[interfacekit] Re: BSession(NG)

Pahtz <pahtz@xxxxxxxxxxxx> wrote:

> BTW, excuse me if you know already but read_port() is not like a socket or 
> file descriptor. You
> will lose data if the bufferSize is too small. You can't read_port() twice on 
> the same message.
Doesn't matter if you use fixed size buffers.

> So with your code, the receiver better have set a buffersize larger than or 
> equal to what the
> sender set. This is an ugly dependency. Please don't tell me we can solve it 
> with pretty
> documentation :-)
It's not ugly. You need to use a fixed maximum buffer size.

> IMO, the solution is to dynamically resize the receive buffer if necessary...
Resizing buffers adds unnecessary complexity, and might be slower.

> You can call port_buffer_size() to find out the size of the message before 
> read_port();
That should have a about the same overhead (slowdown) as calling write_port() 
twice.
Adding the overhead of realloc (which does locking, searching for a free 
buffer, etc)
it will surely be slower.

> It's simple, it works. One malloc() call or none if the buffer is already 
> large enough.
You need to add one free() and one port_buffer_size() plus the realloc() calls 
on the
sender size, plus the overhead of dealing with variable buffer sizes.

I really don't understand why you propose this change. It has no benefit.

regards
Marcus Overhagen

Other related posts: