This document provides an overview of concurrency and parallelism in the Java runtime environment. It discusses the Java thread model and decisions for its design. It also covers implementing multithreading by creating and managing threads, remote method execution using Java RMI, concurrency utilities in java.util.concurrent, thread safety and shared data access, and GUI applications in Java. The document lists several references for further reading on Java concurrency topics.
The document discusses multithreaded programming using Java threads. It covers topics such as defining threads in Java, thread states, accessing shared resources, synchronization, thread priorities, and concurrency models like master/worker, peer processing, and pipelines. Examples are provided to demonstrate creating and running multiple threads that extend the Thread class or implement the Runnable interface in Java.
This document discusses threads and multithreading. It defines a thread as the smallest sequence of instructions that can be managed independently, and notes that multithreading allows a program to manage multiple tasks concurrently. Benefits of multithreading include improved responsiveness, faster execution on multi-core CPUs, lower resource usage, better system utilization, simplified communication between threads, and enabling parallelization. Challenges with multithreading include synchronization between threads accessing shared data and resources, and the risk that a misbehaving thread can crash the entire process. The document provides examples of creating threads in Java using the Runnable interface and by extending the Thread class.
This document discusses multithreading in Java. It begins by defining a process as a program in execution that may contain multiple concurrently executing threads. It then defines a thread as the smallest unit of processing that can run independently within a process. The document goes on to compare threads and processes, discuss how to create multithreads in Java by extending the Thread class or implementing the Runnable interface, provide examples of multithreading code, and list advantages of multithreading like enabling multiple concurrent tasks and improved performance.
The document discusses multithreading in Java. It defines multithreading as executing multiple threads simultaneously, with threads being lightweight subprocesses that share a common memory area. This allows multitasking to be achieved more efficiently than with multiprocessing. The advantages of multithreading include not blocking the user, performing operations together to save time, and exceptions in one thread not affecting others. The document also covers thread states, creating and starting threads, and common thread methods.
Multithreading is the ability of a program or an
operating system process to manage its use by
more than one user at a time and to even manage
multiple requests by the same user without
having to have multiple copies of the
programming running in the computer.
This document provides an overview of threads in Java, including:
- Threads allow for multitasking by executing multiple processes simultaneously. They are lightweight processes that exist within a process and share system resources.
- Threads can be created by extending the Thread class or implementing the Runnable interface. The run() method defines the code executed by the thread.
- Threads transition between states like new, runnable, running, blocked, and dead during their lifecycle. Methods like start(), sleep(), join(), etc. impact the thread states.
- Synchronization is used to control access to shared resources when multiple threads access methods and data outside their run() methods. This prevents issues like inconsistent data.
This document provides an overview of multithreading in 3 sentences or less:
Multithreading allows a program to split into multiple threads that can run simultaneously, improving responsiveness, utilizing multiprocessors efficiently, and structuring programs more effectively. Threads transition between different states like new, runnable, running, blocked, and dead over their lifetime. Common threading techniques include setting thread priority, enabling communication between threads, and avoiding deadlocks when multiple threads depend on each other's locks.
The document discusses multithreaded programming using Java threads. It covers topics such as defining threads in Java, thread states, accessing shared resources, synchronization, thread priorities, and concurrency models like master/worker, peer processing, and pipelines. Examples are provided to demonstrate creating and running multiple threads that extend the Thread class or implement the Runnable interface in Java.
This document discusses threads and multithreading. It defines a thread as the smallest sequence of instructions that can be managed independently, and notes that multithreading allows a program to manage multiple tasks concurrently. Benefits of multithreading include improved responsiveness, faster execution on multi-core CPUs, lower resource usage, better system utilization, simplified communication between threads, and enabling parallelization. Challenges with multithreading include synchronization between threads accessing shared data and resources, and the risk that a misbehaving thread can crash the entire process. The document provides examples of creating threads in Java using the Runnable interface and by extending the Thread class.
This document discusses multithreading in Java. It begins by defining a process as a program in execution that may contain multiple concurrently executing threads. It then defines a thread as the smallest unit of processing that can run independently within a process. The document goes on to compare threads and processes, discuss how to create multithreads in Java by extending the Thread class or implementing the Runnable interface, provide examples of multithreading code, and list advantages of multithreading like enabling multiple concurrent tasks and improved performance.
The document discusses multithreading in Java. It defines multithreading as executing multiple threads simultaneously, with threads being lightweight subprocesses that share a common memory area. This allows multitasking to be achieved more efficiently than with multiprocessing. The advantages of multithreading include not blocking the user, performing operations together to save time, and exceptions in one thread not affecting others. The document also covers thread states, creating and starting threads, and common thread methods.
Multithreading is the ability of a program or an
operating system process to manage its use by
more than one user at a time and to even manage
multiple requests by the same user without
having to have multiple copies of the
programming running in the computer.
This document provides an overview of threads in Java, including:
- Threads allow for multitasking by executing multiple processes simultaneously. They are lightweight processes that exist within a process and share system resources.
- Threads can be created by extending the Thread class or implementing the Runnable interface. The run() method defines the code executed by the thread.
- Threads transition between states like new, runnable, running, blocked, and dead during their lifecycle. Methods like start(), sleep(), join(), etc. impact the thread states.
- Synchronization is used to control access to shared resources when multiple threads access methods and data outside their run() methods. This prevents issues like inconsistent data.
This document provides an overview of multithreading in 3 sentences or less:
Multithreading allows a program to split into multiple threads that can run simultaneously, improving responsiveness, utilizing multiprocessors efficiently, and structuring programs more effectively. Threads transition between different states like new, runnable, running, blocked, and dead over their lifetime. Common threading techniques include setting thread priority, enabling communication between threads, and avoiding deadlocks when multiple threads depend on each other's locks.
The document discusses threads and multithreading in Java. It defines a thread as a single sequential flow of control within a program. Multithreading allows a program to be divided into multiple subprograms that can run concurrently. Threads have various states like newborn, runnable, running, blocked, and dead. The key methods for managing threads include start(), sleep(), yield(), join(), wait(), notify(). Synchronization is needed when multiple threads access shared resources to prevent inconsistencies. Deadlocks can occur when threads wait indefinitely for each other.
