about linux sendto

mandeep.singh.bhatia · 09-14-2010, 06:49 AM

Hi,
I just need to get this clarified. When we send character data buffer with sento over udp socket, does sendto make a copy of the buffer or does it just take the pointer and size and send the data buffer from pointed location.
I ask this for understanding that would it be legal or illegal to allocate a memory buffer then call sendto in non-block mode and then immediately delete the allocated memory, or, a case where we keep a common buffer and in a loop change the value of buffer and call sendto.
Regards,
Mandeep

dugan · 09-14-2010, 09:14 AM

If it sent a pointer, then how would the remote machine be able to access the data? The remote machine can't read memory on the local machine.

I haven't actually checked this, but I think it must send a copy of the buffer.

mandeep.singh.bhatia · 09-15-2010, 12:45 AM

Quote:

Originally Posted by dugan

If it sent a pointer, then how would the remote machine be able to access the data? The remote machine can't read memory on the local machine.

I haven't actually checked this, but I think it must send a copy of the buffer.

Hi, actually I meant that the sendto might just read from the buffer location via the pointer passed and send out data directly from the pointed buffer instead of making its own copy. I wanted to be sure of what is happening and how it happens.
Regards,
Mandeep