1 /******************************************************************************/
2 #ifdef JEMALLOC_H_TYPES
4 typedef struct tcache_bin_info_s tcache_bin_info_t;
5 typedef struct tcache_bin_s tcache_bin_t;
6 typedef struct tcache_s tcache_t;
7 typedef struct tcaches_s tcaches_t;
10 * tcache pointers close to NULL are used to encode state information that is
11 * used for two purposes: preventing thread caching on a per thread basis and
12 * cleaning up during thread shutdown.
14 #define TCACHE_STATE_DISABLED ((tcache_t *)(uintptr_t)1)
15 #define TCACHE_STATE_REINCARNATED ((tcache_t *)(uintptr_t)2)
16 #define TCACHE_STATE_PURGATORY ((tcache_t *)(uintptr_t)3)
17 #define TCACHE_STATE_MAX TCACHE_STATE_PURGATORY
20 * Absolute minimum number of cache slots for each small bin.
22 #define TCACHE_NSLOTS_SMALL_MIN 20
25 * Absolute maximum number of cache slots for each small bin in the thread
26 * cache. This is an additional constraint beyond that imposed as: twice the
27 * number of regions per run for this size class.
29 * This constant must be an even number.
31 #define TCACHE_NSLOTS_SMALL_MAX 200
33 /* Number of cache slots for large size classes. */
34 #define TCACHE_NSLOTS_LARGE 20
36 /* (1U << opt_lg_tcache_max) is used to compute tcache_maxclass. */
37 #define LG_TCACHE_MAXCLASS_DEFAULT 15
40 * TCACHE_GC_SWEEP is the approximate number of allocation events between
41 * full GC sweeps. Integer rounding may cause the actual number to be
42 * slightly higher, since GC is performed incrementally.
44 #define TCACHE_GC_SWEEP 8192
46 /* Number of tcache allocation/deallocation events between incremental GCs. */
47 #define TCACHE_GC_INCR \
48 ((TCACHE_GC_SWEEP / NBINS) + ((TCACHE_GC_SWEEP / NBINS == 0) ? 0 : 1))
50 #endif /* JEMALLOC_H_TYPES */
51 /******************************************************************************/
52 #ifdef JEMALLOC_H_STRUCTS
55 tcache_enabled_false = 0, /* Enable cast to/from bool. */
56 tcache_enabled_true = 1,
57 tcache_enabled_default = 2
61 * Read-only information associated with each element of tcache_t's tbins array
62 * is stored separately, mainly to reduce memory usage.
64 struct tcache_bin_info_s {
65 unsigned ncached_max; /* Upper limit on ncached. */
69 tcache_bin_stats_t tstats;
70 int low_water; /* Min # cached since last GC. */
71 unsigned lg_fill_div; /* Fill (ncached_max >> lg_fill_div). */
72 unsigned ncached; /* # of cached objects. */
74 * To make use of adjacent cacheline prefetch, the items in the avail
75 * stack goes to higher address for newer allocations. avail points
76 * just above the available space, which means that
77 * avail[-ncached, ... -1] are available items and the lowest item will
80 void **avail; /* Stack of available objects. */
84 ql_elm(tcache_t) link; /* Used for aggregating stats. */
85 uint64_t prof_accumbytes;/* Cleared after arena_prof_accum(). */
86 ticker_t gc_ticker; /* Drives incremental GC. */
87 szind_t next_gc_bin; /* Next bin to GC. */
88 tcache_bin_t tbins[1]; /* Dynamically sized. */
90 * The pointer stacks associated with tbins follow as a contiguous
91 * array. During tcache initialization, the avail pointer in each
92 * element of tbins is initialized to point to the proper offset within
97 /* Linkage for list of available (previously used) explicit tcache IDs. */
105 #endif /* JEMALLOC_H_STRUCTS */
106 /******************************************************************************/
107 #ifdef JEMALLOC_H_EXTERNS
109 extern bool opt_tcache;
110 extern ssize_t opt_lg_tcache_max;
112 extern tcache_bin_info_t *tcache_bin_info;
115 * Number of tcache bins. There are NBINS small-object bins, plus 0 or more
118 extern unsigned nhbins;
120 /* Maximum cached size class. */
121 extern size_t tcache_maxclass;
124 * Explicit tcaches, managed via the tcache.{create,flush,destroy} mallctls and
125 * usable via the MALLOCX_TCACHE() flag. The automatic per thread tcaches are
126 * completely disjoint from this data structure. tcaches starts off as a sparse
127 * array, so it has no physical memory footprint until individual pages are
128 * touched. This allows the entire array to be allocated the first time an
129 * explicit tcache is created without a disproportionate impact on memory usage.
