private <A> A getNoLock(long recid, Serializer<A> serializer) {
if (fullTx) {
Fun.Tuple2 tu = mod.get(recid);
if (tu != null) {
if (tu.a == TOMBSTONE) return null;
return (A) tu.a;
}
}
Object oldVal = old.get(recid);
if (oldVal != null) {
if (oldVal == TOMBSTONE) return null;
return (A) oldVal;
}
return TxEngine.this.get(recid, serializer);
}
public void lock(final long recid) {
if (CC.LOG_LOCKS)
Utils.LOG.finest("TRYLOCK R:" + recid + " T:" + Thread.currentThread().getId());
// feel free to rewrite, if you know better (more efficient) way
if (CC.ASSERT && locks.get(recid) == Thread.currentThread()) {
// check node is not already locked by this thread
throw new InternalError("node already locked by current thread: " + recid);
}
while (locks.putIfAbsent(recid, Thread.currentThread()) != null) {
Thread.yield();
}
if (CC.LOG_LOCKS)
Utils.LOG.finest("LOCK R:" + recid + " T:" + Thread.currentThread().getId());
}
public void unlock(final long recid) {
if (CC.LOG_LOCKS)
Utils.LOG.finest("UNLOCK R:" + recid + " T:" + Thread.currentThread().getId());
final Thread t = locks.remove(recid);
if (t != Thread.currentThread()) throw new InternalError("unlocked wrong thread");
}
public void assertNoLocks() {
if (CC.PARANOID) {
LongMap.LongMapIterator<Thread> i = locks.longMapIterator();
while (i.moveToNext()) {
if (i.value() == Thread.currentThread()) {
throw new InternalError("Node " + i.key() + " is still locked");
}
}
}
}
@Override
public <A> void update(long recid, A value, Serializer<A> serializer) {
if (!fullTx) throw new UnsupportedOperationException("read-only");
commitLock.readLock().lock();
try {
mod.put(recid, Fun.t2(value, serializer));
} finally {
commitLock.readLock().unlock();
}
}
@Override
public <A> long put(A value, Serializer<A> serializer) {
if (!fullTx) throw new UnsupportedOperationException("read-only");
commitLock.writeLock().lock();
try {
Long recid = preallocRecidTake();
usedPreallocatedRecids.add(recid);
mod.put(recid, Fun.t2(value, serializer));
return recid;
} finally {
commitLock.writeLock().unlock();
}
}
@Override
public <A> boolean compareAndSwap(
long recid, A expectedOldValue, A newValue, Serializer<A> serializer) {
if (!fullTx) throw new UnsupportedOperationException("read-only");
commitLock.readLock().lock();
try {
Lock lock = locks[Store.lockPos(recid)].writeLock();
lock.lock();
try {
A oldVal = getNoLock(recid, serializer);
boolean ret = oldVal != null && oldVal.equals(expectedOldValue);
if (ret) {
mod.put(recid, Fun.t2(newValue, serializer));
}
return ret;
} finally {
lock.unlock();
}
} finally {
commitLock.readLock().unlock();
}
}
@Override
public void commit() {
if (!fullTx) throw new UnsupportedOperationException("read-only");
commitLock.writeLock().lock();
try {
if (closed) return;
if (uncommitedData) throw new IllegalAccessError("uncomitted data");
txs.remove(ref);
cleanTxQueue();
if (pojo.hasUnsavedChanges()) pojo.save(this);
// check no other TX has modified our data
LongMap.LongMapIterator oldIter = old.longMapIterator();
while (oldIter.moveToNext()) {
long recid = oldIter.key();
for (Reference<Tx> ref2 : txs) {
Tx tx = ref2.get();
if (tx == this || tx == null) continue;
if (tx.mod.containsKey(recid)) {
close();
throw new TxRollbackException();
}
}
}
LongMap.LongMapIterator<Fun.Tuple2> iter = mod.longMapIterator();
while (iter.moveToNext()) {
long recid = iter.key();
if (old.containsKey(recid)) {
close();
throw new TxRollbackException();
}
}
iter = mod.longMapIterator();
while (iter.moveToNext()) {
long recid = iter.key();
Fun.Tuple2 val = iter.value();
Serializer ser = (Serializer) val.b;
Object old = superGet(recid, ser);
if (old == null) old = TOMBSTONE;
for (Reference<Tx> txr : txs) {
Tx tx = txr.get();
if (tx == null || tx == this) continue;
tx.old.putIfAbsent(recid, old);
}
if (val.a == TOMBSTONE) {
superDelete(recid, ser);
} else {
superUpdate(recid, val.a, ser);
}
}
// there are no conflicts, so update the POJO in parent
// TODO sort of hack, is it thread safe?
getWrappedEngine().getSerializerPojo().registered = pojo.registered;
superCommit();
close();
} finally {
commitLock.writeLock().unlock();
}
}
@Override
public void close() {
closed = true;
old.clear();
ref.clear();
}