The document discusses various concepts related to multithreading in Java including thread-safe collections, executors, and synchronizers. It provides details on blocking queues, concurrent hash maps, executors that allow submitting tasks to thread pools, and synchronizers like cyclic barriers, countdown latches, and semaphores that help manage groups of threads. It also discusses how to update Swing components safely from multiple threads using EventQueue methods like invokeLater().
Multithreading allows a program to execute multiple tasks concurrently by using threads. There are two types of threads: single threads where a program uses one thread, and multiple threads where a program uses more than one thread concurrently. The life cycle of a thread involves different states such as newborn, runnable, running, blocked, and dead. Common thread methods include start(), run(), yield(), sleep(), wait(), notify(), and stop().
Multithreading in java is a process of executing multiple threads simultaneously. The thread is basically a lightweight sub-process, the smallest unit of processing. Multiprocessing and multithreading, both are used to achieve multitasking.
This document introduces multi-threading in Java. It discusses that threads allow a program to have multiple paths of execution. Threads can be created by extending the Thread class or implementing the Runnable interface. The key method for threads is run, which contains the logic to be executed. The document covers starting threads, potential problems with threads accessing shared resources, and techniques for thread synchronization like synchronized methods, waits and notifies.
This document discusses Java multithreading. It explains that multithreading allows an application to have multiple points of execution within the same memory space. It outlines how Java supports multithreading through the Thread class and Runnable interface. It also describes concurrency issues that can arise from multithreading, such as race conditions, and how to address them using techniques like synchronized access and locking.
Java Multithreading Using Executors FrameworkArun Mehra
This document provides an overview of using executors to handle multithreading in Java. It discusses key classes and interfaces in the executors framework like Executor, ExecutorService, and Executors. Common thread pools like fixed thread pool and cached thread pool are mentioned. The document also summarizes techniques for naming threads, returning values from threads, creating daemon threads, checking thread status, terminating threads, and handling uncaught exceptions using both the thread and executor APIs. Finally, it covers scheduling tasks using both the timer/timerTask classes and executor service.
Multithreading allows a program to split into multiple subprograms called threads that can run concurrently. Threads go through various states like new, runnable, running, blocked, and dead. There are two main ways to create threads: by extending the Thread class or implementing the Runnable interface. Threads can have different priorities that influence scheduling order. Multithreading allows performing multiple operations simultaneously to save time without blocking the user, and exceptions in one thread do not affect others.
The document discusses multi-threading in Java. It defines multi-threading as allowing multiple threads within a process to execute concurrently. It explains that threads share resources of the process but have their own call stacks and program counters. The document outlines the life cycle of a thread in Java and describes how to create threads by implementing the Runnable interface or extending the Thread class. It provides examples of creating and running threads concurrently in Java.
The document discusses multithreading in Java, including the evolution of threading support across Java releases and examples of implementing multithreading using Threads, ExecutorService, and NIO channels. It also provides examples of how to make operations thread-safe using locks and atomic variables when accessing shared resources from multiple threads. References are included for further reading on NIO-based servers and asynchronous channel APIs introduced in Java 7.
The document discusses the thread model of Java. It states that all Java class libraries are designed with multithreading in mind. Java uses threads to enable asynchronous behavior across the entire system. Once started, a thread can be suspended, resumed, or stopped. Threads are created by extending the Thread class or implementing the Runnable interface. Context switching allows switching between threads by yielding control voluntarily or through prioritization and preemption. Synchronization is needed when threads access shared resources using monitors implicit to each object. Threads communicate using notify() and wait() methods.
A thread is an independent path of execution within a Java program. The Thread class in Java is used to create threads and control their behavior and execution. There are two main ways to create threads - by extending the Thread class or implementing the Runnable interface. The run() method contains the code for the thread's task and threads can be started using the start() method. Threads have different states like New, Runnable, Running, Waiting etc during their lifecycle.
- Java threads allow for multithreaded and parallel execution where different parts of a program can run simultaneously.
- There are two main ways to create a Java thread: extending the Thread class or implementing the Runnable interface.
- To start a thread, its start() method must be called rather than run(). Calling run() results in serial execution rather than parallel execution of threads.
- Synchronized methods use intrinsic locks on objects to allow only one thread to execute synchronized code at a time, preventing race conditions when accessing shared resources.
Threads allow multiple tasks to run concurrently within a single Java program. A thread represents a separate path of execution and threads can be used to improve performance. There are two main ways to create threads: by extending the Thread class or implementing the Runnable interface. Threads transition between different states like new, runnable, running, blocked, and terminated. Synchronization is needed to prevent race conditions when multiple threads access shared resources simultaneously. Deadlocks can occur when threads wait for each other in a circular manner.
This document provides information on processes, threads, concurrency, and parallelism in Java. It discusses that processes have separate memory spaces while threads within the same process share memory. It describes how to create threads by extending Thread or implementing Runnable. It also covers thread states, scheduling, priorities, and daemon threads.
The document discusses multithreading concepts like concurrency and threading, how to create and control threads including setting priorities and states, and how to safely share resources between threads using synchronization, locks, and wait/notify methods to avoid issues like deadlocks. It also covers deprecated thread methods and increased threading support in JDK 1.5.
1. The document discusses threads and multithreading in Java. It defines threads as independent paths of execution within a process and explains how Java supports multithreading.
2. Key concepts covered include the different states a thread can be in (new, ready, running, blocked, dead), thread priorities, synchronization to allow threads to safely access shared resources, and methods to control threads like start(), sleep(), join(), etc.
3. Examples are provided to demonstrate how to create and manage multiple threads that run concurrently and synchronize access to shared resources.
This presentation is about advanced multithreading and concurrency in Java. I have tried my best to explain the concepts with code. Feel free to reach me if you have any questions or concerns.
Implementing subprograms requires saving execution context, allocating activation records, and maintaining dynamic or static chains. Activation records contain parameters, local variables, return addresses, and dynamic/static links. Nested subprograms are supported through static chains that connect activation records. Dynamic scoping searches the dynamic chain for non-local variables, while shallow access uses a central variable table. Blocks are implemented as parameterless subprograms to allocate separate activation records for block variables.
Parallel Programming In Modern World .NET TechnicsIT Weekend
This document discusses parallel programming concepts in .NET, including concurrency vs parallelism, limitations to parallel speedup, Amdahl's Law and Gustafson's Law for calculating parallel speedup, phases of parallel development like finding concurrency and algorithm structures, data parallelism patterns like map-reduce, futures, dynamic task parallelism using pipelines, and asynchronous programming using async and await. Key algorithm structures covered include task parallelism, divide and conquer, and map-reduce patterns. Supporting structures discussed are SPMD, master-worker, and fork/join models. The document also touches on error handling and cancellation techniques in parallel programming.
