onload_move_fd

Description

Move the file descriptor to the current stack. The target stack can be specified with onload_set_stackname(),then use onload_move_fd() to put the socket into the target stack.

A socket can exist only in a single stack. Moving a socket to a different stack does not create a copy of the socket in originator and target stacks. Limited to TCP closed or accepted sockets only.

Definition

int onload_move_fd (int fd)

Formal Parameters

fd - the file descriptor to be moved to the current stack.

Return Value

0 on success

non-zero otherwise.

Notes

• Useful to move fds obtained by accept() to a different Onload stack from the listening socket.
• Cannot be used on actively opened connections, although it is possible to use onload_set_stackname() before calling connect() to achieve the same result.
• The socket must have empty send and retransmit queues (send not called on this socket)
• The socket must have a simple receive queue (no loss, reordering, etc)
• The fd is not yet in an epoll set.
• The onload_move_fd function should not be used if SO_TIMESTAMPING is set to a non-zero value for the originating socket.
• Should not be used simultaneously with other I/O multiplex actions such as poll(), select(), recv() etc on the file descriptor.
• This function is not async-safe and should never be called from any process function handling signals.
• This function cannot be used to hand sockets over to the kernel. It is not possible to use onload_set_stackname (ONLOAD_DONT_ACCELERATE) and then onload_move_fd().