Multi- threading in C Sharp (C#)Threading is fun, because with it you can do a lot more stuff at the same time. For example, keeping your UI updated while your background tasks are running. C# supports parallel execution of code through multi- threading. A thread is an independent execution path, able to run simultaneously with other threads. Here, we examine three simple C# approaches to help your application perform multiple tasks simultaneously. Method 1: Using System. Thread (easy but unsafe, for low risk use)Method 2: Using Application. Do. Events (okay for general purposes)Method 3: Using Background. Worker class (preferred for thread safety)Of the three methods listed above, the method 1 is the easiest, but is considered unsafe. However, I still find it useful as a quick- n- dirty implementation for rapid prototyping developing, running simulations or testing out new algorithms. It also provides for simple pause and resume mechanisms. Download: Demo using System. Threading. Method 2 is an event- driven approach that applies asynchronous event handlers, and then calls Application. Do. Events to repaint the UI. Hence, its more like multi- tasking rather than multi- threading. In addition, it has a slight re- entry flaw supposed inherited from its predecessors. Download: Demo using Application. Do. Events. For now, it seems like method 3 is the generally accepted preferred practice using thread- safe methods. Its a bit more tedious to implement neatly. I have included source code to provide a short framework to illustrate its capabilities. Download: Demo using Background. Worker. Method 1: Using System. Threading (easy)Using System. Threading for threading purposes is bad. The class exposes two dangerous methods Suspend() and Resume() that are considered unsafe, and are given deprecated warnings since . NET 2. 0. However, I still find it useful as a quick- n- dirty implementation for rapid prototyping developing, running simulations or testing out new algorithms. It also provides for simple pause and resume mechanisms. In the early 1970s the creators of the C Programming Language wrote a book of the same name intended to teach the skills necessary to program in C. The figure above shows a simple green rectangle and text message in a browser; remember there is no native support for SVG in Web browsers at this time. This page is dedicated to the ANSI C Programming language. We've assembled links and copies of interesting or educational articles on C programming, look at Windows. We do this by making it simple for students and teachers to create and share online learning materials. Quizlet is proud to be the most popular online educational. Simplest approach if you need to show a prototype to your client quickly. Nevertheless, its important to understand that its major problem is that of deadlocks. You have no way of knowing what code a thread is executing when you suspend it. If you suspend a thread while it holds locks during a security permission evaluation, other threads in the App. Domain might be blocked. If you suspend a thread while it is executing a class constructor, other threads in the App. Domain that attempt to use that class are blocked. Deadlocks can occur very easily. Here’s an example of a program exhibiting deadlock: http: //www. So at any point in time, the thread could be doing anything. Executing suspend stops the thread running in its tracks. Hence, imagine your thread is reading a file and places a lock on it. Welcome to aplusmath.com! Interactive math resources for teachers, parents, and students featuring free math worksheets, math games, math flashcards, and more. Checker Programs Reviewed and Rated. The Largest Unbiased and Independent Checker Program Review Site on the Internet! Please note that all programs reviewed are. You suspend your thread. Same goes for any other resources. Anyway, if you need a quick solution, here is an outline of how the demo source above works. The UI object starts a new thread for the task object. Hence the UI object and the task object run on separate threads. The task object then performs the endless loop. On each iteration, the task object has to perform an invoke to update the UI object on a cross- thread. Thats it, easy. 1. Main. Form. From the framework, each time the form handles an event, it processes all the code associated with that event. All other events wait in a queue. While your code handles the event, your application does not respond. For example, the window does not repaint if another window is dragged on top. When I was on the C# design team, several times a year we would have 'meet the team' events at conferences, where we would take questions from C# enthusiasts. Here's what CPA Technology Advisor said about 1040 Review: '. Works with: ALGOL 68 version Revision 1 - one minor extension to language used - PRAGMA READ, similar to C's #include directive. Its more simple then you think. According to Microsoft: The lock keyword ensures that one thread does not enter a critical section of code while another thread is in. If you call Do. Events in your code, your application will somewhat interrupt your code and handle the other events. For example, if you have a form that adds data to a List. Box and add Do. Events to your code, your form repaints when another window is dragged over it. If you remove Do. Events from your code, your form will not repaint until the click event handler of the button is finished executing. With reference to the demo source code above, we first create an Event. Args object that basically stores the UI update data. So this Event. Args dutifully carries data from the task object to the UI object in each iteration. Before the UI starts running the task, it pre- determines the updates that need that to be done by adding a new event to the task through Add. End. Cycle. Event. Note that Application. Do. Event is supposed to be called at the end the pre- determined set of updates to redraw the UI. Finally, at the end of every iteration in the task object, it calls On. End. Cycle(), which sends the Event. Args object back to the UI through the Event. Handler. 