The document discusses several programming paradigms:
- The object-oriented paradigm deals with active objects that can receive messages to perform methods like printing or copying. Classes are used to define common methods for objects like files.
- Functional programming treats programs as mathematical functions that map inputs to outputs. Functions can be combined to perform tasks like extracting elements from a list.
- Declarative programming uses logical reasoning over facts and rules to deduce answers to queries, as in the language Prolog.
- Common concepts across procedural languages include identifiers that symbolically name data rather than using addresses directly.
The document discusses threads and multithreading in Java. It defines a thread as a single sequential flow of control within a program. Multithreading allows a program to be divided into multiple subprograms that can run concurrently. Threads have various states like newborn, runnable, running, blocked, and dead. The key methods for managing threads include start(), sleep(), yield(), join(), wait(), notify(). Synchronization is needed when multiple threads access shared resources to prevent inconsistencies. Deadlocks can occur when threads wait indefinitely for each other.
The document discusses various concepts related to multithreading in Java including thread-safe collections, executors, and synchronizers. It provides details on blocking queues, concurrent hash maps, executors that allow submitting tasks to thread pools, and synchronizers like cyclic barriers, countdown latches, and semaphores that help manage groups of threads. It also discusses how to update Swing components safely from multiple threads using EventQueue methods like invokeLater().
Multithreading allows a program to execute multiple tasks concurrently by using threads. There are two types of threads: single threads where a program uses one thread, and multiple threads where a program uses more than one thread concurrently. The life cycle of a thread involves different states such as newborn, runnable, running, blocked, and dead. Common thread methods include start(), run(), yield(), sleep(), wait(), notify(), and stop().
Multithreading in java is a process of executing multiple threads simultaneously. The thread is basically a lightweight sub-process, the smallest unit of processing. Multiprocessing and multithreading, both are used to achieve multitasking.
This document introduces multi-threading in Java. It discusses that threads allow a program to have multiple paths of execution. Threads can be created by extending the Thread class or implementing the Runnable interface. The key method for threads is run, which contains the logic to be executed. The document covers starting threads, potential problems with threads accessing shared resources, and techniques for thread synchronization like synchronized methods, waits and notifies.
This document discusses Java multithreading. It explains that multithreading allows an application to have multiple points of execution within the same memory space. It outlines how Java supports multithreading through the Thread class and Runnable interface. It also describes concurrency issues that can arise from multithreading, such as race conditions, and how to address them using techniques like synchronized access and locking.
Java Multithreading Using Executors FrameworkArun Mehra
This document provides an overview of using executors to handle multithreading in Java. It discusses key classes and interfaces in the executors framework like Executor, ExecutorService, and Executors. Common thread pools like fixed thread pool and cached thread pool are mentioned. The document also summarizes techniques for naming threads, returning values from threads, creating daemon threads, checking thread status, terminating threads, and handling uncaught exceptions using both the thread and executor APIs. Finally, it covers scheduling tasks using both the timer/timerTask classes and executor service.
Multithreading allows a program to split into multiple subprograms called threads that can run concurrently. Threads go through various states like new, runnable, running, blocked, and dead. There are two main ways to create threads: by extending the Thread class or implementing the Runnable interface. Threads can have different priorities that influence scheduling order. Multithreading allows performing multiple operations simultaneously to save time without blocking the user, and exceptions in one thread do not affect others.
The document discusses multi-threading in Java. It defines multi-threading as allowing multiple threads within a process to execute concurrently. It explains that threads share resources of the process but have their own call stacks and program counters. The document outlines the life cycle of a thread in Java and describes how to create threads by implementing the Runnable interface or extending the Thread class. It provides examples of creating and running threads concurrently in Java.
The document discusses multithreading in Java, including the evolution of threading support across Java releases and examples of implementing multithreading using Threads, ExecutorService, and NIO channels. It also provides examples of how to make operations thread-safe using locks and atomic variables when accessing shared resources from multiple threads. References are included for further reading on NIO-based servers and asynchronous channel APIs introduced in Java 7.
The document discusses the thread model of Java. It states that all Java class libraries are designed with multithreading in mind. Java uses threads to enable asynchronous behavior across the entire system. Once started, a thread can be suspended, resumed, or stopped. Threads are created by extending the Thread class or implementing the Runnable interface. Context switching allows switching between threads by yielding control voluntarily or through prioritization and preemption. Synchronization is needed when threads access shared resources using monitors implicit to each object. Threads communicate using notify() and wait() methods.
A thread is an independent path of execution within a Java program. The Thread class in Java is used to create threads and control their behavior and execution. There are two main ways to create threads - by extending the Thread class or implementing the Runnable interface. The run() method contains the code for the thread's task and threads can be started using the start() method. Threads have different states like New, Runnable, Running, Waiting etc during their lifecycle.
- Java threads allow for multithreaded and parallel execution where different parts of a program can run simultaneously.
- There are two main ways to create a Java thread: extending the Thread class or implementing the Runnable interface.
- To start a thread, its start() method must be called rather than run(). Calling run() results in serial execution rather than parallel execution of threads.
- Synchronized methods use intrinsic locks on objects to allow only one thread to execute synchronized code at a time, preventing race conditions when accessing shared resources.
Threads allow multiple tasks to run concurrently within a single Java program. A thread represents a separate path of execution and threads can be used to improve performance. There are two main ways to create threads: by extending the Thread class or implementing the Runnable interface. Threads transition between different states like new, runnable, running, blocked, and terminated. Synchronization is needed to prevent race conditions when multiple threads access shared resources simultaneously. Deadlocks can occur when threads wait for each other in a circular manner.
This document provides information on processes, threads, concurrency, and parallelism in Java. It discusses that processes have separate memory spaces while threads within the same process share memory. It describes how to create threads by extending Thread or implementing Runnable. It also covers thread states, scheduling, priorities, and daemon threads.
The document discusses multithreading concepts like concurrency and threading, how to create and control threads including setting priorities and states, and how to safely share resources between threads using synchronization, locks, and wait/notify methods to avoid issues like deadlocks. It also covers deprecated thread methods and increased threading support in JDK 1.5.
