tcp socket program puzzle

[Altera_Forum]

Hello everyone: 

I am learning and testing TCP socket program. In my application, I want to send and receive a great deal of data at one time. So the quantity of data exceed the size of array I can define in the program. I have used different methods to resolve this problem, but the result is not good.   Can any one give me some suggestions? Thanks a lot!

[Altera_Forum]

if i understand you right, you cannot define a buffer, which is big enough; for example: 

 char buffer;  so if i'm right you should try to use the malloc function ; in this case (*EDIT* for buffers greater than 1MB) you need to enable a kernel option to do so (for big portions of memory): Processor type and features --> Allow allocating large blocks.... Greets  helmchen

[Altera_Forum]

--- Quote Start ---  originally posted by helmchen@Jan 23 2007, 05:10 PM if i understand you right, you cannot define a buffer, which is big enough; for example:  char buffer;  so if i&#39;m right you should try to use the malloc function ; in this case (*edit* for buffers greater  than 1mb) you need  to enable a kernel option to do so (for big portions of memory): processor type and features --> allow allocating large blocks.... greets  helmchen <div align='right'><{post_snapback}> (index.php?act=findpost&pid=20794)</div>  --- Quote End ---    Thank you helmchen, you have understand me right. Can I ask two more questions? 1, I have seen the option in the configure interface, but I wonder the kernel take use of what for the large blocks? 2, Can I just use the limited buffer to carry out large data transmission? For example, send several times?(I have tested, but still can&#39;t find good methods..) Thanks again http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif

[Altera_Forum]

<div class='quotetop'>QUOTE </div> 

--- Quote Start ---  1, I have seen the option in the configure interface, but I wonder the kernel take use of what for the large blocks?[/b]  --- Quote End ---   well i&#39;m not a kernel crack. Maybe you take a look at http://www.linuxdevices.com/articles/at7777470166.html (http://www.linuxdevices.com/articles/at7777470166.html) and in the kernel docs.  Maybe someone else can explain it in short.  <div class='quotetop'>QUOTE </div>  --- Quote Start ---  Can I just use the limited buffer to carry out large data transmission? For example, send several times?(I have tested, but still can&#39;t find good methods..[/b]  --- Quote End ---    you can reuse your buffers...

[Altera_Forum]

--- Quote Start ---  Can I just use the limited buffer to carry out large data transmission? For example, send several times?(I have tested, but still can&#39;t find good methods..   --- Quote End ---    you can reuse your buffers... <div align='right'><{post_snapback}> (index.php?act=findpost&pid=20816)</div>   --- Quote End ---    Thanks again, kind helmchen. I have tried to reuse the buffers, for example, server send two times and client receive two times. But the result is not right.. I only found a method that is(TCP): After send and receive once, client close the connection. And then establish another connetion and perform another transmition.. So in this way, If I need reuse my buffer ten times to finish the transmition, I have to establish and close the connection ten times.. Below is a segment of the client program to help you understand me. ----------------------------------------------------------------------  //The first connection, receive 1500 bytes  sockfd = socket(AF_INET,SOCK_STREAM,0);   bzero((struct sockaddr*)&serveraddr,sizeof(serveraddr));  serveraddr.sin_family=AF_INET;  serveraddr.sin_port=htons(5000);  inet_pton(AF_INET,argv[1],&(serveraddr.sin_addr));   if((connect(sockfd,((struct sockaddr*)&serveraddr),sizeof(serveraddr)))<0)  printf("connect error!!\n");  recvbyte=recv(sockfd,recvbuff,1500,0);  printf("recvbyte1=%d\n",recvbyte);  close(sockfd);    //The second connection,receive 1500 bytes.  sockfd = socket(AF_INET,SOCK_STREAM,0);   bzero((struct sockaddr*)&serveraddr,sizeof(serveraddr));  serveraddr.sin_family=AF_INET;  serveraddr.sin_port=htons(5000);  inet_pton(AF_INET,argv[1],&(serveraddr.sin_addr));  if((connect(sockfd,((struct sockaddr*)&serveraddr),sizeof(serveraddr)))<0)  printf("connect error!!\n");  recvbyte=recv(sockfd,recvbuff,1500,0);  printf("recvbyte2=%d\n",recvbyte);  close(sockfd);   ... ---------------------------------------------------------------------  I think it&#39;s not a good way, so I am searching the good ways to reuse buffer. Do you have any good suggestions?

[Altera_Forum]

maybe you can also post the code for sending? 

the receiving code looks good for me.