diff options
| -rw-r--r-- | src/include/txn.h | 2 | ||||
| -rw-r--r-- | src/include/txn.i | 15 | ||||
| -rw-r--r-- | src/txn/txn.c | 11 |
3 files changed, 13 insertions, 15 deletions
diff --git a/src/include/txn.h b/src/include/txn.h index 634363b9216..9f9f282bfa4 100644 --- a/src/include/txn.h +++ b/src/include/txn.h @@ -34,7 +34,7 @@ struct WT_COMPILER_TYPE_ALIGN(WT_CACHE_LINE_ALIGNMENT) __wt_txn_state { }; struct __wt_txn_global { - uint64_t alloc; /* Transaction ID to allocate. */ + WT_SPINLOCK id_lock; volatile uint64_t current; /* Current transaction ID. */ /* The oldest running transaction ID (may race). */ diff --git a/src/include/txn.i b/src/include/txn.i index ceea2e4b581..d7d958e801e 100644 --- a/src/include/txn.i +++ b/src/include/txn.i @@ -314,7 +314,6 @@ __wt_txn_id_alloc(WT_SESSION_IMPL *session, bool publish) { WT_TXN_GLOBAL *txn_global; uint64_t id; - u_int i; txn_global = &S2C(session)->txn_global; @@ -341,20 +340,16 @@ __wt_txn_id_alloc(WT_SESSION_IMPL *session, bool publish) * global current ID, so we want post-increment semantics. Our atomic * add primitive does pre-increment, so adjust the result here. */ - id = __wt_atomic_addv64(&S2C(session)->txn_global.alloc, 1) - 1; + __wt_spin_lock(session, &txn_global->id_lock); + id = txn_global->current; if (publish) { session->txn.id = id; - WT_SESSION_TXN_STATE(session)->id = id; + WT_PUBLISH(WT_SESSION_TXN_STATE(session)->id, id); } - for (i = 0; txn_global->current != id; i++) - if (i < 100) - WT_PAUSE(); - else - __wt_yield(); - - WT_PUBLISH(txn_global->current, id + 1); + ++txn_global->current; + __wt_spin_unlock(session, &txn_global->id_lock); return (id); } diff --git a/src/txn/txn.c b/src/txn/txn.c index f89a8ae1b53..f9af9589172 100644 --- a/src/txn/txn.c +++ b/src/txn/txn.c @@ -594,8 +594,11 @@ __wt_txn_global_init(WT_SESSION_IMPL *session, const char *cfg[]) conn = S2C(session); txn_global = &conn->txn_global; - txn_global->alloc = txn_global->current = - txn_global->last_running = txn_global->oldest_id = WT_TXN_FIRST; + txn_global->current = txn_global->last_running = + txn_global->oldest_id = WT_TXN_FIRST; + + WT_RET(__wt_spin_init(session, + &txn_global->id_lock, "transaction id lock")); WT_RET(__wt_calloc_def( session, conn->session_size, &txn_global->states)); @@ -618,6 +621,6 @@ __wt_txn_global_destroy(WT_SESSION_IMPL *session) conn = S2C(session); txn_global = &conn->txn_global; - if (txn_global != NULL) - __wt_free(session, txn_global->states); + __wt_spin_destroy(session, &txn_global->id_lock); + __wt_free(session, txn_global->states); } |