java heap analyzer

Java's heap is a run-time data area in which the object allocates space. These objects are established through directives such as new, NewArray, Anewarray, and Multianewarray, and they do not require program code to be explicitly released. The heap is responsible for garbage collection, the advantage of the heap is the dynamic allocation of memory size, the lifet

Reprinted from HTTPS://GITHUB.COM/PZXWHC/MINEKNOWCONTAINER/ISSUES/25Including:1. Stack Overflow (stackoverflowerror)2. Heap overflow (Outofmemoryerror:java heap space)3. Permanent generation overflow (outofmemoryerror:permgen space)4. Outofmemoryerror:unable to create native threadThe Java Virtual Machine specification specifies that the JVM's memory is divided i

A heap is a special complete binary tree, which is characterized by that all parent nodes are smaller than child nodes, or that all parent nodes are larger than byte points. The first is called the minimum heap, and the latter is called the maximum heap.For example, the following two:So what's the effect of this feature? Since the title is a heap sort, it can cer

Both stacks and stacks are places where Java is used to store data in Ram. Unlike C ++, Java automatically manages stacks and stacks, and programmers cannot directly set stacks or stacks. The Java heap is a runtime data zone, from which the class objects allocate space. These objects are created using commands such as

voidSiftupusingcomparator (intK, E x) { while(k > 0) { //Find parent Node intParent = (k-1) >>> 1; Object e=Queue[parent]; //when the parent node is small, it satisfies the minimum heap nature and terminates the loop if(Comparator.compare (x, (e) e) >= 0) Break; //Exchange the newly added node and parent node locations to continue the elevation operationQUEUE[K] =e; K=parent; } Queue[k]=x; }The

Eight sort algorithms that must be known [java Implementation] (3) Merge sort algorithms and Heap Sort Algorithms I. Merge Sorting Algorithm Basic Idea: The Merge Sorting method combines two (or more) ordered tables into a new ordered table, that is, the sequence to be sorted is divided into several subsequences, each of which is ordered. Then combine the ordered subsequences into the overall ordered sequen

=Left ; - intj = m +1; - intK =Left ; - while(IRight ) {Use the branching structure to pick out the smallest of each stack of cards to arr - if(Temp[i] Temp[j]) { -arr[k++] = temp[i++]; in } - if(Temp[j] Temp[i]) { toarr[k++] = temp[j++]; + } - }Use the branching structure to put all the remaining stacks of cards in arr the if(I >m) { * while(J Right ) { $arr[k++] = temp[j++];Panax Notoginseng

Stack is advanced after out, LIFO firstQueue is FIFOA heap is a memory space that is requested for a size when the program is running, not when the program is compiled. That is, allocating memory dynamically, without distinction between access and access to general memory. {heap refers to the dynamic memory that the program runs as a request, and the stack refers only to a method that uses the

--){ //K Save the node being judged intk=i; //If the child node of the current K-node exists while(k*2+1LastIndex) { //index of the left child node of the K-node intBiggerindex=2*k+1; //if Biggerindex is less than lastindex, that is, the right child node of the K node represented by biggerindex+1 exists if(biggerindexLastIndex) { //If the value of the right child node is large i

node of the K node represented by biggerindex+1 existsif (biggerindexLastIndex) {//If the value of the right child node is largeif (data[biggerindex]]){//Biggerindex always records the index of a larger child node biggerindex++; } }//If the value of the K-node is less than the value of its larger child nodesif (data[k]Data[biggerindex]) {//Exchange them swap (data,k,biggerindex); // give the Biggerindex to K, start the next loop of the while loop, Re-guarantee that the value of the K-node is gr

Heap Memory Setting principleJVM heap memory is divided into 2 blocks: Permanent space and heap space. Permanent is the persistent generation (Permanent Generation), which mainly holds Java class definition information, which is not related to the Java objects that

Non-heap memory-related configuration-xx:permsizeInitial size of the permanent zone-xx:maxpermsizeMaximum size of the permanent zone use-xx:mxmetaspacesize to configure the maximum size of the JDK1.8 in the-xssThread stack size-xx:maxdirectmemorysizeThe direct memory size, which defaults to the maximum heap space, which is-xmx. When the direct memory usage reaches-xx:maxdirectmemorysize, garbage collection

Java Stacks and heaps ----to the two concepts of the unknown for a long time, finally found a good article, take to share 1. Stacks (stack) and heaps (heap) are places where Java is used to store data in RAM. Unlike C + +, Java automatically manages stacks and heaps, and programmers cannot directly set stacks or he

a type, such as:char ch; float x; int a,b,c;CH is a character type and is allocated to 2 bytes of memory. Different types of variables have different bytes allocated in memory, and they are stored in different ways.Therefore, it is necessary to determine the type of the variable before assigning a value, and determine the type of the variable, that is, determine the size of the memory space to allocate the data, and how the data will be stored in memory.Iv. Storage of

public class StringDemo{private static final String MESSAGE="taobao";public static void main(String [] args) {String a ="tao"+"bao";String b="tao";String c="bao";System.out.println(a==MESSAGE);System.out.println((b+c)==MESSAGE);}}For this problem, we examine the understanding of string types and compiler optimizations.String in Java is not a basic type, but sometimes it is similar to a basic type, such as String B = "Tao"; You can assign a value direc

The previous time to learn the binary tree in the processing of the delete operation encountered a headache problem: the deletion of the node when it is clear that the node is still present on the tree, you must also execute Node.father.left = null, you can delete the node nodes, Looking for a reason to find out or because the Java memory management understanding is not deep enough.The code is as follows:@Testpublic void Testnode () {node Node1 = new

greater than its parent, until the nature of the heap is restored.Extract Maximum value: The maximum is the root element. It is then deleted, so that the root element = the last leaf node element, and then bubbles downward from the root element (Bubble-down) to adjust the heap. Bubbling down operation: each should be adjusted from the node, its left and right children in a total of three nodes select the s

The Java heap is a run-time data area where the objects of the class are allocated space, which are established through directives such as new. Heap is responsible for garbage collection, the advantage of the heap is the ability to dynamically allocate memory size, the lifetime does not have to tell the compiler before

1. Heap: Usually through a binary heap, a real two-fork tree, divided into the smallest heap and the largest heap, with the following properties: Any node is smaller than all descendants of it, and the minimum element is on the root of the heap. The

Implement heap sorting in java Recently, I started to learn about sorting. I plan to organize a sorting algorithm every day. Today, I sorted out the heap sorting algorithm. At first I did not know the process of heap sorting. Note the following: When the coordinates of left and right children are calculated based on th