diff options
Diffstat (limited to 'nuttx/sched/task_exithook.c')
| -rw-r--r-- | nuttx/sched/task_exithook.c | 175 |
1 files changed, 134 insertions, 41 deletions
diff --git a/nuttx/sched/task_exithook.c b/nuttx/sched/task_exithook.c index cbada851a..3fdf08bf7 100644 --- a/nuttx/sched/task_exithook.c +++ b/nuttx/sched/task_exithook.c @@ -104,10 +104,7 @@ static inline void task_atexit(FAR _TCB *tcb) (*tcb->atexitfunc[index])(); - /* Nullify the atexit function. task_exithook may be called more then - * once in most task exit scenarios. Nullifying the atext function - * pointer will assure that the callback is performed only once. - */ + /* Nullify the atexit function to prevent its reuse. */ tcb->atexitfunc[index] = NULL; } @@ -120,10 +117,7 @@ static inline void task_atexit(FAR _TCB *tcb) (*tcb->atexitfunc)(); - /* Nullify the atexit function. task_exithook may be called more then - * once in most task exit scenarios. Nullifying the atext function - * pointer will assure that the callback is performed only once. - */ + /* Nullify the atexit function to prevent its reuse. */ tcb->atexitfunc = NULL; } @@ -161,10 +155,7 @@ static inline void task_onexit(FAR _TCB *tcb, int status) (*tcb->onexitfunc[index])(status, tcb->onexitarg[index]); - /* Nullify the on_exit function. task_exithook may be called more then - * once in most task exit scenarios. Nullifying the atext function - * pointer will assure that the callback is performed only once. - */ + /* Nullify the on_exit function to prevent its reuse. */ tcb->onexitfunc[index] = NULL; } @@ -176,10 +167,7 @@ static inline void task_onexit(FAR _TCB *tcb, int status) (*tcb->onexitfunc)(status, tcb->onexitarg); - /* Nullify the on_exit function. task_exithook may be called more then - * once in most task exit scenarios. Nullifying the on_exit function - * pointer will assure that the callback is performed only once. - */ + /* Nullify the on_exit function to prevent its reuse. */ tcb->onexitfunc = NULL; } @@ -198,20 +186,96 @@ static inline void task_onexit(FAR _TCB *tcb, int status) ****************************************************************************/ #ifdef CONFIG_SCHED_HAVE_PARENT +#ifdef HAVE_GROUP_MEMBERS +static inline void task_sigchild(gid_t pgid, FAR _TCB *ctcb, int status) +{ + FAR struct task_group_s *chgrp = ctcb->group; + FAR struct task_group_s *pgrp; + siginfo_t info; + + DEBUGASSERT(chgrp); + + /* Only the final exiting thread in a task group should generate SIGCHLD. */ + + if (chgrp->tg_nmembers == 1) + { + /* Get the parent task group */ + + pgrp = group_find(chgrp->tg_pgid); + + /* It is possible that all of the members of the parent task group + * have exited. This would not be an error. In this case, the + * child task group has been orphaned. + */ + + if (!pgrp) + { + /* Set the task group ID to an invalid group ID. The dead parent + * task group ID could get reused some time in the future. + */ + + chgrp->tg_pgid = INVALID_GROUP_ID; + return; + } + +#ifdef CONFIG_SCHED_CHILD_STATUS + /* Check if the parent task group has suppressed retention of child exit + * status information. Only 'tasks' report exit status, not pthreads. + * pthreads have a different mechanism. + */ + + if ((pgrp->tg_flags & GROUP_FLAG_NOCLDWAIT) == 0) + { + FAR struct child_status_s *child; + + /* No.. Find the exit status entry for this task in the parent TCB */ + + child = group_findchild(pgrp, getpid()); + DEBUGASSERT(child); + if (child) + { + /* Mark that the child has exit'ed */ + + child->ch_flags |= CHILD_FLAG_EXITED; + + /* Save the exit status */ + + child->ch_status = status; + } + } +#endif /* CONFIG_SCHED_CHILD_STATUS */ + + /* Create the siginfo structure. We don't actually know the cause. + * That is a bug. Let's just say that the child task just exit-ted + * for now. + */ + + info.si_signo = SIGCHLD; + info.si_code = CLD_EXITED; + info.si_value.sival_ptr = NULL; + info.si_pid = ctcb->pid; + info.si_status = status; + + /* Send the signal. We need to use this internal interface so that we + * can provide the correct si_code value with the signal. + */ + + (void)group_signal(pgrp, &info); + } +} + +#else /* HAVE_GROUP_MEMBERS */ + static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) { siginfo_t info; - /* Only the final exiting thread in a task group should generate SIGCHLD. - * If task groups are not supported then we will report