta->start) gc_push_root(ta->start, d);
if (ta->result) gc_push_root(ta->result, d);
gc_mark_task_stack(ta, d);
}
// for chasing down unwanted references
/*
static jl_value_t *lookforme = NULL;
DLLEXPORT void jl_gc_lookfor(jl_value_t *v) { lookforme = v; }
*/
#define MAX_MARK_DEPTH 400
// mark v and recurse on its children (or store them on the mark stack when recursion depth becomes too high)
// it does so assuming the gc bits of v are "bits" and returns the new bits of v
// if v becomes GC_MARKED (old) and some of its children are GC_MARKED_NOESC (young), v is added to the remset
static int push_root(jl_value_t *v, int d, int bits)
{
assert(v != NULL);
jl_value_t *vt = (jl_value_t*)gc_typeof(v);
int refyoung = 0, nptr = 0;
if (vt == (jl_value_t*)jl_weakref_type) {
bits = gc_setmark(v, sizeof(jl_weakref_t), GC_MARKED_NOESC);
goto ret;
}
if ((jl_is_datatype(vt) && ((jl_datatype_t*)vt)->pointerfree)) {
int sz = jl_datatype_size(vt);
bits = gc_setmark(v, sz, GC_MARKED_NOESC);
goto ret;
}
#define MARK(v, s) do { \
s; \
if (d >= MAX_MARK_DEPTH) \
goto queue_the_root; \
if (should_timeout()) \
goto queue_the_root; \
} while (0)
d++;
// some values have special representations
if (vt == (jl_value_t*)jl_simplevector_type) {
size_t l = jl_svec_len(v);
MARK(v, bits = gc_setmark(v, l*sizeof(void*) + sizeof(jl_svec_t), GC_MARKED_NOESC));
jl_value_t **data = ((jl_svec_t*)v)->data;
nptr += l;
for(size_t i=0; i < l; i++) {
jl_value_t *elt = data[i];
if (elt != NULL) {
verify_parent2("svec", v, &data[i], "elem(%d)", (int)i);
refyoung |= gc_push_root(elt, d);
}
}
}
else if (((jl_datatype_t*)(vt))->name == jl_array_typename) {
jl_array_t *a = (jl_array_t*)v;
jl_taggedvalue_t *o = jl_astaggedvalue(v);
int todo = !(bits & GC_MARKED);
if (a->pooled)
#ifdef MEMDEBUG
#define _gc_setmark_pool gc_setmark_big
#else
#define _gc_setmark_pool gc_setmark_pool
#endif
MARK(a,
bits = _gc_setmark_pool(o, GC_MARKED_NOESC);
if (a->how == 2 && todo) {
objprofile_count(MATY, gc_bits(o) == GC_MARKED, array_nbytes(a));
if (gc_bits(o) == GC_MARKED)
perm_scanned_bytes += array_nbytes(a);
else
scanned_bytes += array_nbytes(a);
});
else
MARK(a,
bits = gc_setmark_big(o, GC_MARKED_NOESC);
if (a->how == 2 && todo) {
objprofile_count(MATY, gc_bits(o) == GC_MARKED, array_nbytes(a));
if (gc_bits(o) == GC_MARKED)
perm_scanned_bytes += array_nbytes(a);
else
scanned_bytes += array_nbytes(a);
});
if (a->how == 3) {
jl_value_t *owner = jl_array_data_owner(a);
refyoung |= gc_push_root(owner, d);
goto ret;
}
else if (a->how == 1) {
#ifdef GC_VERIFY
void* val_buf = gc_val_buf((char*)a->data - a->offset*a->elsize);
verify_parent1("array", v, &val_buf, "buffer ('loc' addr is meaningless)");
#endif
gc_setmark_buf((char*)a->data - a->offset*a->elsize, gc_bits(o));
}
if (a->ptrarray && a->data!=NULL) {
size_t l = jl_array_len(a);
if (l > 100000 && d > MAX_MARK_DEPTH-10) {
// don't mark long arrays at high depth, to try to avoid
// copying the whole array into the mark queue
goto queue_the_root;
}
else {
nptr += l;
void *data = a->data;
for(size_t i=0; i < l; i++) {
jl_value_t *elt = ((jl_value_t**)data)[i];
if (elt != NULL) {
verify_parent2("array", v, &((jl_value_t**)data)[i], "elem(%d)", (int)i);
refyoung |= gc_push_root(elt, d);
}
// try to split large array marking (incremental mark TODO)
// if (should_timeout() && l > 1000) goto queue_the_root;
}
}
}
}
else if (vt == (jl_value_t*)jl_module_type) {
// should increase nptr here
MARK(v, bits = gc_setmark(v, sizeof(jl_module_t), GC_MARKED_NOESC));
refyoung |= gc_mark_module((jl_module_t*)v, d);
}
else if (vt == (jl_value_t*)jl_task_type) {
// ditto nptr
MARK(v, bits = gc_setmark(v, sizeof(jl_task_t), GC_MARKED_NOESC));
gc_mark_task((jl_task_t*)v, d);
// tasks should always be remarked since we do not trigger the write barrier
