09_tcp_echo.c File Reference

#include <arpa/inet.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include <serene/rt/fiber/io.h>
#include <serene/runtime.h>

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Data Structures
struct	server_args_t
struct	client_args_t

Functions
static void	set_nonblock (int fd)
static srn_fiber_result_t	server (srn_context_t *ctx, void *arg)
static srn_fiber_result_t	client (srn_context_t *ctx, void *arg)
int	main (void)

Function Documentation

client()

srn_fiber_result_t client ( srn_context_t * ctx, void * arg )

static

Definition at line 77 of file 09_tcp_echo.c.

                                                                {
  (void)ctx;
  client_args_t *c = arg;
  int fd           = socket(AF_INET, SOCK_STREAM, 0);
  if (fd < 0) {
    perror("socket");
    return nullptr;
  }
  set_nonblock(fd);
 
  struct sockaddr_in to = {.sin_family = AF_INET, .sin_port = c->port};
  to.sin_addr.s_addr    = htonl(INADDR_LOOPBACK);
 
  srn_error_t *err = srn_fiber_connect(fd, (struct sockaddr *)&to, sizeof(to));
  if (err != nullptr) {
    printf("client: connect failed: %s\n", err->msg);
    close(fd);
    return nullptr;
  }
 
  const char *msg = "ping";
  (void)srn_fiber_write(fd, msg, strlen(msg), -1);
 
  char buf[64]           = {0};
  srn_io_size_result_t r = srn_fiber_read(fd, buf, sizeof(buf) - 1, -1);
  if (!HAS_ERROR(r)) {
    buf[r.count] = '\0';
  }
  printf("client: sent \"%s\", got back \"%s\"\n", msg, buf);
  close(fd);
  return nullptr;
}

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main()

int main

(

void

)

Definition at line 110 of file 09_tcp_echo.c.

               {
  SERENE_RUNTIME_INIT_WITH_SCHED(engine, sched, nullptr);
  srn_context_t *ctx = srn_context_make(engine);
 
  int lst              = socket(AF_INET, SOCK_STREAM, 0);
  struct sockaddr_in a = {.sin_family = AF_INET};
  a.sin_addr.s_addr    = htonl(INADDR_LOOPBACK);
  if (lst < 0 || bind(lst, (struct sockaddr *)&a, sizeof(a)) != 0 || listen(lst, 4) != 0) {
    perror("listener setup");
    return 1;
  }
  set_nonblock(lst);
  socklen_t al = sizeof(a);
  if (getsockname(lst, (struct sockaddr *)&a, &al) != 0) {
    perror("getsockname");
    return 1;
  }
 
  server_args_t s = {lst};
  client_args_t c = {a.sin_port};
  (void)srn_fiber_spawn(ctx, server, &s);
  (void)srn_fiber_spawn(ctx, client, &c);
 
  srn_sched_run(sched, 1);
  close(lst);
 
  srn_context_release(ctx);
  SERENE_RUNTIME_SHUTDOWN(engine);
  return 0;
}

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server()

srn_fiber_result_t server ( srn_context_t * ctx, void * arg )

static

Definition at line 56 of file 09_tcp_echo.c.

                                                                {
  (void)ctx;
  server_args_t *s         = arg;
  srn_io_accept_result_t a = srn_fiber_accept(s->listener, nullptr, 0);
  if (HAS_ERROR(a)) {
    printf("server: accept failed: %s\n", a.maybe_error->msg);
    return nullptr;
  }
  int conn               = a.fd;
  char buf[64]           = {0};
  srn_io_size_result_t r = srn_fiber_read(conn, buf, sizeof(buf), -1);
  if (HAS_ERROR(r)) {
    printf("server: read failed: %s\n", r.maybe_error->msg);
  } else {
    printf("server: got %zu bytes, echoing them back\n", r.count);
    (void)srn_fiber_write(conn, buf, r.count, -1);
  }
  close(conn);
  return nullptr;
}

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set_nonblock()

void set_nonblock ( int fd )

static

Definition at line 51 of file 09_tcp_echo.c.

                                 {
  int fl = fcntl(fd, F_GETFL, 0);
  (void)fcntl(fd, F_SETFL, fl | O_NONBLOCK);
}

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