SLONG Database::SharedCounter::generate(thread_db* tdbb, ULONG space, ULONG prefetch)
{
fb_assert(space < TOTAL_ITEMS);
ValueCache* const counter = &m_counters[space];
if (m_localOnly)
{
SLONG result = 0;
while ( !(result = (SLONG) ++counter->curVal) )
;
return result;
}
Database* const dbb = tdbb->getDatabase();
SyncLockGuard guard(&dbb->dbb_sh_counter_sync, SYNC_EXCLUSIVE, "Database::SharedCounter::generate");
if (!counter->lock)
{
Lock* const lock =
FB_NEW_RPT(*dbb->dbb_permanent, 0) Lock(tdbb, sizeof(SLONG), LCK_shared_counter);
counter->lock = lock;
lock->lck_key.lck_long = space;
LCK_lock(tdbb, lock, LCK_PW, LCK_WAIT);
}
SLONG result = (SLONG) ++counter->curVal;
if (result > counter->maxVal)
{
LCK_convert(tdbb, counter->lock, LCK_PW, LCK_WAIT);
result = LCK_read_data(tdbb, counter->lock);
// zero IDs are somewhat special, so let's better skip them
if (!result)
result = 1;
counter->curVal = result;
counter->maxVal = result + prefetch - 1;
LCK_write_data(tdbb, counter->lock, counter->maxVal + 1);
LCK_convert(tdbb, counter->lock, LCK_SR, LCK_WAIT);
}
return result;
}
SLONG Database::SharedCounter::generate(thread_db* tdbb, ULONG space, ULONG prefetch)
{
fb_assert(space < TOTAL_ITEMS);
ValueCache* const counter = &m_counters[space];
Database* const dbb = tdbb->getDatabase();
if (!counter->lock)
{
Lock* const lock = FB_NEW_RPT(*dbb->dbb_permanent, sizeof(SLONG)) Lock();
counter->lock = lock;
lock->lck_type = LCK_shared_counter;
lock->lck_owner_handle = LCK_get_owner_handle(tdbb, lock->lck_type);
lock->lck_parent = dbb->dbb_lock;
lock->lck_length = sizeof(SLONG);
lock->lck_key.lck_long = space;
lock->lck_dbb = dbb;
lock->lck_ast = blockingAst;
lock->lck_object = counter;
LCK_lock(tdbb, lock, LCK_PW, LCK_WAIT);
counter->curVal = 1;
counter->maxVal = 0;
}
if (counter->curVal > counter->maxVal)
{
LCK_convert(tdbb, counter->lock, LCK_PW, LCK_WAIT);
counter->curVal = LCK_read_data(tdbb, counter->lock);
if (!counter->curVal)
{
// zero IDs are somewhat special, so let's better skip them
counter->curVal = 1;
}
counter->maxVal = counter->curVal + prefetch - 1;
LCK_write_data(tdbb, counter->lock, counter->maxVal + 1);
}
return counter->curVal++;
}
