import ballerina/io;
import ballerina/lang.runtime;
import ballerina/task;

// Creates a job to be executed by the scheduler.
class Job {

    *task:Job;
    int i = 1;

    // Executes this function when the scheduled trigger fires.
    public function execute() {
        self.i += 1;
        io:println("MyCounter: ", self.i);
    }

    isolated function init(int i) {
        self.i = i;
    }
}

public function main() returns error? {

    // Schedules the task to execute the job every second.
    task:JobId id = check task:scheduleJobRecurByFrequency(new Job(0), 1);

    // Waits for nine seconds.
    runtime:sleep(9);

    // Unschedules the job.
    check task:unscheduleJob(id);
}

Schedule job recurrence by frequency

A task:scheduleJobRecurByFrequency() can be used to execute Ballerina jobs periodically. The task:Job and interval should be specified and optional configurations are start time, end time, and maximum count. For more information on the underlying module, see the Task module.

 
import ballerina/io;
import ballerina/lang.runtime;
import ballerina/task;

class Job {

Creates a job to be executed by the scheduler.

    *task:Job;
    int i = 1;

    public function execute() {
        self.i += 1;
        io:println("MyCounter: ", self.i);
    }

Executes this function when the scheduled trigger fires.

    isolated function init(int i) {
        self.i = i;
    }
}

public function main() returns error? {

    task:JobId id = check task:scheduleJobRecurByFrequency(new Job(0), 1);

Schedules the task to execute the job every second.

    runtime:sleep(9);

Waits for nine seconds.

    check task:unscheduleJob(id);
}

Unschedules the job.

bal run task_frequency_job_execution.bal
MyCounter: 1
MyCounter: 2
MyCounter: 3
MyCounter: 4
MyCounter: 5
MyCounter: 6
MyCounter: 7
MyCounter: 8
MyCounter: 9
MyCounter: 10