As I suggested, add some kind of mutex-mechanism in the layer above the Activiti-layer. Example:
This is just off the top of my head, doesn't actually compile
To make it more "generic" (if you have more of these CRITICAL stuff that needs exception right away before actually performing the operation and getting optimisticLockEx) you can build some kind of callback mechanism (like springs doInTransactions, but then doWhilLockingProcess(processId).
public class YourCompanyService {
private Set<String> processLocks = new HashSet<…>;
…
public boolean printTheCard(String cardIdentifier) {
// Correlate between card-id and task/process to use
String processId = runtimeService.createtaskQuery()……singleResult();
// JVM-wide lock for this specific use-case.
boolean isSafe = false;
synchronized(this) {
isSafe = processLocks.contains(processId);
if(isSafe) {
processLocks.add(processId);
}
}
if(!isSafe) {
throw new MyCompanyException("looks like you're too late…");
}
// important, release the lock in "finally"
try {
// Finish task
taskService……
….
}
finally
{
synchronized(this) {
processLocks.remove(processId);
}
}
}
}
This is just off the top of my head, doesn't actually compile
To make it more "generic" (if you have more of these CRITICAL stuff that needs exception right away before actually performing the operation and getting optimisticLockEx) you can build some kind of callback mechanism (like springs doInTransactions, but then doWhilLockingProcess(processId).
