this is Server-side code (raspberry pi)
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <unistd.h>
#include <wiringPi.h>
#include <softPwm.h>
#include <pthread.h>
void error( char *msg ) {
perror( msg );
exit(1);
}
int func( int a ) {
return 2 * a;
}
void sendData( int sockfd, int x ) {
int n;
char buffer[32];
sprintf( buffer, "%dn", x );
if ( (n = write( sockfd, buffer, strlen(buffer) ) ) < 0 )
error( const_cast<char *>( "ERROR writing to socket") );
buffer[n] = '';
}
int getData( int sockfd ) {
char buffer[32];
int n;
if ( (n = read(sockfd,buffer,31) ) < 0 )
error( const_cast<char *>( "ERROR reading from socket") );
buffer[n] = '';
printf("buffer: %s n",buffer);
return atoi( buffer );
}
int main(int argc, char *argv[]) {
char buf[30];
int sockfd, newsockfd, portno = 1219, clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
int data;
printf( "using port #%dn", portno );
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
error( const_cast<char *>("ERROR opening socket") );
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons( portno );
if (bind(sockfd, (struct sockaddr *) &serv_addr,
sizeof(serv_addr)) < 0)
error( const_cast<char *>( "ERROR on binding" ) );
listen(sockfd,5);
clilen = sizeof(cli_addr);
//--- infinite wait on a connection ---
while ( 1 ) {
printf( "waiting for new client.....n" );
if ( ( newsockfd = accept( sockfd, (struct sockaddr *) &cli_addr, (socklen_t*) &clilen) ) < 0 )
error( const_cast<char *>("ERROR on accept") );
recv(newsockfd,buf,31,0);
printf( "opened new communication with clientn" );
printf( "sockfd: %dn",sockfd );
printf( "newsockfd: %d n ",newsockfd );
int res = strcmp(buf,"go");
printf("res: %dn",res);
write(newsockfd,"message received! [ from raspi server ! ]",50);
while ( 1 ) {
//---- wait for a number from client ---
data = getData( newsockfd );
//recv(newsockfd,buf,31,0);
// printf("%s n",buf);
printf( "got %dn", data );
if ( data < 0 )
break;
data = func( data );
//--- send new data back ---
printf( "sending back %dn", data );
sendData( newsockfd, data );
}
close( newsockfd );
//--- if -2 sent by client, we can quit ---
if ( data == -2 )
break;
}
return 0;
}
As soon as start using this linux socket communication program(when mylaptop, which is the client, gets connected to linux machine ), socket-CAN based program(CAN communication open source library based mcp 2515..) does not work saying that "write : no buffer space available" when i tried to do candump check below picture
I guess it has something to do with the linux socket program i used above code for socket communication between linux machine(raspberry, linux) and my laptop(window). but i don't know how to avoid problem related 'buffer space' and what caused it. Maybe I should flush buffer every time i get socket frame? anyone have some idea what i should do for getting both Socket-CAN and linux socket communication work at the same time?
