I am an RTOS newbie and I am creating a simple real time system for automotive
I am wondering if it possible to create a task inside another task.
I tried to do this by the following method but it doesn't work.
void vTask1 { *pvParameters){
unsigned portBASE_TYPE taskPriority;
taskPriority=uxTaskPriorityGet( NULL );
char x;
while (1){
x= 5 ;
if (x==5)
xTaskCreate( vTask2 , "task2", 1000, "task2 is running", taskPriority+5 , NULL );
}
when I debug that code it hangs at xTaskCreate without executing the new task
and I searched the manual and the internet for something about this but I didn't find any.
would anyone tell me is that possible to do in RTOS or I am doing it in a wrong way?
Tasks can be created before the scheduler has been started (from main), or after the scheduler has been started (from another task). The xTaskCreate() API documentation is here:
http://www.freertos.org/a00125.html . You will also find a set of demo tasks that demonstrate creating and deleting tasks from another task in the main FreeRTOS .zip file download. Look in the FreeRTOS/Demo/Common/Minimal/death.c file (death for suicidal tasks as they delete themselves after creation).
If xTaskCreate() returns NULL then you will probably have run out of heap space. See http://www.freertos.org/a00111.html. I think most of the hundreds or pre-configured examples that come in the zip file download have comments to this effect.
Check the return value of xTaskCreate api.
one more thing the second task which you are creating is vtask2 which is having lower priority than vtask1 the one who is creating . And vtask1 is running in while(1) scheduler will not schedule vtask2.
you can delay or suspend the vtask1 after creating vtask2.
then vtask2 may execute.
Related
I have a pretty simple Anylogic DE model where POs are launched regularly, and a certain amount of material gets to the incoming Queue in one shot (See Sample Picture below). Then the Manufacturing process starts using that material at a regular rate, but I want to check if the material in the queue gets outdated, so I'm using the TimeOut option of that queue, in order to scrap the outdated material (older than 40wks).
The problem is that every time that some material gets scrapped through this Timeout exit, the downstream Manufacturing process "stops" pulling more material, instead of continuing, and it does not get restarted until a new batch of material gets received into the Queue.
What am I doing wrong here? Thanks a lot in advance!!
Kindest regards
Your situation is interesting because there doesn't seem to be anything wrong with what you're doing. So even though what you are doing seems to be correct, I will provide you with a workaround. Instead of the Queue block, use a Wait block. You can assign a timeout and link the timeout port just like you did for the queue (seem image at the end of the answer).
In the On Enter field of the wait block (which I will assume is named Fridge), write the following code:
if( MFG.size() < MFG.capacity ) {
self.free(agent);
}
In the On Enter of MFG block write the following:
if( self.size() < self.capacity && Fridge.size() > 0 ) {
Fridge.free(Fridge.get(0));
}
And finally, in the On Exit of your MFG block write the following:
if( Fridge.size() > 0 ) {
Fridge.free(Fridge.get(0));
}
What we are doing in the above, is we are manually pushing the agents. Each time an agent is processed, the model checks if there is capacity to send more, if yes, a new agent is sent.
I know this is an unpleasant workaround, but it provides you with a solution until AnyLogic support can figure it out.
I need to achieve the ability to monitor and be able to cancel an ALREADY RUNNING job on queue.
There's a lot of answers about deleting QUEUED jobs, but not on an already running one.
This is the situation: I have a "job", which consists of HUNDREDS OF THOUSANDS rows on a database, that need to be queried ONE BY ONE against a web service.
Every row needs to be picked up, queried against a web service, stored the response and its status updated.
I had that already working as a Command (launching from / outputting to console), but now I need to implement queues in order to allow piling up more jobs from more users.
So far I've seen Horizon (which doesn't runs on Windows due to missing process control libs). However, in some demos seen around it lacks (I believe) a couple things I need:
Dynamically configurable timeout (the whole job may take more than 12 hours, depending on the number of rows to process on the selected job)
Ability to CANCEL an ALREADY RUNNING job.
I also considered the option to generate EACH REQUEST as a new job instead of seeing a "job" as the whole collection of rows (this would overcome the timeout thing), but that would give me a Horizon "pending jobs" list of hundreds of thousands of records per job, and that would kill the browser (I know Redis can handle this without itching at all). Further, I guess is not possible to cancel "all jobs belonging to X tag".
