use crate::syscalls::{INHERITED_FD, SPAWN_YIELD_CYCLES_BASE};
use crate::types::{Fd, FdArgs, Message, VmContext, VmId};
use ckb_traits::{CellDataProvider, ExtensionProvider, HeaderProvider};
use ckb_vm::{
Error as VMError, Register, SupportMachine, Syscalls,
registers::{A0, A1, A7},
};
use std::sync::{Arc, Mutex};
#[derive(Debug)]
pub struct InheritedFd {
id: VmId,
message_box: Arc<Mutex<Vec<Message>>>,
}
impl InheritedFd {
pub fn new<DL>(vm_id: &VmId, vm_context: &VmContext<DL>) -> Self
where
DL: CellDataProvider + HeaderProvider + ExtensionProvider + Send + Sync + Clone + 'static,
{
Self {
id: *vm_id,
message_box: Arc::clone(&vm_context.message_box),
}
}
}
impl<Mac: SupportMachine> Syscalls<Mac> for InheritedFd {
fn initialize(&mut self, _machine: &mut Mac) -> Result<(), VMError> {
Ok(())
}
fn ecall(&mut self, machine: &mut Mac) -> Result<bool, VMError> {
if machine.registers()[A7].to_u64() != INHERITED_FD {
return Ok(false);
}
let buffer_addr = machine.registers()[A0].to_u64();
let length_addr = machine.registers()[A1].to_u64();
machine.add_cycles_no_checking(SPAWN_YIELD_CYCLES_BASE)?;
self.message_box
.lock()
.map_err(|e| VMError::Unexpected(e.to_string()))?
.push(Message::InheritedFileDescriptor(
self.id,
FdArgs {
fd: Fd(0),
length: 0,
buffer_addr,
length_addr,
},
));
Err(VMError::Yield)
}
}