Utilize ThreadLocal

kernel/src/process/posix_thread/thread_local.rs

@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use core::cell::{Cell, RefCell};
+
+use ostd::{mm::Vaddr, task::CurrentTask};
+
+use super::RobustListHead;
+use crate::process::signal::SigStack;
+
+/// Local data for a POSIX thread.
+pub struct ThreadLocal {
+    // TID pointers.
+    // https://man7.org/linux/man-pages/man2/set_tid_address.2.html
+    set_child_tid: Cell<Vaddr>,
+    clear_child_tid: Cell<Vaddr>,
+
+    // Robust futexes.
+    // https://man7.org/linux/man-pages/man2/get_robust_list.2.html
+    robust_list: RefCell<Option<RobustListHead>>,
+
+    // Signal.
+    /// `ucontext` address for the signal handler.
+    // FIXME: This field may be removed. For glibc applications with RESTORER flag set, the
+    // `sig_context` is always equals with RSP.
+    sig_context: Cell<Option<Vaddr>>,
+    /// Stack address, size, and flags for the signal handler.
+    sig_stack: RefCell<Option<SigStack>>,
+}
+
+impl ThreadLocal {
+    pub(super) fn new(set_child_tid: Vaddr, clear_child_tid: Vaddr) -> Self {
+        Self {
+            set_child_tid: Cell::new(set_child_tid),
+            clear_child_tid: Cell::new(clear_child_tid),
+            robust_list: RefCell::new(None),
+            sig_context: Cell::new(None),
+            sig_stack: RefCell::new(None),
+        }
+    }
+
+    pub fn set_child_tid(&self) -> &Cell<Vaddr> {
+        &self.set_child_tid
+    }
+
+    pub fn clear_child_tid(&self) -> &Cell<Vaddr> {
+        &self.clear_child_tid
+    }
+
+    pub fn robust_list(&self) -> &RefCell<Option<RobustListHead>> {
+        &self.robust_list
+    }
+
+    pub fn sig_context(&self) -> &Cell<Option<Vaddr>> {
+        &self.sig_context
+    }
+
+    pub fn sig_stack(&self) -> &RefCell<Option<SigStack>> {
+        &self.sig_stack
+    }
+}
+
+/// A trait to provide the `as_thread_local` method for tasks.
+pub trait AsThreadLocal {
+    /// Returns the associated [`ThreadLocal`].
+    fn as_thread_local(&self) -> Option<&ThreadLocal>;
+}
+
+impl AsThreadLocal for CurrentTask {
+    fn as_thread_local(&self) -> Option<&ThreadLocal> {
+        self.local_data().downcast_ref()
+    }
+}