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src/java.base/share/classes/java/lang/ThreadBuilders.java

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 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 package java.lang;
 26 
 27 import java.lang.Thread.Builder.OfPlatform;
 28 import java.lang.Thread.Builder.OfVirtual;
 29 import java.lang.Thread.UncaughtExceptionHandler;
 30 import java.lang.invoke.MethodHandles;
 31 import java.lang.invoke.VarHandle;
 32 import java.util.Locale;
 33 import java.util.Objects;
 34 import java.util.concurrent.Executor;
 35 import java.util.concurrent.ThreadFactory;
 36 import jdk.internal.misc.Unsafe;
 37 import jdk.internal.invoke.MhUtil;


 38 import jdk.internal.vm.ContinuationSupport;
 39 
 40 /**
 41  * Defines static methods to create platform and virtual thread builders.
 42  */
 43 class ThreadBuilders {
 44     private ThreadBuilders() { }
 45 
 46     /**
 47      * Base class for Thread.Builder implementations.
 48      */
 49     private static class BaseThreadBuilder {
 50         private String name;
 51         private long counter;
 52         private int characteristics;
 53         private UncaughtExceptionHandler uhe;
 54 
 55         String name() {
 56             return name;
 57         }

185             if (priority != 0)
186                 thread.priority(priority);
187             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
188             if (uhe != null)
189                 thread.uncaughtExceptionHandler(uhe);
190             return thread;
191         }
192 
193         @Override
194         public Thread start(Runnable task) {
195             Thread thread = unstarted(task);
196             thread.start();
197             return thread;
198         }
199 
200         @Override
201         public ThreadFactory factory() {
202             return new PlatformThreadFactory(group, name(), counter(), characteristics(),
203                     daemonChanged, daemon, priority, stackSize, uncaughtExceptionHandler());
204         }
205 
206     }
207 
208     /**
209      * ThreadBuilder.OfVirtual implementation.
210      */
211     static final class VirtualThreadBuilder
212             extends BaseThreadBuilder implements OfVirtual {
213         private Executor scheduler;
214 
215         VirtualThreadBuilder() {
216         }
217 
218         // invoked by tests
219         VirtualThreadBuilder(Executor scheduler) {
220             if (!ContinuationSupport.isSupported())
221                 throw new UnsupportedOperationException();
222             this.scheduler = Objects.requireNonNull(scheduler);
223         }
224 
225         @Override
226         public OfVirtual name(String name) {
227             setName(name);
228             return this;
229         }
230 
231         @Override
232         public OfVirtual name(String prefix, long start) {
233             setName(prefix, start);
234             return this;
235         }
236 
237         @Override
238         public OfVirtual inheritInheritableThreadLocals(boolean inherit) {
239             setInheritInheritableThreadLocals(inherit);
240             return this;
241         }
242 
243         @Override
244         public OfVirtual uncaughtExceptionHandler(UncaughtExceptionHandler ueh) {
245             setUncaughtExceptionHandler(ueh);
246             return this;
247         }
248 
249         @Override
250         public Thread unstarted(Runnable task) {
251             Objects.requireNonNull(task);
252             var thread = newVirtualThread(scheduler, nextThreadName(), characteristics(), task);




253             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
254             if (uhe != null)
255                 thread.uncaughtExceptionHandler(uhe);
256             return thread;
257         }
258 





259         @Override
260         public Thread start(Runnable task) {
261             Thread thread = unstarted(task);
262             thread.start();
263             return thread;
264         }
265 
266         @Override
267         public ThreadFactory factory() {
268             return new VirtualThreadFactory(scheduler, name(), counter(), characteristics(),
269                     uncaughtExceptionHandler());
270         }


















271     }
272 
273     /**
274      * Base ThreadFactory implementation.
275      */
276     private abstract static class BaseThreadFactory implements ThreadFactory {
277         private static final VarHandle COUNT = MhUtil.findVarHandle(
278                 MethodHandles.lookup(), "count", long.class);
279 
280         private final String name;
281         private final int characteristics;
282         private final UncaughtExceptionHandler uhe;
283 
284         private final boolean hasCounter;
285         private volatile long count;
286 
287         BaseThreadFactory(String name,
288                           long start,
289                           int characteristics,
290                           UncaughtExceptionHandler uhe)  {