I've been thinking about hitting an API route, fire the job and decouple it from the app, but I'm seeing that this requires forking processes.
For the ability to cancel, I would implement a database with job_id, and when the user hits an API to cancel a job, I'd mark it as "halted". On every loop I would check its status and if it finds "halted" then kill itself.
If I've missed any aspect just holler and I'll add it or clarify about it.
So I'm asking for an advice here since I'm new to Laravel: how could I achieve this?
So I finally came up with this (a bit clunky) solution:
In Controller:
public function cancelJob()
{
$jobs = DB::table('jobs')->get();
# I could use a specific ID and user owner filter, etc.
foreach ($jobs as $job) {
DB::table('jobs')->delete($job->id);
}
# This is a file that... well, it's self explaining
touch(base_path(config('files.halt_process_signal')));
return "Job cancelled - It will stop soon";
}
In job class (inside model::chunk() function)
# CHECK FOR HALT SIGNAL AND [OPTIONALLY] STOP THE PROCESS
if ($this->service->shouldHaltProcess()) {
# build stats, do some cleanup, log, etc...
$this->halted = true;
$this->service->stopProcess();
# This FALSE is what it makes the chunk() method to stop looping
return false;
}
In service class:
/**
* Checks the existence of the 'Halt Process Signal' file
*
* #return bool
*/
public function shouldHaltProcess() :bool
{
return file_exists($this->config['files.halt_process_signal']);
}
/**
* Stop the batch process
*
* #return void
*/
public function stopProcess() :void
{
logger()->info("=== HALT PROCESS SIGNAL FOUND - STOPPING THE PROCESS ===");
$this->deleteHaltProcessSignalFile();
return ;
}
It doesn't looks quite elegant, but it works.
I've surfed the whole web and many goes for Horizon or other tools that doesn't fit my case.
If anyone has a better way to achieve this, it's welcome to share.
Laravel queue have 3 important config:
1. retry_after
2. timeout
3. tries
See more: https://laravel.com/docs/5.8/queues
Dynamically configurable timeout (the whole job may take more than 12
hours, depending on the number of rows to process on the selected job)
I think you can config timeout + retry_after about 24h.
Ability to CANCEL an ALREADY RUNNING job.
Delete job in jobs table
Delete process by process id in your server
Hope it help you :)
I have a few questions regarding quartz.net.
What is it that keeps track of if there has been a missfire situation i Quartz.net?
What happens in the following scenarios:
If a job is run but cannot finnish due to some bug, does that count as a missfire or not?
What happens if i republish the solution, is the tracking reset?
Is there a way to receive information on what the scheduler has done and not been able to do?
I have the following code in my Run method:
IJobDetail dailyUserMailJob = new JobDetailImpl("DailyUserMailJob", null, typeof(Jobs.TestJob));
ITrigger trigger = TriggerBuilder.Create()
.WithIdentity("trigger1", "group1")
.WithCronSchedule("0 0 4 1 * ?", x => x.WithMisfireHandlingInstructionFireAndProceed())
.Build();
this.Scheduler.ScheduleJob(dailyUserMailJob, trigger);
this.Scheduler.Start();
The job is supposed to run the first every month on 4 am.
When testing I have set the system clock so that the jobb is missed for one month. According to the documentation when using WithMisfireHandlingInstructionFireAndProceed the job should be run the first thing that happens, but it dosent. Is there something wrong with the code or could it be some other reason the job is not run when using WithMisfireHandlingInstructionFireAndProceed() ?
If a job is missed, there is logic to bring it back. However, there is a "window" on how far back to go.
<add key="quartz.jobStore.misfireThreshold" value="60000"/>
You can increase this value.
If you have an ADOStore, misfires are persisted. Thus "if the power goes out", when restarting...you can recover from misfires.
If you have a RamStore...if "the power goes out", everything was in memory to begin with..so you won't get mis-fire handling, because everything was "in memory" and the memory is lost.
..
If you use Sql Server (AdoStore) and put a Profiler/Trace on it, you'll see the engine "poll" for misfires.......with a "go back this far in time" based on the misfireThreshold.
