sxstate sx_rollback(sx *x)
{
sxmanager *m = x->manager;
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log.buf, sizeof(svlogv));
/* support log free after commit and half-commit mode */
if (x->state == SXCOMMIT) {
int gc = 0;
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
svv *v = lv->v.v;
int size = sv_vsize(v);
if (sv_vunref(m->r, v))
gc += size;
}
ss_quota(m->r->quota, SS_QREMOVE, gc);
sx_promote(x, SXROLLBACK);
return SXROLLBACK;
}
sx_rollback_svp(x, &i, 1);
sx_promote(x, SXROLLBACK);
sx_end(x);
return SXROLLBACK;
}
sxstate sx_begin(sxmanager *m, sx *x, sxtype type, uint64_t vlsn)
{
sx_promote(x, SXREADY);
x->type = type;
x->log_read = -1;
sr_seqlock(m->r->seq);
x->csn = m->csn;
x->id = sr_seqdo(m->r->seq, SR_TSNNEXT);
if (sslikely(vlsn == 0))
x->vlsn = sr_seqdo(m->r->seq, SR_LSN);
else
x->vlsn = vlsn;
sr_sequnlock(m->r->seq);
sx_init(m, x);
ss_spinlock(&m->lock);
ssrbnode *n = NULL;
int rc = sx_matchtx(&m->i, NULL, (char*)&x->id, sizeof(x->id), &n);
if (rc == 0 && n) {
assert(0);
} else {
ss_rbset(&m->i, n, rc, &x->node);
}
if (type == SXRO)
m->count_rd++;
else
m->count_rw++;
ss_spinunlock(&m->lock);
return SXREADY;
}
sxstate sx_set_autocommit(sxmanager *m, sxindex *index, sx *x, svlog *log, svv *v)
{
if (sslikely(m->count_rw == 0)) {
sx_init(m, x, log);
svlogv lv;
lv.index_id = index->dsn;
lv.next = UINT32_MAX;
lv.v = v;
lv.ptr = NULL;
sv_logadd(x->log, index->r, &lv);
sr_seq(index->r->seq, SR_TSNNEXT);
sx_promote(x, SX_COMMIT);
return SX_COMMIT;
}
sx_begin(m, x, SX_RW, log, 0);
int rc = sx_set(x, index, v);
if (ssunlikely(rc == -1)) {
sx_rollback(x);
return SX_ROLLBACK;
}
sxstate s = sx_prepare(x, NULL, NULL);
switch (s) {
case SX_PREPARE:
s = sx_commit(x);
break;
case SX_LOCK:
s = sx_rollback(x);
break;
case SX_ROLLBACK:
break;
default:
assert(0);
}
return s;
}
void sx_init(sxmanager *m, sx *x, svlog *log)
{
x->manager = m;
x->log = log;
sx_promote(x, SX_UNDEF);
ss_listinit(&x->deadlock);
}
sxstate sx_set_autocommit(sxmanager *m, sxindex *index, sx *x, svv *v)
{
if (sslikely(m->count_rw == 0)) {
sx_init(m, x);
svlogv lv;
lv.id = index->dsn;
lv.next = UINT32_MAX;
sv_init(&lv.v, &sv_vif, v, NULL);
sv_logadd(&x->log, m->r->a, &lv, index->ptr);
sr_seq(m->r->seq, SR_TSNNEXT);
sx_promote(x, SXCOMMIT);
return SXCOMMIT;
}
sx_begin(m, x, SXRW, 0);
int rc = sx_set(x, index, v);
if (ssunlikely(rc == -1)) {
sx_rollback(x);
return SXROLLBACK;
}
sxstate s = sx_prepare(x, NULL, NULL);
if (sslikely(s == SXPREPARE))
sx_commit(x);
else
if (s == SXLOCK)
sx_rollback(x);
return s;
}
void sx_gc(sx *x)
{
sxmanager *m = x->manager;
sx_promote(x, SXUNDEF);
sv_logfree(&x->log, m->r->a);
if (m->count_gc == 0)
return;
sx_garbage_collect(m);
}
void sx_gc(sx *x)
{
sxmanager *m = x->manager;
sx_promote(x, SX_UNDEF);
x->log = NULL;
if (m->count_gc == 0)
return;
sx_garbage_collect(m);
}
sxstate sx_rollback(sx *x)
{
assert(x->state != SX_COMMIT);
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log->buf, sizeof(svlogv));
sx_rollback_svp(x, &i, 1);
sx_promote(x, SX_ROLLBACK);
sx_end(x);
return SX_ROLLBACK;
}
sxstate sx_rollback(sx *x)
{
sxmanager *m = x->manager;
ssiter i;
ss_iterinit(ss_bufiter, &i);
ss_iteropen(ss_bufiter, &i, &x->log.buf, sizeof(svlogv));
/* support half-commit mode */
if (x->state == SXCOMMIT) {
for (; ss_iterhas(ss_bufiter, &i); ss_iternext(ss_bufiter, &i))
{
svlogv *lv = ss_iterof(ss_bufiter, &i);
svv *v = lv->v.v;
sv_vfree(m->r, v);
}
sx_promote(x, SXROLLBACK);
return SXROLLBACK;
}
sx_rollback_svp(x, &i, 1);
sx_promote(x, SXROLLBACK);
sx_end(x);
return SXROLLBACK;
}
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);
}
