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infinity discard loop

See original GitHub issue

Hi, I’m not sure is this issue is the same with issues#73 which has been closed.

I’ve tried the same code with two diagram (source1 and source2), and encounter this issue with source2. The only difference between source1 and source2 is that source2 has ‘Task1’ which add one more loop-back to ‘Task2’.

Look into the log, I think there are 2 strange parts. First is, from line 2 in the log, the ‘Task2’ is be discarded two times with same execution id. It is expectable because both ‘Flow2’ and ‘FlowTrue1’ discarding Task2, but should not have same execution id. Second is, the second Flow3’s behavior, which is also triggered by discarding Task2 should also be discarded, but it didn’t. (3-lines above, the first Flow3 is discarded normally) log

here is my code:

'use strict';

const { Engine } = require('bpmn-engine');

const sleep = async (sec) => {
	return new Promise((resolve) => {
		setTimeout(resolve, sec * 1000);
	});
};

const services = {
	doTask1: async (scope, callback) => {
		scope.logger.debug(`##### doing doTask1 <${scope.content.executionId}>`);
		await sleep(1); // calling other heavy service...
		return callback(null);
	},
	doTask2: async (scope, callback) => {
		scope.logger.debug(`##### doing doTask2 <${scope.content.executionId}>`);
		await (async () => {
			await sleep(1); // calling other heavy service...
			scope.environment.variables.passTask2--;
		})();
		return callback(null);
	},
};

(async (source1, source2) => {
	const source = source2; // choice source here

	let engineState;

	const engine = Engine({
		source,
		services,
		variables: { passTask2: 1 },
		extensions: {
			listenUserTask: activity => {
				if (activity.id !== 'UserTask') return;
				activity.on('wait', async (api, context) => {
					// await (async () => {})(); // however, if I uncomment this line, source1 will become normal
					api.owner.logger.debug(`##### log state immediately in wait`);
					engineState = await engine.getState();
				});
			},
		},
	});

	// first execute
	await engine.execute();

	// sleep awhile then resume
	setTimeout(async () => {
		engine.logger.debug(`##### wakeup, resuming...`);

		const recoveredEngine = Engine({
			services,
		}).recover(engineState);

		const api = await recoveredEngine.resume({}, (err, execution) => {
			console.log('completed!!');
		});

