diff options
Diffstat (limited to 'nuttx/sched/task_exithook.c')
| -rw-r--r-- | nuttx/sched/task_exithook.c | 318 |
1 files changed, 243 insertions, 75 deletions
diff --git a/nuttx/sched/task_exithook.c b/nuttx/sched/task_exithook.c index 1813c12ed..889df25e0 100644 --- a/nuttx/sched/task_exithook.c +++ b/nuttx/sched/task_exithook.c @@ -49,6 +49,7 @@ #include <nuttx/fs/fs.h> #include "os_internal.h" +#include "group_internal.h" #include "sig_internal.h" /**************************************************************************** @@ -103,10 +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; } @@ -119,10 +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; } @@ -160,10 +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; } @@ -175,10 +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; } @@ -189,6 +178,89 @@ static inline void task_onexit(FAR _TCB *tcb, int status) #endif /**************************************************************************** + * Name: task_exitstatus + * + * Description: + * Report exit status when main task of a task group exits + * + ****************************************************************************/ + +#ifdef CONFIG_SCHED_CHILD_STATUS +static inline void task_exitstatus(FAR struct task_group_s *group, int status) +{ + FAR struct child_status_s *child; + + /* Check if the parent task group has suppressed retention of + * child exit status information. + */ + + if ((group->tg_flags & GROUP_FLAG_NOCLDWAIT) == 0) + { + /* No.. Find the exit status entry for this task in the parent TCB */ + + child = group_findchild(group, getpid()); + DEBUGASSERT(child); + if (child) + { +#ifndef HAVE_GROUP_MEMBERS + /* No group members? Save the exit status */ + + child->ch_status = status; +#endif + /* Save the exit status.. For the case of HAVE_GROUP_MEMBERS, + * the child status will be as exited until the last member + * of the task group exits. + */ + + child->ch_status = status; + } + } +} +#else + +# define task_exitstatus(group,status) + +#endif /* CONFIG_SCHED_CHILD_STATUS */ + +/**************************************************************************** + * Name: task_groupexit + * + * Description: + * Mark that the final thread of a child task group as exited. + * + ****************************************************************************/ + +#ifdef CONFIG_SCHED_CHILD_STATUS +static inline void task_groupexit(FAR struct task_group_s *group) +{ + FAR struct child_status_s *child; + + /* Check if the parent task group has suppressed retention of child exit + * status information. + */ + + if ((group->tg_flags & GROUP_FLAG_NOCLDWAIT) == 0) + { + /* No.. Find the exit status entry for this task in the parent TCB */ + + child = group_findchild(group, getpid()); + DEBUGASSERT(child); + if (child) + { + /* Mark that all members of the child task group has exit'ed */ + + child->ch_flags |= CHILD_FLAG_EXITED; + } + } +} + +#else + +# define task_groupexit(group) + +#endif /* CONFIG_SCHED_CHILD_STATUS */ + +/**************************************************************************** * Name: task_sigchild * * Description: @@ -197,72 +269,96 @@ static inline void task_onexit(FAR _TCB *tcb, int status) ****************************************************************************/ #ifdef CONFIG_SCHED_HAVE_PARENT -static inline void task_sigchild(FAR _TCB *tcb, int status) +#ifdef HAVE_GROUP_MEMBERS +static inline void task_sigchild(gid_t pgid, FAR _TCB *ctcb, int status) { - FAR _TCB *ptcb; + FAR struct task_group_s *chgrp = ctcb->group; + FAR struct task_group_s *pgrp; siginfo_t info; - /* Only exiting tasks should generate SIGCHLD. pthreads use other - * mechansims. + DEBUGASSERT(chgrp); + + /* Get the parent task group. 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 ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK) + pgrp = group_find(chgrp->tg_pgid); + if (!pgrp) { - /* Keep things stationary through the following */ + /* Set the task group ID to an invalid group ID. The dead parent + * task group ID could get reused some time in the future. + */ - sched_lock(); + chgrp->tg_pgid = INVALID_GROUP_ID; + return; + } - /* Get the TCB of the receiving task */ + /* Save the exit status now if this is the main thread of the task group + * that is exiting. Only the exiting main task of a task group carries + * interpretable exit Check if this is the main task that is exiting. + */ - ptcb = sched_gettcb(tcb->parent); - if (!ptcb) - { - /* The parent no longer exists... bail */ + if ((ctcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK) + { + task_exitstatus(pgrp, status); + } - sched_unlock(); - return; - } + /* But