Method drain

src/wallClock.cpp:79–98

    }

    void drain(ThreadSleepMap& thread_sleep_state) {
        u64 read_limit = _read_ptr + RINGBUF_SIZE;
        do {
            ThreadCpuTime& t = _ringbuf[_read_ptr & (RINGBUF_SIZE - 1)];
            u64 cpu_time = loadAcquire(t.cpu_time);
            if (cpu_time == 0) {
                break;
            }

            u64 trace = t.trace;
            if (__sync_bool_compare_and_swap(&t.cpu_time, cpu_time, 0)) {
                int thread_id = trace >> 32;
                ThreadSleepState& tss = thread_sleep_state[thread_id];
                tss.last_cpu_time = cpu_time;
                tss.call_trace_id = (u32)trace;
                tss.counter = 0;
                _read_ptr++;
            }
        } while (_read_ptr < read_limit);
    }
};

static ThreadCpuTimeBuffer _thread_cpu_time_buf;