131 extern tcaches_t *tcaches;
133 size_t tcache_salloc(const void *ptr);
134 void tcache_event_hard(tsd_t *tsd, tcache_t *tcache);
135 void *tcache_alloc_small_hard(tsd_t *tsd, arena_t *arena, tcache_t *tcache,
136 tcache_bin_t *tbin, szind_t binind, bool *tcache_success);
137 void tcache_bin_flush_small(tsd_t *tsd, tcache_t *tcache, tcache_bin_t *tbin,
138 szind_t binind, unsigned rem);
139 void tcache_bin_flush_large(tsd_t *tsd, tcache_bin_t *tbin, szind_t binind,
140 unsigned rem, tcache_t *tcache);
141 void tcache_arena_associate(tcache_t *tcache, arena_t *arena);
142 void tcache_arena_reassociate(tcache_t *tcache, arena_t *oldarena,
144 void tcache_arena_dissociate(tcache_t *tcache, arena_t *arena);
145 tcache_t *tcache_get_hard(tsd_t *tsd);
146 tcache_t *tcache_create(tsd_t *tsd, arena_t *arena);
147 void tcache_cleanup(tsd_t *tsd);
148 void tcache_enabled_cleanup(tsd_t *tsd);
149 void tcache_stats_merge(tcache_t *tcache, arena_t *arena);
150 bool tcaches_create(tsd_t *tsd, unsigned *r_ind);
151 void tcaches_flush(tsd_t *tsd, unsigned ind);
152 void tcaches_destroy(tsd_t *tsd, unsigned ind);
153 bool tcache_boot(void);
155 #endif /* JEMALLOC_H_EXTERNS */
156 /******************************************************************************/
157 #ifdef JEMALLOC_H_INLINES
159 #ifndef JEMALLOC_ENABLE_INLINE
160 void tcache_event(tsd_t *tsd, tcache_t *tcache);
161 void tcache_flush(void);
162 bool tcache_enabled_get(void);
163 tcache_t *tcache_get(tsd_t *tsd, bool create);
164 void tcache_enabled_set(bool enabled);
165 void *tcache_alloc_easy(tcache_bin_t *tbin, bool *tcache_success);
166 void *tcache_alloc_small(tsd_t *tsd, arena_t *arena, tcache_t *tcache,
167 size_t size, szind_t ind, bool zero, bool slow_path);
168 void *tcache_alloc_large(tsd_t *tsd, arena_t *arena, tcache_t *tcache,
169 size_t size, szind_t ind, bool zero, bool slow_path);
170 void tcache_dalloc_small(tsd_t *tsd, tcache_t *tcache, void *ptr,
171 szind_t binind, bool slow_path);
172 void tcache_dalloc_large(tsd_t *tsd, tcache_t *tcache, void *ptr,
173 size_t size, bool slow_path);
174 tcache_t *tcaches_get(tsd_t *tsd, unsigned ind);
177 #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_TCACHE_C_))
183 cassert(config_tcache);
190 tcache_enabled_get(void)
193 tcache_enabled_t tcache_enabled;
195 cassert(config_tcache);
198 tcache_enabled = tsd_tcache_enabled_get(tsd);
199 if (tcache_enabled == tcache_enabled_default) {
200 tcache_enabled = (tcache_enabled_t)opt_tcache;
201 tsd_tcache_enabled_set(tsd, tcache_enabled);
204 return ((bool)tcache_enabled);
208 tcache_enabled_set(bool enabled)
211 tcache_enabled_t tcache_enabled;
213 cassert(config_tcache);
217 tcache_enabled = (tcache_enabled_t)enabled;
218 tsd_tcache_enabled_set(tsd, tcache_enabled);
224 JEMALLOC_ALWAYS_INLINE tcache_t *
225 tcache_get(tsd_t *tsd, bool create)
