Rewrite Stdin/Stdout

os/src/task/task.rs

@@ -4,8 +4,10 @@ use crate::config::{TRAP_CONTEXT};
 use super::TaskContext;
 use super::{PidHandle, pid_alloc, KernelStack};
 use alloc::sync::{Weak, Arc};
+use alloc::vec;
 use alloc::vec::Vec;
 use spin::{Mutex, MutexGuard};
+use crate::fs::{File, Stdin, Stdout};
 
 pub struct TaskControlBlock {
     // immutable
@@ -24,6 +26,7 @@ pub struct TaskControlBlockInner {
     pub parent: Option<Weak<TaskControlBlock>>,
     pub children: Vec<Arc<TaskControlBlock>>,
     pub exit_code: i32,
+    pub fd_table: Vec<Option<Arc<dyn File + Send + Sync>>>,
 }
 
 impl TaskControlBlockInner {
@@ -74,6 +77,10 @@ impl TaskControlBlock {
                 parent: None,
                 children: Vec::new(),
                 exit_code: 0,
+                fd_table: vec![
+                    Some(Arc::new(Stdin)),
+                    Some(Arc::new(Stdout)),
+                ],
             }),
         };
         // prepare TrapContext in user space
@@ -136,6 +143,15 @@ impl TaskControlBlock {
         let kernel_stack_top = kernel_stack.get_top();
         // push a goto_trap_return task_cx on the top of kernel stack
         let task_cx_ptr = kernel_stack.push_on_top(TaskContext::goto_trap_return());
+        // copy fd table
+        let mut new_fd_table: Vec<Option<Arc<dyn File + Send + Sync>>> = Vec::new();
+        for fd in parent_inner.fd_table.iter() {
+            if let Some(file) = fd {
+                new_fd_table.push(Some(file.clone()));
+            } else {
+                new_fd_table.push(None);
+            }
+        }
         let task_control_block = Arc::new(TaskControlBlock {
             pid: pid_handle,
             kernel_stack,
@@ -148,6 +164,7 @@ impl TaskControlBlock {
                 parent: Some(Arc::downgrade(self)),
                 children: Vec::new(),
                 exit_code: 0,
+                fd_table: new_fd_table,
             }),
         });
         // add child