// for stores to stack slots
refyoung = GC_MARKED_NOESC;
}
else if (vt == (jl_value_t*)jl_symbol_type) {
//gc_setmark_other(v, GC_MARKED); // symbols have their own allocator and are never freed
}
// this check should not be needed but it helps catching corruptions early
else if (gc_typeof(vt) == (jl_value_t*)jl_datatype_type) {
jl_datatype_t *dt = (jl_datatype_t*)vt;
size_t dtsz;
if (dt == jl_datatype_type) {
size_t fieldsize =
jl_fielddesc_size(((jl_datatype_t*)v)->fielddesc_type);
dtsz = NWORDS(sizeof(jl_datatype_t) +
jl_datatype_nfields(v) * fieldsize) * sizeof(void*);
} else {
dtsz = jl_datatype_size(dt);
}
MARK(v, bits = gc_setmark(v, dtsz, GC_MARKED_NOESC));
int nf = (int)jl_datatype_nfields(dt);
// TODO check if there is a perf improvement for objects with a lot of fields
// int fdsz = sizeof(void*)*nf;
// void** children = alloca(fdsz);
// int ci = 0;
for(int i=0; i < nf; i++) {
if (jl_field_isptr(dt, i)) {
nptr++;
jl_value_t **slot = (jl_value_t**)((char*)v +
jl_field_offset(dt, i));
jl_value_t *fld = *slot;
if (fld) {
verify_parent2("object", v, slot, "field(%d)", i);
//children[ci++] = fld;
refyoung |= gc_push_root(fld, d);
}
}
}
//while(ci)
// refyoung |= gc_push_root(children[--ci], d);
}
else {
jl_printf(JL_STDOUT, "GC error (probable corruption) :\n");
jl_(vt);
abort();
}
ret:
#ifdef GC_VERIFY
if (verifying) return bits;
#endif
if ((bits == GC_MARKED) && (refyoung == GC_MARKED_NOESC)) {
remset_nptr += nptr;
FOR_CURRENT_HEAP
// v is an old object referencing young objects
arraylist_push(remset, v);
END
}
return bits;
#undef MARK
queue_the_root:
if (mark_sp >= mark_stack_size) grow_mark_stack();
mark_stack[mark_sp++] = (jl_value_t*)v;
max_msp = max_msp > mark_sp ? max_msp : mark_sp;
return bits;
}
static void visit_mark_stack_inc(int mark_mode)
{
while(mark_sp > 0 && !should_timeout()) {
jl_value_t* v = mark_stack[--mark_sp];
assert(gc_bits(jl_astaggedvalue(v)) == GC_QUEUED ||
gc_bits(jl_astaggedvalue(v)) == GC_MARKED ||
gc_bits(jl_astaggedvalue(v)) == GC_MARKED_NOESC);
push_root(v, 0, gc_bits(jl_astaggedvalue(v)));
}
}
static void visit_mark_stack(int mark_mode)
{
int ct = check_timeout;
check_timeout = 0;
visit_mark_stack_inc(mark_mode);
assert(!mark_sp);
check_timeout = ct;
}
void jl_mark_box_caches(void);
extern JL_THREAD jl_value_t * volatile jl_task_arg_in_transit;
#if defined(GCTIME) || defined(GC_FINAL_STATS)
double clock_now(void);
#endif
extern jl_module_t *jl_old_base_module;
extern jl_array_t *jl_module_init_order;
static int inc_count = 0;
static int quick_count = 0;
// mark the initial root set
static void pre_mark(void)
{
// modules
gc_push_root(jl_main_module, 0);
gc_push_root(jl_current_module, 0);
if (jl_old_base_module) gc_push_root(jl_old_base_module, 0);
gc_push_root(jl_internal_main_module, 0);
gc_push_root(jl_root_task, 0);
gc_push_root(jl_current_task, 0);
// invisible builtin values
if (jl_an_empty_cell) gc_push_root(jl_an_empty_cell, 0);
gc_push_root(jl_exception_in_transit, 0);
gc_push_root(jl_task_arg_in_transit, 0);
if (jl_module_init_order != NULL)
gc_push_root(jl_module_init_order, 0);
size_t i;
// stuff randomly preserved
FOR_EACH_HEAP
for(i=0; i < preserved_values.len; i++) {
gc_push_root((jl_value_t*)preserved_values.items[i], 0);
}
END
// objects currently being finalized
for(i=0; i < to_finalize.len; i++) {
gc_push_root(to_finalize.items[i], 0);
}
jl_mark_box_caches();
gc_push_root(jl_unprotect_stack_func, 0);
gc_push_root(jl_bottom_func, 0);
gc_push_root(jl_typetype_type, 0);
// constants
gc_push_root(jl_emptysvec, 0);
gc_push_root(jl_emptytuple, 0);
gc_push_root(jl_typeof(jl_emptytuple), 0);
gc_push_root(jl_true, 0);
gc_push_root(jl_false, 0);
}
static int n_finalized;
// find unmarked objects that need to be finalized from the finalizer list "list".
