Add ThreadExt and clean up PosixThreadExt

kernel/src/process/clone.rs

@@ -21,7 +21,7 @@ use crate::{
     get_current_userspace,
     prelude::*,
     process::posix_thread::allocate_posix_tid,
-    thread::{Thread, Tid},
+    thread::{ThreadExt, Tid},
 };
 
 bitflags! {
@@ -183,10 +183,10 @@ pub fn clone_child(
     clone_args.flags.check_unsupported_flags()?;
     if clone_args.flags.contains(CloneFlags::CLONE_THREAD) {
         let child_task = clone_child_task(ctx, parent_context, clone_args)?;
-        let child_thread = Thread::borrow_from_task(&child_task);
+        let child_thread = child_task.as_thread().unwrap();
         child_thread.run();
 
-        let child_tid = child_thread.tid();
+        let child_tid = child_thread.as_posix_thread().unwrap().tid();
         Ok(child_tid)
     } else {
         let child_process = clone_child_process(ctx, parent_context, clone_args)?;

kernel/src/process/exit.rs

@@ -7,7 +7,7 @@ use crate::{
         posix_thread::{do_exit, PosixThreadExt},
         signal::signals::kernel::KernelSignal,
     },
-    thread::Thread,
+    thread::ThreadExt,
 };
 
 pub fn do_exit_group(term_status: TermStatus) {
@@ -21,7 +21,7 @@ pub fn do_exit_group(term_status: TermStatus) {
     // Exit all threads
     let tasks = current.tasks().lock().clone();
     for task in tasks {
-        let thread = Thread::borrow_from_task(&task);
+        let thread = task.as_thread().unwrap();
         let posix_thread = thread.as_posix_thread().unwrap();
         if let Err(e) = do_exit(thread, posix_thread, term_status) {
             debug!("Ignore error when call exit: {:?}", e);

kernel/src/process/posix_thread/mod.rs

@@ -22,7 +22,7 @@ use crate::{
     events::Observer,
     prelude::*,
     process::signal::constants::SIGCONT,
-    thread::{Thread, Tid},
+    thread::{Thread, ThreadExt, Tid},
     time::{clocks::ProfClock, Timer, TimerManager},
 };
 
@@ -277,7 +277,7 @@ impl PosixThread {
         let tasks = process.tasks().lock();
         tasks
             .iter()
-            .all(|task| Thread::borrow_from_task(task).is_exited())
+            .all(|task| task.as_thread().unwrap().is_exited())
     }
 
     /// Gets the read-only credentials of the thread.

kernel/src/process/posix_thread/posix_thread_ext.rs

@@ -11,17 +11,12 @@ use crate::{
     fs::fs_resolver::{FsPath, FsResolver, AT_FDCWD},
     prelude::*,
     process::{process_vm::ProcessVm, program_loader::load_program_to_vm, Credentials, Process},
-    thread::{Thread, Tid},
+    thread::{Thread, ThreadExt, Tid},
 };
+
+/// An extension trait for some [`PosixThread`]-like types.
 pub trait PosixThreadExt {
-    /// Returns the thread id.
-    ///
-    /// # Panics
-    ///
-    /// If the thread is not posix thread, this method will panic.
-    fn tid(&self) -> Tid {
-        self.as_posix_thread().unwrap().tid()
-    }
+    /// Returns the associated [`PosixThread`].
     fn as_posix_thread(&self) -> Option<&PosixThread>;
 }
 
@@ -31,9 +26,9 @@ impl PosixThreadExt for Thread {
     }
 }
 
-impl PosixThreadExt for Arc<Task> {
+impl PosixThreadExt for Task {
     fn as_posix_thread(&self) -> Option<&PosixThread> {
-        Thread::borrow_from_task(self).as_posix_thread()
+        self.as_thread()?.as_posix_thread()
     }
 }
 

kernel/src/process/posix_thread/thread_table.rs

@@ -7,7 +7,7 @@ static THREAD_TABLE: SpinLock<BTreeMap<Tid, Arc<Thread>>> = SpinLock::new(BTreeM
 
