static void group_assigngid(FAR struct task_group_s *group)
{
irqstate_t flags;
gid_t gid;
/* Pre-emption should already be enabled, but lets be paranoid careful */
sched_lock();
/* Loop until we create a unique ID */
for (;;)
{
/* Increment the ID counter. This is global data so be extra paranoid. */
flags = irqsave();
gid = ++g_gidcounter;
/* Check for overflow */
if (gid <= 0)
{
g_gidcounter = 1;
irqrestore(flags);
}
else
{
/* Does a task group with this ID already exist? */
irqrestore(flags);
if (group_findbygid(gid) == NULL)
{
/* Now assign this ID to the group and return */
group->tg_gid = gid;
sched_unlock();
return;
}
}
}
}
int task_reparent(pid_t ppid, pid_t chpid)
{
#ifdef CONFIG_SCHED_CHILD_STATUS
FAR struct child_status_s *child;
#endif
FAR struct task_group_s *chgrp;
FAR struct task_group_s *ogrp;
FAR struct task_group_s *pgrp;
struct tcb_s *tcb;
gid_t ogid;
gid_t pgid;
irqstate_t flags;
int ret;
/* Disable interrupts so that nothing can change in the relatinoship of
* the three task: Child, current parent, and new parent.
*/
flags = irqsave();
/* Get the child tasks task group */
tcb = sched_gettcb(chpid);
if (!tcb)
{
ret = -ECHILD;
goto errout_with_ints;
}
DEBUGASSERT(tcb->group);
chgrp = tcb->group;
/* Get the GID of the old parent task's task group (ogid) */
ogid = chgrp->tg_pgid;
/* Get the old parent task's task group (ogrp) */
ogrp = group_findbygid(ogid);
if (!ogrp)
{
ret = -ESRCH;
goto errout_with_ints;
}
/* If new parent task's PID (ppid) is zero, then new parent is the
* grandparent will be the new parent, i.e., the parent of the current
* parent task.
*/
if (ppid == 0)
{
/* Get the grandparent task's task group (pgrp) */
pgid = ogrp->tg_pgid;
pgrp = group_findbygid(pgid);
}
else
{
/* Get the new parent task's task group (pgrp) */
tcb = sched_gettcb(ppid);
if (!tcb)
{
ret = -ESRCH;
goto errout_with_ints;
}
pgrp = tcb->group;
pgid = pgrp->tg_gid;
}
if (!pgrp)
{
ret = -ESRCH;
goto errout_with_ints;
}
/* Then reparent the child. Notice that we don't actually change the
* parent of the task. Rather, we change the parent task group for
* all members of the child's task group.
*/
chgrp->tg_pgid = pgid;
#ifdef CONFIG_SCHED_CHILD_STATUS
/* Remove the child status entry from old parent task group */
child = group_removechild(ogrp, chpid);
if (child)
{
/* Has the new parent's task group supressed child exit status? */
if ((pgrp->tg_flags && GROUP_FLAG_NOCLDWAIT) == 0)
{
/* No.. Add the child status entry to the new parent's task group */
group_addchild(pgrp, child);
}
else
{
/* Yes.. Discard the child status entry */
group_freechild(child);
}
/* Either case is a success */
ret = OK;
}
else
{
/* This would not be an error if the original parent's task group has
* suppressed child exit status.
*/
ret = ((ogrp->tg_flags && GROUP_FLAG_NOCLDWAIT) == 0) ? -ENOENT : OK;
}
#else /* CONFIG_SCHED_CHILD_STATUS */
DEBUGASSERT(otcb->nchildren > 0);
otcb->nchildren--; /* The orignal parent now has one few children */
ptcb->nchildren++; /* The new parent has one additional child */
ret = OK;
#endif /* CONFIG_SCHED_CHILD_STATUS */
errout_with_ints:
irqrestore(flags);
return ret;
}
int group_addrenv(FAR struct tcb_s *tcb)
{
FAR struct task_group_s *group;
FAR struct task_group_s *oldgroup;
irqstate_t flags;
gid_t gid;
int ret;
/* NULL for the tcb means to use the TCB of the task at the head of the
* ready to run list.
*/
if (!tcb)
{
tcb = (FAR struct tcb_s *)g_readytorun.head;
}
DEBUGASSERT(tcb && tcb->group);
group = tcb->group;
/* Does the group have an address environment? */
if ((group->tg_flags & GROUP_FLAG_ADDRENV) == 0)
{
/* No... just return perhaps leaving a different address environment
* intact.
*/
return OK;
}
/* Get the ID of the group that needs the address environment */
gid = group->tg_gid;
DEBUGASSERT(gid != 0);
/* Are we going to change address environments? */
flags = irqsave();
if (gid != g_gid_current)
{
/* Yes.. Is there a current address environment in place? */
if (g_gid_current != 0)
{
/* Find the old group with this ID. */
oldgroup = group_findbygid(g_gid_current);
DEBUGASSERT(oldgroup &&
(oldgroup->tg_flags & GROUP_FLAG_ADDRENV) != 0);
if (oldgroup)
{
/* We need to flush the D-Cache and Invalidate the I-Cache for
* the group whose environment is disappearing.
*/
up_addrenv_coherent(&oldgroup->addrenv);
}
}
/* Instantiate the new address environment (removing the old
* environment in the process). For the case of kernel threads,
* the old mappings will be removed and no new mappings will be
* instantiated.
*/
ret = up_addrenv_select(&group->addrenv, NULL);
if (ret < 0)
{
bdbg("ERROR: up_addrenv_select failed: %d\n", ret);
}
/* Save the new, current group */
g_gid_current = gid;
}
irqrestore(flags);
return OK;
}
static inline void task_sigchild(gid_t pgid, FAR struct tcb_s *ctcb, int status)
{
FAR struct task_group_s *chgrp = ctcb->group;
FAR struct task_group_s *pgrp;
siginfo_t info;
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.
*/
pgrp = group_findbygid(pgid);
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;
}
/* 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.
*/
#ifndef CONFIG_DISABLE_PTHREAD
if ((ctcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_PTHREAD)
#endif
{
task_exitstatus(pgrp, status);
}
/* But only the final exiting thread in a task group, whatever it is,
* should generate SIGCHLD.
*/
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 exited
* for now.
*/
info.si_signo = SIGCHLD;
info.si_code = CLD_EXITED;
info.si_errno = OK;
info.si_value.sival_ptr = NULL;
#ifndef CONFIG_DISABLE_PTHREAD
info.si_pid = chgrp->tg_task;
#else
info.si_pid = ctcb->pid;
#endif
info.si_status = status;
/* Send the signal to one thread in the group */
(void)group_signal(pgrp, &info);
}
}