// this must happen last in the mark phase.
// if dryrun == 1, it does not schedule any actual finalization and only marks finalizers
static void post_mark(arraylist_t *list, int dryrun)
{
n_finalized = 0;
for(size_t i=0; i < list->len; i+=2) {
jl_value_t *v = (jl_value_t*)list->items[i];
jl_value_t *fin = (jl_value_t*)list->items[i+1];
int isfreed = !gc_marked(jl_astaggedvalue(v));
gc_push_root(fin, 0);
int isold = list == &finalizer_list && gc_bits(jl_astaggedvalue(v)) == GC_MARKED && gc_bits(jl_astaggedvalue(fin)) == GC_MARKED;
if (!dryrun && (isfreed || isold)) {
// remove from this list
if (i < list->len - 2) {
list->items[i] = list->items[list->len-2];
list->items[i+1] = list->items[list->len-1];
i -= 2;
}
list->len -= 2;
}
if (isfreed) {
// schedule finalizer or execute right away if it is not julia code
if (gc_typeof(fin) == (jl_value_t*)jl_voidpointer_type) {
void *p = jl_unbox_voidpointer(fin);
if (!dryrun && p)
((void (*)(void*))p)(jl_data_ptr(v));
continue;
}
gc_push_root(v, 0);
if (!dryrun) schedule_finalization(v, fin);
n_finalized++;
}
if (!dryrun && isold) {
arraylist_push(&finalizer_list_marked, v);
arraylist_push(&finalizer_list_marked, fin);
}
}
visit_mark_stack(GC_MARKED_NOESC);
}
// collector entry point and control
static int is_gc_enabled = 1;
DLLEXPORT int jl_gc_enable(int on)
{
int prev = is_gc_enabled;
is_gc_enabled = (on!=0);
return prev;
}
DLLEXPORT int jl_gc_is_enabled(void) { return is_gc_enabled; }
DLLEXPORT int64_t jl_gc_total_bytes(void) { return total_allocd_bytes + allocd_bytes + collect_interval; }
DLLEXPORT uint64_t jl_gc_total_hrtime(void) { return total_gc_time; }
DLLEXPORT GC_Num jl_gc_num(void) { return gc_num; }
DLLEXPORT int64_t jl_gc_diff_total_bytes(void)
{
int64_t oldtb = last_gc_total_bytes;
int64_t newtb = jl_gc_total_bytes();
last_gc_total_bytes = newtb;
return newtb - oldtb;
}
void jl_gc_sync_total_bytes(void) {last_gc_total_bytes = jl_gc_total_bytes();}
#if defined(MEMPROFILE)
static void all_pool_stats(void);
static void big_obj_stats(void);
#endif
#ifdef OBJPROFILE
static void reset_obj_profile()
{
for(int g=0; g < 3; g++) {
htable_reset(&obj_counts[g], 0);
htable_reset(&obj_sizes[g], 0);
}
}
static void print_obj_profile(htable_t nums, htable_t sizes)
{
for(int i=0; i < nums.size; i+=2) {
if (nums.table[i+1] != HT_NOTFOUND) {
void* ty = nums.table[i];
int num = (int)nums.table[i+1] - 1;
size_t sz = (int)ptrhash_get(&sizes, ty) - 1;
jl_printf(JL_STDERR, " %6d : %4d kB of ", num, sz/1024);
if (ty == BUFFTY)
jl_printf(JL_STDERR, "buffer");
else if (ty == MATY)
jl_printf(JL_STDERR, "malloc");
else
jl_static_show(JL_STDERR, (jl_value_t*)ty);
jl_printf(JL_STDERR, "\n");
}
}
}
void print_obj_profiles(void)
{
jl_printf(JL_STDERR, "Transient mark :\n");
print_obj_profile(obj_counts[0], obj_sizes[0]);
jl_printf(JL_STDERR, "Perm mark :\n");
print_obj_profile(obj_counts[1], obj_sizes[1]);
jl_printf(JL_STDERR, "Remset :\n");
print_obj_profile(obj_counts[2], obj_sizes[2]);
}
#endif
#if defined(GC_TIME)
static int saved_mark_sp = 0;
#endif
static int sweep_mask = GC_MARKED;
#define MIN_SCAN_BYTES 1024*1024
static void gc_mark_task_stack(jl_task_t*,int);
void prepare_sweep(void)
{
}
void jl_gc_collect(int full)
{
if (!is_gc_enabled) return;
if (jl_in_gc) return;
char *stack_hi = (char*)gc_get_stack_ptr();
gc_debug_print();
JL_SIGATOMIC_BEGIN();
jl_in_gc = 1;
uint64_t t0 = jl_hrtime();
int recollect = 0;
#if defined(GC_TIME)
int wb_activations = mark_sp - saved_mark_sp;
#endif
int64_t last_perm_scanned_bytes = perm_scanned_bytes;
if (!sweeping) {
inc_count++;
quick_count++;
