Now,I met one problem. First i created one service task to create five tasks .And the five tasks call the same function.When tasks run over,the service task delete himself. ~~~~ void gvfservetask( void *pvParameters ) { xTaskCreate(gvfdownloadtask,"task0",......); xTaskCreate(gvfdownloadtask,"task1",......); xTaskCreate(gvfdownloadtask,"task2",......); xTaskCreate(gvfdownloadtask,"task3",......); xTaskCreate(gvfdownloadtask,"task4",......); if(alltaskrunover) vTaskDelete(NULL); } void gvfdownloadtask(void *pvParameters) { ... ... vTaskDelete(NULL); } ~~~~ When the first time gvfservetask has beed created, the five gvfdownloadtasks run success.At the second time,it,s still success.At the third time,it,s still success. But when gvfservetask run fourth time,none task has been created!!! And I had check the variables,found no problem. So ,i want to check the gvfdownload_task if existed in the list of taskTCB.

Sorry this message didn't appear for such a long time - for some reason it went into the moderation queue. The forum is set such that it should not use the moderation queue, but for some reason this still happens very occassioinally. In any case, I think you were able to receive your answer here: https://sourceforge.net/p/freertos/discussion/382005/thread/a90cb171/

Yes,thank you.