1. 23. 45. Event. Args to store your update dataclass. Nubcake. Event. Args: Event. Args. The Do. Event method has a re- entry problem: Calling Application. Do. Events can cause code to be re- entered or re- performed if a message raises an event. In other words, this approach is not exactly multi- threading, but rather multi- tasking by switching to process event to event in the queue. Rightfully, long running tasks should be running in another thread, then we marshal calls to update the UI back to the UI thread. So Do. Events is considered a hacky solution to this problem because: Application. Do. Events is taken straight from Delphis, and the same re- entry problem has been known for like 1. Michael Starberg(http: //www. Instead, we next look at the . NET 2. 0 Background. Worker class, which is pretty much better designed for such things. And here’s how its done. Method 3: Using Background. Worker class (preferred)Using the Background. Worker class is a multi- threading approach. Following the demo source code available at the top of this page, there are four main parts to this approach. Work. State is used to store the current working status of the task. It also stores the relevant data that will be used for updating the UINubcake. Worker extends from Background. Worker, and this is the multi- threading processor. It contains three important event handlers namely Do. Work, Progress. Changed, and Run. Worker. Completed. Do. Work basically handles the event that starts the looping task, Progress. Changed handles the callback per iteration, and Run. Worker. Completed handles the event when the looping task ends or is terminated. Main. Form is the UI that we want to update, and it contains two important methods. One is Perform. Task that is invoked when a user clicks a start button. And the second is Refresh. State that updates the UI, and it is called by the Progress. Changed method in Nubcake. Worker per iteration. Work. Task is the task manager that performs the set of long running tasks. You can then update the UI by calling the worker. Report. Progress() function that invokes the Progress. Changed method to update the UI via Refresh. State. That is Report. Progress - > Progress. Changed - > Refresh. State - > UI updated. Work. State. But once you get the hang of it, its a pretty neat way to separate your tasks from your UI. And, AFAIK its the encouraged practice. Personally, I think all the methods work. It really depends on your project requirements and risks. Anyway, generally multi- threading or multi- tasking can help improve the responsiveness of the program, and CPU prioritization can also benefit application performance. However, don’t forget that threading has some computational switching costs. So if there are TOO many threads, then each thread may not be given enough time to execute much during its time slice. So, do use these approaches in moderation. Teaching and Learning Center Grants. Center for the Advancement of Teaching and Learning, Elon University: Resa Walch, Project Coordinator. Elon University’s Center for the Advancement of Teaching and Learning promotes engaging, inclusive, and effective teaching, and the scholarship of teaching and learning at Elon University. The Center for the Advancement of Teaching and Learning has encouraged the development of contemplative pedagogies since its founding in 2. Ed Sarath (University of Michigan) and Linda Weintraub (independent artist); reading groups on books including Parker Palmer’s The Courage to Teach and Palmer and Arthur Zajonc’s The Heart of Higher Education; and faculty learning communities on topics like “Minding the Body.” The CATL has also supported Elon faculty participation in the ACMHE’s events such as the 2. West Coast Regional Conference and the 2. Contemplative Campus Conference at Amherst College. CATL’s director, Peter Felten, participated in a 2. Teaching and Learning Centers meeting in Amherst, and has learned from Arthur Zajonc, Paul Wapner, and others in the Fetzer Institute’s Intergenerational Mentoring Program. CATL also sponsors annual events bringing together faculty from across the region, including an August conference that typically draws more than 2. June retreat for mid- career faculty to reflect on teaching. The 2. 01. 2 June three- day retreat, co- hosted with Wake Forest University’s teaching center, involved some two dozen faculty from six colleges and universities in the area, and included significant conversation about the meaning and purposes of teaching. The primary use of grant funds was to build a strong, sustainable faculty learning community related to contemplative pedagogy at Elon University. Established through the Center for Teaching and Learning, the faculty learning community included 1. The group met for discussions regularly, and four members attended the “Creating a Mindful Campus” retreat at the University of North Carolina in Spring 2. Other activities of group members include: attending the Summer Session on Contemplative Pedagogy, submitting a proposal to the 2. ACMHE conference, and launching a research project on contemplative pedagogies. In order to keep the initiative