f-stack/example/echo_client_kernel.c at dev · F-Stack/f-stack · GitHub

History

166 lines (144 loc) · 4.51 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

* Kernel TCP client for issue #842 reproduction.

* Receives 1M timestamp messages, measures first/last latency.

* Compile with -O2.

#include <stdio.h>

#include <stdlib.h>

#include <stdint.h>

#include <string.h>

#include <strings.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/epoll.h>

#include <arpa/inet.h>

#include <netdb.h>

#include <errno.h>

#include <sys/ioctl.h>

#include <unistd.h>

#include <time.h>

#define MAX_EVENTS 10

#define BUFFER_SIZE 4096

static int64_t get_time_difference(const char *buffer, size_t bytes_read)

{

if (bytes_read < 20)

return -1;

int64_t d = strtoll(buffer + (bytes_read - 20), NULL, 10);

struct timespec ts;

clock_gettime(CLOCK_REALTIME, &ts);

int64_t now = (int64_t)ts.tv_sec * 1000000000 + ts.tv_nsec;

return now - d;

}

static int set_nonblocking(int sockfd)

{

int opt = 1;

if (ioctl(sockfd, FIONBIO, &opt)) {

perror("ioctl FIONBIO");

return -1;

}

return 0;

}

int main(int argc, char *argv[])

{

const char *hostname = "9.134.211.87";

const char *port = "12373";

if (argc > 1)

hostname = argv[1];

if (argc > 2)

port = argv[2];

int sockfd = socket(AF_INET, SOCK_STREAM, 0);

if (sockfd < 0) {

perror("socket");

exit(EXIT_FAILURE);

}

struct addrinfo hints, *res;

memset(&hints, 0, sizeof(hints));

hints.ai_family = AF_INET;

hints.ai_socktype = SOCK_STREAM;

if (getaddrinfo(hostname, port, &hints, &res) != 0) {

perror("getaddrinfo");

close(sockfd);

exit(EXIT_FAILURE);

}

if (set_nonblocking(sockfd) == -1) {

close(sockfd);

freeaddrinfo(res);

exit(EXIT_FAILURE);

}

int connect_status = connect(sockfd, res->ai_addr, res->ai_addrlen);

if (connect_status == -1 && errno != EINPROGRESS) {

perror("connect");

close(sockfd);

freeaddrinfo(res);

exit(EXIT_FAILURE);

}

int epoll_fd = epoll_create1(0);

if (epoll_fd == -1) {

perror("epoll_create1");

close(sockfd);

freeaddrinfo(res);

exit(EXIT_FAILURE);

}

struct epoll_event ev, events[MAX_EVENTS];

ev.events = EPOLLOUT | EPOLLIN | EPOLLET;

ev.data.fd = sockfd;

if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sockfd, &ev) == -1) {

perror("epoll_ctl");

close(sockfd);

close(epoll_fd);

freeaddrinfo(res);

exit(EXIT_FAILURE);

}

char request[512];

snprintf(request, sizeof(request),

"GET / HTTP/1.1\r\nHost: %s\r\nConnection: keep-alive\r\n\r\n",

hostname);

int64_t br = 0;

int64_t buffer_reads = 0;

int64_t last_latency = 0;

int64_t first_latency = 0;

struct timespec t0, t1;

clock_gettime(CLOCK_MONOTONIC, &t0);

int done = 0;

while (!done) {

int n = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);

for (int i = 0; i < n; i++) {

if (events[i].events & EPOLLOUT) {

send(sockfd, request, strlen(request), 0);

ev.events = EPOLLIN | EPOLLET;

epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sockfd, &ev);

} else if (events[i].events & EPOLLIN) {

char buffer[BUFFER_SIZE];

int bytes_read;

while ((bytes_read = recv(sockfd, buffer, sizeof(buffer) - 1, 0)) > 0) {

br += bytes_read;

++buffer_reads;

buffer[bytes_read] = '\0';

last_latency = get_time_difference(buffer, bytes_read);

if (first_latency < 10 || first_latency > 10000000000LL)

first_latency = last_latency;

}

if (bytes_read == 0) {

done = 1;

} else if (bytes_read == -1 && errno != EAGAIN) {

perror("recv");

done = 1;

}

clock_gettime(CLOCK_MONOTONIC, &t1);

double elapsed = (t1.tv_sec - t0.tv_sec) + (t1.tv_nsec - t0.tv_nsec) / 1e9;

float avg_bytes = buffer_reads > 0 ? (float)br / (float)buffer_reads : 0;

printf("avg_bytes: %.2f\n", avg_bytes);

printf("buffer_reads: %ld\n", buffer_reads);

printf("bytes_read: %ld\n", br);

printf("first_latency_ns: %ld\n", first_latency);

printf("last_latency_ns: %ld\n", last_latency);

printf("lat_diff_ns: %ld\n", last_latency - first_latency);

printf("total_time_s: %.3f\n", elapsed);

close(sockfd);

close(epoll_fd);

freeaddrinfo(res);

return 0;

}

f-stack/example/echo_client_kernel.c at dev · F-Stack/f-stack · GitHub

Uh oh!

Expand file tree

Breadcrumbs

echo_client_kernel.c

Latest commit

History

Breadcrumbs

echo_client_kernel.c

File metadata and controls