scope.java

bpel执行引擎用来执行bpel业务流程

                                terminateEventHandlers();
                            } else
                                stopEventHandlers();

                            instance(ACTIVE.this);
                        }

                        public void cancelled() { completed(null, CompensationHandler.emptySet()); }
                        public void failure(String reason, Element data) { completed(null, CompensationHandler.emptySet()); }
                    });
                }
                object(false, mlSet);
            } else /* nothing to wait for... */ {
                // Any compensation handlers that were available but not activated will be forgotten.
                Set<CompensationHandler> unreachableCompensationHandlers = _scopeFrame.availableCompensations;
                if (unreachableCompensationHandlers != null)
                    for (Iterator<CompensationHandler> i = unreachableCompensationHandlers.iterator(); i.hasNext(); ) {
                        CompensationHandler ch = i.next();
                        ch.compChannel.forget();
                    }
                _scopeFrame.availableCompensations = null;

                // Maintain a set of links needing dead-path elimination.
                Set<OLink> linksNeedingDPE = new HashSet<OLink>();
                if (_oscope.faultHandler != null)
                    for (Iterator<OCatch> i = _oscope.faultHandler.catchBlocks.iterator(); i.hasNext(); )
                        linksNeedingDPE.addAll(i.next().outgoingLinks);

                // We're done with the main work, if we were terminated, we will
                // need to load the termination handler:
                if (_terminated) {
                    __log.debug("Scope: " + _oscope + " was terminated.");
                    // ??? Should we forward
                    _self.parent.completed(null,_compensations);
                } else if (_fault != null) {

                    sendEvent(new ScopeFaultEvent(_fault.getFaultName(), _fault.getFaultLineNo(),_fault.getExplanation()));

                    // Find a fault handler for our fault.
                    OCatch catchBlock = _oscope.faultHandler == null ? null : findCatch(_oscope.faultHandler, _fault.getFaultName(), _fault.getFaultType());

                    // Collect all the compensation data for completed child scopes.
                    assert !!_eventHandlers.isEmpty();
                    assert _child == null;
                    if (catchBlock == null) {
                        // If we cannot find a catch block for this fault, then we simply propagate the fault
                        // to the parent. NOTE: the "default" fault handler as described in the BPEL spec
                        // must be generated by the compiler.
                        if (__log.isDebugEnabled())
                            __log.debug(_self + ": has no fault handler for "
                                + _fault.getFaultName() + "; scope will propagate FAULT!");


                        _self.parent.completed(_fault, _compensations);
                    } else /* catchBlock != null */ {
                        if (__log.isDebugEnabled())
                            __log.debug(_self + ": has a fault handler for "
                                + _fault.getFaultName() + ": "+ catchBlock);

                        linksNeedingDPE.removeAll(catchBlock.outgoingLinks);

                        // We have to create a scope for the catch block.
                        BpelRuntimeContext ntive = getBpelRuntimeContext();

                        ActivityInfo faultHandlerActivity = new ActivityInfo(genMonotonic(),
                                catchBlock,
                                newChannel(TerminationChannel.class,"FH"), newChannel(ParentScopeChannel.class,"FH"));

                        ScopeFrame faultHandlerScopeFrame = new ScopeFrame(catchBlock,
                                ntive.createScopeInstance(_scopeFrame.scopeInstanceId, catchBlock),
                                _scopeFrame,
                                _compensations,
                                _fault);
                        if (catchBlock.faultVariable != null) {
                            try {
                                VariableInstance vinst =  faultHandlerScopeFrame.resolve(catchBlock.faultVariable);
                                initializeVariable(vinst, _fault.getFaultMessage());

                                // Generating event
                                VariableModificationEvent se = new VariableModificationEvent(vinst.declaration.name);
                                se.setNewValue(_fault.getFaultMessage());
                                if (_oscope.debugInfo != null)
                                    se.setLineNo(_oscope.debugInfo.startLine);
                                sendEvent(se);
                            } catch (Exception ex) {
                                __log.fatal(ex);
                                throw new InvalidProcessException(ex);
                            }
                        }


                        // Create the fault handler scope.
                        instance(new SCOPE(faultHandlerActivity,faultHandlerScopeFrame, SCOPE.this._linkFrame));

                        object(new ParentScopeChannelListener(faultHandlerActivity.parent) {
                            private static final long serialVersionUID = -6009078124717125270L;

                            public void compensate(OScope scope, SynchChannel ret) {
                                // This should never happen.
                                throw new AssertionError("received compensate request!");
                            }

                            public void completed(FaultData fault, Set<CompensationHandler> compensations) {
                                // The compensations that have been registered here, will never be activated,
                                // so we'll forget them as soon as possible.
                                for(Iterator<CompensationHandler> i = compensations.iterator();i.hasNext();)
                                    i.next().compChannel.forget();

