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Add logic to retain child task exit status if so configured

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git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5553 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo
2013-01-23 22:23:46 +00:00
parent f86f863834
commit 340a72b7cd
23 changed files with 846 additions and 223 deletions
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nuttx/sched/task_exithook.c
+82 -41
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@@ -1,7 +1,7 @@
/****************************************************************************
* sched/task_exithook.c
*
* Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
* Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@@ -202,51 +202,86 @@ static inline void task_sigchild(FAR _TCB *tcb, int status)
FAR _TCB *ptcb;
siginfo_t info;
/* Keep things stationary through the following */
/* Only exiting tasks should generate SIGCHLD. pthreads use other
* mechansims.
*/
sched_lock();
/* Get the TCB of the receiving task */
ptcb = sched_gettcb(tcb->parent);
if (!ptcb)
if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK)
{
/* The parent no longer exists... bail */
/* Keep things stationary through the following */
sched_lock();
/* Get the TCB of the receiving task */
ptcb = sched_gettcb(tcb->parent);
if (!ptcb)
{
/* The parent no longer exists... bail */
sched_unlock();
return;
}
#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 ((ptcb->flags & TCB_FLAG_NOCLDWAIT) == 0)
{
FAR struct child_status_s *child;
/* No.. Find the exit status entry for this task in the parent TCB */
child = task_findchild(ptcb, 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;
}
}
#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;
/* 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 = tcb->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)sig_received(ptcb, &info);
sched_unlock();
return;
}
/* Decrement the number of children from this parent */
DEBUGASSERT(ptcb->nchildren > 0);
ptcb->nchildren--;
/* 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;
/* 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 = tcb->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)sig_received(ptcb, &info);
sched_unlock();
}
#else
# define task_sigchild(tcb,status)
@@ -344,6 +379,12 @@ void task_exithook(FAR _TCB *tcb, int status)
(void)lib_flushall(tcb->streams);
#endif
/* Discard any un-reaped child status (no zombies here!) */
#if defined(CONFIG_SCHED_HAVE_PARENT) && defined(CONFIG_SCHED_CHILD_STATUS)
task_removechildren(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