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Refactor prng to not use 64-bit atomics on 32-bit platforms.

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This resolves #495.
This commit is contained in:
Jason Evans 2016-11-07 10:52:44 -08:00
parent a4e83e8593
commit 5d6cb6eb66
7 changed files with 365 additions and 33 deletions
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7
src/arena.c
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@ -1199,7 +1199,7 @@ arena_decay_deadline_init(arena_t *arena)
if (arena->decay.time > 0) {
nstime_t jitter;
nstime_init(&jitter, prng_range(&arena->decay.jitter_state,
nstime_init(&jitter, prng_range_u64(&arena->decay.jitter_state,
nstime_ns(&arena->decay.interval)));
nstime_add(&arena->decay.deadline, &jitter);
}
@ -2565,7 +2565,8 @@ arena_malloc_large(tsdn_t *tsdn, arena_t *arena, szind_t binind, bool zero)
* that is a multiple of the cacheline size, e.g. [0 .. 63) * 64
* for 4 KiB pages and 64-byte cachelines.
*/
r = prng_lg_range(&arena->offset_state, LG_PAGE - LG_CACHELINE);
r = prng_lg_range_zu(&arena->offset_state, LG_PAGE -
LG_CACHELINE, false);
random_offset = ((uintptr_t)r) << LG_CACHELINE;
} else
random_offset = 0;
@ -3503,7 +3504,7 @@ arena_new(tsdn_t *tsdn, unsigned ind)
* deterministic seed.
*/
arena->offset_state = config_debug ? ind :
(uint64_t)(uintptr_t)arena;
(size_t)(uintptr_t)arena;
}
arena->dss_prec = chunk_dss_prec_get();

5
src/ckh.c
View file

@ -99,7 +99,8 @@ ckh_try_bucket_insert(ckh_t *ckh, size_t bucket, const void *key,
* Cycle through the cells in the bucket, starting at a random position.
* The randomness avoids worst-case search overhead as buckets fill up.
*/
offset = (unsigned)prng_lg_range(&ckh->prng_state, LG_CKH_BUCKET_CELLS);
offset = (unsigned)prng_lg_range_u64(&ckh->prng_state,
LG_CKH_BUCKET_CELLS);
for (i = 0; i < (ZU(1) << LG_CKH_BUCKET_CELLS); i++) {
cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) +
((i + offset) & ((ZU(1) << LG_CKH_BUCKET_CELLS) - 1))];
@ -141,7 +142,7 @@ ckh_evict_reloc_insert(ckh_t *ckh, size_t argbucket, void const **argkey,
* were an item for which both hashes indicated the same
* bucket.
*/
i = (unsigned)prng_lg_range(&ckh->prng_state,
i = (unsigned)prng_lg_range_u64(&ckh->prng_state,
LG_CKH_BUCKET_CELLS);
cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) + i];
assert(cell->key != NULL);

2
src/prof.c
View file

@ -874,7 +874,7 @@ prof_sample_threshold_update(prof_tdata_t *tdata)
* pp 500
* (http://luc.devroye.org/rnbookindex.html)
*/
r = prng_lg_range(&tdata->prng_state, 53);
r = prng_lg_range_u64(&tdata->prng_state, 53);
u = (double)r * (1.0/9007199254740992.0L);
tdata->bytes_until_sample = (uint64_t)(log(u) /
log(1.0 - (1.0 / (double)((uint64_t)1U << lg_prof_sample))))