{"id":724,"date":"2010-08-07T13:19:16","date_gmt":"2010-08-07T07:49:16","guid":{"rendered":"http:\/\/JitendraZaa.com\/blog\/?p=724"},"modified":"2010-08-07T13:19:16","modified_gmt":"2010-08-07T07:49:16","slug":"simple-threading-techniques","status":"publish","type":"post","link":"https:\/\/www.jitendrazaa.com\/blog\/java\/simple-threading-techniques\/","title":{"rendered":"Thread, Life Cycle of Thread"},"content":{"rendered":"

Threading:<\/strong><\/p>\n

A process can contain one or more threads.<\/p>\n

In java by\u00a0default two threads will run i.e. main() & garbage collection<\/strong>. we can create as many as threads as possible we want.<\/p>\n

Benefit of threads:<\/strong><\/p>\n

We can delegate a long running tasks which does not require any i\/p from user to a thread resulting in fast execution of main thread(concentrated logic).<\/p>\n

Steps to create thread:<\/span><\/strong><\/p>\n

Method 1:<\/strong><\/p>\n

    \n
  1. Create a class which extends “Thread”\u009d<\/strong><\/li>\n
  2. Override “run()”\u009d.<\/strong><\/li>\n
  3. Create a object of a class which extends thread by using below line of code.<\/li>\n<\/ol>\n

    Thread obj=new <class which extends thread>;<\/em><\/p>\n

    <\/strong> 4. \u00a0Call \u00a0method “start()”\u009d<\/strong>, internally it will call method “run()”\u009d.<\/strong><\/p>\n

    Lifecycle of Thread:<\/span><\/strong><\/p>\n

    Thread is a light weight process.<\/p>\n

    1. New State:<\/strong><\/p>\n

    After the creation of Thread instance the thread is in this state but before the start() method invocation. At this point, the thread is considered not alive.<\/p>\n

    2. Runnable State:<\/strong><\/p>\n

    A \u00a0thread start its life from Runnable State<\/strong>. A thread first enters runnable state<\/strong> after the invoking of start()<\/strong> method but a thread can return to this state after either running, waiting, sleeping or coming back from blocked<\/strong> state also. On this state a thread is waiting for a turn on the process.<\/p>\n

    3. Running State:-<\/strong><\/p>\n

    A thread is running state<\/strong> that means the thread is currently executing. There are several ways to enter in runnable\u00a0 state<\/strong> but there is only one way to enter in running state<\/strong>, the scheduler select a thread from runnable part.<\/strong><\/p>\n

    4. Dead State:-<\/strong><\/p>\n

    A thread can be considered dead when its run()<\/strong> method completes. If any thread comes on this state that means it cannot ever run again.<\/p>\n

    5. Blocked:-<\/strong><\/p>\n

    A thread can enter in this state because of waiting the<\/strong> resources <\/strong>that are hold by another thread<\/strong>.<\/p>\n

    \n\nclass \u00a0temp extends Thread\n{\n   public void run()\n   {\n      System.out.println(\"In run method\"\u009d);\n   }\n}\n\nclass \u00a0TestThread\n{\n   public static void main(String args[])\n   {\n      Thread obj=new temp();\n      Obj.start();\n   }\n}\n<\/pre>\n
    Q. What is the difference between calling method start() & calling method run() of thread?<\/strong><\/p>\n
    i. start method<\/strong> of thread will internally <\/strong>create a new thread<\/strong> & calls<\/strong> run method<\/strong>. The sequence of execution of thread in unpredictable.<\/p>\n
    ii. run method<\/strong> will be called as a<\/strong> normal method in a main<\/strong> thread,if call externally.<\/p>\n
    \n\nclass Temp extends <strong>Thread<\/strong>\n{\n  public void run()\n  {\n     for(int i=0;i<20;i++)\n     {\n         System.oput.println(\"In Run Method\"\u009d);\n     }\n  }\n}\n\nclass TestThread\n{\n   public static void main(String args[])\n  {\n     Thread obj=new Temp();\n     Obj.start();\n     for(int i=0;i<20;i++)\n     {\n           System.out.println(\"In Main Method\"\u009d);\n     }\n   }\n}\n\n<\/pre>\n
    O\/P:-<\/strong><\/p>\n
     <\/strong>In Main Method \/\/ will run fifteen times.<\/span><\/p>\n
    In Run Method \/\/ will run twenty times.<\/span><\/p>\n
    In Main Method \/\/ will run five times.<\/span><\/p>\n
     <\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"
    What is Thread? Life cycle of thread. Difference in start() and run() method of Thread. By Default how many thread runs?<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"jz_research_post":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[3],"tags":[180],"class_list":["post-724","post","type-post","status-publish","format-standard","hentry","category-java","tag-simple-threading-techniques"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":1816,"url":"https:\/\/www.jitendrazaa.com\/blog\/java\/daemon-thread-java\/","url_meta":{"origin":724,"position":0},"title":"Daemon Thread","author":"Jitendra","date":"March 24, 2011","format":false,"excerpt":"Example and Explanation of Daemon thread in JAVA","rel":"","context":"In "JAVA"","block_context":{"text":"JAVA","link":"https:\/\/www.jitendrazaa.com\/blog\/category\/java\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":414,"url":"https:\/\/www.jitendrazaa.com\/blog\/microsoft\/csharp\/background-and-foreground-thread-in-c\/","url_meta":{"origin":724,"position":1},"title":"Background and foreground thread in c#","author":"Jitendra","date":"June 29, 2010","format":false,"excerpt":"Example of Threading in C#. 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