Java thread pool

Thread class:

1 classRunthread implements runnable{2 3     intCounter =0;4 @Override5      PublicSynchronizedvoidrun () {6 7         Try {8Thread.Sleep ( -);9}Catch(interruptedexception e) {Ten e.printstacktrace (); One         }     ASystem. out. println (Thread.CurrentThread (). GetName () +"Count:"+counter++); -     } -  the}

Execute function:

1      Public Static voidMain (string[] args) {2 3Threadpoolexecutor executor =NewThreadpoolexecutor (5,Ten, $, Timeunit.milliseconds,4                 NewArrayblockingqueue<runnable> (Ten));5         6          for(inti =0; I < the; i++) {7Runthread Runthread =NewRunthread ();8System. out. println ("thread pool Number of threads:"+executor.getpoolsize () +", the number of tasks waiting to be executed in the queue:"+9Executor.getqueue (). Size () +", the number of other tasks that have been performed:"+Executor.getcompletedtaskcount ());Ten             Try { One Executor.execute (runthread); A}Catch(Exception e) { - e.printstacktrace (); -             } the              -         } - Executor.shutdown (); -}

Operation Result:

Thread pool number of threads: 0, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:1, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:2, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:3, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:4, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 1, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 2, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 3, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 4, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 6, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 7, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 8, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 9, performed the number of other tasks played: 0Pool-1-thread-2count:0Pool-1-thread-4count:0Pool-1-thread-1count:0Pool-1-thread-3count:0Pool-1-thread-5count:0Pool-1-thread-4count:0Pool-1-thread-2count:0Pool-1-thread-1count:0Pool-1-thread-3count:0Pool-1-thread-5count:0Pool-1-thread-2count:0Pool-1-thread-4count:0Pool-1-thread-1count:0Pool-1-thread-5count:0Pool-1-thread-3count:0

Modify Parameters:

New Threadpoolexecutor (5, ten, Timeunit.milliseconds,new, arrayblockingqueue<runnable> (5));

Output Result:

Thread pool number of threads: 0, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:1, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:2, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:3, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:4, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 1, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 2, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 3, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 4, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:6, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:7, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:8, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:9, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0Pool-1-thread-4count:0Pool-1-thread-2count:0Pool-1-thread-5count:0Pool-1-thread-3count:0Pool-1-thread-1count:0Pool-1-thread-10count:0Pool-1-thread-9count:0Pool-1-thread-8count:0Pool-1-thread-7count:0Pool-1-thread-6count:0Pool-1-thread-4count:0Pool-1-thread-3count:0Pool-1-thread-5count:0Pool-1-thread-2count:0Pool-1-thread-1count:0

Modify Parameters:

Threadpoolexecutor executor = new Threadpoolexecutor (5, 8, $, timeunit.milliseconds,new arrayblockingqueue< Runnable> (5));

Output Result:

Thread pool number of threads: 0, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:1, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:2, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:3, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:4, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 1, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 2, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 3, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 4, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:6, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:7, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0thread pool Number of threads:8, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0java.util.concurrent.RejectedExecutionException:Task [email protected]1884174 rejected from [email protected][running, pool size = 8, Active threads = 8, queued tasks = 5, completed tasks = 0] at java.util.concurrent.threadpoolexecutor$abortpolicy.rejectedexecution (Unknown Source) at Java.util.concurr Ent. Threadpoolexecutor.reject (Unknown source) at Java.util.concurrent.ThreadPoolExecutor.execute (Unknown source) at COM. Uestc.xst.Main.main (Main.java:73) Java.util.concurrent.RejectedExecutionException:Task [email protected] rejected from [email protected]814013[running, pool size = 8, Active threads = 8, queued tasks = 5, completed tasks = 0] at java.util.concurrent.threadpoolexecutor$abortpolicy.rejectedexecution (Unknown Source) at Java.util.concurr Ent. Threadpoolexecutor.reject (Unknown source) at Java.util.concurrent.ThreadPoolExecutor.execute (Unknown source) at COM. Uestc.xst.Main.main (Main.java:73) thread pool number of threads:8, number of tasks waiting to be executed in queue: 5, performed the number of other tasks played: 0Pool-1-thread-3count:0Pool-1-thread-1count:0Pool-1-thread-2count:0Pool-1-thread-4count:0Pool-1-thread-5count:0Pool-1-thread-7count:0Pool-1-thread-6count:0Pool-1-thread-8count:0Pool-1-thread-3count:0Pool-1-thread-2count:0Pool-1-thread-5count:0Pool-1-thread-4count:0Pool-1-thread-1count:0

To continue modifying parameters:

Threadpoolexecutor executor = new Threadpoolexecutor ($, timeunit.milliseconds,new arrayblockingqueue< Runnable> (5));

Output Result:

Thread pool number of threads: 0, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:1, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:2, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:3, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:4, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:5, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:6, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:7, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:8, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:9, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:10, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:11, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:12, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:13, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0thread pool Number of threads:14, number of tasks waiting to be executed in queue: 0, performed the number of other tasks played: 0Pool-1-thread-1count:0Pool-1-thread-5count:0Pool-1-thread-3count:0Pool-1-thread-2count:0Pool-1-thread-4count:0Pool-1-thread-9count:0Pool-1-thread-7count:0Pool-1-thread-10count:0Pool-1-thread-8count:0Pool-1-thread-6count:0Pool-1-thread-11count:0Pool-1-thread-13count:0Pool-1-thread-14count:0Pool-1-thread-15count:0Pool-1-thread-12count:0

Results Analysis:

When thread pool threads reach the core thread size, if it is still on, it is prioritized in the task cache queue, and if the queue is full, a new thread is opened if the maximunpoolsize is not full, and an exception is thrown if the maximunpoolsize is full.

Java thread pool