/*
 * Copyright 2010 Samy Al Bahra.
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include <errno.h>
#include <inttypes.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/time.h>

#ifdef __linux__
#include <sched.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/syscall.h>
#endif

#ifndef CORES 
#define CORES 8
#endif

#include <ck_backoff.h>
#include <ck_cc.h>
#include <ck_pr.h>
#include <stdbool.h>
#include <stddef.h>
#include <ck_hp.h>
#include <ck_stack.h>
#include <ck_hp_stack.h>

static unsigned int threshold;
static unsigned int n_threads;
static unsigned int barrier;
static unsigned int e_barrier;

#ifndef PAIRS
#define PAIRS 1000000 
#endif

struct node {
	unsigned int value;
	ck_hp_hazard_t hazard;
	ck_stack_entry_t stack_entry;
};
static ck_stack_t stack = {NULL, NULL};
static ck_hp_t stack_hp;

CK_STACK_CONTAINER(struct node, stack_entry, stack_container)

struct affinity {
	uint32_t delta;
	uint32_t request;
};

static struct affinity a;

#ifdef __linux__
#ifndef gettid
static pid_t
gettid(void)
{
        return syscall(__NR_gettid);
}
#endif

static int
aff_iterate(struct affinity *acb)
{
        cpu_set_t s;
        int c;

        c = ck_pr_faa_uint(&acb->request, acb->delta);
        CPU_ZERO(&s);
        CPU_SET(c % CORES, &s);

        return sched_setaffinity(gettid(), sizeof(s), &s);
}
#else
static int
aff_iterate(struct affinity *acb)
{
	acb = NULL;
        return (0);
}
#endif

static void *
thread(void *unused)
{
	struct node **entry, *e;
	unsigned int i;
	ck_hp_record_t record;
	void **pointers;
	ck_stack_entry_t *s;

	unused = NULL;
	pointers = malloc(sizeof(void *));
	ck_hp_subscribe(&stack_hp, &record, pointers);

	if (aff_iterate(&a)) {
		perror("ERROR: failed to affine thread");
		exit(EXIT_FAILURE);
	}

	entry = malloc(sizeof(struct node *) * PAIRS);
	if (entry == NULL) {
		fprintf(stderr, "Failed allocation.\n");
		exit(EXIT_FAILURE);
	}

	for (i = 0; i < PAIRS; i++) {
		entry[i] = malloc(sizeof(struct node));
		if (entry == NULL) {
			fprintf(stderr, "Failed individual allocation\n");
			exit(EXIT_FAILURE);
		}
	}

	ck_pr_inc_uint(&barrier);
	while (ck_pr_load_uint(&barrier) < n_threads);

	for (i = 0; i < PAIRS; i++) {
		ck_hp_stack_push_mpmc(&stack, &entry[i]->stack_entry);
		s = ck_hp_stack_pop_mpmc(&record, &stack);
		e = stack_container(s);
		ck_hp_free(&record, &e->hazard, e, s);
	}

	ck_pr_inc_uint(&e_barrier);
	while (ck_pr_load_uint(&e_barrier) < n_threads);

	return (NULL);
}

static void
destructor(void *p)
{

	free(p);
	return;
}

int
main(int argc, char *argv[])
{
	unsigned int i;
	pthread_t *threads;

	if (argc != 4) {
		fprintf(stderr, "Usage: stack <threads> <threshold> <delta>\n");
		exit(EXIT_FAILURE);
	}

	n_threads = atoi(argv[1]);
	threshold = atoi(argv[2]);
	a.delta = atoi(argv[3]);
	a.request = 0;

	threads = malloc(sizeof(pthread_t) * n_threads);

	ck_hp_init(&stack_hp, 1, threshold, destructor);

	for (i = 0; i < n_threads; i++) 
		pthread_create(threads + i, NULL, thread, NULL);

	for (i = 0; i < n_threads; i++) 
		pthread_join(threads[i], NULL);

	return (0);
}