jvm profiler

) Client VM (build 14.3-b01,mixed mode, sharing)Mixed mode explains and compiles the mixed execution mode by default using this patternjava-xint-versionJava HotSpot (TM) Client VM (build 14.3-b01,interpreted mode, sharing)Interpreted pure Interpretation mode disables JIT compilationjava-xcomp-versionJava HotSpot (TM) Client VM (build 14.3-b01,compiled mode, sharing)Compiled pure compilation mode (fallback to interpreted mode to perform a method that cannot be compiled if the method cannot compil

[JVM] template interpreter-how to generate Assembly codes based on bytecode ?, Jvm Interpreter 1. Background Template interpreter for JVM only: How to generate an assembly code based on the opcode and addressing mode. For the bytecode and sink encoding used in this example, see the previous blog post: pass by value or by reference? 2. Addressing Mode This art

A rough understanding of JVM and JVM 1. How Java is cross-platform Java compiles source code into a Class file based on bytecode. bytecode is a file stored in bytes and is combined with cross-platform. It is a set of virtual commands that describe the program to run, this virtual command has nothing to do with any platform. The Java Virtual Machine knows it and the Java Virtual Machine translates it into co

The individual believes that JVM tuning is primarily addressed by the following methods1. Set the appropriate maximum heap memory (maximum and value for Cenozoic and Laosheng generations) and minimum heap memory (the operating system memory size consumed by JVM startup), and set the scale allocation of the heap.2, set up the suitable new generation because of its impact on the system performance and GC reco

Export JVM memory information on CentOS, and export jvm memory from centosFirst, check the Tomcat process Id: [root@iZ25Z ~]# ps aux | grep javawww 2111 4.0 23.5 1637648 452756 ? Sl 10:12 4:35 /usr/java/jdk1.7.0_80/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties ...　　We can see that the Tomcat process Id is 2111, and then use the JDK built-in tool jmap to e

Error: cocould not open... jvm. cfg solution, cocould... jvm. cfgThis is mostly because JDK has been installed on the computer. After you uninstall and reinstall it, an error occurs when you run the java command: cocould not open... jvm. cfg. Open the system environment variable and view the PATH. The following configuration information is displayed: % SystemRoot

Pgc:perm generation (bytes)S0: The first survivor (Survivor area) of the young generation has been used as a percentage of current capacityS1: The second survivor (Survivor area) in the younger generation has been used as a percentage of current capacityE: Eden (Eden) in the young generation has been used as a percentage of current capacityPercentage of current capacity used by O:old generationPercentage of current capacity used by P:perm generationS0CMX: Maximum Capacity (bytes) of the first S

JVM review notes and jvm Review -- Take it easy Garbage collection: Young generation ------- serial, parnew, parallel scavengeTenured gencration --------- CMS, Serial old (MSC), parallel old.The parallel scavenge collector is a new generation collector that uses apparel algorithms and parallel multi-thread collectors.It looks like parnew. What's special?-- The characteristics of parallel scavenge collecto

Jvm performance monitoring and common tools, common tools for jvm monitoring Common JDK command line tools Jps: jps [options] [hostid].-q only displays the jvmid,-m parameter passed to main class,-l class full name, and-v jvm startup parameter. Jstat: jstat [options] vmid [interval [s] | MS] [count]-gc-gcutil Jinfo: jinfo [option] pid Jmap: jmap [opt

JVM-graphics display bytecode execution engine execution process, jvm-bytecode In my previous blog JVM-String comparison-bytecode analysis, I introduced the reasons for String comparison. By analyzing bytecode, this blog will show the internal bytecode execution process of the method. Not to mention, paste the Java method code we will analyze: public static void

JVM re-sorting and JVM re-sorting Reordering is usually a method used by the compiler or runtime environment to re-sort and execute commands to optimize program performance. There are two types of re-sorting: Re-sorting during compilation and re-sorting during runtime, which correspond to the compiling and runtime environments respectively. In a concurrent program, the programmer pays special attention to d

This section Xiao Wang focuses on the next Java memory, first ask: How 1.JVM memory is allocated 2. Why divide the new generation and the old age, in practice which belong to what belongs to the old 3. Briefly describe how JSTAT-GC How 1.JVM memory is allocated 1.1 Concept Introduction Memory is divided into two parts of the stack Stack: Thread Private Heap: Thread sharing Stack: Program counter: The byte

) { e.printStackTrace(); } } } Public class T implements Runnable { Public void Run() {A A =NewA (); System.out.println (Thread.CurrentThread (). GetName () +" "+NewDate ()); } Public Static void Main(string[] args) {T T1 =NewT (); T t2 =NewT (); Thread Thread1 =NewThread (t1); Thread thread2 =NewThread (T2); Thread1.start (); Thread2.start (); } }The results of the operation are as follows: Thread-0 Fri Dec 10:25:00 CST 2013Thread-1 F

class execution mechanism The JVM executes class bytecode based on the stack architecture, and after the thread is created, the program counter (PC) and stack (stack) are generated. The PC holds the offset of the next executed instruction within the method, the stack holds a stack frame, each stack frame corresponds to each call of each method, and the stack frame holds local variables and the operand stack The structure of the stack

JVM-class file full parsing-method table set, jvm-class setMethod table set The previous magic number, minor version number, main board number, constant pool entry, constant pool, access flag, class index, parent index, interface index set, and field table set, then the method table will be followed. The method table is constructed like a field table, which contains several items in sequence: access_flags,

JVM-class file full parsing-Attribute Table set, jvm-class setAttribute Table set In front of magic number, minor version number, main board number, constant pool entry, constant pool, access flag, class index, parent index, interface index set, field table set, method table set, the next step is the set of attribute tables. In the class file, field tables, and method tables, you can carry your own attribu

JVM-concurrency-Java memory model, jvm-concurrency-java modelJava Memory Model (1). Master memory and working memory The Java Memory Model specifies that all variables are stored in the primary memory. Copies of the primary memory of each type of thread variables. All operations (read operations, value assignment operations, etc.) of the thread on the variables must be performed in the working memory, rathe

Jvm theory-constant pool-string, jvm constant pool-string String constant pool-constant item (Cp_info) Structure CONSTANT_String_info {u1 tag = 8; u2 string_index; // store CONSTANT_Utf8_info pointer} CONSTANT_Utf8_info {u1 tag = 1; u2 length; // byte array length u1 bytes [length]; // UTF-8 encoded byte array} Case 1 Public class StringDemo {private String s1 = "String S1 ";} Javac StringDemo. java Javap-

Deep understanding of JVM Reading Notes Mind Map, deep understanding of jvm Reading Notes To prove that I have completed this book and bought a new book, I don't have to worry about it... After 8 minutes of brain image, I feel that the entire person is not good. T_T brain cells do not know the number of dead cells... In fact, it is not thoroughly understood. It is estimated that we will open it again in a f

JVM memory structure --- deep understanding of Java Virtual Machine (jvm) When executing a Java program, the Java Virtual Machine divides the memory it manages into several different data regions. These regions have different purposes and create and destroy data independently based on their respective execution rules. Virtual Machine memory Division ,: The regions with independent threads are as follows: V