shithub: sysbench

ref: a1c8da91f18c8bd3cdc7ce36c70538969e0c5602
dir: /lock.c/

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>

#include "bench.h"

#define NLockIters	1

pthread_mutex_t l = PTHREAD_MUTEX_INITIALIZER;
static int count;

void
nop(void)
{
}

void
work(void)
{
	int i;

	for(i = 0; i < 100*1000; i++)
		count++;
}


void
dolock(void (*work)(void), int n)
{
	int i;

	for(i = 0; i < n; i++){
		pthread_mutex_lock(&l);
		work();
		pthread_mutex_unlock(&l);
	}
}

struct thread_data {
	void (*fn)(void(*)(void), int);
	void (*work)(void);
	int ninc;
	sem_t *start_sem;
};

static void *
thread_worker(void *arg)
{
	struct thread_data *td = arg;
	sem_wait(td->start_sem);
	td->fn(td->work, td->ninc);
	return NULL;
}

void
lockbench(void (*fn)(void(*)(void), int), int nthr, void (*work)(void), int ninc)
{
	pthread_t *threads;
	struct thread_data td;
	sem_t start_sem;
	int i;

	threads = malloc(nthr * sizeof(pthread_t));
	sem_init(&start_sem, 0, 0);
	
	td.fn = fn;
	td.work = work;
	td.ninc = ninc;
	td.start_sem = &start_sem;

	for(i = 0; i < nthr; i++){
		if(pthread_create(&threads[i], NULL, thread_worker, &td) != 0) {
			fprintf(stderr, "pthread_create failed\n");
			exit(1);
		}
	}

	for(i = 0; i < nthr; i++)
		sem_post(&start_sem);

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

	sem_destroy(&start_sem);
	free(threads);
}

void	benchlock1(B *b)	{ lockbench(dolock, 1, nop, b->N); }
void	benchlock4(B *b)	{ lockbench(dolock, 4, nop, b->N); }
void	benchlock16(B *b)	{ lockbench(dolock, 16, nop, b->N); }
void	benchlock64(B *b)	{ lockbench(dolock, 64, nop, b->N); }
void	benchlock512(B *b)	{ lockbench(dolock, 512, nop, b->N); }

void	benchlock1_w(B *b)	{ lockbench(dolock, 1, work, b->N); }
void	benchlock4_w(B *b)	{ lockbench(dolock, 4, work, b->N); }
void	benchlock16_w(B *b)	{ lockbench(dolock, 16, work, b->N); }
void	benchlock64_w(B *b)	{ lockbench(dolock, 64, work, b->N); }
void	benchlock512_w(B *b)	{ lockbench(dolock, 512, work, b->N); }

int
main(int argc, char **argv)
{
	benchinit(argc, argv);

	printf("== locking (fast work) ==\n");
	BM(benchlock1);
	BM(benchlock4);
	BM(benchlock16);
	BM(benchlock64);
	BM(benchlock512);

	printf("== locking (slow work) ==\n");
	BM(benchlock1_w);
	BM(benchlock4_w);
	BM(benchlock16_w);
	BM(benchlock64_w);
	BM(benchlock512_w);
	return 0;
}