1. The document discusses threads and multithreading in Java. It defines threads as independent paths of execution within a process and explains how Java supports multithreading.
2. Key concepts covered include the different states a thread can be in (new, ready, running, blocked, dead), thread priorities, synchronization to allow threads to safely access shared resources, and methods to control threads like start(), sleep(), join(), etc.
3. Examples are provided to demonstrate how to create and manage multiple threads that run concurrently and synchronize access to shared resources.
This presentation is about advanced multithreading and concurrency in Java. I have tried my best to explain the concepts with code. Feel free to reach me if you have any questions or concerns.
Implementing subprograms requires saving execution context, allocating activation records, and maintaining dynamic or static chains. Activation records contain parameters, local variables, return addresses, and dynamic/static links. Nested subprograms are supported through static chains that connect activation records. Dynamic scoping searches the dynamic chain for non-local variables, while shallow access uses a central variable table. Blocks are implemented as parameterless subprograms to allocate separate activation records for block variables.
Parallel Programming In Modern World .NET TechnicsIT Weekend
This document discusses parallel programming concepts in .NET, including concurrency vs parallelism, limitations to parallel speedup, Amdahl's Law and Gustafson's Law for calculating parallel speedup, phases of parallel development like finding concurrency and algorithm structures, data parallelism patterns like map-reduce, futures, dynamic task parallelism using pipelines, and asynchronous programming using async and await. Key algorithm structures covered include task parallelism, divide and conquer, and map-reduce patterns. Supporting structures discussed are SPMD, master-worker, and fork/join models. The document also touches on error handling and cancellation techniques in parallel programming.
The document discusses several programming paradigms:
- The object-oriented paradigm deals with active objects that can receive messages to perform methods like printing or copying. Classes are used to define common methods for objects like files.
- Functional programming treats programs as mathematical functions that map inputs to outputs. Functions can be combined to perform tasks like extracting elements from a list.
- Declarative programming uses logical reasoning over facts and rules to deduce answers to queries, as in the language Prolog.
- Common concepts across procedural languages include identifiers that symbolically name data rather than using addresses directly.
This document discusses subprograms (also called subroutines) in programming languages. It covers:
- The basic definitions and characteristics of subprograms, including headers, parameters, and local variables.
- Different parameter passing methods like pass-by-value, pass-by-reference, and their implementation in common languages.
- Additional features of subprograms including overloading, generics, and functions passing subprograms as parameters.
The document describes the evolution of programming languages from machine languages to high-level languages, and how a program written in a high-level language is translated into machine language. It discusses four main programming paradigms - procedural, object-oriented, functional, and declarative - and provides details on the procedural paradigm. Key aspects of the procedural paradigm include programs made up of procedures that manipulate passive data items, and common procedural languages like FORTRAN, COBOL, Pascal, C, and Ada.
This document outlines a student project submitted to Inam ul Haq at the University of Education, Okara Campus. It includes an introduction, motivation or objective, importance and scope, comparison, findings, summary, and conclusion. The document contains 10 slides covering these sections and references. It follows a typical structure for a student research project or paper.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document provides definitions and history of programming languages and summarizes the five best programming languages to learn. It defines a programming language as a notation for writing computer programs and algorithms. The first programming languages were developed in the 1950s to communicate instructions to computers. Major programming language paradigms like APL, ALGOL, and C emerged from the 1960s to late 1970s. The five best programming languages highlighted are Java, Ruby, Python, C/C++, and JavaScript.
The document discusses several key aspects of programming languages including:
1) There is amazing variety across languages with over 2300 published languages grouped into four main families: imperative, functional, logic, and object-oriented.
2) Programming languages are the subject of ongoing debates around their relative merits and definitions.
3) Languages are constantly evolving as new ideas are introduced and older languages develop new dialects.
4) Languages influence programming practices but programmers can also work against a language's favored style.
This document discusses computer hardware, software, programming languages, and how code is executed. It defines hardware as physical components like the motherboard, disk drive, and fans. Software consists of programs made of instruction sequences that hardware can understand. Programming languages have evolved from low-level machine code and assembly code to high-level languages like C, C++, Java, and PHP. Language translators like assemblers, compilers, and interpreters are used to translate source code into executable machine code that computers can understand.
There are three main types of programming languages: procedural, declarative, and object-oriented. Procedural languages specify operations in a sequence and use subprograms, variables, and data types. Declarative languages declare facts and rules to solve problems using queries. Object-oriented languages are modeled around objects that can have attributes and methods, and classes act as blueprints to create object instances that can inherit properties from other classes.
East Coast DevCon 2014: Concurrency & Parallelism in UE4 - Tips for programmi...Gerke Max Preussner
This document discusses concurrency and parallelism techniques in Unreal Engine 4 (UE4). It covers synchronization primitives like atomics, locking, signaling, and waiting. It also discusses high level constructs like thread-safe containers and helpers. For parallelization, it discusses threading using runnables, task graphs, processes, and messaging. The goal is to provide tips for programming UE4 to take advantage of multiple CPU cores.
High level languages like those using words like "if" and "else" are easier for humans to understand, while low level machine code using binary is what computers can directly understand. Translators are needed to convert high level code to low level code for the computer. There are two main types of translators - interpreters translate code line by line as the program runs, while compilers convert the entire program to object code before it runs. Both have pros and cons related to speed of execution and ease of debugging.
The document discusses different types and levels of abstraction. It describes abstraction as purposefully hiding details to emphasize certain aspects. It outlines various layers of abstraction in programming from overall program design down to individual methods. It also discusses other forms of abstraction like dividing systems into parts and layers of specialization. The document provides examples of abstraction concepts from programming, biology, and other domains.
Modeling and abstraction, software development process [Software Modeling] [C...Ivano Malavolta
This presentation is about a lecture I gave within the "Software Modeling" course of the Computer Science bachelor program, of the Vrije Universiteit Amsterdam.
http://www.ivanomalavolta.com
A programming language is a set of rules that allows humans to tell computers what operations to perform. Programming languages provide tools for developing executable models for problem domains and exist at various levels from high-level languages that are closer to human language to low-level machine code. Some of the principal programming paradigms include imperative, object-oriented, logic/declarative, and functional programming. Popular high-level languages include FORTRAN, COBOL, BASIC, C, C++, Java, and markup languages like HTML and XML.