232 tcache = tsd_tcache_get(tsd);
235 if (unlikely(tcache == NULL) && tsd_nominal(tsd)) {
236 tcache = tcache_get_hard(tsd);
237 tsd_tcache_set(tsd, tcache);
243 JEMALLOC_ALWAYS_INLINE void
244 tcache_event(tsd_t *tsd, tcache_t *tcache)
247 if (TCACHE_GC_INCR == 0)
250 if (unlikely(ticker_tick(&tcache->gc_ticker)))
251 tcache_event_hard(tsd, tcache);
254 JEMALLOC_ALWAYS_INLINE void *
255 tcache_alloc_easy(tcache_bin_t *tbin, bool *tcache_success)
259 if (unlikely(tbin->ncached == 0)) {
260 tbin->low_water = -1;
261 *tcache_success = false;
265 * tcache_success (instead of ret) should be checked upon the return of
266 * this function. We avoid checking (ret == NULL) because there is
267 * never a null stored on the avail stack (which is unknown to the
268 * compiler), and eagerly checking ret would cause pipeline stall
269 * (waiting for the cacheline).
271 *tcache_success = true;
272 ret = *(tbin->avail - tbin->ncached);
275 if (unlikely((int)tbin->ncached < tbin->low_water))
276 tbin->low_water = tbin->ncached;
281 JEMALLOC_ALWAYS_INLINE void *
282 tcache_alloc_small(tsd_t *tsd, arena_t *arena, tcache_t *tcache, size_t size,
283 szind_t binind, bool zero, bool slow_path)
288 size_t usize JEMALLOC_CC_SILENCE_INIT(0);
290 assert(binind < NBINS);
291 tbin = &tcache->tbins[binind];
292 ret = tcache_alloc_easy(tbin, &tcache_success);
293 assert(tcache_success == (ret != NULL));
294 if (unlikely(!tcache_success)) {
295 bool tcache_hard_success;
296 arena = arena_choose(tsd, arena);
297 if (unlikely(arena == NULL))
300 ret = tcache_alloc_small_hard(tsd, arena, tcache, tbin, binind,
301 &tcache_hard_success);
302 if (tcache_hard_success == false)
308 * Only compute usize if required. The checks in the following if
309 * statement are all static.
311 if (config_prof || (slow_path && config_fill) || unlikely(zero)) {
312 usize = index2size(binind);
313 assert(tcache_salloc(ret) == usize);
317 if (slow_path && config_fill) {
318 if (unlikely(opt_junk_alloc)) {
319 arena_alloc_junk_small(ret,
320 &arena_bin_info[binind], false);
321 } else if (unlikely(opt_zero))
322 memset(ret, 0, usize);
325 if (slow_path && config_fill && unlikely(opt_junk_alloc)) {
326 arena_alloc_junk_small(ret, &arena_bin_info[binind],
329 memset(ret, 0, usize);
333 tbin->tstats.nrequests++;
335 tcache->prof_accumbytes += usize;
336 tcache_event(tsd, tcache);
340 JEMALLOC_ALWAYS_INLINE void *
341 tcache_alloc_large(tsd_t *tsd, arena_t *arena, tcache_t *tcache, size_t size,
342 szind_t binind, bool zero, bool slow_path)
348 assert(binind < nhbins);
349 tbin = &tcache->tbins[binind];
350 ret = tcache_alloc_easy(tbin, &tcache_success);
351 assert(tcache_success == (ret != NULL));
352 if (unlikely(!tcache_success)) {
354 * Only allocate one large object at a time, because it's quite
355 * expensive to create one and not use it.
