Hi all, I am fighting with the named_condition again. Currently I am using timed_wait but it does not behave like I expected. Sometimes it is okay (triggers on the given timeout) but sometimes it just returns immediately false (ignoring the timeout). Can someone give me a hint what I am doing wrong? Thanks in advance. Here is a simplified version of what I try to do: using namespace boost::interprocess; using namespace boost::posix_time; _process1_: (WRITER) scoped_lock lock(mtx1); write_sth_to_shared_memory(); flag = true; named_condition1.notify_all(); named_condition2.wait(lock); _process2_: (READER) scoped_lock lock(mtx2); while (true) { while (!flag) { flag = check_flag(); // set up timeout time_duration delay(milliseconds(200)); ptime timeout = ptime(second_clock::universal_time()); timeout += delay; // wait if (named_condition1.timed_wait(lock)) { check_for_interrupt(); break; } else { check_for_interrupt(); continue; } } do_some_reading_from_shared_mem(); named_condition2.notify(all); }