Home / cs-notes / Architecture / Components / Netty / EventLoop / SingleThreadEventExecutor / runAllTasks

    /**
     * Poll all tasks from the task queue and run them via {@link Runnable#run()} method.  This method stops running
     * the tasks in the task queue and returns if it ran longer than {@code timeoutNanos}.
     */
    protected boolean runAllTasks(long timeoutNanos) {
        fetchFromScheduledTaskQueue();
        Runnable task = pollTask();
        if (task == null) {
            afterRunningAllTasks();
            return false;
        }

        final long deadline = timeoutNanos > 0 ? ScheduledFutureTask.nanoTime() + timeoutNanos : 0;
        long runTasks = 0;
        long lastExecutionTime;
        for (;;) {
            safeExecute(task);

            runTasks ++;

            // Check timeout every 64 tasks because nanoTime() is relatively expensive.
            // XXX: Hard-coded value - will make it configurable if it is really a problem.
            if ((runTasks & 0x3F) == 0) {
                lastExecutionTime = ScheduledFutureTask.nanoTime();
                if (lastExecutionTime >= deadline) {
                    break;
                }
            }

            task = pollTask();
            if (task == null) {
                lastExecutionTime = ScheduledFutureTask.nanoTime();
                break;
            }
        }

        afterRunningAllTasks();
        this.lastExecutionTime = lastExecutionTime;
        return true;
    }