352         @Override
353         public Thread newThread(Runnable task) {
354             Objects.requireNonNull(task);
355             String name = nextThreadName();
356             Thread thread = new Thread(group, name, characteristics(), task, stackSize);
357             if (daemonChanged)
358                 thread.daemon(daemon);
359             if (priority != 0)
360                 thread.priority(priority);
361             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
362             if (uhe != null)
363                 thread.uncaughtExceptionHandler(uhe);
364             return thread;
365         }
366     }
367 
368     /**
369      * ThreadFactory for virtual threads.
370      */
371     private static class VirtualThreadFactory extends BaseThreadFactory {
372         private final Executor scheduler;
373 
374         VirtualThreadFactory(Executor scheduler,
375                              String name,
376                              long start,
377                              int characteristics,
378                              UncaughtExceptionHandler uhe) {
379             super(name, start, characteristics, uhe);
380             this.scheduler = scheduler;
381         }
382 
383         @Override
384         public Thread newThread(Runnable task) {
385             Objects.requireNonNull(task);
386             String name = nextThreadName();
387             Thread thread = newVirtualThread(scheduler, name, characteristics(), task);
388             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
389             if (uhe != null)
390                 thread.uncaughtExceptionHandler(uhe);
391             return thread;
392         }
393     }
394 
395     /**
396      * Creates a new virtual thread to run the given task.
397      */
398     static Thread newVirtualThread(Executor scheduler,
399                                    String name,
400                                    int characteristics,
401                                    Runnable task) {

402         if (ContinuationSupport.isSupported()) {
403             return new VirtualThread(scheduler, name, characteristics, task);
404         } else {
405             if (scheduler != null)
406                 throw new UnsupportedOperationException();
407             return new BoundVirtualThread(name, characteristics, task);
408         }
409     }
410 




411     /**
412      * A "virtual thread" that is backed by a platform thread. This implementation
413      * is intended for platforms that don't have the underlying VM support for
414      * continuations. It can also be used for testing.
415      */
416     static final class BoundVirtualThread extends BaseVirtualThread {
417         private static final Unsafe U = Unsafe.getUnsafe();
418         private final Runnable task;
419         private boolean runInvoked;
420 
421         BoundVirtualThread(String name, int characteristics, Runnable task) {
422             super(name, characteristics, true);
423             this.task = task;
424         }
425 
426         @Override
427         public void run() {
428             // run is specified to do nothing when Thread is a virtual thread
429             if (Thread.currentThread() == this && !runInvoked) {
430                 runInvoked = true;

 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 package java.lang;
 26 
 27 import java.lang.Thread.Builder.OfPlatform;
 28 import java.lang.Thread.Builder.OfVirtual;
 29 import java.lang.Thread.UncaughtExceptionHandler;
 30 import java.lang.invoke.MethodHandles;
 31 import java.lang.invoke.VarHandle;
 32 import java.util.Locale;
 33 import java.util.Objects;

 34 import java.util.concurrent.ThreadFactory;
 35 import jdk.internal.misc.Unsafe;
 36 import jdk.internal.invoke.MhUtil;
 37 import jdk.internal.reflect.CallerSensitive;
 38 import jdk.internal.reflect.Reflection;
 39 import jdk.internal.vm.ContinuationSupport;
 40 
 41 /**
 42  * Defines static methods to create platform and virtual thread builders.
 43  */
 44 class ThreadBuilders {
 45     private ThreadBuilders() { }
 46 
 47     /**
 48      * Base class for Thread.Builder implementations.
 49      */
 50     private static class BaseThreadBuilder {
 51         private String name;
 52         private long counter;
 53         private int characteristics;
 54         private UncaughtExceptionHandler uhe;
 55 
 56         String name() {
 57             return name;
 58         }

186             if (priority != 0)
187                 thread.priority(priority);
188             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
189             if (uhe != null)
190                 thread.uncaughtExceptionHandler(uhe);
191             return thread;
192         }
193 
194         @Override
195         public Thread start(Runnable task) {
196             Thread thread = unstarted(task);
197             thread.start();
198             return thread;
199         }
200 
201         @Override
202         public ThreadFactory factory() {
203             return new PlatformThreadFactory(group, name(), counter(), characteristics(),
204                     daemonChanged, daemon, priority, stackSize, uncaughtExceptionHandler());
205         }

206     }
207 
208     /**
209      * ThreadBuilder.OfVirtual implementation.
210      */
211     static final class VirtualThreadBuilder
212             extends BaseThreadBuilder implements OfVirtual {
213         private Thread.VirtualThreadScheduler scheduler;
214 
215         VirtualThreadBuilder() {
216         }
217 







218         @Override
219         public OfVirtual name(String name) {
220             setName(name);
221             return this;
222         }
223 
224         @Override
225         public OfVirtual name(String prefix, long start) {
226             setName(prefix, start);
227             return this;
228         }
229 
230         @Override
231         public OfVirtual inheritInheritableThreadLocals(boolean inherit) {
232             setInheritInheritableThreadLocals(inherit);
233             return this;
234         }
235 
236         @Override
237         public OfVirtual uncaughtExceptionHandler(UncaughtExceptionHandler ueh) {
238             setUncaughtExceptionHandler(ueh);
239             return this;
240         }
241 
242         Thread unstarted(Runnable task, Thread preferredCarrier) {