JSX - developing a statically-typed programming language for the WebKazuho Oku
Kazuho Oku presents JSX, a statically-typed programming language that compiles to JavaScript. JSX aims to improve productivity over JavaScript by enabling errors to be caught at compile-time rather than runtime. It also aims to optimize code size and execution speed compared to JavaScript through type information and compiler optimizations. Oku discusses JSX language features like classes and types, benchmarks showing improved performance over JavaScript, and efforts to bind JSX to W3C standards through automatic translation of interface definition languages.
Lect 1. introduction to programming languagesVarun Garg
A programming language is a set of rules that allows humans to communicate instructions to computers. There are many programming languages because they have evolved over time as better ways to design them have been developed. Programming languages can be categorized based on their generation or programming paradigm such as imperative, object-oriented, logic-based, and functional. Characteristics like writability, readability, reliability and maintainability are important qualities for programming languages.
This document provides an introduction and overview of the Java programming language and environment. It outlines the course content which will cover the history and evolution of Java, the Java programming environment including compilation and interpretation, key features such as platform independence and automatic memory management, and packages and tools. The document also provides examples of Java code for a simple "Hello World" application to demonstrate using the Java Development Kit.
The document discusses the fundamentals of object-oriented programming and Java. It covers key concepts like abstraction, encapsulation, inheritance and polymorphism. It also describes the basic structure of a Java program, including classes, objects, methods and variables. It explains how to set up a Java development environment, compile and run a simple Java program.
This document provides an overview of object-oriented programming concepts in Java including abstraction, encapsulation, inheritance, and polymorphism. It discusses key Java concepts like classes, objects, methods, and access specifiers. It also covers Java fundamentals like variables, data types, operators, control flow statements, comments, and arrays. Additionally, it describes the Java runtime environment, how to set up a Java development environment, compile and run a simple Java program. The document is intended as an introduction to object-oriented programming and the Java programming language.
Java programs run on the Java Virtual Machine (JVM). The JVM provides a runtime environment that executes Java bytecode. Key aspects of Java include its use of object-oriented programming, garbage collection, and strong typing. Popular integrated development environments for Java include Eclipse and IntelliJ IDEA.
The document provides an overview of the Java programming language. It discusses that Java was created by James Gosling at Sun Microsystems in 1995 and the latest version is Java SE 14. It then describes several key concepts and features of Java including: it being object-oriented, simple, secure, platform independent, robust, portable, dynamic, architecture neutral, high performance, multithreaded, and distributed. It also discusses the Java Virtual Machine, Java Runtime Environment, Java Development Kit, and main Java platforms.
The document discusses parallel and distributed computing concepts in Aneka including multiprocessing, multithreading, task-based programming, and parameter sweep applications. It describes key aspects of implementing parallel applications in Aneka such as defining tasks, managing task execution, file handling, and tools for developing parameter sweep jobs. The document also provides an overview of how workflow managers can interface with Aneka.
This document provides an overview of core Java concepts including:
- A brief history of Java's development from 1991 to today.
- Key Java features such as being object-oriented, platform independent, secure, and reliable.
- Object-oriented programming concepts in Java like classes, objects, inheritance, polymorphism.
- Common Java keywords, operators, data types, and variables.
- Additional topics covered include methods, inheritance, interfaces, exceptions, and strings.
This document provides an overview of object-oriented design patterns, including classifications of patterns and descriptions of common patterns. It discusses creational, structural, and behavioral patterns. Specific patterns covered include Observer, Singleton, Builder, Chain of Responsibility, Proxy, Decorator, Template Method, and Service Locator. Diagrams and code examples are provided to illustrate many of the patterns. The conclusion emphasizes that design patterns can improve code quality but require practice to apply effectively.
Threads are lightweight processes that improve application performance through parallelism. Each thread has its own program counter and stack but shares other resources like memory with other threads in a process. Using threads provides advantages like lower overhead context switching compared to processes and allows parallel execution on multi-core systems. There are two types of threads - user level threads managed by libraries and kernel level threads supported by the OS kernel. Threads have a life cycle that involves states like new, ready, running, blocked, and terminated.
Threads are lightweight processes that improve application performance through parallelism. Each thread has its own program counter and stack but shares other resources like memory with other threads in a process. Using threads provides advantages like lower overhead context switching compared to processes and allows parallel execution on multi-core systems. There are two types of threads - user level threads managed by libraries and kernel level threads supported by the OS kernel. Threads have a life cycle that includes states like new, ready, running, blocked, and terminated.
This document introduces threads as a fundamental unit of CPU utilization that forms the basis of multithreaded computer systems. It examines issues related to multithreaded programming and compares single and multithreaded processes. Threads within a process share code, data and heap sections but have their own stack segments. Context switching is cheaper between threads of the same process than between processes. Threads allow overlapping computation and I/O to improve performance.
Threads allow a process to concurrently perform multiple tasks. A thread is the basic unit of CPU utilization and shares resources with other threads in the same process. Multithreading improves responsiveness, allows resource sharing, and enables better utilization of multiprocessor systems. There are different models for mapping user threads to kernel threads, including many-to-one, one-to-one, and many-to-many. Popular thread libraries include Pthreads and Windows threads which provide APIs for thread management. Issues with multithreading include how to handle signals, cancellation, and the fork and exec system calls across threads.
This document provides an overview of Java programming including:
- A brief history of Java originating from Sun Microsystems' Green project in the 1990s.
- An introduction to core Java concepts like the Java Virtual Machine, bytecode, and platforms independence.
- A discussion of object-oriented programming principles like abstraction, encapsulation, and polymorphism and how they are implemented in Java.
- Descriptions of common Java program types like applications and applets and how they are processed by the Java runtime environment.
- An introduction to Unified Modeling Language (UML) diagrams used for software design.
This document provides information about multithreading and I/O in Java. It discusses the Java thread model and how to create threads using the Thread class and Runnable interface. It covers thread states, priorities, synchronization, and inter-thread communication. It also discusses I/O basics in Java including reading from the console using Console, BufferedReader and Scanner, and writing to the console and files.
@MarketaAdamova Slides from 'Road Trip To Component' talk (Dutch Clojure Days 2017)
'Few months ago our company NomNom decided to move all its backend services from Ruby to Clojure. And I think a road trip is best comparison for this migration. There was excitement at start, then panic a few hours down the road wondering what was left behind, but now a constant joy of discovering new things. In this talk I’d like to share how we eventually arrived at Stuart Sierra’s Component. Let’s take a look at how components improved our quickly growing codebase and testing, as well as some of the trade-offs we had to make. Finally I’ll show how components can help with managing running code in production.'