scanned_bytes_goal = inc_count*(live_bytes/gc_inc_steps + mark_sp*sizeof(void*));
scanned_bytes_goal = scanned_bytes_goal < MIN_SCAN_BYTES ? MIN_SCAN_BYTES : scanned_bytes_goal;
if (gc_inc_steps > 1)
check_timeout = 1;
assert(mark_sp == 0);
// 1. mark every object in the remset
reset_remset();
FOR_EACH_HEAP
// avoid counting remembered objects & bindings twice in perm_scanned_bytes
for(int i = 0; i < last_remset->len; i++) {
jl_value_t *item = (jl_value_t*)last_remset->items[i];
objprofile_count(jl_typeof(item), 2, 0);
gc_bits(jl_astaggedvalue(item)) = GC_MARKED;
}
for (int i = 0; i < rem_bindings.len; i++) {
void *ptr = rem_bindings.items[i];
gc_bits(gc_val_buf(ptr)) = GC_MARKED;
}
for (int i = 0; i < last_remset->len; i++) {
jl_value_t *item = (jl_value_t*)last_remset->items[i];
push_root(item, 0, GC_MARKED);
}
END
// 2. mark every object in a remembered binding
int n_bnd_refyoung = 0;
FOR_EACH_HEAP
for (int i = 0; i < rem_bindings.len; i++) {
jl_binding_t *ptr = (jl_binding_t*)rem_bindings.items[i];
// A null pointer can happen here when the binding is cleaned up
// as an exception is thrown after it was already queued (#10221)
if (!ptr->value) continue;
if (gc_push_root(ptr->value, 0) == GC_MARKED_NOESC) {
rem_bindings.items[n_bnd_refyoung] = ptr;
n_bnd_refyoung++;
}
}
rem_bindings.len = n_bnd_refyoung;
END
// 3. walk roots
pre_mark();
visit_mark_stack(GC_MARKED_NOESC);
allocd_bytes_since_sweep += allocd_bytes + (int64_t)collect_interval;
#if defined(GC_TIME) || defined(GC_FINAL_STATS)
uint64_t mark_pause = jl_hrtime() - t0;
#endif
#ifdef GC_TIME
FOR_EACH_HEAP
jl_printf(JL_STDOUT, "GC mark pause %.2f ms | scanned %ld kB = %ld + %ld | stack %d -> %d (wb %d) | remset %d %d\n", NS2MS(mark_pause), (scanned_bytes + perm_scanned_bytes)/1024, scanned_bytes/1024, perm_scanned_bytes/1024, saved_mark_sp, mark_sp, wb_activations, last_remset->len, remset_nptr);
END
saved_mark_sp = mark_sp;
#endif
#ifdef GC_FINAL_STATS
total_mark_time += mark_pause;
#endif
}
#ifdef GC_TIME
int64_t bonus = -1, SAVE = -1, SAVE2 = -1, SAVE3 = -1, pct = -1;
#endif
int64_t estimate_freed = -1;
#if defined(GC_TIME) || defined(GC_FINAL_STATS)
uint64_t post_time = 0, finalize_time = 0;
#endif
if (mark_sp == 0 || sweeping) {
#if defined(GC_TIME) || defined(GC_FINAL_STATS)
uint64_t sweep_t0 = jl_hrtime();
#endif
int64_t actual_allocd = allocd_bytes_since_sweep;
if (!sweeping) {
// marking is over
#if defined(GC_TIME) || defined(GC_FINAL_STATS)
post_time = jl_hrtime();
#endif
// 4. check for objects to finalize
post_mark(&finalizer_list, 0);
if (prev_sweep_mask == GC_MARKED) {
post_mark(&finalizer_list_marked, 0);
}
#if defined(GC_TIME) || defined(GC_FINAL_STATS)
post_time = jl_hrtime() - post_time;
#endif
estimate_freed = live_bytes - scanned_bytes - perm_scanned_bytes + actual_allocd;
gc_verify();
#if defined(MEMPROFILE)
all_pool_stats();
big_obj_stats();
#endif
#ifdef OBJPROFILE
print_obj_profiles();
reset_obj_profile();
#endif
total_allocd_bytes += allocd_bytes_since_sweep;
if (prev_sweep_mask == GC_MARKED_NOESC)
promoted_bytes += perm_scanned_bytes - last_perm_scanned_bytes;
// 5. next collection decision
int not_freed_enough = estimate_freed < (7*(actual_allocd/10));
int large_frontier = remset_nptr*sizeof(void*) >= default_collect_interval; // many pointers in the intergen frontier => "quick" mark is not quick
if ((full || large_frontier || ((not_freed_enough || promoted_bytes >= collect_interval) && (promoted_bytes >= default_collect_interval || prev_sweep_mask == GC_MARKED))) && n_pause > 1) {
if (prev_sweep_mask != GC_MARKED || full) {
if (full) recollect = 1; // TODO enable this?
