ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2025-01-06 19:14:14 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx: simplify safe64_reset().

Browse Source
This commit is contained in:
Леонид Юрьев (Leonid Yuriev) 2022-07-08 22:04:37 +03:00
parent ad5a83586b
commit baea4c81c9
1 changed files with 19 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
src/core.c
View File

@ -1086,40 +1086,34 @@ static __always_inline uint64_t safe64_txnid_next(uint64_t txnid) {
return txnid; return txnid;
} }
#if defined(MDBX_HAVE_C11ATOMICS) && defined(__LCC__) /* Atomically make target value >= SAFE64_INVALID_THRESHOLD */
#define safe64_reset(p, single_writer) \
atomic_store64(p, UINT64_MAX, \
(single_writer) ? mo_AcquireRelease \
: mo_SequentialConsistency)
#else
static __always_inline void safe64_reset(MDBX_atomic_uint64_t *p, static __always_inline void safe64_reset(MDBX_atomic_uint64_t *p,
bool single_writer) { bool single_writer) {
#if !MDBX_64BIT_CAS if (single_writer) {
if (!single_writer) { #if MDBX_64BIT_ATOMIC && MDBX_WORDBITS >= 64
STATIC_ASSERT(xMDBX_TXNID_STEP > 1); atomic_store64(p, UINT64_MAX, mo_AcquireRelease);
#else
atomic_store32(&p->high, UINT32_MAX, mo_AcquireRelease);
#endif /* MDBX_64BIT_ATOMIC && MDBX_WORDBITS >= 64 */
} else {
#if MDBX_64BIT_CAS && MDBX_64BIT_ATOMIC
/* atomically make value >= SAFE64_INVALID_THRESHOLD by 64-bit operation */
atomic_store64(p, UINT64_MAX, mo_SequentialConsistency);
#elif MDBX_64BIT_CAS
/* atomically make value >= SAFE64_INVALID_THRESHOLD by 32-bit operation */
atomic_store32(&p->high, UINT32_MAX, mo_SequentialConsistency);
#else
/* it is safe to increment low-part to avoid ABA, since xMDBX_TXNID_STEP > 1 /* it is safe to increment low-part to avoid ABA, since xMDBX_TXNID_STEP > 1
* and overflow was preserved in safe64_txnid_next() */ * and overflow was preserved in safe64_txnid_next() */
STATIC_ASSERT(xMDBX_TXNID_STEP > 1);
atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */; atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */;
atomic_store32( atomic_store32(&p->high, UINT32_MAX, mo_SequentialConsistency);
&p->high, UINT32_MAX,
mo_Relaxed) /* atomically make >= SAFE64_INVALID_THRESHOLD */;
atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */; atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */;
} else #endif /* MDBX_64BIT_CAS && MDBX_64BIT_ATOMIC */
#endif /* !MDBX_64BIT_CAS */ }
#if MDBX_64BIT_ATOMIC
/* atomically make value >= SAFE64_INVALID_THRESHOLD by 64-bit operation */
atomic_store64(p, UINT64_MAX,
single_writer ? mo_AcquireRelease
: mo_SequentialConsistency);
#else
/* atomically make value >= SAFE64_INVALID_THRESHOLD by 32-bit operation */
atomic_store32(&p->high, UINT32_MAX,
single_writer ? mo_AcquireRelease : mo_SequentialConsistency);
#endif /* MDBX_64BIT_ATOMIC */
assert(p->weak >= SAFE64_INVALID_THRESHOLD); assert(p->weak >= SAFE64_INVALID_THRESHOLD);
mdbx_jitter4testing(true); mdbx_jitter4testing(true);
} }
#endif /* LCC && MDBX_HAVE_C11ATOMICS */
static __always_inline bool safe64_reset_compare(MDBX_atomic_uint64_t *p, static __always_inline bool safe64_reset_compare(MDBX_atomic_uint64_t *p,
txnid_t compare) { txnid_t compare) {