A receive item for receiving a single object capability. More...

#include <ipc_types>

Collaboration diagram for L4::Ipc::Small_buf:

Public Member Functions
	Small_buf (L4::Cap< void > cap, unsigned long flags=0) noexcept
	Create a receive item from a C++ cap.
	Small_buf (l4_cap_idx_t cap, unsigned long flags=0) noexcept
	Create a receive item from a C cap.
l4_umword_t	raw () const noexcept
	Return the raw data.

Detailed Description

A receive item for receiving a single object capability.

This class is the main abstraction for receiving object capabilities via Ipc::Istream. To receive an object capability, an instance of Small_buf that refers to an empty capability slot must be inserted into the Ipc::Istream before the receive operation.

In an RPC interface, a Small_buf must be combined with a Snd_fpage output argument. The Small_buf argument is removed from the server function signature. Instead, the adjacent Snd_fpage output argument is used by the server function to send the capability. On the client side, the caller can check the Snd_fpage output argument what has been received. See the following example:

L4_RPC(l4_ret_t, test, (L4::Ipc::Small_buf cap, L4::Ipc::Snd_fpage &snd_cap));

L4::Ipc::Small_buf

A receive item for receiving a single object capability.

Definition ipc_types:234

L4::Ipc::Snd_fpage

Send item or return item.

Definition ipc_types:300

L4_RPC

#define L4_RPC(res, name, args, attr...)

Define an RPC call (type and callable).

Definition ipc_iface:542

l4_ret_t