diff options
Diffstat (limited to 'nuttx/sched/sched_waitid.c')
| -rw-r--r-- | nuttx/sched/sched_waitid.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/nuttx/sched/sched_waitid.c b/nuttx/sched/sched_waitid.c index a3f7221df..37ee26ce0 100644 --- a/nuttx/sched/sched_waitid.c +++ b/nuttx/sched/sched_waitid.c @@ -159,8 +159,29 @@ int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) * TCB is actually a child of this task. */ +#ifdef CONFIG_SCHED_CHILD_STATUS + if (rtcb->children == NULL) + { + /* There are no children */ + + err = ECHILD; + goto errout_with_errno; + } + else if (idtype == P_PID) + { + if (task_findchild(rtcb, (pid_t)id) == NULL) + { + /* This specific pid is not a child */ + + err = ECHILD; + goto errout_with_errno; + } + } +#else if (rtcb->nchildren == 0) { + /* There are no children */ + err = ECHILD; goto errout_with_errno; } @@ -175,11 +196,64 @@ int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) goto errout_with_errno; } } +#endif /* Loop until the child that we are waiting for dies */ for (;;) { +#ifdef CONFIG_SCHED_CHILD_STATUS + /* Check if the task has already died. Signals are not queued in + * NuttX. So a possibility is that the child has died and we + * missed the death of child signal (we got some other signal + * instead). + */ + + DEBUGASSERT(rtcb->children); + if (rtcb->children == NULL) + { + /* This should not happen. I am just wasting your FLASH. */ + + err = ECHILD; + goto errout_with_errno; + } + else if (idtype == P_PID) + { + FAR struct child_status_s *child; + + /* We are waiting for a specific PID. Get the current status + * of the child task. + */ + + child = task_findchild(rtcb, (pid_t)id); + DEBUGASSERT(child); + if (!child) + { + /* Yikes! The child status entry just disappeared! */ + + err = ECHILD; + goto errout_with_errno; + } + + /* Did the child exit? */ + + if ((child->ch_flags & CHILD_FLAG_EXITED) != 0) + { + /* The child has exited. Return the saved exit status */ + + info->si_signo = SIGCHLD; + info->si_code = CLD_EXITED; + info->si_value.sival_ptr = NULL; + info->si_pid = (pid_t)id; + info->si_status = child->ch_status; + + /* Discard the child entry and break out of the loop */ + + (void)task_removechild(rtcb, (pid_t)id); + task_freechild(child); + } + } +#else /* Check if the task has already died. Signals are not queued in * NuttX. So a possibility is that the child has died and we * missed the death of child signal (we got some other signal @@ -197,6 +271,7 @@ int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) err = EINTR; goto errout_with_errno; } +#endif /* Wait for any death-of-child signal */ |