CS代考计算机代写 /* Creates several threads all at the same priority and ensures

/* Creates several threads all at the same priority and ensures
that they consistently run in the same round-robin order.

Based on a test originally submitted for Stanford’s CS 140 in
winter 1999 by by Matt Franklin
, Greg Hutchins
, Yu Ping Hu .
Modified by arens. */

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

struct simple_thread_data
{
int id; /* Sleeper ID. */
int iterations; /* Iterations so far. */
struct lock *lock; /* Lock on output. */
int **op; /* Output buffer position. */
};

#define THREAD_CNT 16
#define ITER_CNT 16

static thread_func simple_thread_func;

void
test_priority_fifo (void)
{
struct simple_thread_data data[THREAD_CNT];
struct lock lock;
int *output, *op;
int i, cnt;

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

/* Make sure our priority is the default. */
ASSERT (thread_get_priority () == PRI_DEFAULT);

msg (“%d threads will iterate %d times in the same order each time.”,
THREAD_CNT, ITER_CNT);
msg (“If the order varies then there is a bug.”);

output = op = malloc (sizeof *output * THREAD_CNT * ITER_CNT * 2);
ASSERT (output != NULL);
lock_init (&lock);

thread_set_priority (PRI_DEFAULT + 2);
for (i = 0; i < THREAD_CNT; i++) { char name[16]; struct simple_thread_data *d = data + i; snprintf (name, sizeof name, "%d", i); d->id = i;
d->iterations = 0;
d->lock = &lock;
d->op = &op;
thread_create (name, PRI_DEFAULT + 1, simple_thread_func, d);
}

thread_set_priority (PRI_DEFAULT);
/* All the other threads now run to termination here. */
ASSERT (lock.holder == NULL);

cnt = 0;
for (; output < op; output++) { struct simple_thread_data *d; ASSERT (*output >= 0 && *output < THREAD_CNT); d = data + *output; if (cnt % THREAD_CNT == 0) printf ("(priority-fifo) iteration:"); printf (" %d", d->id);
if (++cnt % THREAD_CNT == 0)
printf (“
”);
d->iterations++;
}
}

static void
simple_thread_func (void *data_)
{
struct simple_thread_data *data = data_;
int i;

for (i = 0; i < ITER_CNT; i++) { lock_acquire (data->lock);
*(*data->op)++ = data->id;
lock_release (data->lock);
thread_yield ();
}
}