Dear Sean,
had the same idea and just implemented a "LockableTS" ... and tested it.
Seems to be working for me, but I am currently not on a persisted table but a local in memory only.
For performance I moved the persistance to a custom datatable, that is only updated one / minute.
So finally it's working! Even my brutal test from the beginning is working.
For everybody interested, here is the code:
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.TimeUnit;
import com.thingworx.logging.LogUtilities;
import com.thingworx.metadata.annotations.ThingworxServiceDefinition;
import com.thingworx.metadata.annotations.ThingworxServiceParameter;
import com.thingworx.metadata.annotations.ThingworxServiceResult;
import org.slf4j.Logger;
public class LockableTS {
private final ReentrantLock mtx = new ReentrantLock(true);
@ThingworxServiceDefinition(name = "lock", description = "", category = "", isAllowOverride = false, aspects = {"isAsync:false"})
@ThingworxServiceResult(name = "Result", description = "", baseType = "NOTHING", aspects = {})
public void lock() {
mtx.lock();
}
@ThingworxServiceDefinition(name = "tryLock", description = "", category = "", isAllowOverride = false, aspects = {"isAsync:false"})
@ThingworxServiceResult(name = "Result", description = "", baseType = "BOOLEAN", aspects = {})
public Boolean tryLock( @ThingworxServiceParameter(name = "TimeOut", description = "", baseType = "LONG") Long TimeOut)
throws Exception {
return mtx.tryLock((long)TimeOut, TimeUnit.MILLISECONDS);
}
@ThingworxServiceDefinition(name = "unlock", description = "", category = "", isAllowOverride = false, aspects = {"isAsync:false"})
@ThingworxServiceResult(name = "Result", description = "", baseType = "NOTHING", aspects = {})
public void unlock() {
mtx.unlock();
}
@ThingworxServiceDefinition(name = "isLocked", description = "", category = "", isAllowOverride = false, aspects = {"isAsync:false"})
@ThingworxServiceResult(name = "Result", description = "", baseType = "BOOLEAN", aspects = {})
public Boolean isLocked() {
return mtx.isLocked();
}
}
Usage in the code:
try {
me.lock();
do_something_critical();
} finally {
me.unlock();
}
The try/finally is important, if the do_something_critical can throw exceptions.
Otherwise the lock will be left locked.