This document provides an overview of Akka and Akka Cluster, frameworks for building distributed and fault-tolerant applications using actors. It discusses concurrency paradigms like message passing actors, Akka's implementation of the actor model, clustering with Akka Cluster, and using CRDTs for distributed shared state. It also previews demos of building a web crawler application and clustering it across nodes with Akka Cluster.
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Privacy Preservation Issues in Association Rule Mining in Horizontally Partit...Abhra Basak
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XML (eXtensible Markup Language) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is designed to transport and store data with a focus on what data is. XML has several advantages over HTML such as being extensible, content-oriented, and providing a standard data infrastructure and data validation capabilities. XML documents form a tree structure with properly nested elements. XML uses tags to mark elements and attributes to provide additional information about elements.
Spanner is Google's globally distributed database that is scalable, multi-version, and synchronously replicated across data centers. It provides ACID transactions through the use of TrueTime, a GPS and atomic clock powered service that provides a consistent view of global time, enabling external consistency across distributed transactions through timestamp ordering and global commit ordering.
The document discusses Sourav Ganguly's leadership and impact as the captain of the Indian cricket team. It highlights how he brought aggression, toughness and optimism to the team, instilled a fighting spirit, backed young talent, and led India to several important victories including reaching the 2003 Cricket World Cup final. His leadership transformed Indian cricket and laid the foundation for future success, including winning the 2011 World Cup.
Usability evaluation of the IIT Mandi WebsiteAbhra Basak
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The document provides guidance on choosing courses for an upcoming semester at IIT Mandi using multi-attribute decision making. It outlines 5 alternatives for selecting courses and credit hours: taking a standard course load of 7 classes for 21 credits; taking an overload of more than 21 credits; taking a lighter course load; dropping the semester to do an internship abroad; or focusing on clearing backlogs and personal projects. It evaluates each alternative based on 4 attributes: career opportunities, quality of college life, exposure to interests, and chances of achieving a good GPA. Based on this analysis, taking an audit course is ranked the best choice as it offers high career opportunities, moderate college life impact, high interest exposure, and high chances of a
The document provides information about the S&P CNX Nifty and NASDAQ-100 stock indices.
The S&P CNX Nifty tracks the performance of the 50 largest Indian companies listed on the National Stock Exchange of India based on market capitalization. It covers 23 sectors of the Indian economy. The NASDAQ-100 tracks the performance of 100 of the largest domestic and international non-financial companies listed on the Nasdaq Stock Market based on market capitalization. Both indices have eligibility criteria for initial and continued inclusion and use formulae to calculate index values based on the market values and weights of constituent securities.
Dive into the realm of operating systems (OS) with Pravash Chandra Das, a seasoned Digital Forensic Analyst, as your guide. 🚀 This comprehensive presentation illuminates the core concepts, types, and evolution of OS, essential for understanding modern computing landscapes.
Beginning with the foundational definition, Das clarifies the pivotal role of OS as system software orchestrating hardware resources, software applications, and user interactions. Through succinct descriptions, he delineates the diverse types of OS, from single-user, single-task environments like early MS-DOS iterations, to multi-user, multi-tasking systems exemplified by modern Linux distributions.
Crucial components like the kernel and shell are dissected, highlighting their indispensable functions in resource management and user interface interaction. Das elucidates how the kernel acts as the central nervous system, orchestrating process scheduling, memory allocation, and device management. Meanwhile, the shell serves as the gateway for user commands, bridging the gap between human input and machine execution. 💻
The narrative then shifts to a captivating exploration of prominent desktop OSs, Windows, macOS, and Linux. Windows, with its globally ubiquitous presence and user-friendly interface, emerges as a cornerstone in personal computing history. macOS, lauded for its sleek design and seamless integration with Apple's ecosystem, stands as a beacon of stability and creativity. Linux, an open-source marvel, offers unparalleled flexibility and security, revolutionizing the computing landscape. 🖥️
Moving to the realm of mobile devices, Das unravels the dominance of Android and iOS. Android's open-source ethos fosters a vibrant ecosystem of customization and innovation, while iOS boasts a seamless user experience and robust security infrastructure. Meanwhile, discontinued platforms like Symbian and Palm OS evoke nostalgia for their pioneering roles in the smartphone revolution.
The journey concludes with a reflection on the ever-evolving landscape of OS, underscored by the emergence of real-time operating systems (RTOS) and the persistent quest for innovation and efficiency. As technology continues to shape our world, understanding the foundations and evolution of operating systems remains paramount. Join Pravash Chandra Das on this illuminating journey through the heart of computing. 🌟
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
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5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
Skybuffer AI: Advanced Conversational and Generative AI Solution on SAP Busin...Tatiana Kojar
Skybuffer AI, built on the robust SAP Business Technology Platform (SAP BTP), is the latest and most advanced version of our AI development, reaffirming our commitment to delivering top-tier AI solutions. Skybuffer AI harnesses all the innovative capabilities of the SAP BTP in the AI domain, from Conversational AI to cutting-edge Generative AI and Retrieval-Augmented Generation (RAG). It also helps SAP customers safeguard their investments into SAP Conversational AI and ensure a seamless, one-click transition to SAP Business AI.
With Skybuffer AI, various AI models can be integrated into a single communication channel such as Microsoft Teams. This integration empowers business users with insights drawn from SAP backend systems, enterprise documents, and the expansive knowledge of Generative AI. And the best part of it is that it is all managed through our intuitive no-code Action Server interface, requiring no extensive coding knowledge and making the advanced AI accessible to more users.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
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Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
Letter and Document Automation for Bonterra Impact Management (fka Social Sol...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on automated letter generation for Bonterra Impact Management using Google Workspace or Microsoft 365.
Interested in deploying letter generation automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
leewayhertz.com-AI in predictive maintenance Use cases technologies benefits ...alexjohnson7307
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Fueling AI with Great Data with Airbyte WebinarZilliz
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Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
3. • Concurrency and Parallelism in the Java Runtime Environment
• The Java Thread Model - Decisions for Design
• Implementing Multithreading – Creating and Managing Threads
• Remote Method Execution – Java RMI
• The Concurrency Utilities – java.util.concurrent
• Thread Safety – Shared Access to Data
• GUI Applications in Java
5. • Allows you to run the Java Compiler at the same time that
you are using an editor
Process-based multitasking
• A text editor can format text at the same time that it is
printing
Thread-based multitasking
10. • Thread priorities are integers assigned by the Java runtime that
specify the relative priority of one thread to another.
