1. Write a function named my_spawn/3 that spawns a process and prints a message when it dies.
Solution in exercise_1/.
2. Solve exercise 1 with the on_exit function shown in chapter 13.
Solution in exercise_2/.
3. Write a function named my_spawn/4 that spawns a process and kills it after it runs for more than the given number of seconds.
Solution in exercise_3/.
4. Write a function that creates a registered process that prints "I'm still running" every 5 seconds. Create another function that monitors this function and restarts it if it dies.
Solution in exercise_4/.
5. Write a function that spawns and monitors several processes. If any monitored processes dies, restart the monitored process.
Solution in exercise_5/. The code is in worker_supervisor.erl
Example usage:
erlc worker_supervisors.erl
erl
% Start the supervisor with a list of children
1> SupervisorPid = worker_supervisor:start(worker_supervisor:definition()).
I'm still running
I'm still running
% Get one of the child processes
2> WorkerData = worker_supervisor:get_workers(SupervisorPid).
[{<0.41.0>,#Ref<0.0.4.148>,-576460742360537501,{worker_supervisor,test,[]}},
{<0.42.0>,#Ref<0.0.4.149>,-576460742360529319,{worker_supervisor,test,[]}}]
3> [{Pid, _, _, _}|_] = WorkerData.
% And kill it to verify it got restarted
4> exit(Pid, test).
6. Write a function that spawns and monitors several processes. If any monitored processes dies, kill all the processes and restart them.
Solution in exercise_6/. The code is in worker_supervisor.erl
erlc worker_supervisors.erl
erl
% Start the supervisor with a list of children
1> SupervisorPid = worker_supervisor:start(worker_supervisor:definition()).
I'm still running
I'm still running
% Get one of the child processes
2> WorkerData = worker_supervisor:get_workers(SupervisorPid).
[{<0.41.0>,#Ref<0.0.4.148>,-576460742360537501,{worker_supervisor,test,[]}},
{<0.42.0>,#Ref<0.0.4.149>,-576460742360529319,{worker_supervisor,test,[]}}]
3> [{Pid, _, _, _}|_] = WorkerData.
% And kill it to verify it got restarted
4> exit(Pid, test).