On 8/18/22 18:49, Shriramana Sharma wrote:
> Hello. I want to parallelize a computation which has two for loops
An option is to add tasks individually but I am not sure how wise doing
this and I don't know how to determine whether all tasks are completed.
In any case, Roy Margalit's DConf 2022 presentation is very much on
topic. :)
http://dconf.org/2022/index.html#roym
And the following program cannot show any benefit because the tasks are
so short.
import std.stdio;
import std.parallelism;
import std.conv;
enum I = 1_000;
enum J = 1_000;
void main() {
auto results = new int[I * J];
// In case you want a new TaskPool:
// auto tp = new TaskPool(totalCPUs);
// (And use tp. below instead of taskPool.)
foreach (i; 0 .. I) {
foreach (j; 0 .. J) {
taskPool.put(task!foo(i, j, results));
}
}
// WARNING: I am not sure whether one can trust the results are
// ready yet. (?)
//
// parallel() does call yieldForce() on each task but we don't seem
// to have that option for tasks that are .put() into the pool. (?)
enum toPrint = 10;
writeln(results[0..toPrint]);
writeln("[...]");
writeln(results[$-toPrint..$]);
}
void foo(size_t i, size_t j, int[] results) {
results[i * J + j] = to!int(i * J + j);
}
Ali