SIGCHLD when the - * task exits. + /* If task groups are not supported then we will report SIGCHLD when the + * task exits. Unfortunately, there could still be threads in the group + * that are still running. */ -#ifdef CONFIG_SCHED_CHILD_STATUS - if (ctcb->group->tg_nmembers == 1) -#else if ((ctcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK) -#endif { #ifdef CONFIG_SCHED_CHILD_STATUS /* Check if the parent task group has suppressed retention of child exit @@ -225,7 +289,7 @@ static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) /* No.. Find the exit status entry for this task in the parent TCB */ - child = task_findchild(ptcb, getpid()); + child = group_findchild(ptcb->group, getpid()); DEBUGASSERT(child); if (child) { @@ -238,12 +302,15 @@ static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) child->ch_status = status; } } -#else + +#else /* CONFIG_SCHED_CHILD_STATUS */ + /* Decrement the number of children from this parent */ DEBUGASSERT(ptcb->nchildren > 0); ptcb->nchildren--; -#endif + +#endif /* CONFIG_SCHED_CHILD_STATUS */ /* Create the siginfo structure. We don't actually know the cause. * That is a bug. Let's just say that the child task just exit-ted @@ -260,16 +327,16 @@ static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) * can provide the correct si_code value with the signal. */ -#ifdef HAVE_GROUP_MEMBERS - (void)group_signal(ptcb, &info); -#else (void)sig_received(ptcb, &info); -#endif } } -#else -# define task_sigchild(ptct,ctcb,status) -#endif + +#endif /* HAVE_GROUP_MEMBERS */ +#else /* CONFIG_SCHED_HAVE_PARENT */ + +# define task_sigchild(x,ctcb,status) + +#endif /* CONFIG_SCHED_HAVE_PARENT */ /**************************************************************************** * Name: task_leavegroup @@ -282,6 +349,18 @@ static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) #ifdef CONFIG_SCHED_HAVE_PARENT static inline void task_leavegroup(FAR _TCB *ctcb, int status) { +#ifdef HAVE_GROUP_MEMBERS + DEBUGASSERT(ctcb && ctcb->group); + + /* Keep things stationary throughout the following */ + + sched_lock(); + + /* Send SIGCHLD to all members of the parent's task group */ + + task_sigchild(ctcb->group->tg_pgid, ctcb, status); + sched_unlock(); +#else FAR _TCB *ptcb; /* Keep things stationary throughout the following */ @@ -289,12 +368,12 @@ static inline void task_leavegroup(FAR _TCB *ctcb, int status) sched_lock(); /* Get the TCB of the receiving, parent task. We do this early to - * handle multiple calls to task_leavegroup. ctcb->parent is set to an + * handle multiple calls to task_leavegroup. ctcb->ppid is set to an * invalid value below and the following call will fail if we are * called again. */ - ptcb = sched_gettcb(ctcb->parent); + ptcb = sched_gettcb(ctcb->ppid); if (!ptcb) { /* The parent no longer exists... bail */ @@ -307,14 +386,11 @@ static inline void task_leavegroup(FAR _TCB *ctcb, int status) task_sigchild(ptcb, ctcb, status); - /* Set the parent to an impossible PID. We do this because under certain - * conditions, task_exithook() can be called multiple times. If this - * function is called again, sched_gettcb() will fail on the invalid - * parent PID above and all will be well. - */ + /* Forget who our parent was */ - ctcb->parent = INVALID_PROCESS_ID; + ctcb->ppid = INVALID_PROCESS_ID; sched_unlock(); +#endif } #else # define task_leavegroup(ctcb,status) @@ -385,6 +461,16 @@ static inline void task_exitwakeup(FAR _TCB *tcb, int status) void task_exithook(FAR _TCB *tcb, int status) { + /* Under certain conditions, task_exithook() can be called multiple times. + * A bit in the TCB was set the first time this function was called. If + * that bit is set, then just ext doing nothing more.. + */ + + if ((tcb->flags & TCB_FLAG_EXIT_PROCESSING) != 0) + { + return; + } + /* If exit function(s) were registered, call them now before we do any un- * initialization. NOTE: In the case of task_delete(), the exit function * will *not* be called on the thread execution of the task being deleted! @@ -433,4 +519,11 @@ void task_exithook(FAR _TCB *tcb, int status) #ifndef CONFIG_DISABLE_SIGNALS sig_cleanup(tcb); /* Deallocate Signal lists */ #endif + + /* This function can be re-entered in certain cases. Set a flag + * bit in the TCB to not that we have already completed this exit + * processing. + */ + + tcb->flags |= TCB_FLAG_EXIT_PROCESSING; } |