}
if (large_frontier)
collect_interval = last_long_collect_interval;
if (not_freed_enough || large_frontier) {
if (collect_interval < default_collect_interval)
collect_interval = default_collect_interval;
else if (collect_interval <= 2*(max_collect_interval/5)) {
collect_interval = 5*(collect_interval/2);
}
}
last_long_collect_interval = collect_interval;
sweep_mask = GC_MARKED;
promoted_bytes = 0;
quick_count = 0;
}
else {
collect_interval = default_collect_interval/2;
#ifdef GC_DEBUG_ENV
sweep_mask = gc_debug_env.sweep_mask;
#else
sweep_mask = GC_MARKED_NOESC;
#endif
}
if (sweep_mask == GC_MARKED)
perm_scanned_bytes = 0;
scanned_bytes = 0;
// 5. start sweeping
sweep_weak_refs();
gc_sweep_once(sweep_mask);
sweeping = 1;
gc_scrub(stack_hi);
}
if (gc_sweep_inc(sweep_mask)) {
// sweeping is over
// 6. if it is a quick sweep, put back the remembered objects in queued state
// so that we don't trigger the barrier again on them.
FOR_EACH_HEAP
if (sweep_mask == GC_MARKED_NOESC) {
for (int i = 0; i < remset->len; i++) {
gc_bits(jl_astaggedvalue(remset->items[i])) = GC_QUEUED;
}
for (int i = 0; i < rem_bindings.len; i++) {
void *ptr = rem_bindings.items[i];
gc_bits(gc_val_buf(ptr)) = GC_QUEUED;
}
}
else {
remset->len = 0;
rem_bindings.len = 0;
n_full_sweep++;
}
END
sweeping = 0;
#ifdef GC_TIME
SAVE2 = freed_bytes;
SAVE3 = allocd_bytes_since_sweep;
pct = actual_allocd ? (freed_bytes*100)/actual_allocd : -1;
#endif
prev_sweep_mask = sweep_mask;
allocd_bytes = -(int64_t)collect_interval;
inc_count = 0;
live_bytes += -freed_bytes + allocd_bytes_since_sweep;
allocd_bytes_since_sweep = 0;
jl_gc_total_freed_bytes += freed_bytes;
freed_bytes = 0;
#if defined(GC_FINAL_STATS) || defined(GC_TIME)
finalize_time = jl_hrtime();
#endif
if (!jl_gc_finalizers_inhibited) {
run_finalizers();
}
#if defined(GC_FINAL_STATS) || defined(GC_TIME)
finalize_time = jl_hrtime() - finalize_time;
#endif
}
#if defined(GC_FINAL_STATS) || defined(GC_TIME)
uint64_t sweep_pause = jl_hrtime() - sweep_t0;
#endif
#ifdef GC_FINAL_STATS
total_sweep_time += sweep_pause - finalize_time - post_time;
total_fin_time += finalize_time + post_time;
#endif
#ifdef GC_TIME
jl_printf(JL_STDOUT, "GC sweep pause %.2f ms live %ld kB (freed %d kB EST %d kB [error %d] = %d%% of allocd %d kB b/r %ld/%ld) (%.2f ms in post_mark, %.2f ms in %d fin) (marked in %d inc) mask %d | next in %d kB\n", NS2MS(sweep_pause), live_bytes/1024, SAVE2/1024, estimate_freed/1024, (SAVE2 - estimate_freed), pct, SAVE3/1024, bonus/1024, SAVE/1024, NS2MS(post_time), NS2MS(finalize_time), n_finalized, inc_count, sweep_mask, -allocd_bytes/1024);
#endif
}
n_pause++;
uint64_t pause = jl_hrtime() - t0;
total_gc_time += pause;
#ifdef GC_FINAL_STATS
max_pause = max_pause < pause ? pause : max_pause;
#endif
jl_in_gc = 0;
JL_SIGATOMIC_END();
#ifdef GC_TIME
if (estimate_freed != SAVE2) {
// this should not happen but it does
// mostly because of gc_counted_* allocations
}
#endif
if (recollect) {
n_pause--;
jl_gc_collect(0);
}
}
// allocator entry points
void *allocb(size_t sz)
{
buff_t *b;
size_t allocsz = sz + sizeof(buff_t);
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
#ifdef MEMDEBUG
b = (buff_t*)alloc_big(allocsz);
