static inline void
sx_garbage_collect(sxmanager *m)
{
uint64_t min_csn = sx_csn(m);
sxv *gc = NULL;
uint32_t count = 0;
sxv *next;
sxv *v = m->gc;
for (; v; v = next)
{
next = v->gc;
assert(v->v->flags & SVGET);
assert(sx_vcommitted(v));
if (v->csn > min_csn) {
v->gc = gc;
gc = v;
count++;
continue;
}
sx_untrack(v);
sx_vfree(m->r, m->asxv, v);
}
m->count_gc = count;
m->gc = gc;
}
sxstate sx_commit(sx *x)
{
if (x->state == SX_COMMIT)
return SX_COMMIT;
assert(x->state == SX_PREPARE);
sxmanager *m = x->manager;
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log->buf, sizeof(svlogv));
uint64_t csn = ++m->csn;
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
sxv *v = lv->ptr;
if ((int)v->lo == x->log_read)
break;
/* abort conflict reader */
if (v->prev && !sx_vcommitted(v->prev)) {
sxindex *i = v->prev->index;
assert(sv_vflags(v->prev->v, i->r) & SVGET);
sx_vabort(v->prev);
}
/* abort waiters */
sx_vabort_all(v->next);
/* mark stmt as commited */
sx_vcommit(v, csn);
lv->ptr = NULL;
/* schedule read stmt for gc */
sxindex *i = v->index;
if (sv_vflags(v->v, i->r) & SVGET) {
sv_vref(v->v);
v->gc = m->gc;
m->gc = v;
m->count_gc++;
} else {
sx_untrack(v);
sx_vpool_push(&m->pool, v);
}
}
/* rollback latest reads */
sx_rollback_svp(x, &i, 0);
sx_promote(x, SX_COMMIT);
sx_end(x);
return SX_COMMIT;
}
sxstate sx_commit(sx *x)
{
assert(x->state == SXPREPARE);
sxmanager *m = x->manager;
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log.buf, sizeof(svlogv));
uint64_t csn = ++m->csn;
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
sxv *v = lv->v.v;
if ((int)v->lo == x->log_read)
break;
/* abort conflict reader */
if (v->prev && !sx_vcommitted(v->prev)) {
assert(v->prev->v->flags & SVGET);
sx_vabort(v->prev);
}
/* abort waiters */
sx_vabort_all(v->next);
/* mark stmt as commited */
sx_vcommit(v, csn);
/* translate log version from sxv to svv */
sv_init(&lv->v, &sv_vif, v->v, NULL);
/* schedule read stmt for gc */
if (v->v->flags & SVGET) {
sv_vref(v->v);
v->gc = m->gc;
m->gc = v;
m->count_gc++;
} else {
sx_untrack(v);
ss_free(m->asxv, v);
}
}
/* rollback latest reads */
sx_rollback_svp(x, &i, 0);
sx_promote(x, SXCOMMIT);
sx_end(x);
return SXCOMMIT;
}
sxstate sx_prepare(sx *x, sxpreparef prepare, void *arg)
{
uint64_t lsn = sr_seq(x->manager->seq, SR_LSN);
/* proceed read-only transactions */
if (x->type == SX_RO || sv_logcount_write(x->log) == 0)
return sx_promote(x, SX_PREPARE);
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log->buf, sizeof(svlogv));
sxstate rc;
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
sxv *v = lv->ptr;
if ((int)v->lo == x->log_read)
break;
if (sx_vaborted(v))
return sx_promote(x, SX_ROLLBACK);
if (sslikely(v->prev == NULL)) {
rc = sx_preparecb(x, lv, lsn, prepare, arg);
if (ssunlikely(rc != 0))
return sx_promote(x, SX_ROLLBACK);
continue;
}
if (sx_vcommitted(v->prev)) {
if (v->prev->csn > x->csn)
return sx_promote(x, SX_ROLLBACK);
continue;
}
/* force commit for read-only conflicts */
sxindex *i = v->prev->index;
if (sv_vflags(v->prev->v, i->r) & SVGET) {
rc = sx_preparecb(x, lv, lsn, prepare, arg);
if (ssunlikely(rc != 0))
return sx_promote(x, SX_ROLLBACK);
continue;
}
return sx_promote(x, SX_LOCK);
}
return sx_promote(x, SX_PREPARE);
}
sxstate sx_prepare(sx *x, sxpreparef prepare, void *arg)
{
uint64_t lsn = sr_seq(x->manager->r->seq, SR_LSN);
/* proceed read-only transactions */
if (x->type == SXRO || sv_logcount_write(&x->log) == 0)
return sx_promote(x, SXPREPARE);
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log.buf, sizeof(svlogv));
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
sxv *v = lv->v.v;
if ((int)v->lo == x->log_read)
break;
if (sx_vaborted(v))
return sx_promote(x, SXROLLBACK);
if (sslikely(v->prev == NULL)) {
if (prepare && lsn != x->vlsn) {
sxindex *i = v->index;
if (prepare(x, &lv->v, arg, i->ptr))
return sx_promote(x, SXROLLBACK);
}
continue;
}
if (sx_vcommitted(v->prev)) {
if (v->prev->csn > x->csn)
return sx_promote(x, SXROLLBACK);
continue;
}
/* force commit for read-only conflicts */
if (v->prev->v->flags & SVGET)
continue;
return sx_promote(x, SXLOCK);
}
return sx_promote(x, SXPREPARE);
}
