Threading

Thread Main Topics
  • Sleep, join, yield methods
  • Inter thread communication - wait() and notify(),  Blocking queues
  • Thread safety - Synchronized, Lock, Custom Locks
  • Semaphores
  • Dead Lock and Prevention techniques
  • ExecutorService
  • java.util.concurrent Package
Advantages of Runnable over Thread:
  1. As we are not modifying Threads behavior. There is no need for extending the thread. Composition is the preferred way. 
  2. Single Inheritance problem
  3. Extending Thread makes your logic tightly coupled with the Thread. You cannot pass the logic to other threads say threads created with executor. You have to always execute with the same thread.

Methods:
Join() - Thread instance method. Wait for the thread that is called on to die.
yield()- Static Method. Will move the currently running thread to Runnable state. No guarantee that the thread changes its state immediately.


Comments

Post a Comment

Popular posts from this blog

SQL Analytical Functions - Partition by (to split resultset into groups)

Partition by:  Splits the resultset into groups.  Employees -Table EMPLOYEE_ID FIRST_NAME SALARY ----------- -------------------- ---------- 100 Steven 24000 101 Neena 17000 102 Lex 17000 103 Alexander 9000 104 Bruce 6000 105 David 4800 106 Valli 4800 107 Diana 4200 select e.employee_id, e.department_id, salary, row_number() over (partition by department_id order by salary desc) as rownumber from employees e; The above query splits the result into small subgroups for every department.  Syntax :  Function(arg1,..., argn) OVER ( [PARTITION BY <..>] [ORDER BY <....>]  [<window_clause>] ) partition by  - create  subgroups for e...
Continue Reading »

Distributed database design using CAP theorem

Image
CAP is a theorem/standard which can be applied while designing distributed systems like distributed databases. A distributed database is a set of databases(nodes) which are spread across the network.  These set of databases(nodes) in the distributed database can be either designed as either a  master/slave  or a  sharded model . Consistency -  Database should return the latest write on the DB. Availability -  Database should return data in a decent amount of time .  But, the data might not be latest. Partition tolerant - I n spite of n/w failure, the database should always be available. A distributed database can be designed either as a CP, AP, CA but not with all the 3 capabilities.  AP - Available and Partition tolerant  -  Sharded model (Data is distributed, No Master)  -      Availability  - Because, the data is distributed, any of the nodes can return the data. So, always availabl...
Continue Reading »

Easy approach to work with files in Java - Java NIO(New input output)

  NIO - New IO package. Introduced in 1.4. It is buffer based and non-blocking. Hence, faster than IO package. It supports symbolic links, posix file attributes(works only on OS's which are POSIX compliant), ACL (Access control list). Paths and Files are the main classes Creating a potential file reference: Path path = Paths.get("c:/demo/"); //possible file reference Creating a directory, file, write to the file, read from the file: //create all the non existing directories in the path. Ignores creating a directory, if that directory already exists Path directories = Files.createDirectories("c:/demo/example1/properties/"); Path newFilePath = Files.createFile("c:/demo/README.txt"); //Creating a file //Writting bytes to the file Files.write(newFilePath, "This is a dummy text".getBytes(StandardCharsets.UTF_8)); //Reading bytes from file String readFile = new String(Files.readAllBytes(newFilePath), "UTF-8"); Files.readAllBytes reads all...
Continue Reading »