Struct HostVTable 

#[repr(C)]
pub struct HostVTable {
    pub retain_context: unsafe extern "C" fn(u64) -> i32,
    pub release_context: unsafe extern "C" fn(u64),
    pub invoke: unsafe extern "C" fn(u64, *const u8, usize, *mut *mut u8, *mut usize) -> i32,
    pub free_host_buf: unsafe extern "C" fn(*mut u8, usize),
}

Host callback function pointer table.

Safety

• All function pointers remain valid from actr_init until process exit.
• The host guarantees serialized entry per guest instance.
• All buffers returned by invoke must be released with free_host_buf.
• Context tokens remain valid while retained by the guest.

Fields

retain_context: unsafe extern "C" fn(u64) -> i32

Retain a host bridge token for a cloned or background context.

release_context: unsafe extern "C" fn(u64)

Release a previously retained host bridge token.

invoke: unsafe extern "C" fn(u64, *const u8, usize, *mut *mut u8, *mut usize) -> i32

Invoke a host operation encoded as AbiFrame through a retained token.

free_host_buf: unsafe extern "C" fn(*mut u8, usize)

Free a host-allocated buffer returned by invoke.