java - What change did really happen in Async Task after Android Gingerbread? -

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what change did android team make in async task after android 2.3. when executed following code getting same result in both android 2.3 , 3.0.

package com.sample.asynctask;  import android.app.activity; import android.os.asynctask; import android.os.bundle; import android.util.log;  public class asynctasktestactivity extends activity {     private static final string tag = "asynctasktestactivity";      /** called when activity first created. */     @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.main);         //executorservice executorservice = executors.newfixedthreadpool(1);         (int = 1; <= 20; i++) {             testtask testtask = new testtask(i);             testtask.execute();         }     }      private static class testtask extends asynctask<void, integer, void> {         int i;         public testtask(int i) {             log.i(tag, "constructor " + i);             this.i = i;         }          @override         protected void onpreexecute() {             // todo auto-generated method stub             super.onpreexecute();             log.i(tag, "onpreexecute " + i);         }          @override         protected void doinbackground(void... params) {             log.i(tag, + " thread goes sleep");             try {                 thread.sleep(20000);             } catch (interruptedexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             }             log.i(tag, + " thread wakes up");             return null;         }          @override         protected void onpostexecute(void result) {             // todo auto-generated method stub             super.onpostexecute(result);             log.i(tag, "onpostexecute " + i);         }     } }

my assumption in gingerbread: 5 async task executes @ 1 thread pool @ time. assumption in honeycomb: 1 async task executes @ 1 thread pool @ time. concurrent execution.

but, both gingerbread , honeycomb executes 5 async tasks @ same time.

and when number async task increased 140.i not getting java.util.concurrent.rejectedexecutionexception .

whether assumptions correct? happening inside there?

whether assumptions correct?

your assumptions correct, well, sort of.

what happening inside there?

the default executor inside android.os.asynctask:

... ...  private static volatile executor sdefaultexecutor = serial_executor;  ... ...

has been reset in android.app.activitythread:

... ...  // if app honeycomb mr1 or earlier, switch asynctask // implementation use pool executor.  normally, use // serialized executor default. has happen in // main thread main looper set right. if (data.appinfo.targetsdkversion <= android.os.build.version_codes.honeycomb_mr1) {     asynctask.setdefaultexecutor(asynctask.thread_pool_executor); }  ... ...

what change did happen in async task after android gingerbread?

check out asynctask change history, more specifically, one:

mar 17, 2011 - asynctask uses poll executor apps through hc mr1 , t…

when number async task increased 140, not getting java.util.concurrent.rejectedexecutionexception.

this factor of total number of tasks , execution time per each task, in world, total task number 140 (which bigger 128), however, total number of thread allocated threadpool @ given time smaller 128, in word, there idle threads (due last task finished , release resource) available in case. can try increase execution time per each task example thread.sleep(10000), give rejectedexecutionexception.


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