Pintos: pintos/src/tests/threads/priority-change.c Source File

00001 /* Verifies that lowering a thread's priority so that it is no
00002    longer the highest-priority thread in the system causes it to
00003    yield immediately. */
00004 
00005 #include <stdio.h>
00006 #include "tests/threads/tests.h"
00007 #include "threads/init.h"
00008 #include "threads/thread.h"
00009 
00010 static thread_func changing_thread;
00011 
00012 void
00013 test_priority_change (void) 
00014 {
00015   /* This test does not work with the MLFQS. */
00016   ASSERT (!thread_mlfqs);
00017 
00018   msg ("Creating a high-priority thread 2.");
00019   thread_create ("thread 2", PRI_DEFAULT + 1, changing_thread, NULL);
00020   msg ("Thread 2 should have just lowered its priority.");
00021   thread_set_priority (PRI_DEFAULT - 2);
00022   msg ("Thread 2 should have just exited.");
00023 }
00024 
00025 static void
00026 changing_thread (void *aux UNUSED) 
00027 {
00028   msg ("Thread 2 now lowering priority.");
00029   thread_set_priority (PRI_DEFAULT - 1);
00030   msg ("Thread 2 exiting.");
00031 }