277 lines
8.0 KiB
C
277 lines
8.0 KiB
C
/****************************************************************************
|
|
* sched/group/group_signal.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <sched.h>
|
|
#include <assert.h>
|
|
#include <signal.h>
|
|
#include <errno.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/signal.h>
|
|
|
|
#include "sched/sched.h"
|
|
#include "group/group.h"
|
|
#include "signal/signal.h"
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
#ifdef HAVE_GROUP_MEMBERS
|
|
struct group_signal_s
|
|
{
|
|
FAR siginfo_t *siginfo; /* Signal to be dispatched */
|
|
FAR struct tcb_s *dtcb; /* Default, valid TCB */
|
|
FAR struct tcb_s *utcb; /* TCB with this signal unblocked */
|
|
FAR struct tcb_s *atcb; /* This TCB was awakened */
|
|
FAR struct tcb_s *ptcb; /* This TCB received the signal */
|
|
};
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: group_signal_handler
|
|
*
|
|
* Description:
|
|
* Callback from group_foreachchild that handles one member of the group.
|
|
*
|
|
* Input Parameters:
|
|
* pid - The ID of the group member that may be signalled.
|
|
* arg - A pointer to a struct group_signal_s instance.
|
|
*
|
|
* Returned Value:
|
|
* 0 (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifdef HAVE_GROUP_MEMBERS
|
|
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;
|
|
|
|
/* Get the TCB associated with the group member */
|
|
|
|
tcb = nxsched_get_tcb(pid);
|
|
DEBUGASSERT(tcb != NULL && tcb->group != NULL && info != NULL);
|
|
|
|
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).
|
|
*/
|
|
|
|
ret = nxsig_ismember(&tcb->sigwaitmask, info->siginfo->si_signo);
|
|
if (ret == 1 && !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 = nxsig_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 (!nxsig_ismember(&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 a action associated with the task group? */
|
|
|
|
sigact = nxsig_find_action(tcb->group, 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 = nxsig_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 */
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: group_signal
|
|
*
|
|
* Description:
|
|
* Send a signal to every member of the group.
|
|
*
|
|
* Input Parameters:
|
|
* group - The task group that needs to be signalled.
|
|
*
|
|
* Returned Value:
|
|
* 0 (OK) on success; a negated errno value on failure.
|
|
*
|
|
* Assumptions:
|
|
* Called during task termination in a safe context. No special precautions
|
|
* are required here. Because signals can be sent from interrupt handlers,
|
|
* this function may be called indirectly in the context of an interrupt
|
|
* handler.
|
|
*
|
|
****************************************************************************/
|
|
|
|
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).
|
|
*/
|
|
|
|
#ifdef CONFIG_SMP
|
|
irqstate_t flags = enter_critical_section();
|
|
#else
|
|
sched_lock();
|
|
#endif
|
|
|
|
/* 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)
|
|
{
|
|
tcb = info.dtcb;
|
|
}
|
|
else
|
|
{
|
|
ret = -ECHILD;
|
|
goto errout;
|
|
}
|
|
|
|
/* Now deliver the signal to the selected group member */
|
|
|
|
ret = nxsig_tcbdispatch(tcb, siginfo);
|
|
}
|
|
|
|
errout:
|
|
#ifdef CONFIG_SMP
|
|
leave_critical_section(flags);
|
|
#else
|
|
sched_unlock();
|
|
#endif
|
|
return ret;
|
|
|
|
#else
|
|
|
|
return -ENOSYS;
|
|
|
|
#endif
|
|
}
|