From fcbf23762f42529d5d51c5af154a617e01055ae3 Mon Sep 17 00:00:00 2001
From: Ian Chen <ianre657@gmail.com>
Date: Mon, 31 May 2021 13:09:21 +0800
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20=F0=9F=90=9B=20close=20file=20descr?=
 =?UTF-8?q?iptors?=
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---
 impl-c/fs/vfs.c            |  2 +-
 impl-c/include/proc/task.h |  3 +++
 impl-c/proc/sched.c        | 11 +----------
 impl-c/proc/task.c         | 39 ++++++++++++++++++++++++++++++++++++--
 4 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/impl-c/fs/vfs.c b/impl-c/fs/vfs.c
index 1e8eb5497..28a830fb9 100644
--- a/impl-c/fs/vfs.c
+++ b/impl-c/fs/vfs.c
@@ -173,7 +173,7 @@ struct file *vfs_open(const char *pathname, int flags) {
 }
 
 int vfs_close(struct file *file) {
-  // 1. release the file descriptor
+  kfree(file);
   return 0;
 }
 
diff --git a/impl-c/include/proc/task.h b/impl-c/include/proc/task.h
index 65b8d6c3d..65e7900b6 100644
--- a/impl-c/include/proc/task.h
+++ b/impl-c/include/proc/task.h
@@ -41,6 +41,9 @@ struct task_struct {
 };
 
 struct task_struct *task_create(void *func);
+
+void task_free(struct task_struct *task);
+
 void cur_task_exit();
 
 extern uint32_t new_tid;
diff --git a/impl-c/proc/sched.c b/impl-c/proc/sched.c
index 30208bae7..43fe9f186 100644
--- a/impl-c/proc/sched.c
+++ b/impl-c/proc/sched.c
@@ -69,17 +69,8 @@ void kill_zombies() {
     task = ((struct task_entry *)entry)->task;
     log_println("recycle space for task:%d", task->id);
     list_del(entry);
-
     kfree(entry);
-    // TODO: manage parent code free and child code free
-    // if (task->code) {
-    //   kfree(task->code);
-    // }
-    if (task->user_stack) {
-      kfree((void *)task->user_stack);
-    }
-    kfree((void *)task->kernel_stack);
-    kfree(task);
+    task_free(task);
   }
 }
 
diff --git a/impl-c/proc/task.c b/impl-c/proc/task.c
index 001f6a231..3379136ea 100644
--- a/impl-c/proc/task.c
+++ b/impl-c/proc/task.c
@@ -28,6 +28,7 @@ static const int _DO_LOG = 0;
 static void foo();
 
 extern void fork_child_eret();
+static inline void close_fd(struct task_struct *task, int fd);
 
 uint32_t new_tid = 0;
 
@@ -70,6 +71,25 @@ struct task_struct *task_create(void *func) {
   return t;
 }
 
+void task_free(struct task_struct *task) {
+  // TODO: manage parent code free and child code free
+  // if (task->code) {
+  //   kfree(task->code);
+  // }
+  if (task->user_stack) {
+    kfree((void *)task->user_stack);
+  }
+  kfree((void *)task->kernel_stack);
+
+  // Close all file descriptors
+  for (int i = 0; i < TASK_MX_NUM_FD; i++) {
+    if (task->fd[i] != NULL) {
+      close_fd(task, i);
+    }
+  }
+  kfree(task);
+}
+
 int sys_getpid() {
   struct task_struct *task = get_current();
   return task->id;
@@ -94,6 +114,7 @@ int sys_open(const char *pathname, int flags) {
   for (int i = 0; i < TASK_MX_NUM_FD; i++) {
     if (task->fd[i] == NULL) {
       task->fd[i] = file;
+      task->fd_size++;
       return i;
     }
   }
@@ -101,13 +122,27 @@ int sys_open(const char *pathname, int flags) {
   return -1;
 }
 
+void close_fd(struct task_struct *task, int fd) {
+  if (task->fd[fd] != NULL) {
+    vfs_close(task->fd[fd]);
+    task->fd[fd] = NULL;
+  }
+  // check for bugs
+  task->fd_size--;
+  if (task->fd_size < 0) {
+    uart_println("[Task free] BUG!!! fd not synce");
+    while (1) {
+      ;
+    }
+  }
+}
+
 int sys_close(int fd) {
   struct task_struct *task = get_current();
   if ((fd < 0 || fd > TASK_MX_NUM_FD) || (task->fd[fd] == NULL)) {
     return -1;
   }
-  task->fd[fd] = NULL;
-  task->fd_size--;
+  close_fd(task, fd);
   return 0;
 }