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

00001 /* Tests that the highest-priority thread waiting on a semaphore
00002    is the first to wake up. */
00003 
00004 #include <stdio.h>
00005 #include "tests/threads/tests.h"
00006 #include "threads/init.h"
00007 #include "threads/malloc.h"
00008 #include "threads/synch.h"
00009 #include "threads/thread.h"
00010 #include "devices/timer.h"
00011 
00012 static thread_func priority_sema_thread;
00013 static struct semaphore sema;
00014 
00015 void
00016 test_priority_sema (void) 
00017 {
00018   int i;
00019   
00020   /* This test does not work with the MLFQS. */
00021   ASSERT (!thread_mlfqs);
00022 
00023   sema_init (&sema, 0);
00024   thread_set_priority (PRI_MIN);
00025   for (i = 0; i < 10; i++) 
00026     {
00027       int priority = PRI_DEFAULT - (i + 3) % 10 - 1;
00028       char name[16];
00029       snprintf (name, sizeof name, "priority %d", priority);
00030       thread_create (name, priority, priority_sema_thread, NULL);
00031     }
00032 
00033   for (i = 0; i < 10; i++) 
00034     {
00035       sema_up (&sema);
00036       msg ("Back in main thread."); 
00037     }
00038 }
00039 
00040 static void
00041 priority_sema_thread (void *aux UNUSED) 
00042 {
00043   sema_down (&sema);
00044   msg ("Thread %s woke up.", thread_name ());
00045 }