{"product":{"product_id":"0321349601","title":"Java Concurrency in Practice","price":"46.49","image_url":"https://m.media-amazon.com/images/I/51UKYyBwTpL._SL500_.jpg","url":"https://www.amazon.com/dp/0321349601"},"comments":[{"body":"If you use Java in the workplace I highly recommend [Java Concurrency in Practice by Brian Goetz](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601). \r\n\r\nIts old but rigorous and really helped me understand the more general concepts of concurrency","subreddit_name":"learnprogramming","author":"_the_urban_goose"},{"body":"My first questions is do you have any state that need to be shared by the masses and springs? And would that shared state need to be updated by multiple threads?\r\n\r\nMulti-threading get's fairly complex, especially around the details of when data from one thread is published for another thread to read. You would also have to worry about potential race conditions around when values are read and written.\r\n\r\nIf you do have shared state you will probably want to dig into the nuances of concurrency in java. I would recommend checking out this book: https://smile.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601/\r\n\r\nIf you don't have to worry about sharing state it should be a bit easier.\r\n\r\nI haven't done anything as complex with threading as you are trying to do here. I wonder if a runnable for each object would be overkill, as opposed to just splitting the objects you want to update into multiple lists, and having each thread just run through one of those lists. It might be worth experimenting to see what gives you the best performance.","subreddit_name":"learnjava","author":"Nephyst"},{"body":"So long as you aren't depending on what happens when race conditions occur, you'll be perfectly fine.\r\n\r\nRead [Java Concurrency in Practice](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601) and you'll be safe regardless of the architecture you decide to run on.\r\n\r\nThe only people in trouble are those relying on undefined behavior.","subreddit_name":"java","author":"cogman10"},{"body":"[Java Concurrency in Practice](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601)\r\nNot only does it cover the specifics of the java concurrency packages and how to use them, but discusses lots of good programming practices that are essential to being a good programmer and not covered in many other books.","subreddit_name":"ExperiencedDevs","author":"porto88"},{"body":"In short, unless you spend all of your time writing boring, vanilla business logic, you will spend a lot of time with your fact in this book [\"Java Concurrency in practice\"](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601/ref=sr_1_1?ie=UTF8\u0026amp;qid=1504977482\u0026amp;sr=8-1\u0026amp;keywords=brian+goetz+thread) by Brian Goetz, which is a good book, but at some point you may wonder just what the hell you are doing with your life and if programming with thread has to be so complicated.    \r\n\r\nPretty sure Rich already did this and we can learn from his journey. ","subreddit_name":"Clojure","author":"sankyo"},{"body":"\u0026gt; But it is still a lot more complicated that just letting the computer handle multithreading for you like you would in Java, C#, python\r\n\r\nNot at all. [Java Concurrency In Practice](https://www.amazon.ca/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601) is 384 pages long for a reason. The way Node does concurrency is way simpler than using threads with manual synchronization.","subreddit_name":"node","author":"Patman128"},{"body":"Highly recommend learning it right the first time by reading [Java Concurrency in Practice](http://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601/ref=sr_1_1?ie=UTF8\u0026amp;qid=1420323757\u0026amp;sr=8-1\u0026amp;keywords=java+concurrency+in+practice).","subreddit_name":"java","author":"phonyphonecall"},{"body":"1. Read the java train book:  \r\n[https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601)\r\n2. It's better to not share memory than to share memory.\r\n\r\nYou need 2 things to have a race condition, mutability and shared memory.  The best way to avoid a race condition is to eliminate one or both of those.  In java, that means working with promises and merging the results rather than trying to worry about locks keeping state in sync.\r\n\r\nSure, for ultra-high performance threading, this advice has to be ignored.  However, you shouldn't default to ignoring it.  It's a whole lot easier to get concurrency right when you aren't weaving locks.\r\n\r\nThat being said, if you have to mess with locks, get familiar with java.util.concurrent ( [https://docs.oracle.com/javase/8/docs/api/index.html?java/util/concurrent/package-summary.html](https://docs.oracle.com/javase/8/docs/api/index.html?java/util/concurrent/package-summary.html) )  So many of the constructs you might create have already been made both better AND thread safe.\r\n\r\nIn this specific example, LongAdder would do a much better job than anything you might cook up on your own.","subreddit_name":"java","author":"cogman10"},{"body":"A book on concurrency/multithreading in your backend language of choice.\r\n\r\nFor example, I mostly work in C++ and Java so here are some books I have in my book shelf:\r\n\r\nhttps://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601\r\n\r\nhttps://www.amazon.com/C-Concurrency-Action-Anthony-Williams-dp-1617294691/dp/1617294691/","subreddit_name":"cscareerquestions","author":"sjsu_dropout"},{"body":"If you've worked with Java before [this is a great book](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601)","subreddit_name":"cscareerquestions","author":"nutrecht"},{"body":"[Java Concurrency in Practice](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601/). Ainda é relevante.","subreddit_name":"brdev","author":"thedailycode"},{"body":"https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601\r\n\r\nOr if you don't want to buy a book: https://docs.oracle.com/javase/tutorial/essential/concurrency/index.html","subreddit_name":"learnjava","author":"nutrecht"},{"body":"https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601/\r\n\r\nThis book is a great resource if you want to gain a deep understanding of multi-threading in java.\r\n\r\nIf you can design the algorithm such that you don't have to share mutable memory across multiple threads you will save yourself a lot of work. Mutable means any object or value that can be modified after it is created. The way threads share memory is un-intuitive and complex, and implementing things incorrectly can lead to deadlocks where the program will not be able to complete. These issues are notoriously difficult to debug.\r\n\r\nI don't have a good understanding of how edge detection works, but my understanding is it involves looking at each pixel and comparing it to neighboring pixels.\r\n\r\nI would suggest making the input image immutable before passing it to the threads. Each thread could be assigned a subset of the image array, and the main thread can assemble the results into a single object. This avoids any threads having to modify any shared data, which reduces a lot possibility of weird failure states by a lot.\r\n\r\nA super easy way to create a thread is to use a CompletableFuture. You provide it with a function, which could take the image and some information on which subset it has been assigned. Once it is done processing the thread that created it can access the results.\r\n\r\nBy default this will use the common fork/join thread pool, which has threads equal to the number of CPU cores the machine has minus 1. If your machine has 2 CPU cores, the fork join pool will get 1 thread, which basically disables multi-threading. You can define a custom Executor with a larger pool size and pass it into the CompletableFuture. Baeldung has a really good article on how to use them: https://www.baeldung.com/java-completablefuture","subreddit_name":"learnjava","author":"HecknChonker"},{"body":"[http://gee.cs.oswego.edu/dl/jmm/cookbook.html](http://gee.cs.oswego.edu/dl/jmm/cookbook.html)\r\n\r\n[https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601)","subreddit_name":"programming","author":"Ringdingcoder"},{"body":"This book [https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601](https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601) is really helpful.","subreddit_name":"cscareerquestions","author":"wsdfre"}]}