2015-09-05 21:06 GMT+02:00 Hartmut Kaiser <hartmut.kaiser@gmail.com>:

HPX itself uses TLS to store

a) a reference to the current scheduler responsible for the particular kernel-thread, and
b) a reference to the currently active (running) fiber object.

Both uses are safe as they are maintained by the runtime.

what does that mean 'maintained by the runtime'?

void bar( ptr_scheduler_thread_local_var) {

printf("%p\n", ptr_scheduler_thread_local_var);

suspend_and_migrate_fiber();

}

void foo() {

while ( true) {

      bar( return_ptr_of_scheduler_thread_local_var() );
      ...
   }
}

in this example b) accesses a) (TLS of scheduler) prints in to stdout suspends active fiber and migrates it to another thread

after resumption the address of the TLS-scheduler is printed out ...

how does your code look like after compiler optimization?!