support query stack info (#317)

core/src/coroutine/korosensei.rs

@@ -3,6 +3,7 @@ use crate::common::constants::CoroutineState;
 use crate::coroutine::listener::Listener;
 use crate::coroutine::local::CoroutineLocal;
 use crate::coroutine::suspender::Suspender;
+use crate::coroutine::StackInfo;
 use corosensei::stack::{DefaultStack, Stack};
 use corosensei::trap::TrapHandlerRegs;
 use corosensei::CoroutineResult;
@@ -27,7 +28,7 @@ pub struct Coroutine<'c, Param, Yield, Return> {
     inner: corosensei::Coroutine<Param, Yield, Result<Return, &'static str>, DefaultStack>,
     pub(crate) state: Cell<CoroutineState<Yield, Return>>,
     pub(crate) stack_size: usize,
-    pub(crate) stack_bottom: RefCell<VecDeque<usize>>,
+    pub(crate) stack_infos: RefCell<VecDeque<StackInfo>>,
     pub(crate) listeners: VecDeque<&'c dyn Listener<Yield, Return>>,
     pub(crate) local: CoroutineLocal<'c>,
 }
@@ -327,9 +328,12 @@ impl<'c, Param, Yield, Return> Coroutine<'c, Param, Yield, Return> {
                 return Ok(callback());
             }
             return DefaultStack::new(stack_size).map(|stack| {
-                co.stack_bottom.borrow_mut().push_front(stack.limit().get());
+                co.stack_infos.borrow_mut().push_back(StackInfo {
+                    stack_top: stack.base().get(),
+                    stack_bottom: stack.limit().get(),
+                });
                 let r = corosensei::on_stack(stack, callback);
-                _ = co.stack_bottom.borrow_mut().pop_front();
+                _ = co.stack_infos.borrow_mut().pop_back();
                 r
             });
         }
@@ -362,7 +366,10 @@ where
     {
         let stack_size = stack_size.max(crate::common::page_size());
         let stack = DefaultStack::new(stack_size)?;
-        let stack_bottom = RefCell::new(VecDeque::from([stack.limit().get()]));
+        let stack_infos = RefCell::new(VecDeque::from([StackInfo {
+            stack_top: stack.base().get(),
+            stack_bottom: stack.limit().get(),
+        }]));
         let co_name = name.clone().leak();
         let inner = corosensei::Coroutine::with_stack(stack, move |y, p| {
             catch!(
@@ -382,7 +389,7 @@ where
             name,
             inner,
             stack_size,
-            stack_bottom,
+            stack_infos,
             state: Cell::new(CoroutineState::Ready),
             listeners: VecDeque::default(),
             local: CoroutineLocal::default(),

core/src/coroutine/mod.rs

@@ -2,6 +2,7 @@ use crate::common::constants::CoroutineState;
 use crate::coroutine::listener::Listener;
 use crate::coroutine::local::CoroutineLocal;
 use crate::{impl_current_for, impl_display_by_debug, impl_for_named};
+use std::collections::VecDeque;
 use std::fmt::{Debug, Formatter};
 use std::ops::Deref;
 
@@ -41,6 +42,18 @@ macro_rules! co {
     };
 }
 
+/// The coroutine stack information.
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct StackInfo {
+    /// The base address of the stack. This is the highest address
+    /// since stacks grow downwards on most modern architectures.
+    pub stack_top: usize,
+    /// The maximum limit address of the stack. This is the lowest address
+    /// since stacks grow downwards on most modern architectures.
+    pub stack_bottom: usize,
+}
+
 /// Coroutine state abstraction and impl.
 mod state;
 
@@ -74,7 +87,14 @@ impl<'c, Param, Yield, Return> Coroutine<'c, Param, Yield, Return> {
     /// This can only be done safely in coroutine.
     pub unsafe fn remaining_stack(&self) -> usize {
         let current_ptr = psm::stack_pointer() as usize;
-        current_ptr - self.stack_bottom.borrow().front().copied().unwrap()
+        current_ptr - self.stack_infos.borrow().back().unwrap().stack_bottom
+    }
+
+    /// Queries the current stack info of this coroutine.
+    ///
+    /// The first used stack index is 0 and increases with usage.
+    pub fn stack_infos(&self) -> VecDeque<StackInfo> {
+        self.stack_infos.borrow().clone()
     }
 
     /// Grows the call stack if necessary.