在本机的进程间通信中,TCP和UNIX域套接字是两种比较简单方便的通信方式,TCP基本以回路地址形式表现,回路地址在本机通信上还是要比UNIX域套接字多了封包/解包/校验和/序列确认等操作
那么对于这两种方式的性能比较可以参考以下文章:
同时做了一个简单的对比测试,虚拟机上(1CPU、256M内存),单进程server、client,10w次5字节echo server结果(进行多次,差不多平均结果,系统其它参数未观察):
回路地址:
real 0m5.879s
user 0m0.012s
sys 0m2.763s
UNIX域套接字:
real 0m11.433s
user 0m0.019s
sys 0m4.641s
其实网络协议处理主要消耗CPU资源,但相对来说资源消耗还是比较低的,不过对于要求非常高的短连接网络并发处理,TIME_WAIT对于回路地址是个问题,这点UNIX域套接字非常有优势。
以下为测试代码:
1. unix域套接字server
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#undef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
int main(int argc, char *argv[])
{
int sock = 0;
int conn = 0;
socklen_t addrlen = 0;
struct sockaddr_un addr;
char buf[64] = {0};
unlink("foo.socket");
if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
printf("socket failed\n");
return -1;
}
addr.sun_family = AF_UNIX;
strcpy(addr.sun_path, "foo.socket");
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
if (bind(sock, (struct sockaddr *)&addr, addrlen) < 0) {
printf("bind failed\n");
return -1;
}
printf("UNIX domain socket bound\n");
if (listen(sock, 128) < 0) {
printf("listen failed\n");
return -1;
}
while (1) {
if ((conn = accept(sock, (struct sockaddr *)NULL, NULL)) < 0) {
printf("accept connect failed\n");
continue;
}
if (readn(conn, buf, 5) < 0) {
printf("read msg failed\n");
return -1;
}
buf[5] = '\0';
//printf("readn: %s\n", buf);
if (write(conn, buf, strlen(buf)) < 0) {
printf("write msg failed\n");
return -1;
}
close(conn);
}
close(sock);
return 0;
}
2. unix域套接字client
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#undef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
int main(int argc, char *argv[])
{
int i = 0;
int sock = 0;
socklen_t addrlen;
struct sockaddr_un addr;
char buf[64] = {0};
while (i++ < 100000) {
if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
printf("socket failed\n");
return -1;
}
addr.sun_family = AF_UNIX;
strcpy(addr.sun_path, "foo.socket");
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
if (connect(sock, (struct sockaddr *)&addr, addrlen) < 0) {
printf("connet failed\n");
return -1;
}
if (write(sock, "helo\n", 5) < 0) {
printf("write msg failed\n");
return -1;
}
if (readn(sock, buf, 5) < 0) {
printf("read msg failed\n");
return -1;
}
buf[5] = '\0';
//printf("readn: %s", buf);
close(sock);
}
return 0;
}
3. socket套接字server
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
int main(int argc, char** argv)
{
int on = 1;
int sock = 0;
int conn = 0;
struct sockaddr_in addr;
char buf[64];
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
printf("socket failed\n");
return -1;
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(6666);
if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
printf("bind failed\n");
return -1;
}
if (listen(sock, 128) < 0) {
printf("listen failed\n");
return -1;
}
while (1) {
if ((conn = accept(sock, (struct sockaddr *)NULL, NULL)) < 0) {
printf("accept connect failed\n");
continue;
}
if (readn(conn, buf, 5) < 0) {
printf("read msg failed\n");
return -1;
}
buf[5] = '\0';
//printf("readn: %s", buf);
if (write(conn, buf, strlen(buf)) < 0) {
printf("write msg failed\n");
return -1;
}
close(conn);
}
close(sock);
return 0;
}
4. socket套接字client
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
int main(int argc, char *argv[])
{
int i = 0;
int sock = 0;
struct sockaddr_in addr;
char buf[64] = {0};
while (i++ < 100000) {
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
printf("socket failed\n");
return -1;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(6666);
addr.sin_addr.s_addr = inet_addr("127.0.0.1");
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
printf("connect failed\n");
return -1;
}
if (write(sock, "helo\n", 5) < 0) {
printf("write msg failed\n");
return -1;
}
if (readn(sock, buf, 5) < 0) {
printf("read msg failed\n");
return -1;
}
buf[5] = '\0';
//printf("reand: %s", buf);
close(sock);
}
return 0;
}
5. 读数据共用函数
int readn(int fd, char *buf, int buflen)
{
int nleft = 0;
int nread = 0;
char *ptr = NULL;
ptr = buf;
nleft = buflen;
while (nleft > 0) {
if ((nread = read(fd, ptr, nleft)) < 0) {
if (EINTR == errno) {
nread = 0;
}
else {
return -1;
}
}
else if (0 == nread) {
break;
}
nleft -= nread;
ptr += nread;
}
return buflen - nleft;
}