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frw.c
165 lines (152 loc) · 2.83 KB
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frw.c
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#define _XOPEN_SOURCE 500
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
#include <time.h>
#include <signal.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <sys/stat.h>
#define PAGE_SZ 4096
void
timeit(char *msg)
{
char *t_msg = "timeit:";
static struct timespec ts1, ts2, *ts;
static int first_in = 0;
first_in = !first_in;
if(first_in)
ts = &ts1;
else
ts = &ts2;
clock_gettime(CLOCK_MONOTONIC, ts);
if(!first_in)
{
if(!msg) msg=t_msg;
printf("%d:%s: time delta msecs=%ld\n", getpid(), msg, (ts2.tv_sec - ts1.tv_sec)*1000 + (ts2.tv_nsec - ts1.tv_nsec)/1000000);
}
}
void
read_fd(int fd, int max_pages, int rand_flag)
{
char page_buf[PAGE_SZ];
int i;
int offset = random();
lseek(fd, offset, random()%2?SEEK_SET:SEEK_END);
for(i=0; i<max_pages; i++)
{
if(rand_flag)
{
if(pread(fd, page_buf, sizeof(page_buf), (random()%max_pages)*PAGE_SZ)<0)
{
perror("pread:");
}
}
else
{
if(read(fd, page_buf, sizeof(page_buf))<0)
{
perror("read:");
}
}
}
}
void
write_fd(int fd, int max_pages, int rand_flag)
{
char page_buf[PAGE_SZ];
int i;
memset(page_buf, random()%255, sizeof(page_buf));
lseek(fd, 0, SEEK_SET);
for(i=0; i<max_pages; i++)
{
if(rand_flag)
{
if(pwrite(fd, page_buf, sizeof(page_buf), (random()%max_pages)*PAGE_SZ)<0);
{
perror("pwrite:");
}
}
else
{
if(write(fd, page_buf, sizeof(page_buf))<0)
{
perror("write:");
}
}
}
}
int slam_fd;
void
sigterm_hdlr(int signo)
{
printf("Quitting\n");
close(slam_fd);
_exit(0);
}
int
main(int argc, char *argv[])
{
char **argp = ++argv;
char *fname;
char *op;
int max_pages;
int rest_secs;
int iteration = 0;
#define NARGS 4
if(argc < NARGS + 1)
{
printf("frw <fname> <op=r/w> <max_pages> <rest_secs>\n");
printf("op = r - read , w - random, s - fsync write\n");
return -2;
}
fname = *argp++;
op = *argp++;
sscanf(*argp++, "%d", &max_pages);
sscanf(*argp++, "%d", &rest_secs);
printf("fname = %s op=%s max_pages = %d rest_secs = %d\n", fname, op, max_pages, rest_secs);
if(op[0] == 'r')
{
slam_fd = open(fname, O_RDWR);
}
else
{
slam_fd = open(fname, O_WRONLY| O_TRUNC);
if(slam_fd < 0 )
slam_fd = creat(fname, 0666);
}
if(slam_fd < 0)
{
perror("open:");
return -2;
}
signal(SIGINT, sigterm_hdlr);
signal(SIGTERM, sigterm_hdlr);
while(1)
{
timeit(NULL);
if(op[0] == 'r')
{
read_fd(slam_fd, max_pages, op[1]=='r');
timeit("read");
}
else
{
write_fd(slam_fd, max_pages, op[1]=='r');
if(op[0] == 's')
{
fsync(slam_fd);
timeit("write fsync");
}
else
{
timeit("write");
}
}
printf("%d:iter=%d\n", getpid(), iteration++);
sleep(rest_secs);
}
return 0;
}