I want to dump all the classes loaded by the virtual machine through the ClassDump in sa-jdi.jar. ClassDump supports dump classes from jvm processes or jvm core dump. for online applications, you should not dump, pid directly if you want to get a co...
there is some doubt about the reading semantics of volatile: Why can t normal read and volatile read after volatile read be reordered? volatile read I know it is to fetch variable values directly from main memory, but since they are both reads, will i...
public class Main{ public staic void main(String[] args){ System.out.println(Class.forName("a.b.old.C")); } } Class.forName needs to be changed due to some special requirements, and when using this method, if the package name o...
what should I learn if I want to develop a monitoring tool for JVM? ...
as the title shows, many books and materials do not explicitly mention which operations are atomic, which is very important in writing concurrent programs. ...
CPU occupancy is as high as 60-70% for a period of time after tomcat is enabled. Baidu, many people said to check in JavaStack, the following is a few thread information with high occupancy in jstack "ajp-nio-8009-ClientPoller-1" -sharp55 ...
new method protected String constructScalar(ScalarNode node) { return node.getValue(); } old method protected Object constructScalar(ScalarNode node) { return node.getValue(); } in an old program, the retur...
public class A { public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException { System.out.println( ClassLoader.getSystemClassLoader().toString()); Unsafe unsafe = UnsafeUtil.getUnsafe(); Person person = new...
for example, is the JVM, of the generation collection algorithm GC used to divide the young and the old, or no matter which GC algorithm is used, the heap is divided into the young and the old? ...
java used user-mode threads before 1.2. why did it change to lightweight processes to implement threads? Aren t user-mode threads more efficient? Although the management and scheduling is a little complicated! ...
Use the top command to check memory under linux. at first it seems to be stable at 800m, but the memory increases by 23m every ten minutes or so. it is suspected that there is a memory leak, and it is normal and stable to use visualVM to observe the...
in the process of learning Java, there are some problems that you need to use Java disassembly tool javap to view bytecode instructions, but there are some problems when viewing bytecode instructions, assuming the following simple code, public static v...
for example, the member variable of a class: Object obj = new Object(); obj is an instance of an object. In a broad sense, it is stored on the "stack " and points to the memory address on the "heap ". Specifically, I have the impression that obj sho...
Why does JAVA have multiple loaders I know that the function of the loader is to get the binary byte stream through the class name. It is mainly divided into four kinds of loaders: startup class-> extension class-> application class-> custom class. I al...
The code is as follows: package referenceCoutingGC; ** * * testGC()ogjAogjBGC * * public class referenceCoutingGC { public Object instance = null; private static final int _1MB = 1024*1024; private byte[] bigSize = ...
ask two questions: is there any difference in jvm execution between using fully qualified names and using import, except for the difference in length? If there is a difference, which is more efficient? use the class name. What is the difference in ...
the program first executes a start method to take up a lot of memory, and then executes endEmpty to call System.gc () to run, the task manager can see that the memory footprint of the program immediately reaches 4G, but the memory footprint of th...
Let s not talk about the principle of the train algorithm here. the train algorithm is the gc algorithm used by the G1 collector D _ C are three objects that need to be called to each other. There are no other citations. But when the algorithm sc...
in most cases in JAVA, objects are allocated in Eden by default, and when GC is triggered, if there is not enough space in survivor, it will be put into the old age. suppose the following scenario: eden:80M survivor1:10M survivor2:10M now survivor2 is...
console shows that ChildClass has been loaded, why not output c init ...
just started to learn the front end, source code in the "success " and "fail ", why there are no colons? I learned something like this. is it written in a new way? < H1 > what I imagined it to be: < H1 > { url: opts.loginUrl, ... succes...
in this case, the relative path of the picture is written in the style, as follows -sharpuserBtn select{ width: 300px; -webkit-appearance: none; -moz-appearance: none; appearance: none; border:solid 1px -sharpc...
how to adjust the camera of android, and the problem of passing value? for example: for a page I wrote in vue, click on the camera that needs to be tuned to android, and android will send me the value. How can I accept it in vue? -sharp-sharp-sharp prob...
nuxt$axiosaxios.js ...
scene description when the H5 page in app is opened and loaded, it transmits information to IOS through scheme protocol: window.location.href = menhong: activityMoments question The above is equivalent to jumping to a "non-existent " page...