+/* Problem 1-1: Alarm Clock tests.
+
+ Based on a test originally submitted for Stanford's CS 140 in
+ winter 1998 by Rob Baesman <rbaesman@cs.stanford.edu>, Ben
+ Taskar <btaskar@cs.stanford.edu>, and Toli Kuznets
+ <tolik@cs.stanford.edu>. */
+
+#include "threads/test.h"
+#include <stdio.h>
+#include "threads/malloc.h"
+#include "threads/synch.h"
+#include "threads/thread.h"
+#include "devices/timer.h"
+
+/* Number of iterations. */
+#define ITERATION_CNT 1
+
+static void test_sleep (int iterations);
+
+void
+test (void)
+{
+ test_sleep (ITERATION_CNT);
+}
+
+struct sleep_thread_data
+ {
+ int64_t start; /* Start time. */
+ int duration; /* Number of ticks to sleep. */
+ int iterations; /* Number of iterations to run. */
+ struct semaphore done; /* Completion semaphore. */
+ tid_t tid; /* Thread ID. */
+
+ struct lock *lock; /* Lock on access to remaining members. */
+ int *product; /* Largest product so far. */
+ char **out; /* Output pointer. */
+ };
+
+static void sleeper (void *);
+
+static void
+test_sleep (int iterations)
+{
+ struct sleep_thread_data threads[5];
+ const int thread_cnt = sizeof threads / sizeof *threads;
+ char *output, *cp;
+ struct lock lock;
+ int64_t start;
+ int product;
+ int i;
+
+ printf ("\n"
+ "Testing %d sleeps per thread.\n"
+ "If successful, product of iteration count and\n"
+ "sleep duration will appear in nondescending order.\n",
+ iterations);
+
+ /* Start all the threads. */
+ product = 0;
+ lock_init (&lock, "product");
+ cp = output = malloc (128 * iterations * thread_cnt);
+ ASSERT (output != NULL);
+ start = timer_ticks ();
+ for (i = 0; i < thread_cnt; i++)
+ {
+ struct sleep_thread_data *t;
+ char name[16];
+
+ snprintf (name, sizeof name, "thread %d", i);
+ t = threads + i;
+ t->start = start;
+ t->duration = (i + 1) * 10;
+ t->iterations = iterations;
+ sema_init (&t->done, 0, name);
+ t->tid = thread_create (name, PRI_DEFAULT, sleeper, t);
+
+ t->lock = &lock;
+ t->product = &product;
+ t->out = &cp;
+ }
+
+ /* Wait for all the threads to finish. */
+ for (i = 0; i < thread_cnt; i++)
+ sema_down (&threads[i].done);
+
+ printf ("%s...done\n", output);
+}
+
+static void
+sleeper (void *t_)
+{
+ struct sleep_thread_data *t = t_;
+ int i;
+
+ for (i = 1; i <= t->iterations; i++)
+ {
+ int old_product;
+ int new_product = i * t->duration;
+
+ timer_sleep ((t->start + new_product) - timer_ticks ());
+
+ lock_acquire (t->lock);
+ old_product = *t->product;
+ *t->product = new_product;
+ *t->out += snprintf (*t->out, 128,
+ "%s: duration=%d, iteration=%d, product=%d\n",
+ thread_name (), t->duration, i, new_product);
+ if (old_product > new_product)
+ *t->out += snprintf (*t->out, 128,
+ "%s: Out of order sleep completion (%d > %d)!\n",
+ thread_name (), old_product, new_product);
+ lock_release (t->lock);
+ }
+
+ /* Signal completion. */
+ sema_up (&t->done);
+}