8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.nio.fs;
27
28 import sun.misc.ManagedLocalsThread;
29 import jdk.internal.misc.Unsafe;
30 import java.util.concurrent.ExecutionException;
31
32 /**
33 * Base implementation of a task (typically native) that polls a memory location
34 * during execution so that it may be aborted/cancelled before completion. The
35 * task is executed by invoking the {@link runInterruptibly} method defined
36 * here and cancelled by invoking Thread.interrupt.
37 */
38
39 abstract class Cancellable implements Runnable {
40 private static final Unsafe unsafe = Unsafe.getUnsafe();
41
42 private final long pollingAddress;
43 private final Object lock = new Object();
44
45 // the following require lock when examining or changing
46 private boolean completed;
47 private Throwable exception;
48
101 } finally {
102 synchronized (lock) {
103 completed = true;
104 unsafe.freeMemory(pollingAddress);
105 }
106 }
107 }
108
109 /**
110 * The task body. This should periodically poll the memory location
111 * to check for cancellation.
112 */
113 abstract void implRun() throws Throwable;
114
115 /**
116 * Invokes the given task in its own thread. If this (meaning the current)
117 * thread is interrupted then an attempt is make to cancel the background
118 * thread by writing into the memory location that it polls cooperatively.
119 */
120 static void runInterruptibly(Cancellable task) throws ExecutionException {
121 Thread t = new ManagedLocalsThread(task);
122 t.start();
123 boolean cancelledByInterrupt = false;
124 while (t.isAlive()) {
125 try {
126 t.join();
127 } catch (InterruptedException e) {
128 cancelledByInterrupt = true;
129 task.cancel();
130 }
131 }
132 if (cancelledByInterrupt)
133 Thread.currentThread().interrupt();
134 Throwable exc = task.exception();
135 if (exc != null)
136 throw new ExecutionException(exc);
137 }
138 }
|
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.nio.fs;
27
28 import jdk.internal.misc.Unsafe;
29 import java.util.concurrent.ExecutionException;
30
31 /**
32 * Base implementation of a task (typically native) that polls a memory location
33 * during execution so that it may be aborted/cancelled before completion. The
34 * task is executed by invoking the {@link runInterruptibly} method defined
35 * here and cancelled by invoking Thread.interrupt.
36 */
37
38 abstract class Cancellable implements Runnable {
39 private static final Unsafe unsafe = Unsafe.getUnsafe();
40
41 private final long pollingAddress;
42 private final Object lock = new Object();
43
44 // the following require lock when examining or changing
45 private boolean completed;
46 private Throwable exception;
47
100 } finally {
101 synchronized (lock) {
102 completed = true;
103 unsafe.freeMemory(pollingAddress);
104 }
105 }
106 }
107
108 /**
109 * The task body. This should periodically poll the memory location
110 * to check for cancellation.
111 */
112 abstract void implRun() throws Throwable;
113
114 /**
115 * Invokes the given task in its own thread. If this (meaning the current)
116 * thread is interrupted then an attempt is make to cancel the background
117 * thread by writing into the memory location that it polls cooperatively.
118 */
119 static void runInterruptibly(Cancellable task) throws ExecutionException {
120 Thread t = new Thread(null, task, "NIO-Task", 0, false);
121 t.start();
122 boolean cancelledByInterrupt = false;
123 while (t.isAlive()) {
124 try {
125 t.join();
126 } catch (InterruptedException e) {
127 cancelledByInterrupt = true;
128 task.cancel();
129 }
130 }
131 if (cancelledByInterrupt)
132 Thread.currentThread().interrupt();
133 Throwable exc = task.exception();
134 if (exc != null)
135 throw new ExecutionException(exc);
136 }
137 }
|