		api.signal({ id: 'UserTask' });
	}, 5000);
})(`
<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" id="Definition_GeneralFlow" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="4.1.1">
  <bpmn:process id="Process_GeneralFlow" isExecutable="true">
    <bpmn:startEvent id="Start" name="Start">
      <bpmn:outgoing>Flow1</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:endEvent id="End" name="End">
      <bpmn:incoming>FlowFalse2</bpmn:incoming>
      <bpmn:incoming>FlowLater</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:serviceTask id="Task2" name="Task2" implementation="\${environment.services.doTask2}">
      <bpmn:incoming>FlowTrue1</bpmn:incoming>
      <bpmn:incoming>Flow1</bpmn:incoming>
      <bpmn:outgoing>Flow3</bpmn:outgoing>
    </bpmn:serviceTask>
    <bpmn:userTask id="UserTask" name="UserTask">
      <bpmn:incoming>FlowFirst</bpmn:incoming>
      <bpmn:outgoing>Flow4</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:exclusiveGateway id="Gateway1" name="Gateway1">
      <bpmn:incoming>Flow3</bpmn:incoming>
      <bpmn:outgoing>FlowFirst</bpmn:outgoing>
      <bpmn:outgoing>FlowLater</bpmn:outgoing>
    </bpmn:exclusiveGateway>
    <bpmn:exclusiveGateway id="Gateway2" name="Gateway2">
      <bpmn:incoming>Flow4</bpmn:incoming>
      <bpmn:outgoing>FlowFalse2</bpmn:outgoing>
      <bpmn:outgoing>FlowTrue1</bpmn:outgoing>
    </bpmn:exclusiveGateway>
    <bpmn:sequenceFlow id="Flow1" name="Flow1" sourceRef="Start" targetRef="Task2" />
    <bpmn:sequenceFlow id="Flow3" name="Flow3" sourceRef="Task2" targetRef="Gateway1" />
    <bpmn:sequenceFlow id="Flow4" name="Flow4" sourceRef="UserTask" targetRef="Gateway2" />
    <bpmn:sequenceFlow id="FlowFirst" name="FlowFirst" sourceRef="Gateway1" targetRef="UserTask">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">this.environment.variables.passTask2&gt;=0</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowLater" name="FlowLater" sourceRef="Gateway1" targetRef="End">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">this.environment.variables.passTask2&lt;0</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowFalse2" name="FlowFalse2" sourceRef="Gateway2" targetRef="End">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">false</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowTrue1" name="FlowTrue1" sourceRef="Gateway2" targetRef="Task2">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">true</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
  </bpmn:process>
</bpmn:definitions>`, `
<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" id="Definition_GeneralFlow" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="4.1.1">
  <bpmn:process id="Process_GeneralFlow" isExecutable="true">
    <bpmn:startEvent id="Start" name="Start">
      <bpmn:outgoing>Flow1</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:endEvent id="End" name="End">
      <bpmn:incoming>FlowFalse2</bpmn:incoming>
      <bpmn:incoming>FlowLater</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:serviceTask id="Task1" name="Task1" implementation="\${environment.services.doTask1}">
      <bpmn:incoming>Flow1</bpmn:incoming>
      <bpmn:incoming>FlowFalse1</bpmn:incoming>
      <bpmn:outgoing>Flow2</bpmn:outgoing>
    </bpmn:serviceTask>
    <bpmn:serviceTask id="Task2" name="Task2" implementation="\${environment.services.doTask2}">
      <bpmn:incoming>Flow2</bpmn:incoming>
      <bpmn:incoming>FlowTrue1</bpmn:incoming>
      <bpmn:outgoing>Flow3</bpmn:outgoing>
    </bpmn:serviceTask>
    <bpmn:userTask id="UserTask" name="UserTask">
      <bpmn:incoming>FlowFirst</bpmn:incoming>
      <bpmn:outgoing>Flow4</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:exclusiveGateway id="Gateway1" name="Gateway1">
      <bpmn:incoming>Flow3</bpmn:incoming>
      <bpmn:outgoing>FlowFirst</bpmn:outgoing>
      <bpmn:outgoing>FlowLater</bpmn:outgoing>
    </bpmn:exclusiveGateway>
    <bpmn:exclusiveGateway id="Gateway2" name="Gateway2">
      <bpmn:incoming>Flow4</bpmn:incoming>
      <bpmn:outgoing>FlowFalse1</bpmn:outgoing>
      <bpmn:outgoing>FlowFalse2</bpmn:outgoing>
      <bpmn:outgoing>FlowTrue1</bpmn:outgoing>
    </bpmn:exclusiveGateway>
    <bpmn:sequenceFlow id="Flow1" name="Flow1" sourceRef="Start" targetRef="Task1" />
    <bpmn:sequenceFlow id="Flow2" name="Flow2" sourceRef="Task1" targetRef="Task2" />
    <bpmn:sequenceFlow id="Flow3" name="Flow3" sourceRef="Task2" targetRef="Gateway1" />
    <bpmn:sequenceFlow id="Flow4" name="Flow4" sourceRef="UserTask" targetRef="Gateway2" />
    <bpmn:sequenceFlow id="FlowFirst" name="FlowFirst" sourceRef="Gateway1" targetRef="UserTask">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">this.environment.variables.passTask2&gt;=0</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowLater" name="FlowLater" sourceRef="Gateway1" targetRef="End">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">this.environment.variables.passTask2&lt;0</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowFalse1" name="FlowFalse1" sourceRef="Gateway2" targetRef="Task1">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">false</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowFalse2" name="FlowFalse2" sourceRef="Gateway2" targetRef="End">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">false</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
    <bpmn:sequenceFlow id="FlowTrue1" name="FlowTrue1" sourceRef="Gateway2" targetRef="Task2">
      <bpmn:conditionExpression xsi:type="bpmn:tFormalExpression" language="javascript">true</bpmn:conditionExpression>
    </bpmn:sequenceFlow>
  </bpmn:process>
</bpmn:definitions>`);

source1’s diagram: source1

source2’s diagram: source2

Issue Analytics

  • State:closed
  • Created 3 years ago
  • Comments:8 (5 by maintainers)

github_iconTop GitHub Comments

1reaction
paed01commented, Aug 18, 2020

No problem. Thank you for making me aware of the bug.

If you consider this issue solved, please close it.

0reactions
aowakennomaicommented, Aug 18, 2020

Got it! Thank you very much 😃

Read more comments on GitHub >

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