Question

I have a pthread that I created and now I want that in a specific time interval the thread execute some code. But the user should also be able to cancel the thread. How can I cancel a thread and ensure that the thread is not cancelled when it execute the code?

In Java you handle this with

while(!isInterrupted)

Is there any similar solution with pthreads.

Answer 1

In the Question’s example code you are checking some variable. This is not the normal pattern for interrupting threads in Java.

In Java, you interrupt a thread by calling the interrupt() method.

The thread then checks if it is interrupted inside IO and system calls (which can throw InterruptedException when this happens; this means a thread that is sleeping or waiting on IO can be awoken when interrupted) or by sampling the isInterrupted() flag (typically used in a condition in a loop, as in Question).

The distinction is important; checking some flag variable you’ve declared is only possible in loops and your own code; the Java interrupting system works for all threads and all non-CPU-blocking code without special effort on the part of the programmer.

Pthreads has the pthread_cancel() pattern which works like the Java interrupting pattern.