Ändere Verzögerung von einem Thread in threadpool

Question

Ich füge Threads mit verschiedenen Aufgaben und verschiedenen Verzögerungen zu meinem threadpool hinzu und alles funktioniert ziemlich gut.

static ScheduledExecutorService scheduleTaskExecutor; 
static ScheduledFuture<?> future1; 
static ScheduledFuture<?> future2; 
static ScheduledFuture<?> future3; 

public void onCreate(Bundle savedInstanceState) { 
    scheduleTaskExecutor = Executors.newScheduledThreadPool(3); 
    future1 = scheduleTaskExecutor.scheduleWithFixedDelay(new Runnable1() {...}, 0, olddelay1, TimeUnit.SECONDS); // Task 1 
    future2 = scheduleTaskExecutor.scheduleWithFixedDelay(new Runnable2() {...}, 0, olddelay2, TimeUnit.SECONDS); // Task 2 
    future3 = scheduleTaskExecutor.scheduleWithFixedDelay(new Runnable3() {...}, 0, olddelay3, TimeUnit.SECONDS); // Task 3 
} 

Später während der Laufzeit mag ich die Verzögerung eines dieser Themen ändern (egal welche), werden die andere mit der alten Verzögerung arbeiten. Ich dachte, die ScheduledFuture-Referenzen könnten helfen und versuchten den folgenden Code (zum Beispiel für den zweiten Thread), aber nach der Ausführung gibt es nur noch einen Thread im Threadpool (Task 2).

public void changeDelay2(int newdelay2){ 
    future2.cancel(true); 
    future2 = scheduleTaskExecutor.scheduleWithFixedDelay(new Runnable2() {...}, 0, newdelay2, TimeUnit.SECONDS); // Task 2 
} 

Gibt es also eine Möglichkeit, die Verzögerung von nur einem Thread zu ändern?

Answer 1

Sie tun es genau so, wie Sie es getan haben - es muss einen anderen Fehler in Ihrem Code geben.

Hier ist ein vollständiges, funktionierendes Beispiel, das das gleiche tut, was Sie tun. Die Ausgabe unten zeigt, dass es wie vorgesehen funktioniert.

public class Reschedule { 

    public static void main(String[] args) throws InterruptedException { 
     long start = System.currentTimeMillis(); 
     ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor(); 

     // Schedule three tasks 
     ScheduledFuture future1 = executor.scheduleAtFixedRate(() -> { 
      System.out.printf("%03ds: This is the first runnable, reporting in%n", (System.currentTimeMillis() - start)/1000); 
     }, 0, 5, TimeUnit.SECONDS); 
     ScheduledFuture future2 = executor.scheduleAtFixedRate(() -> { 
      System.out.printf("%03ds: This is the second runnable, reporting in%n", (System.currentTimeMillis() - start)/1000); 
     }, 2, 10, TimeUnit.SECONDS); 
     ScheduledFuture future3 = executor.scheduleAtFixedRate(() -> { 
      System.out.printf("%03ds: This is the third runnable, reporting in%n", (System.currentTimeMillis() - start)/1000); 
     }, 5, 15, TimeUnit.SECONDS); 

     // Wait some 
     Thread.sleep(30000); 

     // Reschedule the second task 
     System.out.printf("%03ds: Rescheduling the second runnable to run at 20 second intervals%n", (System.currentTimeMillis() - start)/1000); 
     future2.cancel(true); 
     future2 = executor.scheduleAtFixedRate(() -> { 
      System.out.printf("%03ds: This is the second runnable, reporting in%n", (System.currentTimeMillis() - start)/1000); 
     }, 2, 20, TimeUnit.SECONDS); 
    } 
} 

Wie Sie in der folgenden Ausgabe sehen die zweite Aufgabe setzt er Umschuldung und ändert es alle 10 Sekunden alle 20 Sekunden und die erste und dritte Aufgaben sind nicht betroffen vom Laufen.

Ausgang:

000s: This is the first runnable, reporting in 
002s: This is the second runnable, reporting in 
005s: This is the first runnable, reporting in 
005s: This is the third runnable, reporting in 
010s: This is the first runnable, reporting in 
012s: This is the second runnable, reporting in 
015s: This is the first runnable, reporting in 
020s: This is the first runnable, reporting in 
020s: This is the third runnable, reporting in 
022s: This is the second runnable, reporting in 
025s: This is the first runnable, reporting in 
030s: This is the first runnable, reporting in 
030s: Rescheduling the second runnable to run at 20 second intervals 
032s: This is the second runnable, reporting in 
035s: This is the first runnable, reporting in 
035s: This is the third runnable, reporting in 
040s: This is the first runnable, reporting in 
045s: This is the first runnable, reporting in 
050s: This is the first runnable, reporting in 
050s: This is the third runnable, reporting in 
052s: This is the second runnable, reporting in 
055s: This is the first runnable, reporting in 
060s: This is the first runnable, reporting in 
065s: This is the first runnable, reporting in 
065s: This is the third runnable, reporting in 
070s: This is the first runnable, reporting in 
072s: This is the second runnable, reporting in