Published on

Published in: Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Mark and sweep
  • JVM

    1. 1. Sreyachandran.v Sreya.chandran31@gmail.com www.facebook.com/sreya twitter.com/username in.linkedin.com/in/profilename JVM
    2. 2. Disclaimer: This presentation is prepared by trainees of baabtra as a part of mentoring program. This is not official document of baabtra –Mentoring Partner Baabtra-Mentoring Partner is the mentoring division of baabte System Technologies Pvt . Ltd
    3. 3. JAVA • Java programming language was originally developed by Sun Microsystems. • Object Oriented : In Java, everything is an Object based. • Platform independent.
    4. 4. Virtual Machine • A virtual machine (VM) is a software implementation of a machine (for example, a computer) that executes programs like a physical machine. • Virtual machines are separated into two major classifications: system virtual machine and process virtual machine.
    5. 5. JVM • A Java virtual machine (JVM) is a process virtual machine that can execute java byte code. • JVM converts Java byte code into machine language and executes it. • JVM is platform dependent : JVMs are available for many hardware and software platforms. • JVM gives Java the flexibility of platform independence.
    6. 6. Diagram of JVM Java source code Byte codeJava compiler Java Virtual Machine Java Interpreter Computer Operating System Byte code loaded into JVM
    7. 7. Block Diagram Class loader sub system Execution engine
    8. 8. Class loader • All Java virtual machines include one class loader that is embedded in the virtual machine. • Class loader loads java classes into java virtual machine. • Class loader reads bytecode and creates the instance of java.lang.class.
    9. 9. Execution engine • The execution engine helps JVM to convert bytecode into machine code. • A mechanism responsible for executing the instructions contained in the methods of loaded classes.
    10. 10. Stack • Stack stores various method arguments and local variables of any method . • There are three registers that help in stack manipulation. – Vars register – Frame register – Optop register
    11. 11. Sections in stack • Local variable – This section contain all local variable being used by current method. • Execution environment – Execution section is used to maintain the operation of stack itself. • Operand stack – The operand stack is used as a work space by bytecode instruction.
    12. 12. Method Area • This is the area where byte code is placed. • The program counter points to the next instruction in the method area. • After the execution of an instruction , JVM set pc to next instruction.
    13. 13. Garbage Collected Heap • The object in java program are stored in Garbage collected heap. • Arrays in java program are objects, hence they also stored in heap. • Java does not have a free operator to free any previously allocated memory. • Java done this automatically by Garbage collection mechanism.
    14. 14. • JRE is an acronym for Java Runtime Environment. • Java Runtime Environment contains JVM, class libraries, and other supporting files. • It does not contain any development tools such as compiler, debugger, etc JRE
    15. 15. JDK • JDK is an acronym for Java Development Kit . It physically exists . It contains JRE + development tools.
    16. 16. JIT • Just-in-time Compiler -is the part of the Java Virtual Machine (JVM) that is used to speed up the execution time. • JIT compiles parts of the byte code that have similar functionality at the same time, and hence reduces the amount of time needed for compilation.
    17. 17. Is java a compiled or interpreted language ? • Java is a compiled language because the source code is converted into byte code. • Java is an interpreted language because the byte code is interpreted by a virtual machine.
    18. 18. THANK YOU
    19. 19. Want to learn more about programming or Looking to become a good programmer? Are you wasting time on searching so many contents online? Do you want to learn things quickly? Tired of spending huge amount of money to become a Software professional? Do an online course @ baabtra.com We put industry standards to practice. Our structured, activity based courses are so designed to make a quick, good software professional out of anybody who holds a passion for coding.
    20. 20. Follow us @ twitter.com/baabtra Like us @ facebook.com/baabtra Subscribe to us @ youtube.com/baabtra Become a follower @ slideshare.net/BaabtraMentoringPartner Connect to us @ in.linkedin.com/in/baabtra Give a feedback @ massbaab.com/baabtra Thanks in advance www.baabtra.com | www.massbaab.com |www.baabte.com
    21. 21. Emarald Mall (Big Bazar Building) Mavoor Road, Kozhikode, Kerala, India. Ph: + 91 – 495 40 25 550 NC Complex, Near Bus Stand Mukkam, Kozhikode, Kerala, India. Ph: + 91 – 495 40 25 550 Cafit Square, Hilite Business Park, Near Pantheerankavu, Kozhikode Start up Village Eranakulam, Kerala, India. Email: info@baabtra.com Contact Us