• A thread can voluntarily relinquish control.
• A thread can be preempted by a higher priority thread.
11. • An elegant twist to an age-old model of inter-process
synchronization – the monitor.
• Most multithreaded systems expose monitors as objects that the
program must explicitly acquire and manipulate.
• Java provides a cleaner solution : each object has its own implicit
monitor, automatically called while invoking synchronized methods.
15. Source : Parallel Programming for Multicore and Cluster Systems - Rauber & Runger
16. Source : Parallel Programming for Multicore and Cluster Systems - Rauber & Runger
17. • Thread execution
• start() – Start a thread by calling its run() method
• run() – Entry point for the thread
• Thread blocking
• sleep() – Suspend a thread for a period of time
• yield() – Voluntarily relinquish thread control to another thread of
the same priority
18. • Thread lifetime and termination
• isAlive() – Determine if a thread is still running
• join() – Wait for a thread to terminate
• Thread communication
• wait() – Instructs the calling thread to give up the monitor and
sleep until some other thread enters the same monitor and calls
notify()
• notify() – Wakes up a thread that called wait() on the same object
• notifyAll() – Wakes up all threads that called wait() on the same
object
20. • The RMI facility allows you to invoke operations on objects running in
other JVMs.
• When a remote method is called, the RMI stub, created by the RMI
compiler, packages the method parameters and sends them over the
network.
• The remote system unpacks the arguments and then calls the remote
method.
23. • Implements the classic semaphore
Semaphore
• Waits until a specified number of events have occurred
CountDownLatch
• Enables a group of threads to wait at a predefined execution point
CyclicBarrier
• Exchanges data between two threads
Exchanger
33. • GUI systems use a single thread called the Event Dispatch Thread for
handling GUI events
• Multithreaded GUIs tend to be particularly prone to deadlocks.
• Swing is single-threaded particularly because of observations of
AWT which tried to be provide a higher degree of multi threaded
access.
• Longer running tasks triggered by event listeners in the even
dispatch thread are switched over to different threads to ensure the
GUI doesn’t freeze.
35. • Concurrency and Parallelism in the Java Runtime Environment
• The Java Thread Model - Decisions for Design
• Implementing Multithreading – Creating and Managing Threads
• Remote Method Execution – Java RMI
• The Concurrency Utilities – java.util.concurrent
• Thread Safety – Shared Access to Data
• GUI Applications in Java
36. • Android – A Java based mobile application platform
• Java Swing, AWT and Applets
• Process scheduling in Java Operating Systems
38. • Tim Peierls, Brian Goetz, Joshua Bloch, Joseph Bowbeer, Doug Lea, and
David Holmes. 2005. Java Concurrency in Practice. Addison-Wesley
Professional.
• Kazuaki Ishizaki, Shahrokh Daijavad, and Toshio Nakatani. 2011.
Refactoring Java programs using concurrent libraries. In Proceedings of the
Workshop on Parallel and Distributed Systems: Testing, Analysis, and
Debugging (PADTAD '11)
• Dan Grossman and Ruth E. Anderson. 2012. Introducing parallelism and
concurrency in the data structures course. In Proceedings of the 43rd ACM
technical symposium on Computer Science Education (SIGCSE '12)
39. • Alan D. Fekete. 2008. Teaching students to develop thread-safe java classes.
In Proceedings of the 13th annual conference on Innovation and technology in
computer science education (ITiCSE '08)
• Doug Lea. Concurrent Programming in Java: Design principles and patterns,
Addison-Wesley. First edition, October 1996 (also, German, Chinese, and
Japanese translations, and an on-line supplement). Second edition,
November 1999.
• Brian Goetz, with Tim Peierls, Joshua Bloch, Joseph Bowbeer, David Holmes,
Doug Lea, Java Concurrency in Practice, Addison Wesley, 2006.
Editor's Notes
Multitasking – Thread-based and Process-basedProcess-based multitasking – Allows you to run the Java Compiler at the same time that you are using an editorThread-based multitasking – A text editor can format text at the same time that it is printing
The Java Code and the Java libraries are together compiled to byte code.
The byte code is then interpreted in the Java Virtual Machine (JVM) as executable instructions.Unlike many computer languages, Java provides built-in support for multithreading.All Java programs are multi-threaded (Inherent concurrency)The Garbage Collector always runs as a separate thread in the background.The Java runtime system depends upon threads for many things, and all the class libraries are designed with multithreading in mind.
Single Threaded systems use an approach called an event loop with polling.In this model, a single thread of control runs in an infinite loop, polling a single event queue to decide what to do next.Until an event handler returns, nothing else can happen in the system. This wastes CPU time.It can also result in one part of a program dominating the system, and preventing any other events from being processed.When a thread blocks, i.e., suspends execution, because it is waiting for some other resource, the entire program stops running.The benefit of Java’s multithreading is that the main loop / polling mechanism is eliminated.When a thread blocks in a Java program, only the single thread that is blocked pauses. All other threads continue to run.
As an absolute value, a priority is meaningless. A higher priority thread doesn’t run any faster than a lower priority thread if it is the only thread running.Instead a thread’s priority is used to decide when to switch from one thread to the next. This is called a context switch.Relinquish: This is done by explicitly yielding, sleeping, or blocking on pending I/O. In this scenario, all other threads are examined, and the highest priority thread that is ready to run is given the CPU.Pre-emption: In this case a lower priority thread that does not yield the processor is simply preempted – no matter what it is doing – by a higher priority thread. Basically, as soon as a higher priority thread wants to run, it does. This is called preemptive multitasking.
If you want two threads to communicate and share a complicated data structure, you need some way to ensure that they don’t conflict with each other.You can think of a monitor as a very small box that can hold only one thread. Once a thread enters a monitor, all other threads must wait until the thread exits the monitor.In this way, the monitor can be used to protect a shared asset from being manipulated by more than one thread at a time.Once a thread is inside a synchronised method, no other thread can call any other synchronised methods on the same object. This helps you write very clear and concise multithreaded code, because synchronisation support is built into the language.