b->header = 0x4EADE800;
b->pooled = 0;
#else
if (allocsz > GC_MAX_SZCLASS + sizeof(buff_t)) {
b = (buff_t*)alloc_big(allocsz);
b->header = 0x4EADE800;
b->pooled = 0;
}
else {
b = (buff_t*)pool_alloc(&pools[szclass(allocsz)]);
b->header = 0x4EADE800;
b->pooled = 1;
}
#endif
return &b->data[0];
}
/* this function is horribly broken in that it is unable to fix the bigval_t pointer chain after the realloc
* so it is basically just completely invalid in the bigval_t case
void *reallocb(void *b, size_t sz)
{
buff_t *buff = gc_val_buf(b);
if (buff->pooled) {
void* b2 = allocb(sz);
memcpy(b2, b, page_metadata(buff)->osize);
return b2;
}
else {
size_t allocsz = LLT_ALIGN(sz + sizeof(bigval_t), 16);
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
bigval_t *bv = bigval_header(buff);
bv = (bigval_t*)realloc_a16(bv, allocsz, bv->sz&~3);
if (bv == NULL)
jl_throw(jl_memory_exception);
return &bv->data[0];
}
}
*/
DLLEXPORT jl_value_t *jl_gc_allocobj(size_t sz)
{
size_t allocsz = sz + sizeof_jl_taggedvalue_t;
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
#ifdef MEMDEBUG
return jl_valueof(alloc_big(allocsz));
#endif
if (allocsz <= GC_MAX_SZCLASS + sizeof(buff_t))
return jl_valueof(pool_alloc(&pools[szclass(allocsz)]));
else
return jl_valueof(alloc_big(allocsz));
}
DLLEXPORT jl_value_t *jl_gc_alloc_0w(void)
{
const int sz = sizeof_jl_taggedvalue_t;
#ifdef MEMDEBUG
return jl_valueof(alloc_big(sz));
#endif
return jl_valueof(_pool_alloc(&pools[szclass(sz)], sz));
}
DLLEXPORT jl_value_t *jl_gc_alloc_1w(void)
{
const int sz = LLT_ALIGN(sizeof_jl_taggedvalue_t + sizeof(void*), 16);
#ifdef MEMDEBUG
return jl_valueof(alloc_big(sz));
#endif
return jl_valueof(_pool_alloc(&pools[szclass(sz)], sz));
}
DLLEXPORT jl_value_t *jl_gc_alloc_2w(void)
{
const int sz = LLT_ALIGN(sizeof_jl_taggedvalue_t + sizeof(void*) * 2, 16);
#ifdef MEMDEBUG
return jl_valueof(alloc_big(sz));
#endif
return jl_valueof(_pool_alloc(&pools[szclass(sz)], sz));
}
DLLEXPORT jl_value_t *jl_gc_alloc_3w(void)
{
const int sz = LLT_ALIGN(sizeof_jl_taggedvalue_t + sizeof(void*) * 3, 16);
#ifdef MEMDEBUG
return jl_valueof(alloc_big(sz));
#endif
return jl_valueof(_pool_alloc(&pools[szclass(sz)], sz));
}
#ifdef GC_FINAL_STATS
static double process_t0;
#include <malloc.h>
void jl_print_gc_stats(JL_STREAM *s)
{
double gct = total_gc_time/1e9;
malloc_stats();
double ptime = clock_now()-process_t0;
jl_printf(s, "exec time\t%.5f sec\n", ptime);
if (n_pause > 0) {
jl_printf(s, "gc time \t%.5f sec (%2.1f%%) in %d (%d full) collections\n",
NS_TO_S(total_gc_time), (NS_TO_S(total_gc_time)/ptime)*100, n_pause, n_full_sweep);
jl_printf(s, "gc pause \t%.2f ms avg\n\t\t%2.0f ms max\n",
NS2MS(total_gc_time)/n_pause, NS2MS(max_pause));
jl_printf(s, "\t\t(%2d%% mark, %2d%% sweep, %2d%% finalizers)\n",
(int)(total_mark_time * 100 / total_gc_time),
(int)(total_sweep_time * 100 / total_gc_time),
(int)(total_fin_time * 100 / total_gc_time));
}
int i = 0;
while (i < REGION_COUNT && regions[i]) i++;
jl_printf(s, "max allocated regions : %d\n", i);
struct mallinfo mi = mallinfo();
jl_printf(s, "malloc size\t%d MB\n", mi.uordblks/1024/1024);
jl_printf(s, "max page alloc\t%ld MB\n", max_pg_count*GC_PAGE_SZ/1024/1024);