 /// Adds a posix thread to global thread table
 pub fn add_thread(tid: Tid, thread: Arc<Thread>) {
-    debug_assert_eq!(tid, thread.tid());
+    debug_assert_eq!(tid, thread.as_posix_thread().unwrap().tid());
     THREAD_TABLE.lock().insert(tid, thread);
 }
 

kernel/src/process/process/mod.rs

@@ -21,7 +21,7 @@ use crate::{
     fs::{file_table::FileTable, fs_resolver::FsResolver, utils::FileCreationMask},
     prelude::*,
     sched::priority::{AtomicNice, Nice},
-    thread::Thread,
+    thread::{Thread, ThreadExt},
     time::clocks::ProfClock,
     vm::vmar::Vmar,
 };
@@ -174,13 +174,7 @@ impl Process {
     ///  - the function is called in the bootstrap context;
     ///  - or if the current task is not associated with a process.
     pub fn current() -> Option<Arc<Process>> {
-        Some(
-            Task::current()?
-                .data()
-                .downcast_ref::<Arc<Thread>>()?
-                .as_posix_thread()?
-                .process(),
-        )
+        Some(Task::current()?.as_posix_thread()?.process())
     }
 
     #[allow(clippy::too_many_arguments)]
@@ -292,7 +286,7 @@ impl Process {
         let task = tasks[0].clone();
         // should not hold the lock when run thread
         drop(tasks);
-        let thread = Thread::borrow_from_task(&task);
+        let thread = task.as_thread().unwrap();
         thread.run();
     }
 
@@ -336,8 +330,10 @@ impl Process {
         self.tasks
             .lock()
             .iter()
-            .find(|task| task.tid() == self.pid)
-            .map(|task| Thread::borrow_from_task(task.as_ref()))
+            .find_map(|task| {
+                let thread = task.as_thread().unwrap();
+                (thread.as_posix_thread().unwrap().tid() == self.pid).then_some(thread)
+            })
             .cloned()
     }
 

kernel/src/process/signal/pause.rs

@@ -8,7 +8,7 @@ use super::sig_mask::SigMask;
 use crate::{
     prelude::*,
     process::posix_thread::PosixThreadExt,
-    thread::Thread,
+    thread::ThreadExt,
     time::wait::{ManagedTimeout, TimeoutExt},
 };
 
@@ -109,7 +109,7 @@ impl Pause for Waiter {
         // No fast paths for `Waiter`. If the caller wants a fast path, it should do so _before_
         // the waiter is created.
 
-        let current_thread = self.task().data().downcast_ref::<Arc<Thread>>();
+        let current_thread = self.task().as_thread();
 
         let Some(posix_thread) = current_thread
             .as_ref()
@@ -143,7 +143,7 @@ impl Pause for Waiter {
             })
         });
 
-        let current_thread = self.task().data().downcast_ref::<Arc<Thread>>();
+        let current_thread = self.task().as_thread();
 
         if let Some(posix_thread) = current_thread
             .as_ref()

kernel/src/process/wait.rs

@@ -92,7 +92,7 @@ fn reap_zombie_child(process: &Process, pid: Pid) -> ExitCode {
     let child_process = process.children().lock().remove(&pid).unwrap();
     assert!(child_process.is_zombie());
     for task in &*child_process.tasks().lock() {
-        thread_table::remove_thread(task.tid());
+        thread_table::remove_thread(task.as_posix_thread().unwrap().tid());
     }
 
     // Lock order: session table -> group table -> process table -> group of process

kernel/src/syscall/mod.rs

@@ -348,7 +348,7 @@ macro_rules! log_syscall_entry {
             let pid = $crate::current!().pid();
             let tid = {
                 use $crate::process::posix_thread::PosixThreadExt;
-                $crate::current_thread!().tid()
+                $crate::current_thread!().as_posix_thread().unwrap().tid()
             };
             log::info!(
                 "[pid={}][tid={}][id={}][{}]",

kernel/src/thread/kernel_thread.rs

@@ -5,7 +5,7 @@ use ostd::{
     task::{Task, TaskOptions},
 };
 
