From 9d370fc3632fc2891c7a8e0af747491688ecb121 Mon Sep 17 00:00:00 2001
From: Masayuki Ishikawa <masayuki.ishikawa@gmail.com>
Date: Tue, 2 Mar 2021 08:38:58 +0900
Subject: [PATCH] sched: task: Call nxtask_flushstreams() without critical
 section

Summary:
- During investigating critical section with semaphores, I noticed
  that nxtask_flushstreams() is called with a critical section.
- The function calls lib_flushall() which handles a semaphore
  in userspace.
- So it should be done without a critical section

Impact:
- SMP only

Testing:
- Tested with ostest the following configs
- esp32-devkitc:smp (QEMU), sabre-6quad:smp (QEMU)
- maix-bit:smp (QEMU), sim:smp
- spresense:smp
- Tested with nxplayer and stress test with spresense:wifi_smp

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
---
 sched/task/task_exithook.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/sched/task/task_exithook.c b/sched/task/task_exithook.c
index 8378c0c8fc..0e34a99ab7 100644
--- a/sched/task/task_exithook.c
+++ b/sched/task/task_exithook.c
@@ -586,7 +586,6 @@ void nxtask_exithook(FAR struct tcb_s *tcb, int status, bool nonblocking)
   tcb->cpcount = 0;
 #endif
 
-#if defined(CONFIG_SCHED_ATEXIT) || defined(CONFIG_SCHED_ONEXIT)
   /* If exit function(s) were registered, call them now before we do any un-
    * initialization.
    *
@@ -604,14 +603,28 @@ void nxtask_exithook(FAR struct tcb_s *tcb, int status, bool nonblocking)
 
   if (!nonblocking)
     {
+#if defined(CONFIG_SCHED_ATEXIT) || defined(CONFIG_SCHED_ONEXIT)
       nxtask_atexit(tcb);
 
       /* Call any registered on_exit function(s) */
 
       nxtask_onexit(tcb, status);
-    }
 #endif
 
+      /* If this is the last thread in the group, then flush all streams
+       * (File descriptors will be closed when the TCB is deallocated).
+       *
+       * NOTES:
+       * 1. We cannot flush the buffered I/O if nonblocking is requested.
+       *    that might cause this logic to block.
+       * 2. This function will only be called with non-blocking == true
+       *    only when called through _exit(). _exit() behavior does not
+       *    require that the streams be flushed
+       */
+
+      nxtask_flushstreams(tcb);
+    }
+
   /* If the task was terminated by another task, it may be in an unknown
    * state.  Make some feeble effort to recover the state.
    */
@@ -632,22 +645,6 @@ void nxtask_exithook(FAR struct tcb_s *tcb, int status, bool nonblocking)
 
   nxtask_exitwakeup(tcb, status);
 
-  /* If this is the last thread in the group, then flush all streams (File
-   * descriptors will be closed when the TCB is deallocated).
-   *
-   * NOTES:
-   * 1. We cannot flush the buffered I/O if nonblocking is requested.
-   *    that might cause this logic to block.
-   * 2. This function will only be called with non-blocking == true
-   *    only when called through _exit(). _exit() behavior does not
-   *    require that the streams be flushed
-   */
-
-  if (!nonblocking)
-    {
-      nxtask_flushstreams(tcb);
-    }
-
   /* Leave the task group.  Perhaps discarding any un-reaped child
    * status (no zombies here!)
    */