only the final exiting thread in a task group, whatever it is, + * should generate SIGCHLD. + */ -#ifdef CONFIG_SCHED_CHILD_STATUS - /* Check if the parent task has suppressed retention of child exit - * status information. Only 'tasks' report exit status, not pthreads. - * pthreads have a different mechanism. + if (chgrp->tg_nmembers == 1) + { + /* Mark that all of the threads in the task group have exited */ + + task_groupexit(pgrp); + + /* 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. */ - if ((ptcb->flags & TCB_FLAG_NOCLDWAIT) == 0) - { - FAR struct child_status_s *child; + 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. + */ - /* No.. Find the exit status entry for this task in the parent TCB */ + (void)group_signal(pgrp, &info); + } +} - child = task_findchild(ptcb, getpid()); - DEBUGASSERT(child); - if (child) - { - /* Mark that the child has exit'ed */ +#else /* HAVE_GROUP_MEMBERS */ - child->ch_flags |= CHILD_FLAG_EXITED; +static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status) +{ + siginfo_t info; - /* Save the exit status */ + /* 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. + */ + + if ((ctcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK) + { +#ifdef CONFIG_SCHED_CHILD_STATUS + /* Save the exit status now of the main thread */ + + task_exitstatus(ptcb->group, status); + +#else /* CONFIG_SCHED_CHILD_STATUS */ - child->ch_status = status; - } - } -#else /* Decrement the number of children from this parent */ DEBUGASSERT(ptcb->nchildren > 0); ptcb->nchildren--; -#endif - /* 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, nchildren will be decremented once and - * all will be well. - */ - - tcb->parent = INVALID_PROCESS_ID; +#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 @@ -272,7 +368,7 @@ static inline void task_sigchild(FAR _TCB *tcb, int status) info.si_signo = SIGCHLD; info.si_code = CLD_EXITED; info.si_value.sival_ptr = NULL; - info.si_pid = tcb->pid; + info.si_pid = ctcb->pid; info.si_status = status; /* Send the signal. We need to use this internal interface so that we @@ -280,11 +376,72 @@ static inline void task_sigchild(FAR _TCB *tcb, int status) */ (void)sig_received(ptcb, &info); + } +} + +#endif /* HAVE_GROUP_MEMBERS */ +#else /* CONFIG_SCHED_HAVE_PARENT */ + +# define task_sigchild(x,ctcb,status) + +#endif /* CONFIG_SCHED_HAVE_PARENT */ + +/**************************************************************************** + * Name: task_leavegroup + * + * Description: + * Send the SIGCHILD signal to the parent thread + * + ****************************************************************************/ + +#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 */ + + sched_lock(); + + /* Get the TCB of the receiving, parent task. We do this early to + * 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->ppid); + if (!ptcb) + { + /* The parent no longer exists... bail */ + sched_unlock(); + return; } + + /* Send SIGCHLD to all members of the parent's task group */ + + task_sigchild(ptcb, ctcb, status); + + /* Forget who our parent was */ + + ctcb->ppid = INVALID_PROCESS_ID; + sched_unlock(); +#endif } #else -# define task_sigchild(tcb,status) +# define task_leavegroup(ctcb,status) #endif /**************************************************************************** @@ -352,6 +509,16 @@ 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! @@ -363,9 +530,9 @@ void task_exithook(FAR _TCB *tcb, int status) task_onexit(tcb, status); - /* Send SIGCHLD to the parent of the exit-ing task */ + /* Leave the task group */ - task_sigchild(tcb, status); + task_leavegroup(tcb, status); /* Wakeup any tasks waiting for this task to exit */ @@ -376,26 +543,27 @@ void task_exithook(FAR _TCB *tcb, int status) */ #if CONFIG_NFILE_STREAMS > 0 - (void)lib_flushall(tcb->streams); + (void)lib_flushall(&tcb->group->tg_streamlist); #endif - /* Discard any un-reaped child status (no zombies here!) */ + /* Leave the task group. Perhaps discarding any un-reaped child + * status (no zombies here!) + */ -#if defined(CONFIG_SCHED_HAVE_PARENT) && defined(CONFIG_SCHED_CHILD_STATUS) - task_removechildren(tcb); +#ifdef HAVE_TASK_GROUP + group_leave(tcb); #endif - /* Free all file-related resources now. This gets called again - * just be be certain when the TCB is delallocated. However, we - * really need to close files as soon as possible while we still - * have a functioning task. - */ - - (void)sched_releasefiles(tcb); - /* Deallocate anything left in the TCB's queues */ #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; } |