From ee23e4def16a5643a0dff83358eaf189801dac53 Mon Sep 17 00:00:00 2001
From: WuZheng <hello_weekday@163.com>
Date: Thu, 14 Nov 2024 17:19:21 +0800
Subject: [PATCH] fix bugs for pipe's write end closure and exit group

---
 api/ruxos_posix_api/src/imp/pipe.rs        | 12 +++++++++---
 api/ruxos_posix_api/src/imp/pthread/mod.rs |  9 ++++++---
 api/ruxos_posix_api/src/imp/task.rs        |  3 +--
 modules/ruxtask/src/fs.rs                  | 10 ++++++++++
 4 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/api/ruxos_posix_api/src/imp/pipe.rs b/api/ruxos_posix_api/src/imp/pipe.rs
index 8b61a3f1..6fb29a04 100644
--- a/api/ruxos_posix_api/src/imp/pipe.rs
+++ b/api/ruxos_posix_api/src/imp/pipe.rs
@@ -7,7 +7,7 @@
  *   See the Mulan PSL v2 for more details.
  */
 
-use alloc::sync::Arc;
+use alloc::sync::{Weak, Arc};
 use core::ffi::c_int;
 
 use axerrno::{LinuxError, LinuxResult};
@@ -87,6 +87,8 @@ impl PipeRingBuffer {
 pub struct Pipe {
     readable: bool,
     buffer: Arc<Mutex<PipeRingBuffer>>,
+    // to find the write end when the read end is closed
+    _write_end_closed: Option<Weak<Mutex<PipeRingBuffer>>>,
 }
 
 impl Pipe {
@@ -95,10 +97,12 @@ impl Pipe {
         let read_end = Pipe {
             readable: true,
             buffer: buffer.clone(),
+            _write_end_closed: None,
         };
         let write_end = Pipe {
             readable: false,
-            buffer,
+            buffer: buffer.clone(),
+            _write_end_closed: Some(Arc::downgrade(&buffer)),
         };
         (read_end, write_end)
     }
@@ -112,7 +116,9 @@ impl Pipe {
     }
 
     pub fn write_end_close(&self) -> bool {
-        Arc::strong_count(&self.buffer) == 1
+        let write_end_count = Arc::weak_count(&self.buffer);
+        // error!("Pipe::write_end_close <= buffer: {:#?} {:#?}", write_end_count, Arc::as_ptr(&self.buffer));
+        write_end_count == 0
     }
 }
 
diff --git a/api/ruxos_posix_api/src/imp/pthread/mod.rs b/api/ruxos_posix_api/src/imp/pthread/mod.rs
index 759512cf..405d5b13 100644
--- a/api/ruxos_posix_api/src/imp/pthread/mod.rs
+++ b/api/ruxos_posix_api/src/imp/pthread/mod.rs
@@ -12,7 +12,7 @@ use core::cell::UnsafeCell;
 use core::ffi::{c_int, c_void};
 
 use axerrno::{LinuxError, LinuxResult};
-use ruxtask::AxTaskRef;
+use ruxtask::{current, AxTaskRef};
 use spin::RwLock;
 
 use crate::ctypes;
@@ -228,9 +228,12 @@ pub fn sys_pthread_exit(retval: *mut c_void) -> ! {
 
 /// Exits the current thread. The value `retval` will be returned to the joiner.
 pub fn sys_exit_group(status: c_int) -> ! {
-    error!("sys_exit_group <= {:#?}", status);
+    debug!("sys_exit_group <= status: {:#?}", status);
 
     // TODO: exit all threads, send signal to all threads
+    
+    //  drop all file opened by current task
+    current().fs.lock().as_mut().unwrap().close_all_files();
 
     #[cfg(feature = "multitask")]
     ruxtask::exit(status);
@@ -322,7 +325,7 @@ pub unsafe fn sys_clone(
                 TID_TO_PTHREAD.write().insert(tid, ForceSendSync(ptr));
                 0
             };
-            warn!("will sys_clone <= pid: {}", pid);
+            debug!("will sys_clone <= pid: {}", pid);
             return Ok(pid);
         } else {
             debug!("ONLY support CLONE_THREAD and SIGCHLD");
diff --git a/api/ruxos_posix_api/src/imp/task.rs b/api/ruxos_posix_api/src/imp/task.rs
index b4227b8a..17d365c8 100644
--- a/api/ruxos_posix_api/src/imp/task.rs
+++ b/api/ruxos_posix_api/src/imp/task.rs
@@ -54,7 +54,7 @@ pub fn sys_getppid() -> c_int {
 
 /// Wait for a child process to exit and return its status.
 ///
-/// TOSO, wstatus, options, and rusage are not implemented yet.
+/// TODO: part of options, and rusage are not implemented yet.
 pub fn sys_wait4(
     pid: c_int,
     wstatus: *mut c_int,
@@ -104,7 +104,6 @@ pub fn sys_wait4(
                 if parent_pid == ruxtask::current().id().as_u64() {
                     if task.state() == ruxtask::task::TaskState::Exited {
                         // add to to_remove list
-                        let task_ref = process_map.get(child_pid).unwrap();
                         unsafe {
                             // lower 8 bits of exit_code is the signal number, while upper 8 bits of exit_code is the exit status
                             // according to "bits/waitstatus.h" in glibc source code.
diff --git a/modules/ruxtask/src/fs.rs b/modules/ruxtask/src/fs.rs
index 75d71a33..b603d237 100644
--- a/modules/ruxtask/src/fs.rs
+++ b/modules/ruxtask/src/fs.rs
@@ -216,6 +216,16 @@ pub struct FileSystem {
     pub root_dir: Arc<RootDirectory>,
 }
 
+impl FileSystem {
+    pub fn close_all_files(&mut self) {
+        for fd in 0..self.fd_table.capacity() {
+            if let Some(_) = self.fd_table.get(fd) {
+                self.fd_table.remove(fd).unwrap();
+            }
+        }
+    }
+}
+
 impl Clone for FileSystem {
     fn clone(&self) -> Self {
         let mut new_fd_table = FlattenObjects::new();