如果你将系统的日期返回时钟计时程序将不能运行任何的计划任务直到时钟达到日期返回以前的时间为止。
If you roll back the system date, cron will not run any scheduled jobs until the clock reaches the date that the system had before the date roll-back.
例如，您可能在调用内部设计时程序集的行中得到NullReferenceException，而您无法调试该错误，因此您只能纳闷哪个服务在哪个地方失败了。
For example, you may get a NullReferenceException on a line that calls the internal design-time assemblies, which you can't debug, so you're left wondering which service failed where.
我还为创建使用反射的对象编写了类似的计时测试程序，但这种情况下的差异不象字段和方法调用情况下那么显著。
I also wrote a similar timing test program for creating objects using reflection. The differences for this case aren't nearly as significant as for the field and method call cases, though.
实际上，对程序行为和计时的细微更改可能导致这些异常的意外出现。
In fact, subtle changes in program behaviour and timing can cause them to appear unexpectedly. Some examples are.
两个程序的计时都是在附录3中给出的驱动器程序完成的，运行的环境是在4.704ghz下运行的POWER 6电脑。
Timing for both programs was done with the driver program given in Appendix 3, on a POWER6 computer running at 4.704 GHz.
如果可以正确构建xev程序，则需要执行一项简单更改，从而按照更精确的计时输出击键事件。
If you can build the xev program correctly, you'll need to make one simple change to print out the keystroke events with more precise timings.
当您需要进行元程序设计时，请打开您的工具箱，加入几种允许延迟绑定的语言。
When you need to do metaprogramming, open up your toolbox and throw in some languages that allow delayed binding.
在进行应用程序设计时，必须认真考虑这些问题，但是这些问题超出了本文的讨论范围。
These issues must be carefully considered in the application design, but they are beyond the scope of this article.
当计时器的计时单元数达到零时，它将调用超时处理程序例程为该连接处理相应的超时。
When the number of ticks reaches zero for a timer, it calls the timeout handler routine to handle the corresponding timeout for that connection.
如果应用程序域卸载，该计时器实例将停止激发事件。
If your application domain unloads, the timer instance will stop firing its events.
此应用程序的安全性是从管理界面通过定义一个本地密码以便访问界面或运行审计时使用得到确保的。
The application can be secured from the management interface by defining a local password which will subsequently be required to access the interface or run audits.
更新固件的用户则不同，他们只要安装大量截屏程序中的任何一个，然后晃动下手机或是在计时器倒数至零就可以截屏了。
Compare this to rooted users, who can just install any of a number of apps that can take screenshots if you shake the phone, or after a timer counts down.
确定编译是否存在问题的最好方法是打开详细输出，确定编译发生的时间，进而确定它们是否影响应用程序计时。
Your best approach to see if compilation could be a problem is to turn on verbose output, indicating when compilations occur to see if they might affect your application timings.
除了科学计算和偶尔的计时测试或基准测试程序，其它情况下几乎都用不着它。
With the exception of scientific computing and the occasional timing test or benchmark, it just doesn't come up.
RT应用程序要求低暂停时间，因为那通常表示应用程序响应具有较高的计时限制。
Low pause times are a requirement for RT applications because they usually represent the upper timing bound for application responsiveness.
尽管它提供的精确性比高精确度计时器要低，但它对于在处理物理设备时提供错误覆盖的传统驱动程序超时来说比较理想。
Although it offers less accuracy than high-resolution timers, it is ideal for traditional driver time-outs that provide coverage of error cases when dealing with physical devices.
当展开设计时，您的远见卓识和创造力将开始展示如何让应用程序体系结构改进整个组织。
As your designs unfold, your foresight and creativity will begin to show how application architecture can improve the overall organization.
清单4展示了该代码，它是一个带有两个命令行参数的应用程序，这两个参数分别给出类名和要计时的方法名。
Listing 4 shows this code, in the form of an application that takes a pair of command-line arguments giving the class name and method name to be timed.
但是JIT编译器本身的行为并不是应用程序计时中的意外偏差的唯一来源。
But the activity of the JIT compiler itself isn't the only source of unexpected variations in application-level timings.
清理可能包括终止会话、取消计时器、取消回调处理程序或清理可能需要的任何数据结构。
This can include invalidating sessions, canceling timers, canceling callback handlers or cleaning up any data structures that may need it.
只需要确认你不会让这个程序跑一整个晚上，你可以为这些声音设定一个计时器，到时它们会自动关闭。
Just to make sure you don't leave it running all night, you can set up the sounds with a timer so that it'll shut off automatically.
应用程序越大、越复杂，其中的数据移动就越多，设计时考虑到的问题也必须越复杂。
The larger and more complex the application, the more data movement there is and the more complex your design considerations must be.
有了这些在设计时明确定义的界限，程序员就不太可能在代码里偷偷塞进不符合设计的额外功能。
With these boundaries well defined at design-time, the programmer is less likely to try to sneak additional functionality into code that was never meant to accommodate it.
尽管简单计时器api简单有效，但它并不能提供实时应用程序所需的准确性。
Although the simple timer API is easy and efficient, it does not offer the accuracy required for real-time applications.
下次您会发现，在您自己考虑(也可能要在躲避)多线程应用程序设计时，您可能想转而采用jcsp库。
Next time you find yourself considering (and perhaps shying away from) a multithreaded application design, you may want to turn instead to the JCSP library.
规则匹配和命令仅在应用程序一直处于不活动状态时才执行，因此任何键盘或鼠标活动都将重置应用程序不活动计时器。
Rules-matching and commands are only performed when the applications have been inactive, so any keyboard or mouse activity resets the application-inactivity timers.
现在，程序可以接受请求了，重新装载计时器也启动了。
At this point, the program is ready to accept requests, but the reload timer is also in operation.
RTSJ包含了对异步事件处理的支持，触发异步事件的事件包括大量包含计时器的源代码、操作系统信号、超过时限和其他应用程序定义的事件。
The RTSJ includes support for handling asynchronous events triggered by a number of sources including timers, operating-system signals, missed deadlines, and other application-defined events.
之所以会产生这种需求，是因为大多数计费程序包在设计时都没有考虑到电子商务。
The need arises because most accounting packages were not designed with e-commerce in mind.
之所以会产生这种需求，是因为大多数计费程序包在设计时都没有考虑到电子商务。
The need arises because most accounting packages were not designed with e-commerce in mind.
应用推荐