/* 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_simultaneous (void)
{
test_sleep (3, 5);
}
/* Information about the test. */
struct sleep_test
{
int64_t start; /* Current time at start of test. */
int iterations; /* Number of iterations per thread. */
int *output_pos; /* Current position in output buffer. */
};
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;
int *output;
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 (“Each thread sleeps 10 ticks each time.”);
msg (“Within an iteration, all threads should wake up on the same tick.”);
/* Allocate memory. */
output = malloc (sizeof *output * iterations * thread_cnt * 2);
if (output == NULL)
PANIC (“couldn’t allocate memory for test”);
/* Initialize test. */
test.start = timer_ticks () + 100;
test.iterations = iterations;
test.output_pos = output;
/* Start threads. */
ASSERT (output != NULL);
for (i = 0; i < thread_cnt; i++)
{
char name[16];
snprintf (name, sizeof name, "thread %d", i);
thread_create (name, PRI_DEFAULT, sleeper, &test);
}
/* Wait long enough for all the threads to finish. */
timer_sleep (100 + iterations * 10 + 100);
/* Print completion order. */
msg ("iteration 0, thread 0: woke up after %d ticks", output[0]);
for (i = 1; i < test.output_pos - output; i++)
msg ("iteration %d, thread %d: woke up %d ticks later",
i / thread_cnt, i % thread_cnt, output[i] - output[i - 1]);
free (output);
}
/* Sleeper thread. */
static void
sleeper (void *test_)
{
struct sleep_test *test = test_;
int i;
/* Make sure we're at the beginning of a timer tick. */
timer_sleep (1);
for (i = 1; i <= test->iterations; i++)
{
int64_t sleep_until = test->start + i * 10;
timer_sleep (sleep_until – timer_ticks ());
*test->output_pos++ = timer_ticks () – test->start;
thread_yield ();
}
}