Add MutexBlocking.

os/src/sync/mod.rs

@@ -2,4 +2,4 @@ mod up;
 mod mutex;
 
 pub use up::UPSafeCell;
-pub use mutex::{Mutex, MutexSpin};
+pub use mutex::{Mutex, MutexSpin, MutexBlocking};

os/src/sync/mutex.rs

@@ -1,5 +1,8 @@
 use super::UPSafeCell;
-use crate::task::suspend_current_and_run_next;
+use crate::task::{block_current_and_run_next, suspend_current_and_run_next};
+use crate::task::TaskControlBlock;
+use crate::task::{add_task, current_task};
+use alloc::{sync::Arc, collections::VecDeque};
 
 pub trait Mutex: Sync + Send {
     fn lock(&self);
@@ -38,3 +41,47 @@ impl Mutex for MutexSpin {
         *locked = false;
     }
 }
+
+pub struct MutexBlocking {
+    inner: UPSafeCell<MutexBlockingInner>,
+}
+
+pub struct MutexBlockingInner {
+    locked: bool,
+    wait_queue: VecDeque<Arc<TaskControlBlock>>,
+}
+
+impl MutexBlocking {
+    pub fn new() -> Self {
+        Self {
+            inner: unsafe {
+                UPSafeCell::new(MutexBlockingInner {
+                    locked: false,
+                    wait_queue: VecDeque::new(),
+                })
+            },
+        }
+    }
+}
+
+impl Mutex for MutexBlocking {
+    fn lock(&self) {
+        let mut mutex_inner = self.inner.exclusive_access();
+        if mutex_inner.locked {
+            mutex_inner.wait_queue.push_back(current_task().unwrap());
+            drop(mutex_inner);
+            block_current_and_run_next();
+        } else {
+            mutex_inner.locked = true;
+        }
+    }
+
+    fn unlock(&self) {
+        let mut mutex_inner = self.inner.exclusive_access(); 
+        assert_eq!(mutex_inner.locked, true);
+        mutex_inner.locked = false;
+        if let Some(waking_task) = mutex_inner.wait_queue.pop_front() {
+            add_task(waking_task);
+        }
+    }
+}

os/src/syscall/mod.rs

@@ -46,7 +46,7 @@ pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
         SYSCALL_THREAD_CREATE => sys_thread_create(args[0]),
         SYSCALL_GETTID => sys_gettid(),
         SYSCALL_WAITTID => sys_waittid(args[0]) as isize,
-        SYSCALL_MUTEX_CREATE => sys_mutex_create(),
+        SYSCALL_MUTEX_CREATE => sys_mutex_create(args[0] == 1),
         SYSCALL_MUTEX_LOCK => sys_mutex_lock(args[0]),
         SYSCALL_MUTEX_UNLOCK => sys_mutex_unlock(args[0]),
         _ => panic!("Unsupported syscall_id: {}", syscall_id),

os/src/syscall/sync.rs

@@ -1,8 +1,8 @@
 use crate::task::current_process;
-use crate::sync::MutexSpin;
+use crate::sync::{MutexSpin, MutexBlocking};
 use alloc::sync::Arc;
 
-pub fn sys_mutex_create() -> isize {
+pub fn sys_mutex_create(blocking: bool) -> isize {
     let process = current_process();
     let mut process_inner = process.inner_exclusive_access();
     if let Some(id) = process_inner
@@ -11,7 +11,11 @@ pub fn sys_mutex_create() -> isize {
         .enumerate()
         .find(|(_, item)| item.is_none())
         .map(|(id, _)| id) {
-        process_inner.mutex_list[id] = Some(Arc::new(MutexSpin::new())); 
+        process_inner.mutex_list[id] = if !blocking {
+            Some(Arc::new(MutexSpin::new()))
+        } else {
+            Some(Arc::new(MutexBlocking::new()))
+        };
         id as isize
     } else {
         process_inner.mutex_list.push(Some(Arc::new(MutexSpin::new())));

os/src/task/mod.rs

@@ -52,6 +52,15 @@ pub fn suspend_current_and_run_next() {
     schedule(task_cx_ptr);
 }
 
+pub fn block_current_and_run_next() {
+    let task = take_current_task().unwrap();
+    let mut task_inner = task.inner_exclusive_access();
+    let task_cx_ptr = &mut task_inner.task_cx as *mut TaskContext;
+    task_inner.task_status = TaskStatus::Blocking;
+    drop(task_inner);
+    schedule(task_cx_ptr);
+}
+
 pub fn exit_current_and_run_next(exit_code: i32) {
     let task = take_current_task().unwrap();
     let mut task_inner = task.inner_exclusive_access();

os/src/task/task.rs

@@ -74,4 +74,5 @@ impl TaskControlBlock {
 pub enum TaskStatus {
     Ready,
     Running,
+    Blocking,
 }