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sharedMemClient.cpp
124 lines (101 loc) · 2.46 KB
/
sharedMemClient.cpp
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//============================================================================
// Name : sharedMemClient.cpp
// Author : luliang
// Version :
// Copyright : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/shm.h>
#include <time.h>
const char * path = "/home/luliang/result";
void err_sys(const char *str) {
printf("%s\n", str);
exit(-1);
}
void read(void *data, int len) {
key_t shm_key = ftok(path, 1);
int shmid = shmget(shm_key, 0, 0);
if (shmid < 0)
err_sys("shmget error");
void *mem = shmat(shmid, (const void*) 0, 0);
if (mem < 0)
err_sys("shmat error");
memcpy(data, mem, len);
}
void write(void *data, int len) {
key_t shm_key = ftok(path, 1);
int shmid = shmget(shm_key, 0, 0);
if (shmid < 0)
err_sys("shmget error");
void *mem = shmat(shmid, (const void*) 0, 0);
if (mem < 0)
err_sys("shmat error");
memcpy(mem, data, len);
}
void readwrap(int len) {
printf("mallocing...");
time_t start, end;
start = clock();
void *data = malloc(len);
end = clock();
printf("%f seconds.\n", (double) (end - start) / CLOCKS_PER_SEC);
printf("Reading...");
start = clock();
read(data, len);
end = clock();
printf("%f seconds.\n", (double) (end - start) / CLOCKS_PER_SEC);
free(data);
}
void writewrap(int len) {
printf("mallocing...");
time_t start, end;
start = clock();
void *data = malloc(len);
end = clock();
printf("%f seconds.\n", (double) (end - start) / CLOCKS_PER_SEC);
printf("Writing...");
start = clock();
write(data, len);
end = clock();
printf("%f seconds.\n", (double) (end - start) / CLOCKS_PER_SEC);
free(data);
}
int main() {
int shm_size;
{
shm_size = (1 << 20);
printf("%d read write testing...\n", shm_size);
writewrap(shm_size);
readwrap(shm_size);
}
{
shm_size = (1 << 20) * 10;
printf("%d read write testing...\n", shm_size);
writewrap(shm_size);
readwrap(shm_size);
}
{
shm_size = (1 << 20) * 100;
printf("%d read write testing...\n", shm_size);
writewrap(shm_size);
readwrap(shm_size);
}
{
shm_size = (1 << 20) * 300;
printf("%d read write testing...\n", shm_size);
writewrap(shm_size);
readwrap(shm_size);
}
{
shm_size = (1 << 20) * 500;
printf("%d read write testing...\n", shm_size);
writewrap(shm_size);
readwrap(shm_size);
}
printf("finished!\n");
return 0;
}