int sig_dispatch(pid_t pid, FAR siginfo_t *info)
{
#ifdef HAVE_GROUP_MEMBERS
FAR struct tcb_s *stcb;
FAR struct task_group_s *group;
/* Get the TCB associated with the pid */
stcb = sched_gettcb(pid);
if (stcb)
{
/* The task/thread associated with this PID is still active. Get its
* task group.
*/
group = stcb->group;
}
else
{
/* The task/thread associated with this PID has exited. In the normal
* usage model, the PID should correspond to the PID of the task that
* created the task group. Try looking it up.
*/
group = group_findbypid(pid);
}
/* Did we locate the group? */
if (group)
{
/* Yes.. call group_signal() to send the signal to the correct group
* member.
*/
return group_signal(group, info);
}
else
{
return -ESRCH;
}
#else
FAR struct tcb_s *stcb;
/* Get the TCB associated with the pid */
stcb = sched_gettcb(pid);
if (!stcb)
{
return -ESRCH;
}
return sig_tcbdispatch(stcb, info);
#endif
}
static void pthread_condtimedout(int argc, uint32_t pid, uint32_t signo)
{
#ifdef HAVE_GROUP_MEMBERS
FAR struct tcb_s *tcb;
siginfo_t info;
/* The logic below if equivalent to sigqueue(), but uses sig_tcbdispatch()
* instead of sig_dispatch(). This avoids the group signal deliver logic
* and assures, instead, that the signal is delivered specifically to this
* thread that is known to be waiting on the signal.
*/
/* Get the waiting TCB. sched_gettcb() might return NULL if the task has
* exited for some reason.
*/
tcb = sched_gettcb((pid_t)pid);
if (tcb)
{
/* Create the siginfo structure */
info.si_signo = signo;
info.si_code = SI_QUEUE;
info.si_errno = ETIMEDOUT;
info.si_value.sival_ptr = NULL;
#ifdef CONFIG_SCHED_HAVE_PARENT
info.si_pid = (pid_t)pid;
info.si_status = OK;
#endif
/* Process the receipt of the signal. The scheduler is not locked as
* is normally the case when this function is called because we are in
* a watchdog timer interrupt handler.
*/
(void)sig_tcbdispatch(tcb, &info);
}
#else /* HAVE_GROUP_MEMBERS */
/* Things are a little easier if there are not group members. We can just
* use sigqueue().
*/
#ifdef CONFIG_CAN_PASS_STRUCTS
union sigval value;
/* Send the specified signal to the specified task. */
value.sival_ptr = NULL;
(void)sigqueue((int)pid, (int)signo, value);
#else
(void)sigqueue((int)pid, (int)signo, NULL);
#endif
#endif /* HAVE_GROUP_MEMBERS */
}
static inline void task_sigchild(FAR struct tcb_s *ptcb,
FAR struct tcb_s *ctcb, int status)
{
siginfo_t info;
/* 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.
*/
#ifndef CONFIG_DISABLE_PTHREAD
if ((ctcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_PTHREAD)
#endif
{
#ifdef CONFIG_SCHED_CHILD_STATUS
/* Save the exit status now of the main thread */
task_exitstatus(ptcb->group, status);
#else /* CONFIG_SCHED_CHILD_STATUS */
/* Decrement the number of children from this parent */
DEBUGASSERT(ptcb->nchildren > 0);
ptcb->nchildren--;
#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 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 = ctcb->group->tg_task;
#else
info.si_pid = ctcb->pid;
#endif
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_tcbdispatch(ptcb, &info);
}
}
int pthread_kill(pthread_t thread, int signo)
{
#ifdef HAVE_GROUP_MEMBERS
/* If group members are support then pthread_kill() differs from kill().
* kill(), in this case, must following the POSIX rules for delivery of
* signals in the group environment. Otherwise, kill(), like
* pthread_kill() will just deliver the signal to the thread ID it is
* requested to use.
*/
#ifdef CONFIG_SCHED_HAVE_PARENT
FAR struct tcb_s *rtcb = (FAR struct tcb_s *)g_readytorun.head;
#endif
FAR struct tcb_s *stcb;
siginfo_t info;
int ret;
/* Make sure that the signal is valid */
if (!GOOD_SIGNO(signo))
{
ret = -EINVAL;
goto errout;
}
/* Keep things stationary through the following */
sched_lock();
/* Create the siginfo structure */
info.si_signo = signo;
info.si_code = SI_USER;
info.si_value.sival_ptr = NULL;
#ifdef CONFIG_SCHED_HAVE_PARENT
info.si_pid = rtcb->pid;
info.si_status = OK;
#endif
/* Get the TCB associated with the thread */
stcb = sched_gettcb((pid_t)thread);
if (!stcb)
{
ret = -ESRCH;
goto errout_with_lock;
}
/* Dispatch the signal to thread, bypassing normal task group thread
* dispatch rules.