-use super::{oops, status::ThreadStatus, Thread};
+use super::{oops, status::ThreadStatus, Thread, ThreadExt};
 use crate::{prelude::*, sched::priority::Priority};
 
 /// The inner data of a kernel thread.
@@ -77,7 +77,7 @@ impl ThreadOptions {
     /// Builds a new kernel thread and runs it immediately.
     pub fn spawn(self) -> Arc<Thread> {
         let task = self.build();
-        let thread = Thread::borrow_from_task(&task).clone();
+        let thread = task.as_thread().unwrap().clone();
         thread.run();
         thread
     }

kernel/src/thread/mod.rs

@@ -65,10 +65,7 @@ impl Thread {
     /// This function returns `None` if the current task is not associated with
     /// a thread, or if called within the bootstrap context.
     pub fn current() -> Option<Arc<Self>> {
-        Task::current()?
-            .data()
-            .downcast_ref::<Arc<Thread>>()
-            .cloned()
+        Task::current()?.as_thread().cloned()
     }
 
     /// Returns the task associated with this thread.
@@ -76,15 +73,6 @@ impl Thread {
         self.task.upgrade().unwrap()
     }
 
-    /// Gets the Thread from task's data.
-    ///
-    /// # Panics
-    ///
-    /// This method panics if the task is not a thread.
-    pub fn borrow_from_task(task: &Task) -> &Arc<Self> {
-        task.data().downcast_ref::<Arc<Thread>>().unwrap()
-    }
-
     /// Runs this thread at once.
     pub fn run(&self) {
         self.status.store(ThreadStatus::Running, Ordering::Release);
@@ -173,3 +161,15 @@ impl Thread {
         &*self.data
     }
 }
+
+/// An extension trait for [`Thread`]-like types.
+pub trait ThreadExt {
+    /// Returns the associated [`Thread`].
+    fn as_thread(&self) -> Option<&Arc<Thread>>;
+}
+
+impl ThreadExt for Task {
+    fn as_thread(&self) -> Option<&Arc<Thread>> {
+        self.data().downcast_ref::<Arc<Thread>>()
+    }
+}

kernel/src/thread/work_queue/worker.rs

@@ -11,8 +11,7 @@ use super::worker_pool::WorkerPool;
 use crate::{
     prelude::*,
     sched::priority::{Priority, PriorityRange},
-    thread::kernel_thread::ThreadOptions,
-    Thread,
+    thread::{kernel_thread::ThreadOptions, ThreadExt},
 };
 
 /// A worker thread. A `Worker` will attempt to retrieve unfinished
@@ -72,7 +71,7 @@ impl Worker {
     }
 
     pub(super) fn run(&self) {
-        let thread = Thread::borrow_from_task(&self.bound_task);
+        let thread = self.bound_task.as_thread().unwrap();
         thread.run();
     }
 

kernel/src/thread/work_queue/worker_pool.rs

@@ -17,8 +17,7 @@ use super::{simple_scheduler::SimpleScheduler, worker::Worker, WorkItem, WorkPri
 use crate::{
     prelude::*,
     sched::priority::{Priority, PriorityRange},
-    thread::kernel_thread::ThreadOptions,
-    Thread,
+    thread::{kernel_thread::ThreadOptions, ThreadExt},
 };
 
 /// A pool of workers.
@@ -83,7 +82,7 @@ impl LocalWorkerPool {
     fn add_worker(&self) {
         let worker = Worker::new(self.parent.clone(), self.cpu_id);
         self.workers.disable_irq().lock().push_back(worker.clone());
-        Thread::borrow_from_task(worker.bound_task()).run();
+        worker.bound_task().as_thread().unwrap().run();
     }
 
     fn remove_worker(&self) {
@@ -258,7 +257,7 @@ impl Monitor {
     }
 
     pub fn run(&self) {
-        Thread::borrow_from_task(&self.bound_task).run()
+        self.bound_task.as_thread().unwrap().run()
     }
 
     fn run_monitor_loop(self: &Arc<Self>) {