我可以在单个进程中运行FuelPHP Task吗？

Question

I want to run FuelPHP Task every minute by cron. But I don't want to run duplicate FuelPHP Task.

Do you have any idea ?

I tried to control by pid, But getmypid() return same value always...

Answer 1

Another solution is (if you don't need to send data to your process, but it reads the data itself (eg. from database)) you can use a process manager with a long running task (basically in an infinite loop). (Actually you also need a process manager in a queue-based solution as well, since it requires workers on the receiver side)

I usually use Supervisord for this purpose.

A simple, long running application:

while (true) {
    // do something
    sleep(1);
}

The advantage of supervisord is that it can restart your process if it stops for some reason.

Answer 2

For such tasks, your best option might be to use some sort of queuing system. I found the best looking Bernard . You should take a look.

( Edit: I made an assumption about your task based on your need to have them not to overlap, and that's why I recommended queues. If it's something new to you, take a look at them, and decide which is better for you, if it doesn't fit best for you, someone searching for single task keywords may still find queues useful, so I leave it in the answer.)

If your environment doesn't allow such a solution for some reason, or you truly simply need a method to tell if the previous process is running, or not, you should just create a lockfile in the temp directory, something like mytask.lock when a task starts, and delete it when it terminates (finishes, or crashes). You can then check if the file is present.

This is a common solution for this problem, but using queue systems is much more flexible, and much more elegant.

Other possibility is to use pidfiles, which are not empty, but store the process ID of the first running task, so you can even terminate that, or send messages to it. Same with lockfiles, you put it in your temp directory, and name it like mytask.pid (or whatever you want, but *.pid is common).