Hello again... next code I stuck and can’t find out what’s wrong is import java.util.Scanner; public class Main { public static void main(String[] args) {
as application threads are paused for a period that is proportional to the size of the heap. The Java HotSpot VM has implemented an optional concurrent collector for the old object space that can take advantage of spare processor cycles
all the CPUs on the server allocated for this application were being occupied by this infinite loop. If the author of this naive HTML escape tool had decided to use one of the well known libraries available for HTML escaping, such asHtmlEscapersfromGoogle Guava, this probably wouldn’t have ...
for input)". If the thread is in some well known methods like Object.wait, Thread.sleep, etc., or if the I/O channel is interruptible, then this will "inject" an exception into the thread which will be safely thrown. However, this will not work if the thread is in an ...
This works well when the initialization value is available and the initialization can be put on one line. However, this form of initialization has limitations because of its simplicity. If initialization requires some logic (for example, error handling or aforloop to fill a complex array), simpl...
Problems can arise in defining responsibilities for clean-up: if object A and object B share pointer C, should A delete C, or should B? This eliminates the problem: neither A nor B should (or could) delete C using either C# or Java. Both A and B use C as long as they need to,...
The safest way to avoid these problems while maintaining the power of XML is to reduce privileges (as described in Guideline 9-2) and to use the most restrictive configuration possible for the XML parser. Reducing privileges still allows you to grant some access, such as inclusion to pages ...
You will have no problems if the transaction consists of all sends or all receives or if the receives come before the sends. But if you try to use a request/reply mechanism, whereby you send a message and then try to receive a reply to the sent message in the same transaction, the ...
One executes the GetIncThread.run() method in an infinite loop. The other exe- cutes the PutIncThread.run() method in an infinite loop. The loops for both threads access the sharedMap and sharedInt vari- ables at the same time. The sharedMap variable is used as a re- ceiver object...
For example, here is a class that uses a semaphore to control access to apool of items: 通过semaphore的构造方法可以确定所有权限的最大个数,使用Semaphore的acquire()方法(无参数)可以获得一个permit,只要线程获取的次数<创建的个数就无需阻塞,如果超过构造时最大的个数,就进行阻塞,而semaphore的release()...