fork-join

问题 I am trying to create a module for carry select adder in verilog. Everything works fine except the following portion where it is causing compilation error. module csa(a,b,s,cout); input[15:0] a,b; output [15:0] s; output cout; wire zero_c1, zero_c2,zero_c3,zero_c4,zero_c5; wire one_c1, one_c2,one_c3,one_c4,one_c5; wire temp_c1,temp_c2,temp_c3,temp_c4,temp_c5; wire [15:0] s_zero, s_one; initial begin fork fa(s[0], temp_c1,a[0],b[0],0); fa_one(s_zero[1],s_one[1],zero_c1,one_c1,a[1],b[1]); fa

问题 Question As Fork-Join seems to be the current hype and recommended in many answers, I thought: why not do some research on how fast it actually is? To measure this, I wrote a small program (see code below) that does some adding of numbers and forked it out with various parameters, including number of threads, fork-depth and fork-spread, then measured the time for execution and especially the time spent for actual calculation vs. time spent on forking. Abstract Answer While being implemented

问题 Here, I've used forkJoin from rxjs to subscribe to an array of observables parallelly. But I want to subscribe to them one by one, What will be the best solution? Below is my code : var observables = []; Observable.forkJoin(observables) .subscribe(() => { this.msgs = []; this.msgs.push({ severity: 'success', summary: 'Saved Successfully' }); this.onSaveComplete(); }, (error: any) => this.errorMessage = <any>error); }, (error: any) => this.errorMessage = <any>error); 回答1: Alternate of forkJoin

问题 I am trying to implement a divide-and-conquer solution to some large data. I use fork and join to break down things into threads. However I have a question regarding the fork mechanism: if I set my divide and conquer condition as: @Override protected SomeClass compute(){ if (list.size()<LIMIT){ //Do something here ... }else{ //Divide the list and invoke sub-threads SomeRecursiveTaskClass subWorker1 = new SomeRecursiveTaskClass(list.subList()); SomeRecursiveTaskClass subWorker2 = new

问题 What I want I want to work on optimization of fork/join algorithm. By optimization I mean just calculation of optimal number of threads, or if you want - calculation of SEQUENTIAL_THRESHOLD (see code below). // PSEUDOCODE Result solve(Problem problem) { if (problem.size < SEQUENTIAL_THRESHOLD) return solveSequentially(problem); else { Result left, right; INVOKE-IN-PARALLEL { left = solve(extractLeftHalf(problem)); right = solve(extractRightHalf(problem)); } return combine(left, right); } }

问题 I'm comparing two variations on a test program. Both are operating with a 4-thread ForkJoinPool on a machine with four cores. In 'mode 1', I use the pool very much like an executor service. I toss a pile of tasks into ExecutorService.invokeAll . I get better performance than from an ordinary fixed thread executor service (even though there are calls to Lucene, that do some I/O, in there). There is no divide-and-conquer here. Literally, I do ExecutorService es = new ForkJoinPool(4); es

问题 I am trying to transform each element of an array of length 10,00,00,000. My first approach is using a single thread in a simple main method. My next approach is using fork-join framework of java by dividing the array into chunks of 10,00,000. But the total time taken to transform the array is almost same in both the approaches. public class SerialComputation { public static void main(String[] args) { Integer[] array = new Integer[100000000]; for (int i = 0; i < array.length; i++) { array[i]

问题 I designed a RecursiveTask Here is the code for task I designed. public class SearchTask extends RecursiveTask<Map<Short, Long>> { private static final long serialVersionUID = 1L; private int majorDataThreshold = 16001; private ConcurrentNavigableMap<Short, Long> dataMap; private long fromRange; private long toRange; private boolean fromInclusive; private boolean toInclusive; public SearchTask(final Map<Short, Long> dataSource, final long fromRange, final long toRange, final boolean

问题 Is it necessary that I use join() with fork() or I may use also either of join() , get() , invoke() . I checked the API and besides that get() throws InterruptedException and ExecutionException I don't see differences... And invoke() seems totally the same. However I have always seen related fork() with join() rather than the other two methods... don't they provide parallelism? What's the purpose of having invoke() and join() totally the same? I can understand get() got by implementing future

问题 I'm new to c language and Linux. I have a problem related to fork(),getpid()and exec()function. I wrote a c program using fork() call the code of my program is following" code: #include <stdio.h> #include <sys/types.h> #include <unistd.h> #include <stdlib.h> void fun() { printf("\n this is trial for child process"); } int main (int argc, char const *argv[]) { int i,status,pid,t; if(pid=fork()<0) { printf("\nfailed to create the process\n"); } if(pid=fork()==0) { printf("\n the child process