/*-
 * Copyright (C) 2008 Jason Evans <jasone@FreeBSD.org>.
 * 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(s), this list of conditions and the following disclaimer as
 *    the first lines of this file unmodified other than the possible
 *    addition of one or more copyright notices.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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.
 *
 *******************************************************************************
 *
 * This microbenchmark tests concurrent throughput of malloc(3), but each
 * thread performs a unique number of allocation/deallocation cycles in order
 * potentially create a dynamic imbalance in the number of active threads as
 * threads finish varying amounts of work.
 *
 *******************************************************************************
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include <limits.h>
#include <pthread.h>

typedef struct {
	unsigned long		thread;
	bool			verbose;
	unsigned long long	allocs;
	size_t			minsize;
	size_t			maxsize;
} thread_args_t;

void *
thread_enter(void *vargs)
{
	thread_args_t *args = (thread_args_t *)vargs;
	unsigned long long i, size_total;
	unsigned ctx;
	size_t size;
	void *ptr;

	for (i = size_total = 0, ctx = (unsigned)args->thread;
	    i < args->allocs; i++, size_total += size) {
		size = args->minsize + (((float)rand_r(&ctx) / (float)RAND_MAX)
		    * (args->maxsize - args->minsize));
		ptr = calloc(1, size);
		if (ptr == NULL) {
			fprintf(stderr,
			    "imbalance: Thread %lu: Error in calloc(1, %zu)\n",
			    args->thread, size);
			_exit(1);
		}
		free(ptr);
	}

	if (args->verbose) {
		fprintf(stderr,
		    "Thread %lu completed %llu cycles, %llu bytes\n",
		    args->thread, args->allocs, size_total);
	}

	return (NULL);
}

void
usage(FILE *fp)
{
	fprintf(fp, "imbalance usage:\n");
	fprintf(fp, "    imbalance [<options>]\n");
	fprintf(fp, "\n");
	fprintf(fp, "    Option       | Description\n");
	fprintf(fp, "    -------------+-----------------------------\n");
	fprintf(fp, "    -h           | Print usage and exit.\n");
	fprintf(fp, "    -v           | Print verbose output.\n");
	fprintf(fp, "    -t <threads> | Number of worker threads.\n");
	fprintf(fp, "    -x <mult>    | Allocation count multiplier.\n");
	fprintf(fp, "    -s <size>    | Minimum allocation size.\n");
	fprintf(fp, "    -S <size>    | Maximum allocation size.\n");
}

int
main(int argc, char **argv)
{
	int c, err;
	bool opt_verbose = false;
	unsigned long opt_threads = 16;
	unsigned long long opt_mult = (1LLU << 28);
	size_t opt_minsize = 1;
	size_t opt_maxsize = 8192;
	pthread_t *threads;
	thread_args_t *thread_args;
	unsigned long i;

	opterr = 0;
	optind = 1;
	while ((c = getopt(argc, argv, "hvt:x:s:S:")) != -1) {
		switch (c) {
		case 'h':
			usage(stdout);
			_exit(0);
		case 'v':
			opt_verbose = true;
			break;
		case 't':
			errno = 0;
			opt_threads = strtoul(optarg, NULL, 0);
			if (opt_threads == ULONG_MAX && errno != 0) {
				fprintf(stderr,
				    "imbalance: Error in option '-%c %s': %s\n",
				    c, optarg, strerror(errno));
				usage(stderr);
				_exit(1);
			} else if (opt_threads == 0) {
				fprintf(stderr,
				    "imbalance: Invalid option '-%c %s'\n",
				    c, optarg);
				usage(stderr);
				_exit(1);
			}
			break;
		case 'x':
			errno = 0;
			opt_mult = strtoull(optarg, NULL, 0);
			if (opt_mult == ULLONG_MAX && errno != 0) {
				fprintf(stderr,
				    "imbalance: Error in option '-%c %s': %s\n",
				    c, optarg, strerror(errno));
				usage(stderr);
				_exit(1);
			} else if (opt_mult == 0) {
				fprintf(stderr,
				    "imbalance: Invalid option '-%c %s'\n",
				    c, optarg);
				usage(stderr);
				_exit(1);
			}
			break;
		case 's':
			errno = 0;
			opt_minsize = strtoull(optarg, NULL, 0);
			if (opt_minsize == ULLONG_MAX && errno != 0) {
				fprintf(stderr,
				    "imbalance: Error in option '-%c %s': %s\n",
				    c, optarg, strerror(errno));
				usage(stderr);
				_exit(1);
			}
			break;
		case 'S':
			errno = 0;
			opt_maxsize = strtoull(optarg, NULL, 0);
			if (opt_maxsize == ULLONG_MAX && errno != 0) {
				fprintf(stderr,
				    "imbalance: Error in option '-%c %s': %s\n",
				    c, optarg, strerror(errno));
				usage(stderr);
				_exit(1);
			}
			break;
		default:
			fprintf(stderr, "imbalance: Unrecognized option\n");
			usage(stderr);
			_exit(1);
		}
	}

	if (opt_maxsize < opt_minsize) {
		fprintf(stderr,
		    "imbalance: Maximum size smaller than minimum size"
		    " (%zu < %zu)\n", opt_maxsize, opt_minsize);
		usage(stderr);
		_exit(1);
	}

	if (opt_verbose) {
		fprintf(stdout, "imbalance: Verbose output enabled\n");
		fprintf(stdout, "imbalance: Number of threads: %lu\n",
		    opt_threads);
		fprintf(stdout,
		    "imbalance: Allocation count multiplier: %llu\n",
		    opt_mult);
		fprintf(stdout, "imbalance: Allocation size [%zu..%zu]\n",
		    opt_minsize, opt_maxsize);
	}

	threads = (pthread_t *)malloc(sizeof(pthread_t) * opt_threads);
	if (threads == NULL) {
		fprintf(stderr, "imbalance: Error in malloc()\n");
		_exit(1);
	}

	thread_args = (thread_args_t *)malloc(sizeof(thread_args_t) *
	    opt_threads);
	if (thread_args == NULL) {
		fprintf(stderr, "imbalance: Error in malloc()\n");
		_exit(1);
	}
	for (i = 0; i < opt_threads; i++) {
		thread_args[i].thread = i;
		thread_args[i].verbose = opt_verbose;
		thread_args[i].allocs = opt_mult * (unsigned long long)(i + 1);
		thread_args[i].minsize = opt_minsize;
		thread_args[i].maxsize = opt_maxsize;
	}

	/* Permute the allocs fields within the thread_args array. */
	unsigned ctx;
	for (i = 0, ctx = (unsigned)getpid(); i < opt_threads; i++) {
		unsigned long long t;
		unsigned long pick = i + (((float)rand_r(&ctx) /
		    (float)RAND_MAX) * (opt_threads - i - 1));
		t = thread_args[i].allocs;
		thread_args[i].allocs = thread_args[pick].allocs;
		thread_args[pick].allocs = t;
	}

	for (i = 0; i < opt_threads; i++) {
		if ((err = pthread_create(&threads[i], NULL, thread_enter,
		    (void *)&thread_args[i])) != 0) {
			fprintf(stderr,
			    "imbalance: Error in pthread_create(): %s\n",
			    strerror(err));
			_exit(1);
		}
	}

	for (i = 0; i < opt_threads; i++) {
		if ((err = pthread_join(threads[i], NULL)) != 0) {
			fprintf(stderr,
			    "imbalance: Error in pthread_join(): %s\n",
			    strerror(err));
			_exit(1);
		}
	}

	return (0);
}