[incubator-nuttx] 02/02: sched/sched/sched_waitid.c: Discard the child entry

[xi...@apache.org]

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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git

commit bce576c0bd3d25f41f4fb084a2f8a921805d140d
Author: Yoshinori Sugino <ys...@gmail.com>
AuthorDate: Fri Dec 4 15:20:40 2020 +0900

    sched/sched/sched_waitid.c: Discard the child entry
    
    Summary:
     - Discard the child entry after receiving SIGCHLD.
    
    Impact:
     - waitid
    
    Testing:
    hifive1-revb:nsh (CONFIG_SCHED_HAVE_PARENT=y, CONFIG_SCHED_CHILD_STATUS=y, CONFIG_SIG_DEFAULT=y)
    on QEMU
    
    static int task_main(int argc, char *argv[])
    {
      sleep(1);
      return 0;
    }
    
    int main(int argc, FAR char *argv[])
    {
      pid_t pid;
      siginfo_t info;
      int ret;
    
      pid = task_create("task1", 224, 1024, task_main, NULL);
      task_create("task2", 224, 1024, task_main, NULL);
    
      waitid(P_PID, pid, &info, WEXITED);
      waitid(P_ALL, 0, &info, WEXITED);
      ret = waitid(P_ALL, 0, &info, WEXITED | WNOHANG);
    
      assert(ret == -1);
    
      return 0;
    }
---
 sched/sched/sched_waitid.c | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/sched/sched/sched_waitid.c b/sched/sched/sched_waitid.c
index 8aac112..3b119d3 100644
--- a/sched/sched/sched_waitid.c
+++ b/sched/sched/sched_waitid.c
@@ -74,12 +74,15 @@ static void exited_child(FAR struct tcb_s *rtcb,
    * information).
    */
 
-  info->si_signo           = SIGCHLD;
-  info->si_code            = CLD_EXITED;
-  info->si_errno           = OK;
-  info->si_value.sival_ptr = NULL;
-  info->si_pid             = child->ch_pid;
-  info->si_status          = child->ch_status;
+  if (info)
+    {
+      info->si_signo           = SIGCHLD;
+      info->si_code            = CLD_EXITED;
+      info->si_errno           = OK;
+      info->si_value.sival_ptr = NULL;
+      info->si_pid             = child->ch_pid;
+      info->si_status          = child->ch_status;
+    }
 
   /* Discard the child entry */
 
@@ -364,6 +367,19 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
                 {
                   /* Yes... return success */
 
+#ifdef CONFIG_SCHED_CHILD_STATUS
+                  if (retains)
+                    {
+                      child = group_find_child(rtcb->group, info->si_pid);
+                      DEBUGASSERT(child);
+
+                      if ((child->ch_flags & CHILD_FLAG_EXITED) != 0)
+                        {
+                          exited_child(rtcb, child, NULL);
+                        }
+                    }
+#endif
+
                   break;
                 }
             }
@@ -374,6 +390,19 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
             {
               /* Return success */
 
+#ifdef CONFIG_SCHED_CHILD_STATUS
+                  if (retains)
+                    {
+                      child = group_find_child(rtcb->group, info->si_pid);
+
+                      if (child &&
+                          (child->ch_flags & CHILD_FLAG_EXITED) != 0)
+                        {
+                          exited_child(rtcb, child, NULL);
+                        }
+                    }
+#endif
+
               break;
             }