See this link:
http://nurkiewicz.blogspot.com/2012/04/quartz-scheduler-misfire-instructions.html
for more detailed info. Which has a "withMisfireHandlingInstructionFireAndProceed" note.
I'm running a distributed job on a cluster. I need to execute a script that sends me an email when the last task finishes (rather, all the tasks are complete). I have my script ready, but I'm not sure how to go about finding task completion. Is there a task ID analogous to labindex?
The reason I want to build this email feature into the job is so that I can just quit MATLAB after submission and collect my data when it's done. That way I won't waste resources pinging it often to get its state.
jobMgr = findResource(parameters for your cluster's job manager...);
job = createJob(jobMgr);
set(job, 'JobData', yourdata);
set(job, 'MaximumNumberOfWorkers', yourmaxworkers);
set(job, 'PathDependencies', yourpathdeps);
set(job, 'FileDependencies', yourfiledeps);
set(job, 'Timeout', yourtimeout);
for m = 1:numjobs
task(m) = createTask(job, #parallelfoo, 1, {m});
% Calls taskFinish when the task completes
set(task(m), 'FinishedFcn', {#taskFinish, m});
end
Elsewhere, you'll have defined a function taskFinish that gets a callback when each task completes.
function taskFinish(taskObj, eventData, tasknum)
disp(['Task ' num2str(tasknum) ' completed']);
end
Note, this code was written for the original release of the Distributed Computing Toolbox (which was subsequently renamed the Parallel Computing Toolbox), so it's possible that there are more elegant ways of accomplishing what you're trying to do. This gets the job done though, with one caveat -- my understanding is that this callback functionality only works if you're running the MATLAB job manager on your cluster (not one of the third party MPI job managers such as TORQUE).
I'm not sure if this answers much of your question, but you can get at the Task ID when running on the workers like so:
t = getCurrentTask();
tid = t.ID;
However, note that most schedulers execute tasks in an arbitrary order...
I have a few jobs setup in Quartz to run at set intervals. The problem is though that when the service starts it tries to start all the jobs at once... is there a way to add a delay to each job using the .xml config?
Here are 2 job trigger examples:
<simple>
<name>ProductSaleInTrigger</name>
<group>Jobs</group>
<description>Triggers the ProductSaleIn job</description>
<misfire-instruction>SmartPolicy</misfire-instruction>
<volatile>false</volatile>
<job-name>ProductSaleIn</job-name>
<job-group>Jobs</job-group>
<repeat-count>RepeatIndefinitely</repeat-count>
<repeat-interval>86400000</repeat-interval>
</simple>
<simple>
<name>CustomersOutTrigger</name>
<group>Jobs</group>
<description>Triggers the CustomersOut job</description>
<misfire-instruction>SmartPolicy</misfire-instruction>
<volatile>false</volatile>
<job-name>CustomersOut</job-name>
<job-group>Jobs</job-group>
<repeat-count>RepeatIndefinitely</repeat-count>
<repeat-interval>43200000</repeat-interval>
</simple>
As you see there are 2 triggers, the first repeats every day, the next repeats twice a day.
My issue is that I want either the first or second job to start a few minutes after the other... (because they are both in the end, accessing the same API and I don't want to overload the request)
Is there a repeat-delay or priority property? I can't find any documentation saying so..
I know you are doing this via XML but in code you can set the StartTimeUtc to delay say 30 seconds like this...
trigger.StartTimeUtc = DateTime.UtcNow.AddSeconds(30);
This isn't exactly a perfect answer for your XML file - but via code you can use the StartAt extension method when building your trigger.
/* calculate the next time you want your job to run - in this case top of the next hour */
var hourFromNow = DateTime.UtcNow.AddHours(1);
var topOfNextHour = new DateTime(hourFromNow.Year, hourFromNow.Month, hourFromNow.Day, hourFromNow.Hour, 0, 0);
/* build your trigger and call 'StartAt' */
TriggerBuilder.Create().WithIdentity("Delayed Job").WithSimpleSchedule(x => x.WithIntervalInSeconds(60).RepeatForever()).StartAt(new DateTimeOffset(topOfNextHour))
You've probably already seen this by now, but it's possible to chain jobs, though it's not supported out of the box.
http://quartznet.sourceforge.net/faq.html#howtochainjobs