plsql - Is there a best way to avoid execution of process more than once in Oracle?

Question

Let's say that I have a procedure called myproc. This is a complex process and i cannot allow two instances executing at the same time the proc.

Actually I do this using the dbms_application_info.set_module:

procedure start_process is
begin
  dbms_application_info.set_module('myproc', 'running');
end;

and verify before run the process:

select 'S'
  from v$session v
 where v.module = 'myproc'
   and v.action = 'running';

In the database level, is there a better way to check this?

Answer 1

Use dbms_lock.allocate_unique along with dbms_lock.request. The usage notes says:

The first session to call ALLOCATE_UNIQUE with a new lock name causes a unique lock ID to be generated and stored in the dbms_lock_allocated table. Subsequent calls (usually by other sessions) return the lock ID previously generated.

I think this could be what you're after.