357 arena = arena_choose(tsd, arena);
358 if (unlikely(arena == NULL))
361 ret = arena_malloc_large(tsd, arena, binind, zero);
365 size_t usize JEMALLOC_CC_SILENCE_INIT(0);
367 /* Only compute usize on demand */
368 if (config_prof || (slow_path && config_fill) ||
370 usize = index2size(binind);
371 assert(usize <= tcache_maxclass);
374 if (config_prof && usize == LARGE_MINCLASS) {
375 arena_chunk_t *chunk =
376 (arena_chunk_t *)CHUNK_ADDR2BASE(ret);
377 size_t pageind = (((uintptr_t)ret - (uintptr_t)chunk) >>
379 arena_mapbits_large_binind_set(chunk, pageind,
383 if (slow_path && config_fill) {
384 if (unlikely(opt_junk_alloc))
385 memset(ret, 0xa5, usize);
386 else if (unlikely(opt_zero))
387 memset(ret, 0, usize);
390 memset(ret, 0, usize);
393 tbin->tstats.nrequests++;
395 tcache->prof_accumbytes += usize;
398 tcache_event(tsd, tcache);
402 JEMALLOC_ALWAYS_INLINE void
403 tcache_dalloc_small(tsd_t *tsd, tcache_t *tcache, void *ptr, szind_t binind,
407 tcache_bin_info_t *tbin_info;
409 assert(tcache_salloc(ptr) <= SMALL_MAXCLASS);
411 if (slow_path && config_fill && unlikely(opt_junk_free))
412 arena_dalloc_junk_small(ptr, &arena_bin_info[binind]);
414 tbin = &tcache->tbins[binind];
415 tbin_info = &tcache_bin_info[binind];
416 if (unlikely(tbin->ncached == tbin_info->ncached_max)) {
417 tcache_bin_flush_small(tsd, tcache, tbin, binind,
418 (tbin_info->ncached_max >> 1));
420 assert(tbin->ncached < tbin_info->ncached_max);
422 *(tbin->avail - tbin->ncached) = ptr;
424 tcache_event(tsd, tcache);
427 JEMALLOC_ALWAYS_INLINE void
428 tcache_dalloc_large(tsd_t *tsd, tcache_t *tcache, void *ptr, size_t size,
433 tcache_bin_info_t *tbin_info;
435 assert((size & PAGE_MASK) == 0);
436 assert(tcache_salloc(ptr) > SMALL_MAXCLASS);
437 assert(tcache_salloc(ptr) <= tcache_maxclass);
439 binind = size2index(size);
441 if (slow_path && config_fill && unlikely(opt_junk_free))
442 arena_dalloc_junk_large(ptr, size);
444 tbin = &tcache->tbins[binind];
445 tbin_info = &tcache_bin_info[binind];
446 if (unlikely(tbin->ncached == tbin_info->ncached_max)) {
447 tcache_bin_flush_large(tsd, tbin, binind,
448 (tbin_info->ncached_max >> 1), tcache);
450 assert(tbin->ncached < tbin_info->ncached_max);
452 *(tbin->avail - tbin->ncached) = ptr;
454 tcache_event(tsd, tcache);
457 JEMALLOC_ALWAYS_INLINE tcache_t *
458 tcaches_get(tsd_t *tsd, unsigned ind)
460 tcaches_t *elm = &tcaches[ind];
461 if (unlikely(elm->tcache == NULL))
462 elm->tcache = tcache_create(tsd, arena_choose(tsd, NULL));
463 return (elm->tcache);
467 #endif /* JEMALLOC_H_INLINES */
468 /******************************************************************************/