jl_printf(s, "total freed\t%" PRIuPTR " b\n", jl_gc_total_freed_bytes);
jl_printf(s, "free rate\t%.1f MB/sec\n", (jl_gc_total_freed_bytes/gct)/1024/1024);
}
#endif
// Per-thread initialization (when threading is fully implemented)
static void jl_mk_thread_heap(void) {
FOR_CURRENT_HEAP
const int* szc = sizeclasses;
pool_t *p = HEAP(norm_pools);
for(int i=0; i < N_POOLS; i++) {
assert((szc[i] < 16 && szc[i] % sizeof(void*) == 0) ||
(szc[i] % 16 == 0));
p[i].osize = szc[i];
p[i].freelist = NULL;
p[i].newpages = NULL;
p[i].end_offset = GC_POOL_END_OFS(szc[i]);
}
arraylist_new(&preserved_values, 0);
arraylist_new(&weak_refs, 0);
mallocarrays = NULL;
mafreelist = NULL;
big_objects = NULL;
arraylist_new(&rem_bindings, 0);
remset = &HEAP(_remset)[0];
last_remset = &HEAP(_remset)[1];
arraylist_new(remset, 0);
arraylist_new(last_remset, 0);
END
}
// System-wide initializations
void jl_gc_init(void)
{
gc_debug_init();
jl_mk_thread_heap();
arraylist_new(&finalizer_list, 0);
arraylist_new(&finalizer_list_marked, 0);
arraylist_new(&to_finalize, 0);
collect_interval = default_collect_interval;
last_long_collect_interval = default_collect_interval;
allocd_bytes = -default_collect_interval;
#ifdef GC_VERIFY
for(int i = 0; i < 4; i++)
arraylist_new(&bits_save[i], 0);
arraylist_new(&lostval_parents, 0);
arraylist_new(&lostval_parents_done, 0);
#endif
#ifdef OBJPROFILE
for(int g=0; g<3; g++) {
htable_new(&obj_counts[g], 0);
htable_new(&obj_sizes[g], 0);
}
#endif
#ifdef GC_FINAL_STATS
process_t0 = clock_now();
#endif
#ifdef _P64
// on a big memory machine, set max_collect_interval to totalmem/ncores/2
size_t maxmem = (uv_get_total_memory()/jl_cpu_cores())/2;
if (maxmem > max_collect_interval)
max_collect_interval = maxmem;
#endif
}
// GC summary stats
#if defined(MEMPROFILE)
// TODO repair this
static size_t pool_stats(pool_t *p, size_t *pwaste, size_t *np, size_t *pnold)
{
gcval_t *v;
gcpage_t *pg = p->pages;
size_t osize = p->osize;
size_t nused=0, nfree=0, npgs=0, nold = 0;
while (pg != NULL) {
npgs++;
v = (gcval_t*)(pg->data + GC_PAGE_OFFSET);
char *lim = (char*)v + GC_PAGE_SZ - GC_PAGE_OFFSET - osize;
int i = 0;
while ((char*)v <= lim) {
if (!gc_marked(v)) {
nfree++;
}
else {
nused++;
if (gc_bits(v) == GC_MARKED) {
nold++;
}
}
v = (gcval_t*)((char*)v + osize);
i++;
}
gcpage_t *nextpg = NULL;
pg = nextpg;
}
*pwaste = npgs * GC_PAGE_SZ - (nused * p->osize);
*np = npgs;
*pnold = nold;
if (npgs != 0) {
jl_printf(JL_STDOUT,
"%4d : %7d/%7d objects (%3d%% old), %5d pages, %5d kB, %5d kB waste\n",
p->osize,
nused,
nused+nfree,
nused ? (nold*100)/nused : 0,
npgs,
(nused*p->osize)/1024,
*pwaste/1024);
}
return nused*p->osize;
}
static void all_pool_stats(void)
{
int i;
size_t nb=0, w, tw=0, no=0,tp=0, nold=0,noldbytes=0, b, np, nol;
for(i=0; i < N_POOLS; i++) {
b = pool_stats(&norm_pools[i], &w, &np, &nol);
nb += b;
no += (b/norm_pools[i].osize);
tw += w;
tp += np;
nold += nol;
noldbytes += nol*norm_pools[i].osize;
}
jl_printf(JL_STDOUT,
"%d objects (%d%% old), %d kB (%d%% old) total allocated, %d total fragments (%d%% overhead), in %d pages\n",
no, (nold*100)/no, nb/1024, (noldbytes*100)/nb, tw, (tw*100)/nb, tp);