*/
ret = sig_tcbdispatch(stcb, &info);
sched_unlock();
if (ret < 0)
{
goto errout;
}
return OK;
errout_with_lock:
sched_unlock();
errout:
return -ret;
#else
/* If group members are not supported then pthread_kill is basically the
* same as kill().
*/
int ret;
set_errno(EINVAL);
ret = kill((pid_t)thread, signo);
if (ret != OK)
{
ret = get_errno();
}
return ret;
#endif
}
static int group_signal_handler(pid_t pid, FAR void *arg)
{
FAR struct group_signal_s *info = (FAR struct group_signal_s *)arg;
FAR struct tcb_s *tcb;
FAR sigactq_t *sigact;
int ret;
DEBUGASSERT(info);
/* Get the TCB associated with the group member */
tcb = sched_gettcb(pid);
DEBUGASSERT(tcb);
if (tcb)
{
/* Set this one as the default if we have not already set the default. */
if (!info->dtcb)
{
info->dtcb = tcb;
}
/* Is the thread waiting for this signal (in this case, the signal is
* probably blocked).
*/
if (sigismember(&tcb->sigwaitmask, info->siginfo->si_signo) && !info->atcb)
{
/* Yes.. This means that the task is suspended, waiting for this
* signal to occur. Stop looking and use this TCB. The
* requirement is this: If a task group receives a signal and
* more than one thread is waiting on that signal, then one and
* only one indeterminate thread out of that waiting group will
* receive the signal.
*/
ret = sig_tcbdispatch(tcb, info->siginfo);
if (ret < 0)
{
return ret;
}
/* Limit to one thread */
info->atcb = tcb;
if (info->ptcb != NULL);
{
return 1; /* Terminate the search */
}
}
/* Is this signal unblocked on this thread? */
if (!sigismember(&tcb->sigprocmask, info->siginfo->si_signo) &&
!info->ptcb && tcb != info->atcb)
{
/* Yes.. remember this TCB if we have not encountered any
* other threads that have the signal unblocked.
*/
if (!info->utcb)
{
info->utcb = tcb;
}
/* Is there also an action associated with the task? */
sigact = sig_findaction(tcb, info->siginfo->si_signo);
if (sigact)
{
/* Yes.. then use this thread. The requirement is this:
* If a task group receives a signal then one and only one
* indeterminate thread in the task group which is not
* blocking the signal will receive the signal.
*/
ret = sig_tcbdispatch(tcb, info->siginfo);
if (ret < 0)
{
return ret;
}
/* Limit to one thread */
info->ptcb = tcb;
if (info->atcb != NULL)
{
return 1; /* Terminate the search */
}
}
}
}
return 0; /* Keep searching */
}
int group_signal(FAR struct task_group_s *group, FAR siginfo_t *siginfo)
{
#ifdef HAVE_GROUP_MEMBERS
struct group_signal_s info;
FAR struct tcb_s *tcb;
int ret;
DEBUGASSERT(group && siginfo);
info.siginfo = siginfo;
info.dtcb = NULL; /* Default, valid TCB */
info.utcb = NULL; /* TCB with this signal unblocked */
info.atcb = NULL; /* This TCB was awakened */
info.ptcb = NULL; /* This TCB received the signal */
/* Make sure that pre-emption is disabled to that we signal all of the
* members of the group before any of them actually run. (This does
* nothing if were were called from an interrupt handler).
*/
sched_lock();
/* Now visit each member of the group and perform signal handling checks. */
ret = group_foreachchild(group, group_signal_handler, &info);
if (ret < 0)
{
goto errout;
}
/* We need to dispatch the signal in any event (if nothing else so that it
* can be added to the pending signal list). If we found a thread with the
* signal unblocked, then use that thread.
*/
if (info.atcb == NULL && info.ptcb == NULL)
{
if (info.utcb)
{
tcb = info.utcb;
}
/* Otherwise use the default TCB. There should always be a default
* TCB. It will have the signal blocked, but can be used to get the
* signal to a pending state.
*/
else /* if (info.dtcb) */
{
DEBUGASSERT(info.dtcb);
tcb = info.dtcb;
}
/* Now deliver the signal to the selected group member */
ret = sig_tcbdispatch(tcb, siginfo);
}
errout:
sched_unlock();
return ret;
#else
return -ENOSYS;
#endif
}
