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@rinevo /Makefile
Last active Aug 29, 2015

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マルチスレッドで分割コピーする実験
#Makefile
malticopy: malticopy.c
g++ -o malticopy malticopy.c -lrt
clean:
rm -f malticopy
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <pthread.h>
#define BUF_LEN 256
// 処理速度測定
static struct timespec tpBefore, tpAfter;
struct timespec GetTime()
{
struct timespec tp = {0, 0};
if (clock_gettime(CLOCK_REALTIME, &tp)) {
printf("clock_gettime error!\n");
} else {
//printf("sec=%ld, nsec=%ld\n", tp.tv_sec, tp.tv_nsec);
}
return tp;
}
long DiffTime()
{
long sec = tpAfter.tv_sec - tpBefore.tv_sec;
long nsec = tpAfter.tv_nsec - tpBefore.tv_nsec;
if (nsec < 0) {
sec--;
nsec += 1000000000L;
}
return (sec * 1000000000L + nsec);
}
// 1バイトづつループコピー
void *test1(void *dest, const void *src, size_t n)
{
char *rbuf = (char*)src;
char *wbuf = (char*)dest;
for (int i=0; i<n; i++) {
*wbuf = *rbuf;
rbuf++;
wbuf++;
}
return dest;
}
// 8バイトづつループコピー
void *test2(void *dest, const void *src, size_t n)
{
const int ADD = 8;
char *rbuf = (char*)src;
char *wbuf = (char*)dest;
for (int i=0; i<n; i+=ADD) {
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
*wbuf = *rbuf; rbuf++; wbuf++;
}
return dest;
}
// マルチスレッドで分割コピー
typedef struct {
void *dest;
const void *src;
size_t n;
} cpybuf_t;
void *test3_sub(void *arg)
{
cpybuf_t *buf = (cpybuf_t*)arg;
//test1(buf->dest, buf->src, buf->n);
memcpy(buf->dest, buf->src, buf->n);
return 0;
}
void *test3(void *dest, const void *src, size_t n)
{
const int THSIZE = 3;
pthread_t pt[THSIZE];
cpybuf_t buf[THSIZE];
buf[0].dest = dest;
buf[0].src = src;
buf[0].n = n / THSIZE;
pthread_create(&pt[0], NULL, &test3_sub, &buf[0]);
for (int i=1; i<THSIZE; i++) {
buf[i].dest = (char*)buf[i-1].dest + buf[0].n;
buf[i].src = (char*)buf[i-1].src + buf[0].n;
buf[i].n = buf[0].n;
pthread_create(&pt[i], NULL, &test3_sub, &buf[i]);
}
for (int i=0; i<THSIZE; i++) {
pthread_join(pt[i], NULL);
}
return dest;
}
// メイン
int main(int argc, char **argv)
{
FILE *fp = NULL;
char buf[BUF_LEN];
char *fbuf = NULL;
char *wbuf = NULL;
char *bk = NULL;
int err = 0;
int rlen = 0;
int size = 0;
// 引数チェック
if (argc < 3) {
return 1;
}
// 読込ファイルオープン
if ((fp = fopen(argv[1], "rb")) == 0) {
printf("read file open error: %s", argv[1]);
return 1;
}
// 読込ファイルサイズ取得
fseek(fp, 0, SEEK_END);
size = ftell(fp);
fseek(fp, 0, SEEK_SET);
printf("read file size=%d\n", size);
// メモリ確保
fbuf = (char*)malloc(size);
bk = fbuf; // 読込メモリの先頭ポインタを退避
wbuf = (char*)malloc(size);
// ファイル読込
while((rlen = fread(buf, sizeof(char), BUF_LEN, fp)) == BUF_LEN) {
memcpy(fbuf, buf, rlen);
fbuf += rlen;
}
if (rlen > 0) {
memcpy(fbuf, buf, rlen);
}
fclose(fp);
fbuf = bk; // 読込メモリのポインタを先頭に戻す
// 1バイトずつコピー
tpBefore = GetTime();
test1(wbuf, fbuf, size);
tpAfter = GetTime();
printf("test01: %lfsec\n", (double)DiffTime() / 1000000000);
// 8バイトずつコピー
tpBefore = GetTime();
test2(wbuf, fbuf, size);
tpAfter = GetTime();
printf("test02: %lfsec\n", (double)DiffTime() / 1000000000);
// 分割コピー
tpBefore = GetTime();
test3(wbuf, fbuf, size);
tpAfter = GetTime();
printf("test03: %lfsec\n", (double)DiffTime() / 1000000000);
// memcpy
tpBefore = GetTime();
memcpy(wbuf, fbuf, size);
tpAfter = GetTime();
printf("memcpy: %lfsec\n", (double)DiffTime() / 1000000000);
// 書込ファイルオープン
if ((fp = fopen(argv[2], "wb")) == 0) {
printf("write file open error: %s", argv[2]);
return 1;
}
// ファイル書込
fwrite(wbuf, sizeof(char), size, fp);
fclose(fp);
// メモリ開放
free(fbuf);
free(wbuf);
return 0;
}
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