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#define _GNU_SOURCE
#define _FILE_OFFSET_BITS 64
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <inttypes.h>
#include <time.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <sched.h>
#include <string.h>
#include <getopt.h>
#include <stdbool.h>
#include <linux/fs.h>
#include "dev.h"
#define MAX_BUFSIZE (64 * 1024 * 1024)
static inline long long time_to_ns(struct timespec *ts)
{
return (long long)ts->tv_sec * 1000 * 1000 * 1000 + ts->tv_nsec;
}
static long long get_ns(void)
{
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
return time_to_ns(&ts);
}
long long time_read(struct device *dev, off_t pos, size_t size)
{
long long now = get_ns();
ssize_t ret;
if (size > MAX_BUFSIZE)
return -ENOMEM;
do {
ret = pread(dev->fd, dev->readbuf, size, pos % dev->size);
if (ret > 0) {
size -= ret;
pos += ret;
}
} while (ret > 0 || errno == -EAGAIN);
if (ret) {
perror("time_read");
return 0;
}
return get_ns() - now;
}
long long time_write(struct device *dev, off_t pos, size_t size, enum writebuf which)
{
long long now = get_ns();
ssize_t ret;
unsigned long *p;
if (size > MAX_BUFSIZE)
return -ENOMEM;
p = dev->writebuf[which];
do {
ret = pwrite(dev->fd, p, size, pos % dev->size);
if (ret > 0) {
size -= ret;
pos += ret;
}
} while (ret > 0 || errno == -EAGAIN);
if (ret) {
perror("time_write");
return 0;
}
return get_ns() - now;
}
long long time_erase(struct device *dev, off_t pos, size_t size)
{
long long now = get_ns();
ssize_t ret;
unsigned long long args[2] = { size, pos % dev->size };
if (size > MAX_BUFSIZE)
return -ENOMEM;
ret = ioctl(dev->fd, BLKDISCARD, &args);
if (ret) {
perror("time_erase");
}
return get_ns() - now;
}
static void set_rtprio(void)
{
int ret;
struct sched_param p = {
.sched_priority = 10,
};
ret = sched_setscheduler(0, SCHED_FIFO, &p);
if (ret)
perror("sched_setscheduler");
}
int setup_dev(struct device *dev, const char *filename)
{
int err;
void *p;
set_rtprio();
dev->fd = open(filename, O_RDWR | O_DIRECT | O_SYNC | O_NOATIME);
if (dev->fd < 0) {
perror(filename);
return -errno;
}
dev->size = lseek(dev->fd, 0, SEEK_END);
if (dev->size < 0) {
perror("seek");
return -errno;
}
err = posix_memalign(&dev->readbuf, 4096, MAX_BUFSIZE);
if (err)
return -err;
err = posix_memalign(&p, 4096, MAX_BUFSIZE);
if (err)
return -err;
memset(p, 0, MAX_BUFSIZE);
dev->writebuf[WBUF_ZERO] = p;
err = posix_memalign(&p, 4096, MAX_BUFSIZE);
if (err)
return -err;
memset(p, 0xff, MAX_BUFSIZE);
dev->writebuf[WBUF_ONE] = p;
err = posix_memalign(&p , 4096, MAX_BUFSIZE);
if (err)
return -err;
memset(p, 0x5a, MAX_BUFSIZE);
dev->writebuf[WBUF_RAND] = p;
return 0;
}
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