CS代考计算机代写 /* Creates N threads, each of which sleeps a different, fixed

/* Creates N threads, each of which sleeps a different, fixed
duration, M times. Records the wake-up order and verifies
that it is valid. */

#include
#include “tests/threads/tests.h”
#include “threads/init.h”
#include “threads/malloc.h”
#include “threads/synch.h”
#include “threads/thread.h”
#include “devices/timer.h”

static void test_sleep (int thread_cnt, int iterations);

void
test_alarm_single (void)
{
test_sleep (5, 1);
}

void
test_alarm_multiple (void)
{
test_sleep (5, 7);
}

/* Information about the test. */
struct sleep_test
{
int64_t start; /* Current time at start of test. */
int iterations; /* Number of iterations per thread. */

/* Output. */
struct lock output_lock; /* Lock protecting output buffer. */
int *output_pos; /* Current position in output buffer. */
};

/* Information about an individual thread in the test. */
struct sleep_thread
{
struct sleep_test *test; /* Info shared between all threads. */
int id; /* Sleeper ID. */
int duration; /* Number of ticks to sleep. */
int iterations; /* Iterations counted so far. */
};

static void sleeper (void *);

/* Runs THREAD_CNT threads thread sleep ITERATIONS times each. */
static void
test_sleep (int thread_cnt, int iterations)
{
struct sleep_test test;
struct sleep_thread *threads;
int *output, *op;
int product;
int i;

/* This test does not work with the MLFQS. */
ASSERT (!thread_mlfqs);

msg (“Creating %d threads to sleep %d times each.”, thread_cnt, iterations);
msg (“Thread 0 sleeps 10 ticks each time,”);
msg (“thread 1 sleeps 20 ticks each time, and so on.”);
msg (“If successful, product of iteration count and”);
msg (“sleep duration will appear in nondescending order.”);

/* Allocate memory. */
threads = malloc (sizeof *threads * thread_cnt);
output = malloc (sizeof *output * iterations * thread_cnt * 2);
if (threads == NULL || output == NULL)
PANIC (“couldn’t allocate memory for test”);

/* Initialize test. */
test.start = timer_ticks () + 100;
test.iterations = iterations;
lock_init (&test.output_lock);
test.output_pos = output;

/* Start threads. */
ASSERT (output != NULL);
for (i = 0; i < thread_cnt; i++) { struct sleep_thread *t = threads + i; char name[16]; t->test = &test;
t->id = i;
t->duration = (i + 1) * 10;
t->iterations = 0;

snprintf (name, sizeof name, “thread %d”, i);
thread_create (name, PRI_DEFAULT, sleeper, t);
}

/* Wait long enough for all the threads to finish. */
timer_sleep (100 + thread_cnt * iterations * 10 + 100);

/* Acquire the output lock in case some rogue thread is still
running. */
lock_acquire (&test.output_lock);

/* Print completion order. */
product = 0;
for (op = output; op < test.output_pos; op++) { struct sleep_thread *t; int new_prod; ASSERT (*op >= 0 && *op < thread_cnt); t = threads + *op; new_prod = ++t->iterations * t->duration;

msg (“thread %d: duration=%d, iteration=%d, product=%d”,
t->id, t->duration, t->iterations, new_prod);

if (new_prod >= product)
product = new_prod;
else
fail (“thread %d woke up out of order (%d > %d)!”,
t->id, product, new_prod);
}

/* Verify that we had the proper number of wakeups. */
for (i = 0; i < thread_cnt; i++) if (threads[i].iterations != iterations) fail ("thread %d woke up %d times instead of %d", i, threads[i].iterations, iterations); lock_release (&test.output_lock); free (output); free (threads); } /* Sleeper thread. */ static void sleeper (void *t_) { struct sleep_thread *t = t_; struct sleep_test *test = t->test;
int i;

for (i = 1; i <= test->iterations; i++)
{
int64_t sleep_until = test->start + i * t->duration;
timer_sleep (sleep_until – timer_ticks ());
lock_acquire (&test->output_lock);
*test->output_pos++ = t->id;
lock_release (&test->output_lock);
}
}