Add test: Support limiting the number of parallel processing subroutines

Author: marianrh-apa

utils_test.go

@@ -49,6 +49,33 @@ func testParallelN(n, procs int) bool {
 	return true
 }
 
+func TestParallelMaxProcs(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000} {
+		for _, p := range []int{1, 2, 4, 8, 16, 100} {
+			if !testParallelMaxProcsN(n, p) {
+				t.Fatalf("test [parallel %d %d] failed", n, p)
+			}
+		}
+	}
+}
+
+func testParallelMaxProcsN(n, procs int) bool {
+	data := make([]bool, n)
+	MaxProcs = procs
+	parallel(0, n, func(is <-chan int) {
+		for i := range is {
+			data[i] = true
+		}
+	})
+	MaxProcs = 0
+	for i := 0; i < n; i++ {
+		if !data[i] {
+			return false
+		}
+	}
+	return true
+}
+
 func TestClamp(t *testing.T) {
 	testCases := []struct {
 		f float64