243             Objects.requireNonNull(task);
244             var thread = newVirtualThread(scheduler,
245                                           preferredCarrier,
246                                           nextThreadName(),
247                                           characteristics(),
248                                           task);
249             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
250             if (uhe != null)
251                 thread.uncaughtExceptionHandler(uhe);
252             return thread;
253         }
254 
255         @Override
256         public Thread unstarted(Runnable task) {
257             return unstarted(task, null);
258         }
259 
260         @Override
261         public Thread start(Runnable task) {
262             Thread thread = unstarted(task);
263             thread.start();
264             return thread;
265         }
266 
267         @Override
268         public ThreadFactory factory() {
269             return new VirtualThreadFactory(scheduler, name(), counter(), characteristics(),
270                     uncaughtExceptionHandler());
271         }
272 
273         @SuppressWarnings("removal")
274         @CallerSensitive
275         @Override
276         public OfVirtual scheduler(Thread.VirtualThreadScheduler scheduler) {
277             if (!ContinuationSupport.isSupported()) {
278                 throw new UnsupportedOperationException();
279             }
280             // can't mix custom default scheduler and API prototypes at this time
281             if (scheduler != VirtualThread.defaultScheduler()
282                     && VirtualThread.defaultScheduler() != VirtualThread.builtinScheduler(true)) {
283                 throw new UnsupportedOperationException();
284             }
285             Class<?> caller = Reflection.getCallerClass();
286             caller.getModule().ensureNativeAccess(OfVirtual.class, "scheduler", caller, false);
287             this.scheduler = Objects.requireNonNull(scheduler);
288             return this;
289         }
290     }
291 
292     /**
293      * Base ThreadFactory implementation.
294      */
295     private abstract static class BaseThreadFactory implements ThreadFactory {
296         private static final VarHandle COUNT = MhUtil.findVarHandle(
297                 MethodHandles.lookup(), "count", long.class);
298 
299         private final String name;
300         private final int characteristics;
301         private final UncaughtExceptionHandler uhe;
302 
303         private final boolean hasCounter;
304         private volatile long count;
305 
306         BaseThreadFactory(String name,
307                           long start,
308                           int characteristics,
309                           UncaughtExceptionHandler uhe)  {

371         @Override
372         public Thread newThread(Runnable task) {
373             Objects.requireNonNull(task);
374             String name = nextThreadName();
375             Thread thread = new Thread(group, name, characteristics(), task, stackSize);
376             if (daemonChanged)
377                 thread.daemon(daemon);
378             if (priority != 0)
379                 thread.priority(priority);
380             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
381             if (uhe != null)
382                 thread.uncaughtExceptionHandler(uhe);
383             return thread;
384         }
385     }
386 
387     /**
388      * ThreadFactory for virtual threads.
389      */
390     private static class VirtualThreadFactory extends BaseThreadFactory {
391         private final Thread.VirtualThreadScheduler scheduler;
392 
393         VirtualThreadFactory(Thread.VirtualThreadScheduler scheduler,
394                              String name,
395                              long start,
396                              int characteristics,
397                              UncaughtExceptionHandler uhe) {
398             super(name, start, characteristics, uhe);
399             this.scheduler = scheduler;
400         }
401 
402         @Override
403         public Thread newThread(Runnable task) {
404             Objects.requireNonNull(task);
405             String name = nextThreadName();
406             Thread thread = newVirtualThread(scheduler, null, name, characteristics(), task);
407             UncaughtExceptionHandler uhe = uncaughtExceptionHandler();
408             if (uhe != null)
409                 thread.uncaughtExceptionHandler(uhe);
410             return thread;
411         }
412     }
413 
414     /**
415      * Creates a new virtual thread to run the given task.
416      */
417     private static Thread newVirtualThread(Thread.VirtualThreadScheduler scheduler,
418                                            Thread preferredCarrier,
419                                            String name,
420                                            int characteristics,
421                                            Runnable task) {
422         if (ContinuationSupport.isSupported()) {
423             return new VirtualThread(scheduler, preferredCarrier, name, characteristics, task);
424         } else {
425             if (scheduler != null)
426                 throw new UnsupportedOperationException();
427             return new BoundVirtualThread(name, characteristics, task);
428         }
429     }
430 
431     static Thread newVirtualThread(String name, int characteristics, Runnable task) {
432        return newVirtualThread(null, null, name, characteristics, task);
433     }
434 
435     /**
436      * A "virtual thread" that is backed by a platform thread. This implementation
437      * is intended for platforms that don't have the underlying VM support for
438      * continuations. It can also be used for testing.
439      */
440     static final class BoundVirtualThread extends BaseVirtualThread {
441         private static final Unsafe U = Unsafe.getUnsafe();
442         private final Runnable task;
443         private boolean runInvoked;
444 
445         BoundVirtualThread(String name, int characteristics, Runnable task) {
446             super(name, characteristics, true);
447             this.task = task;
448         }
449 
450         @Override
451         public void run() {
452             // run is specified to do nothing when Thread is a virtual thread
453             if (Thread.currentThread() == this && !runInvoked) {
454                 runInvoked = true;
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