rename green_threads to stackful_coroutine, add #[inline(never)] in t_yield fun, then run correctly

This commit is contained in:
Yu Chen 2022-04-29 11:10:29 +08:00
parent 81d3ffce64
commit 119eb9d634

View File

@ -1,5 +1,6 @@
#![no_std]
#![no_main]
#![feature(naked_functions)]
#![feature(asm)]
@ -10,15 +11,16 @@ extern crate user_lib;
extern crate alloc;
use core::arch::asm;
#[macro_use]
use alloc::vec;
use alloc::vec::Vec;
//use user_lib::{close, open, read, OpenFlags}; //for linux
use user_lib::{exit};
// In our simple example we set most constraints here.
//const DEFAULT_STACK_SIZE: usize = 1024 * 1024 * 2; //for linux
const DEFAULT_STACK_SIZE: usize = 1024;
const MAX_TASKS: usize = 4;
const DEFAULT_STACK_SIZE: usize = 4096; //128 got SEGFAULT, 256(1024, 4096) got right results.
const MAX_TASKS: usize = 5;
static mut RUNTIME: usize = 0;
pub struct Runtime {
@ -107,10 +109,10 @@ impl Runtime {
/// This is where we start running our runtime. If it is our base task, we call yield until
/// it returns false (which means that there are no tasks scheduled) and we are done.
pub fn run(&mut self) -> ! {
pub fn run(&mut self){
while self.t_yield() {}
// std::process::exit(0); //for linux
exit(0);
println!("All tasks finished!");
}
/// This is our return function. The only place we use this is in our `guard` function.
@ -124,11 +126,12 @@ impl Runtime {
}
/// This is the heart of our runtime. Here we go through all tasks and see if anyone is in the `Ready` state.
/// If no task is `Ready` we're all done. This is an extremely simple sceduler using only a round-robin algorithm.
/// If no task is `Ready` we're all done. This is an extremely simple scheduler using only a round-robin algorithm.
///
/// If we find a task that's ready to be run we change the state of the current task from `Running` to `Ready`.
/// Then we call switch which will save the current context (the old context) and load the new context
/// into the CPU which then resumes based on the context it was just passed.
#[inline(never)]
fn t_yield(&mut self) -> bool {
let mut pos = self.current;
while self.tasks[pos].state != State::Ready {
@ -150,9 +153,7 @@ impl Runtime {
self.current = pos;
unsafe {
let old: *mut TaskContext = &mut self.tasks[old_pos].ctx;
let new: *const TaskContext = &self.tasks[pos].ctx;
asm!("call switch", in("a0") old, in("a1") new, clobber_abi("C"));
switch(&mut self.tasks[old_pos].ctx, &self.tasks[pos].ctx);
}
// NOTE: this might look strange and it is. Normally we would just mark this as `unreachable!()` but our compiler
@ -257,53 +258,10 @@ pub fn yield_task() {
/// to as saved context and in general our assembly will not work as expected.
///
/// see: https://github.com/rust-lang/rfcs/blob/master/text/1201-naked-fns.md
// global_asm!(r#"
// .section .text
// .globl __switch
// __switch:
// sd x1, 0x00(a0)
// sd x2, 0x08(a0)
// sd x8, 0x10(a0)
// sd x9, 0x18(a0)
// sd x18, 0x20(a0)
// sd x19, 0x28(a0)
// sd x20, 0x30(a0)
// sd x21, 0x38(a0)
// sd x22, 0x40(a0)
// sd x23, 0x48(a0)
// sd x24, 0x50(a0)
// sd x25, 0x58(a0)
// sd x26, 0x60(a0)
// sd x27, 0x68(a0)
// sd x1, 0x70(a0)
// ld x1, 0x00(a1)
// ld x2, 0x08(a1)
// ld x8, 0x10(a1)
// ld x9, 0x18(a1)
// ld x18, 0x20(a1)
// ld x19, 0x28(a1)
// ld x20, 0x30(a1)
// ld x21, 0x38(a1)
// ld x22, 0x40(a1)
// ld x23, 0x48(a1)
// ld x24, 0x50(a1)
// ld x25, 0x58(a1)
// ld x26, 0x60(a1)
// ld x27, 0x68(a1)
// ld t0, 0x70(a1)
// jr t0
// "#);
// extern "C" {
// pub fn __switch(old: *mut TaskContext, new: *const TaskContext);
// }
#[naked]
#[no_mangle]
unsafe extern "C" fn switch() {
unsafe fn switch(old: *mut TaskContext, new: *const TaskContext) {
//unsafe extern "C" fn switch() {
// a0: _old, a1: _new
asm!("
sd x1, 0x00(a0)
@ -344,13 +302,15 @@ unsafe extern "C" fn switch() {
}
#[no_mangle]
pub fn main() -> ! {
pub fn main() {
println!("stackful_coroutine begin...");
println!("TASK 0(Runtime) STARTING");
let mut runtime = Runtime::new();
runtime.init();
runtime.spawn(|| {
println!("TASK 1 STARTING");
let id = 1;
for i in 0..10 {
for i in 0..4 {
println!("task: {} counter: {}", id, i);
yield_task();
}
@ -359,11 +319,31 @@ pub fn main() -> ! {
runtime.spawn(|| {
println!("TASK 2 STARTING");
let id = 2;
for i in 0..15 {
for i in 0..8 {
println!("task: {} counter: {}", id, i);
yield_task();
}
println!("TASK 2 FINISHED");
});
runtime.spawn(|| {
println!("TASK 3 STARTING");
let id = 3;
for i in 0..12 {
println!("task: {} counter: {}", id, i);
yield_task();
}
println!("TASK 3 FINISHED");
});
runtime.spawn(|| {
println!("TASK 4 STARTING");
let id = 4;
for i in 0..16 {
println!("task: {} counter: {}", id, i);
yield_task();
}
println!("TASK 4 FINISHED");
});
runtime.run();
println!("stackful_coroutine PASSED");
exit(0);
}