11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @bug 8322732
27 * @summary ForkJoinPool utilizes available workers even with arbitrary task dependencies
28 */
29 import java.util.concurrent.Callable;
30 import java.util.concurrent.ForkJoinPool;
31 import java.util.concurrent.atomic.AtomicInteger;
32
33 public class Starvation {
34 static final AtomicInteger count = new AtomicInteger();
35 static final Callable<Void> noop = new Callable<Void>() {
36 public Void call() {
37 return null; }};
38 static final class AwaitCount implements Callable<Void> {
39 private int c;
40 AwaitCount(int c) { this.c = c; }
41 public Void call() {
42 while (count.get() == c) Thread.onSpinWait();
43 return null; }};
44
45 public static void main(String[] args) throws Exception {
46 try (var pool = new ForkJoinPool(2)) {
47 for (int i = 0; i < 100_000; i++) {
48 var future1 = pool.submit(new AwaitCount(i));
49 var future2 = pool.submit(noop);
50 future2.get();
51 count.set(i + 1);
52 future1.get();
53 }
54 }
55 }
56 }
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @bug 8322732
27 * @summary ForkJoinPool utilizes available workers even with arbitrary task dependencies
28 */
29 import java.util.concurrent.Callable;
30 import java.util.concurrent.ForkJoinPool;
31 import java.util.concurrent.ForkJoinTask;
32 import java.util.concurrent.atomic.AtomicInteger;
33
34 public class Starvation {
35 static final AtomicInteger count = new AtomicInteger();
36 static final Callable<Void> noop = new Callable<Void>() {
37 public Void call() {
38 return null; }};
39 static final class AwaitCount implements Callable<Void> {
40 private volatile int c;
41 AwaitCount(int c) { this.c = c; }
42 public Void call() {
43 while (count.get() == c) Thread.onSpinWait();
44 return null; }};
45
46 public static void main(String[] args) throws Exception {
47 try (var pool = new ForkJoinPool(2)) {
48 for (int i = 0; i < 100_000; i++) {
49 var future1 = pool.submit(new AwaitCount(i));
50 var future2 = pool.submit(ForkJoinTask.adapt(noop));
51 future2.get();
52 count.set(i + 1);
53 future1.get();
54 }
55 }
56 }
57 }
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