I know the difference between the two clearly. Concurrency is performing multiple tasks alternately, while parallelism is performing multiple tasks at once. However, there is confusion in this code because a certain instructor has a different opinion than me. Here is code: I thought that running this code on …
Tag: parallel-processing
How to set the Thread priority on parallel iteration with standard Java API?
I found in this tutorial a way to iterate in parallel a collection of objects by setting threads priority, but this example uses the Burningwave Core library: is there a way to do the same with the standard Java API? I found in this tutorial a way to iterate in parallel a collection of objects by setting thre…
Asynchronous execution/operation with CompletableFuture in Java 8+
In Java, is calling get() method while looping on CompletableFuture instances as good as doing synchronous operations although CompletableFuture is used for async calls? Answer ‘get()’ waits until the future is completed. If that’s what you want, it’s what you use. There’s no gen…
Unexpected behaviour of Threads
I am trying to achieve that thread2 should complete first, then thread1, For this O am using join() method. But if I uncomment the System.out.println() present in the try block of thread1 class. then code give null pointer exception. Why in try block I need to add line, it doesn’t make any sense that ad…
Kotlin process waits for all threads to finish?
I wrote this simple testing program: As I can see, the output is: My expectation is that at-least the “Thread End” message will not be printed, Cause that main function is ended and this main thread should be done running. Is Kotlin process always waiting for threads to finish before done? Answer …
Executor Service – InvokeAll: How to Map response?
I am working on parallel execution of 5 Tasks with Executor service, all the 5 tasks returns back with different object results-set depending upon the task. I am using executor service for parallel execution of tasks : But how do we map the result set back with the task(s) ? It may not return back the respons…
Parallel matrix multiplication in java
I am trying to implement matrix multiplication with multiple threads. Everything seems to work correctly, however, it work much slower than the usual algorithm. Here is my code Here, I create a new thread for each element in the resulting matrix. I than write these threads to an array, start them and, finally…
Will using a parallel stream on a single-core processor be slower than using a sequential stream?
I am applying an operation to every element in a very large LinkedList<LinkedList<Double>>: On my computer (quad-core), parallel streams seem to be faster than using sequential streams: However, not every computer is going to be multi-core. My question is, will using parallel streams on a single-p…
Java 8’s streams: why parallel stream is slower?
I am playing with Java 8’s streams and cannot understand the performance results I am getting. I have 2 core CPU (Intel i73520M), Windows 8 x64, and 64-bit Java 8 update 5. I am doing simple map over …
How to wait for a number of threads to complete?
What is a way to simply wait for all threaded process to finish? For example, let’s say I have: How do I alter this so the main() method pauses at the comment until all threads’ run() methods exit? Thanks! Answer You put all threads in an array, start them all, and then have a loop Each join will …