                                _self.parent.completed(fault, CompensationHandler.emptySet());
                            }

                            public void cancelled() { completed(null, CompensationHandler.emptySet()); }
                            public void failure(String reason, Element data) { completed(null, CompensationHandler.emptySet()); }
                        });
                    }
                } else /* completed ok */ {
                    if (_oscope.compensationHandler != null) {
                        CompensationHandler compensationHandler = new CompensationHandler(
                            _scopeFrame,
                            newChannel(CompensationChannel.class),
                            _startTime,
                            System.currentTimeMillis());
                        _self.parent.completed(null, Collections.singleton(compensationHandler));
                        instance(new COMPENSATIONHANDLER_(compensationHandler, _compensations));
                    } else /* no compensation handler */ {
                        _self.parent.completed(null, _compensations);
                    }
                }

                // DPE links needing DPE (i.e. the unselected catch blocks).
                dpe(linksNeedingDPE);
            }
        }

        private void terminateEventHandlers() {
            for (Iterator<EventHandlerInfo> i = _eventHandlers.iterator();i.hasNext(); ) {
                EventHandlerInfo ehi = i.next();
                if (!ehi.terminateRequested && !ehi.stopRequested) {
                    replication(ehi.tc).terminate();
                    ehi.terminateRequested = true;
                }
            }
        }

        private void stopEventHandlers() {
            for (Iterator<EventHandlerInfo> i = _eventHandlers.iterator();i.hasNext();) {
                EventHandlerInfo ehi = i.next();
                if (!ehi.stopRequested && !ehi.terminateRequested) {
                    ehi.cc.stop();
                    ehi.stopRequested = true;
                }
            }
        }

    }


    private static OCatch findCatch(OFaultHandler fh, QName faultName, OVarType faultType) {
        OCatch bestMatch = null;
        for (Iterator<OCatch> i = fh.catchBlocks.iterator(); i.hasNext();) {
            OCatch c = i.next();

            // First we try to eliminate this catch block based on fault-name mismatches:
            if (c.faultName != null) {
                if (faultName == null)
                    continue;
                if (!faultName.equals(c.faultName))
                    continue;
            }

            // Then we try to eliminate this catch based on type incompatibility:
            if (c.faultVariable != null) {
                if (faultType == null)
                    continue;
                else if (c.faultVariable.type instanceof OMessageVarType) {
                    if (faultType instanceof OMessageVarType
                        && ((OMessageVarType)faultType).equals(c.faultVariable.type)) {
                        // Don't eliminate.
                    }
                    else if (faultType instanceof OElementVarType
                            && ((OMessageVarType)c.faultVariable.type).docLitType !=null
                            && !((OMessageVarType)c.faultVariable.type).docLitType.equals(faultType)) {
                        // Don't eliminate.
                    }
                    else {
                        continue;  // Eliminate.
                    }
                } else if (c.faultVariable.type instanceof OElementVarType) {
                    if (faultType instanceof OElementVarType && faultType.equals(c.faultVariable.type)) {
                        // Don't eliminate
                    }
                    else if (faultType instanceof OMessageVarType
                            && ((OMessageVarType)faultType).docLitType != null
                            && ((OMessageVarType)faultType).docLitType.equals(c.faultVariable.type)) {
                        // Don't eliminate
                    }
                    else {
                        continue; // eliminate
                    }
                } else {
                    continue; // Eliminate
                }
            }

            // If we got to this point we did not eliminate this catch block. However, we don't just
            // use the first non-eliminated catch, we instead try to find the best match.
            if (bestMatch == null) {
                // Obviously something is better then nothing.
                bestMatch = c;
            } else {
                // Otherwise we prefer name and variable matches but prefer name-only matches to
                // variable-only matches. 
                int existingScore = (bestMatch.faultName == null ? 0 : 2) + (bestMatch.faultVariable == null ? 0 : 1);
                int currentScore = (c.faultName == null ? 0 : 2) + (c.faultVariable == null ? 0 : 1);
                if (currentScore > existingScore) {
                    bestMatch = c;
                }
            }
        }
        return bestMatch;
    }

    static final class EventHandlerInfo implements Serializable {
        private static final long serialVersionUID = -9046603073542446478L;
        final OBase o;
        final EventHandlerControlChannel cc;
        final ParentScopeChannel psc;
        final TerminationChannel tc;
        boolean terminateRequested;
        boolean stopRequested;

        EventHandlerInfo(OBase o, EventHandlerControlChannel cc, ParentScopeChannel psc, TerminationChannel tc) {
            this.o = o;
            this.cc = cc;
            this.psc = psc;
            this.tc = tc;
        }
    }

}