synchtest.c

/*
 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
 *      The President and Fellows of Harvard College.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Synchronization test code.
 */

#include <types.h>
#include <lib.h>
#include <clock.h>
#include <thread.h>
#include <synch.h>
#include <test.h>

#define NSEMLOOPS     63
#define NLOCKLOOPS    120
#define NCVLOOPS      5
#define NTHREADS      32

static volatile unsigned long testval1;
static volatile unsigned long testval2;
static volatile unsigned long testval3;
#ifdef UW
static struct semaphore *testsem = 0;
static struct lock *testlock = 0;
static struct cv *testcv = 0;
static struct semaphore *donesem = 0;
#else
static struct semaphore *testsem;
static struct lock *testlock;
static struct cv *testcv;
static struct semaphore *donesem;
#endif

#ifdef UW
static
void
cleanitems(void)
{
        kprintf("cleanitems: Destroying sems, locks, and cvs\n");
        sem_destroy(testsem);
        lock_destroy(testlock);
        cv_destroy(testcv);
        sem_destroy(donesem);
        }
#endif

static
void
inititems(void)
{
        if (testsem==NULL) {
                testsem = sem_create("testsem", 2);
                if (testsem == NULL) {
                        panic("synchtest: sem_create failed\n");
                }
        }
        if (testlock==NULL) {
                testlock = lock_create("testlock");
                if (testlock == NULL) {
                        panic("synchtest: lock_create failed\n");
                }
        }
        if (testcv==NULL) {
#ifdef UW
                testcv = cv_create("testcv");
#else
                testcv = cv_create("testlock");
#endif
                if (testcv == NULL) {
                        panic("synchtest: cv_create failed\n");
                }
        }
        if (donesem==NULL) {
                donesem = sem_create("donesem", 0);
                if (donesem == NULL) {
                        panic("synchtest: sem_create failed\n");
                }
        }
}

static
void
semtestthread(void *junk, unsigned long num)
{
        int i;
        (void)junk;

        /*
         * Only one of these should print at a time.
         */
        P(testsem);
        kprintf("Thread %2lu: ", num);
        for (i=0; i<NSEMLOOPS; i++) {
                kprintf("%c", (int)num+64);
        }
        kprintf("\n");
        V(donesem);
#ifdef UW
  thread_exit();
#endif
}

int
semtest(int nargs, char **args)
{
        int i, result;

        (void)nargs;
        (void)args;

        inititems();
        kprintf("Starting semaphore test...\n");
        kprintf("If this hangs, it's broken: ");
        P(testsem);
        P(testsem);
        kprintf("ok\n");

        for (i=0; i<NTHREADS; i++) {
                result = thread_fork("semtest", NULL, semtestthread, NULL, i);
                if (result) {
                        panic("semtest: thread_fork failed: %s\n", 
                              strerror(result));
                }
        }

        for (i=0; i<NTHREADS; i++) {
                V(testsem);
                P(donesem);
        }

        /* so we can run it again */
        V(testsem);
        V(testsem);

#ifdef UW
  cleanitems();
#endif
        kprintf("Semaphore test done.\n");
        return 0;
}

static
void
fail(unsigned long num, const char *msg)
{
        kprintf("thread %lu: Mismatch on %s\n", num, msg);
        kprintf("Test failed\n");

        lock_release(testlock);

        V(donesem);
        thread_exit();
}

static
void
locktestthread(void *junk, unsigned long num)
{
        int i;
        (void)junk;

        for (i=0; i<NLOCKLOOPS; i++) {
                lock_acquire(testlock);
                testval1 = num;
                testval2 = num*num;
                testval3 = num%3;

                if (testval2 != testval1*testval1) {
                        fail(num, "testval2/testval1");
                }

                if (testval2%3 != (testval3*testval3)%3) {
                        fail(num, "testval2/testval3");
                }

                if (testval3 != testval1%3) {
                        fail(num, "testval3/testval1");
                }

                if (testval1 != num) {
                        fail(num, "testval1/num");
                }

                if (testval2 != num*num) {
                        fail(num, "testval2/num");
                }

                if (testval3 != num%3) {
                        fail(num, "testval3/num");
                }

                lock_release(testlock);
        }
        V(donesem);
#ifdef UW
  thread_exit();
#endif
}


int
locktest(int nargs, char **args)
{
        int i, result;

        (void)nargs;
        (void)args;

        inititems();
        kprintf("Starting lock test...\n");

        for (i=0; i<NTHREADS; i++) {
                result = thread_fork("synchtest", NULL, locktestthread,
                                     NULL, i);
                if (result) {
                        panic("locktest: thread_fork failed: %s\n",
                              strerror(result));
                }
        }
        for (i=0; i<NTHREADS; i++) {
                P(donesem);
        }

#ifdef UW
  cleanitems();
#endif
        kprintf("Lock test done.\n");

        return 0;
}

static
void
cvtestthread(void *junk, unsigned long num)
{
        int i;
        volatile int j;
        time_t secs1, secs2;
        uint32_t nsecs1, nsecs2;

        (void)junk;

        for (i=0; i<NCVLOOPS; i++) {
                lock_acquire(testlock);
                while (testval1 != num) {
                        gettime(&secs1, &nsecs1);
                        cv_wait(testcv, testlock);
                        gettime(&secs2, &nsecs2);

                        if (nsecs2 < nsecs1) {
                                secs2--;
                                nsecs2 += 1000000000;
                        }
                        
                        nsecs2 -= nsecs1;
                        secs2 -= secs1;

                        /* Require at least 2000 cpu cycles (we're 25mhz) */
                        if (secs2==0 && nsecs2 < 40*2000) {
                                kprintf("cv_wait took only %u ns\n", nsecs2);
                                kprintf("That's too fast... you must be "
                                        "busy-looping\n");
                                V(donesem);
                                thread_exit();
                        }

                }
                kprintf("Thread %lu\n", num);
                testval1 = (testval1 + NTHREADS - 1)%NTHREADS;

                /*
                 * loop a little while to make sure we can measure the
                 * time waiting on the cv.
                 */
                for (j=0; j<3000; j++);

                cv_broadcast(testcv, testlock);
                lock_release(testlock);
        }
        V(donesem);
#ifdef UW
  thread_exit();
#endif
}

int
cvtest(int nargs, char **args)
{

        int i, result;

        (void)nargs;
        (void)args;

        inititems();
        kprintf("Starting CV test...\n");
#ifdef UW
        kprintf("%d threads should print out in reverse order %d times.\n", NTHREADS, NCVLOOPS);
#else
        kprintf("Threads should print out in reverse order.\n");
#endif

        testval1 = NTHREADS-1;

        for (i=0; i<NTHREADS; i++) {
                result = thread_fork("synchtest", NULL, cvtestthread, NULL, i);
                if (result) {
                        panic("cvtest: thread_fork failed: %s\n",
                              strerror(result));
                }
        }
        for (i=0; i<NTHREADS; i++) {
                P(donesem);
        }

#ifdef UW
  cleanitems();
#endif
        kprintf("CV test done\n");

        return 0;
}