}
static void big_obj_stats(void)
{
bigval_t *v = big_objects;
size_t nused=0, nbytes=0;
while (v != NULL) {
if (gc_marked(&v->_data)) {
nused++;
nbytes += v->sz&~3;
}
v = v->next;
}
v = big_objects_marked;
size_t nused_old=0, nbytes_old=0;
while (v != NULL) {
if (gc_marked(&v->_data)) {
nused_old++;
nbytes_old += v->sz&~3;
}
v = v->next;
}
mallocarray_t *ma = mallocarrays;
while (ma != NULL) {
if (gc_marked(jl_astaggedvalue(ma->a))) {
nused++;
nbytes += array_nbytes(ma->a);
}
ma = ma->next;
}
jl_printf(JL_STDOUT, "%d kB (%d%% old) in %d large objects (%d%% old)\n", (nbytes + nbytes_old)/1024, nbytes + nbytes_old ? (nbytes_old*100)/(nbytes + nbytes_old) : 0, nused + nused_old, nused+nused_old ? (nused_old*100)/(nused + nused_old) : 0);
}
#endif //MEMPROFILE
DLLEXPORT void *jl_gc_counted_malloc(size_t sz)
{
maybe_collect();
allocd_bytes += sz;
gc_num.malloc++;
void *b = malloc(sz);
if (b == NULL)
jl_throw(jl_memory_exception);
return b;
}
DLLEXPORT void *jl_gc_counted_calloc(size_t nm, size_t sz)
{
maybe_collect();
allocd_bytes += nm*sz;
gc_num.malloc++;
void *b = calloc(nm, sz);
if (b == NULL)
jl_throw(jl_memory_exception);
return b;
}
DLLEXPORT void jl_gc_counted_free(void *p, size_t sz)
{
free(p);
freed_bytes += sz;
gc_num.freecall++;
}
DLLEXPORT void *jl_gc_counted_realloc_with_old_size(void *p, size_t old, size_t sz)
{
maybe_collect();
if (sz < old)
freed_bytes += (old - sz);
else
allocd_bytes += (sz - old);
gc_num.realloc++;
void *b = realloc(p, sz);
if (b == NULL)
jl_throw(jl_memory_exception);
return b;
}
DLLEXPORT void *jl_malloc(size_t sz)
{
int64_t *p = (int64_t *)jl_gc_counted_malloc(sz + 16);
p[0] = sz;
return (void *)(p + 2);
}
DLLEXPORT void *jl_calloc(size_t nm, size_t sz)
{
int64_t *p;
size_t nmsz = nm*sz;
p = (int64_t *)jl_gc_counted_calloc(nmsz + 16, 1);
p[0] = nmsz;
return (void *)(p + 2);
}
DLLEXPORT void jl_free(void *p)
{
int64_t *pp = (int64_t *)p - 2;
size_t sz = pp[0];
jl_gc_counted_free(pp, sz + 16);
}
DLLEXPORT void *jl_realloc(void *p, size_t sz)
{
int64_t *pp = (int64_t *)p - 2;
size_t szold = pp[0];
int64_t *pnew = (int64_t *)jl_gc_counted_realloc_with_old_size(pp, szold + 16, sz + 16);
pnew[0] = sz;
return (void *)(pnew + 2);
}
DLLEXPORT void *jl_gc_managed_malloc(size_t sz)
{
maybe_collect();
size_t allocsz = LLT_ALIGN(sz, 16);
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
allocd_bytes += allocsz;
gc_num.malloc++;
void *b = malloc_a16(allocsz);
if (b == NULL)
jl_throw(jl_memory_exception);
return b;
}
DLLEXPORT void *jl_gc_managed_realloc(void *d, size_t sz, size_t oldsz, int isaligned, jl_value_t* owner)
{
maybe_collect();
size_t allocsz = LLT_ALIGN(sz, 16);
if (allocsz < sz) // overflow in adding offs, size was "negative"
jl_throw(jl_memory_exception);
if (gc_bits(jl_astaggedvalue(owner)) == GC_MARKED) {
perm_scanned_bytes += allocsz - oldsz;
live_bytes += allocsz - oldsz;
}
else if (allocsz < oldsz)
freed_bytes += (oldsz - allocsz);
else
allocd_bytes += (allocsz - oldsz);
gc_num.realloc++;
void *b;
if (isaligned)
b = realloc_a16(d, allocsz, oldsz);
else
b = realloc(d, allocsz);
if (b == NULL)
jl_throw(jl_memory_exception);
return b;
}
#ifdef __cplusplus
}
#endif