If you want two threads to communicate and share a complicated data structure, you need some way to ensure that they don’t conflict with each other.You can think of a monitor as a very small box that can hold only one thread. Once a thread enters a monitor, all other threads must wait until the thread exits the monitor.In this way, the monitor can be used to protect a shared asset from being manipulated by more than one thread at a time.Once a thread is inside a synchronised method, no other thread can call any other synchronised methods on the same object. This helps you write very clear and concise multithreaded code, because synchronisation support is built into the language.
The program needs to define how separate threads communicate with each other.Java provides a clean, low-cost way for two or more threads to talk to each other, via calls to predefined methods that all objects have.Java’s messaging system allows a thread to enter a synchronized method on an object, and then wait there until another thread explicitly notifies it to come out.
Create an instance of a class that extends class Thread.This class must override the run() method, which is the entry point of the new thread.It must also call start() to begin execution of the new thread.
Create a class that implements the interface Runnable.An object of class Thread is instantiated from within the class.The class should override the method run() which is the entry point for the new thread.
Inside run(), the code constitutes the new thread. run() establishes the entry point for another concurrent thread of execution within the program. Thus thread will end when run() returns.After the new thread is created, it will not start running until its start() method is called, which is declared within Thread. In essence, start() executes a call to run().A thread can be paused / suspended for a period of time using sleep(). Another thread can interrupt a sleeping thread. The sleeping thread then throws an InterruptedException that has to be caught explicitly by the program.
The byte code is then interpreted in the Java Virtual Machine (JVM) as executable instructions.
As conceptually pure as Java’s original support for multithreading is, it is not ideal for all applications – especially those that make extensive use of multiple threads. For example the original multithreading support does not provide several high-level features, such as semaphores, thread pools, and execution managers, that facilitate the creation of intensive concurrent programs.JDK 5 added the concurrency utilities, also commonly referred to as the concurrent API.The concurrency utilities are contained in the java.util.concurrent package and its subpackages java.util.concurrent.atomic and java.util.concurrent.locksjava.util.concurrent defines the core features that support alternatives to the built-in approaches to synchronization and interthread communication.
Offer high level ways of synchronizing the interactions between multiple threads. Collectively, they enable one to handle several formerly difficult synchronization situations with ease. Each synchronizer provides a solution to a specific type of synchronization problem. This enables each synchronizer to be optimized for its intended use.A semaphore controls access to a shared resource through the use of a counter. If the counter is greater than 0, then access is allowed. If it is zero, then access is denied. What the counter is counting are permits that allow access to the shared resource.Sometimes you will want a thread to wait until one or more events have occurred. A CountDownLatch is initially created with a count of the number of events that must occur before the latch is released.When a set of two or more threads must wait at a predetermined execution point until all threads in the set have reached that point, to handle such a situation the API supplies a CyclicBarrier class. It enables you to define a synchronization object that suspends until the specified number of threads has reached the barrier point.Most interesting of the synchronizer classes is the Exchanger. It is designed to simplify the exchange of data between two threads. The operation of an Exchanger is astoundingly simple. It simply waits until two separate threads call its exchange() method. When that occurs, it exchanges the data supplied by the threads. This mechanism is both elegant and easy to use. For example, one thread might prepare a buffer for receiving information over a network connection, another might fill that buffer with the information from the connection.
They manage thread execution. At the top of the Executor hierarchy is the Executor interface, which is used to initiate a thread. It defines execute().The ExecutorService extends Executor and provides methods that manage execution. There are two implemetations of ExecutorService : ThreadPoolExecutor and ScheduledPoolExecutor. Related to Executors are Future and Callable interfaces. Callable defines a thread that defines a value. An application can use Callable objects to compute results that are then returned to the invoking thread. This is a powerful mechanism because it facilitates the coding of numerical computations in which partial reults are computed simultaneously. It could also be used to return status codes to indicate successful completion of threads. A callable task is executed by the ExecutorService, by calling its submit() method.A Future contains a value that is returned by a thread after it executes. Thus its value becomes defined in the future, when the thread terminates. It is a generic interface that represents a value that will be returned by a Callable object.
The package defines several concurrent collection classes such as ConcurrentHashMap,ConcurrentLinkedQueue, CopyOnWriteArrayList. These offer concurrent alternatives to their related classes defined by the collections framework.
TimeUnit is an enumeration that is used to specify the granularity of the timing. The arguments of this type generally indicate a timeout period.Caution: there is no guarantee that the system is capable of the specified resolution, even if any of these values is allowed to be specified.
The java.util.concurrent.locks package provides support for locks, which are objects that offer an alternative to using “synchronized” to control access to a shared resource. Before accessing a shared resource, the lock that protects the resource is acquired. When access to the resource is complete, the lock is released. If a second thread attempts to acquire the lock when it is in use by another thread, the second thread will suspend until the lock is released.All locks implement the Lock interface. The methods defined by Lock are:lock(), unlock(), lockInterruptibly() – waits until the invoking lock can be acquired unless interrupted, newCondition() – returns a Condition object that is associated with the invoking lock, tryLock() – attempts to acquire the lock, if unavailable, it will not wait, or will wait for no longer than the period specified.ReentrantLock implements Lock. It is a lock that can be repeatedly entered by the thread that currently holds the lock. (There should be an equal number of calls to unlock() to offset all calls to lock().) Otherwise, a thread seeking to acquire the lock will suspend until the lock is not in use.
The java.util.concurrent.atomic package offers an alternative to the other synchronization features when reading or writing the values of some types of variables. This package offers methods that get, set, or compare the value of a variable in one uninterruptible atomic operation. This means that no lock or other synchronization mechanism is required.In general, the atomic operations offer a convenient, and possibly more efficient, alternative to the other synchronization mechanisms when only a single variable is involved.
As classes and objects can be accessed by multiple threads when shared between them we need to ensure they are thread-safe.When is a class thread safe?It behaves correctly(ambiguous)Independent of thread scheduling and interleavingWithout additional synchronization
Synchronized keyword: The primary mechanism for synchronization.Every object has an intrinsic lock or monitor associated with it. A thread needing exclusive and consistent access has to acquire the intrinsic lock.Every class also has such a lock associated with it for synchronizing access to static methods.Critical Sections of a program are marked with the synchronized keyword. Particularly useful for fine grained concurrencyVolatile keyword: This keyword enables the thread to bypass the cache when accessing the data.