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/*

 * Copyright (C) 2001-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - 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.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

 */

#include <test.h>

#include <arch.h>

#include <arch/smp/atomic.h>

#include <print.h>

#include <proc/thread.h>

#include <arch/types.h>

#include <arch/context.h>

#include <panic.h>

#include <synch/waitq.h>

#include <synch/rwlock.h>

#include <synch/synch.h>

#define READERS		50

#define WRITERS		50

static rwlock_t rwlock;

static spinlock_t lock;

static waitq_t can_start;

__u32 seed = 0xdeadbeaf;

static __u32 random(__u32 max);

static void writer(void *arg);

static void reader(void *arg);

static void failed(void);

__u32 random(__u32 max)

{

	__u32 rc;

	spinlock_lock(&lock);	

	rc = seed % max;

	seed = (((seed<<2) ^ (seed>>2)) * 487) + rc;

	spinlock_unlock(&lock);

	return rc;

}

void writer(void *arg)

{

	int rc, to;

	waitq_sleep(&can_start);

	to = random(40000);

	printf("cpu%d, tid %d w+ (%d)\n", CPU->id, THREAD->tid, to);

	rc = rwlock_write_lock_timeout(&rwlock, to);

	if (SYNCH_FAILED(rc)) {

		printf("cpu%d, tid %d w!\n", CPU->id, THREAD->tid);

		return;

	};

	printf("cpu%d, tid %d w=\n", CPU->id, THREAD->tid);

	if (rwlock.readers_in) panic("Oops.");

	thread_usleep(random(1000000));

	if (rwlock.readers_in) panic("Oops.");	

	rwlock_write_unlock(&rwlock);

	printf("cpu%d, tid %d w-\n", CPU->id, THREAD->tid);	

}

void reader(void *arg)

{

	int rc, to;

	waitq_sleep(&can_start);

	to = random(2000);

	printf("cpu%d, tid %d r+ (%d)\n", CPU->id, THREAD->tid, to);

	rc = rwlock_read_lock_timeout(&rwlock, to);

	if (SYNCH_FAILED(rc)) {

		printf("cpu%d, tid %d r!\n", CPU->id, THREAD->tid);

		return;

	}

	printf("cpu%d, tid %d r=\n", CPU->id, THREAD->tid);

	thread_usleep(30000);

	rwlock_read_unlock(&rwlock);

	printf("cpu%d, tid %d r-\n", CPU->id, THREAD->tid);		

}

void failed(void)

{

	printf("Test failed prematurely.\n");

	thread_exit();

}

void test(void)

{

	context_t ctx;

	__u32 i, k;

	printf("Read/write locks test #4\n");

	waitq_initialize(&can_start);

	rwlock_initialize(&rwlock);

	for (; ;) {

		thread_t *thrd;

		context_save(&ctx);

		printf("sp=%X, readers_in=%d\n", ctx.sp, rwlock.readers_in);

		k = random(7) + 1;

		printf("Creating %d readers\n", k);

		for (i=0; i<k; i++) {

			thrd = thread_create(reader, NULL, TASK, 0);

			if (thrd)

				thread_ready(thrd);

			else

				failed();

		}

		k = random(5) + 1;

		printf("Creating %d writers\n", k);

		for (i=0; i<k; i++) {

			thrd = thread_create(writer, NULL, TASK, 0);

			if (thrd)

				thread_ready(thrd);

			else

				failed();

		}

		thread_usleep(20000);

		waitq_wakeup(&can_start, WAKEUP_ALL);

	}		

}