moving forward, the group has invited more faculty members to join them and attend a fall meeting, and has discussed the possibility of hosting an annual retreat for faculty, developing an Elon Faculty Scholar in Contemplative Pedagogy program, and investigating funding for curriculum infusion grants. This project is collaborative effort between Professor Resa Walch and Dr. Peter Felten. Peter Felten is assistant provost, director of the Center for the Advancement of Teaching and Learning, and associate professor of history at Elon University. He has published widely on engaged learning and the scholarship of teaching, and he is on the editorial boards of the International Journal for Academic Development and the International Journal for the Scholarship of Teaching and Learning. Peter is president (2. POD Network, an international association for teaching and learning centers in higher education. Felten frequently speaks and presents at colleges and universities worldwide on faculty development, scholarship of teaching and learning, and visual literacy. His recent research focuses on how students learn and develop in college, and on the possibilities of student- faculty partnerships in the scholarship of teaching and learning. Resa Walch is chair of the Department of Health and Human Performance, and Faculty Fellow for Substance Education at Elon University. She teaches classes in “Contemporary Issues in Wellness,” “Substance Abuse and Human Behavior” and “Perspectives in Women’s Health.” Most recently, she developed a new course, “Health of the Human Spirit,” that incorporates contemplative pedagogy. She has 2. 8- years of experience in higher education as a counselor, educator, director of substance education, student life administrator and faculty member. She presents at regional, national and international conferences on the effective use of clickers in an engaged classroom, applying trend data as primary prevention for first year students, and effective teaching and learning collaborations across disciplines. She is involved in an ongoing scholarship of teaching and learning project, “Avoiding Pedagogical Solitude: An Interdisciplinary Collaboration,” with a faculty member in Human Service Studies at Elon University. How did you discover contemplative pedagogy? Resa Walch: An integral part of the mission of Elon University is to create an academic community that transforms mind, body and spirit. Integrating this part of the mission into the curriculum is not without challenges. Transformation of mind, body and spirit is difficult to define and complicated to measure. Particularly complex is defining transformation of spirit. Five years ago, I began work on a sabbatical proposal: Mind, Body and Spirit. Needless to say, this was much too ambitious for one semester. I decided to begin my sabbatical project by focusing on an investigation of why many, if not most, college health textbooks either leave out health of the human spirit or integrate it into related chapters with no more than three to five pages devoted to the topic. Health related disciplines often teach a widely accepted paradigm of health and wellness that includes balance in mind, body, spirit and social well- being. In this paradigm, spirituality is defined as meaning and purpose in life, a sense of hope and optimism and connectedness to self, to others and to the community, rather than participation in organized religion. While some argue that definitions of spirituality must be rooted in the study of religion, this is not the currently held view in health and health related disciplines. As I moved forward with my sabbatical project, I discovered articles on contemplative pedagogy and concluded this pedagogy fits with developing a connectedness to self, others and the community. Additionally, I had been using contemplative pedagogy, specifically mindful practices, for several years when teaching about health of the human spirit. Once I made the connection to contemplative pedagogy, I continued to read articles, attend meetings and explore other ways of using contemplative pedagogy in all my classes. This ongoing interest led to my commitment to apply for the grant so that Elon can move forward with a faculty learning community around contemplative pedagogy. What is your core educational mission and what role does contemplative pedagogy play? Which needs and/or challenges in higher education do you think contemplative approaches can address? My core educational mission is to create multiple, effective entry points in the curriculum for discipline specific health courses and interdisciplinary health related courses. It is impossible to meet this mission without exploring contemplative pedagogy. I believe this exploration is best accomplished through a faculty learning community where we learn from each other while investigating, creating, implementing and assessing contemplative pedagogy across disciplines. I am fortunate to be in an academic environment that includes a core group of faculty across disciplines who want to explore and practice contemplative pedagogy. And, Elon’s Center for the Advancement of Teaching and Learning fully supports starting this learning community. Most would agree that students come to college with the intent to learn more about themselves, others, and the world. Contemplative pedagogy provides an approach for students to be more present when listening to their own narratives and developing an interior learning space to explore and integrate the narratives of others, thus expanding what one knows about self, others and the world.
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