burritos/src/kernel/thread.rs

117 lines
3.3 KiB
Rust

use std::{rc::Rc, cell::RefCell};
use super::process::Process;
use crate::{simulator::machine::{NUM_INT_REGS, NUM_FP_REGS, STACK_REG}};
const STACK_FENCEPOST: u32 = 0xdeadbeef;
/// Polymorphic macro to get thread without passing a name by default
#[macro_export]
macro_rules! get_new_thread {
() => { Thread::new(DEFAULT_THREAD_NAME) };
($a:literal) => {
Thread::new(&$a.to_string())
};
}
#[derive(PartialEq, Debug)]
pub struct ThreadContext {
pub int_registers: [i64; NUM_INT_REGS],
pub float_registers: [f32; NUM_FP_REGS],
pub pc: u64,
}
#[derive(PartialEq, Debug)]
pub struct Thread {
name: String,
pub process: Option<Rc<RefCell<Process>>>,
pub thread_context: ThreadContext,
pub stack_pointer: i32,
}
impl Thread {
/// Thread constructor
pub fn new(name: &str) -> Self {
Self {
name: String::from(name),
process: None,
// simulation_context: UContextT::new(),
thread_context: ThreadContext {
int_registers: [0; NUM_INT_REGS],
float_registers: [0f32; NUM_FP_REGS],
pc: 0
},
stack_pointer: 0,
}
}
pub fn init_thread_context(&mut self, initial_pc_reg: u64, initial_sp: u64, arg: i64) {
self.thread_context.pc = initial_pc_reg;
self.thread_context.int_registers[10] = arg;
self.thread_context.int_registers[STACK_REG] = initial_sp as i64;
}
/// Check if a thread has overflowed its stack
///
/// This assertion doesn't catch all stack overflow conditions and your program may still crash because of an overflow.
///
pub fn check_overflow(&self) {
// if self.simulator_context.stackBottom != STACK_FENCEPOST {
// panic!("thread {} has overflowed", self.get_name())
// }
}
pub fn get_name(&self) -> String {
self.name.clone()
}
/// Return reference to an optional Process
/// can be None if Thread hasn't been initialize
pub fn get_process_owner(&self) -> &Option<Rc<RefCell<Process>>> {
&self.process
}
}
#[cfg(test)]
mod test {
use super::{Thread, ThreadContext, NUM_INT_REGS, NUM_FP_REGS};
const DEFAULT_THREAD_NAME: &str = "test_thread";
/// This macro allows for getting a Thread for which we've ensured proper initial state
/// in case a commit further down the line changes the initial state of threads generated
/// from Thread::new
macro_rules! expected_initial_state {
() => { expected_initial_state!(DEFAULT_THREAD_NAME) };
($a:expr) => { {
let mut x = Thread::new($a);
x.name = $a.to_string();
x.process = Option::None;
x.thread_context = ThreadContext {
int_registers: [0; NUM_INT_REGS],
float_registers: [0f32; NUM_FP_REGS],
pc: 0
};
x.stack_pointer = 0;
x }
};
}
#[test]
fn test_macro() {
let t = get_new_thread!("hello");
assert_eq!(t.get_name(), "hello");
let t = get_new_thread!(1);
assert_eq!(t.get_name(), "1");
}
#[test]
fn check_init() {
let t = get_new_thread!();
let expected_state = expected_initial_state!();
assert_eq!(t, expected_state)
}
}