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- /****************************************************************************
- * sched/group/group_join.c
- *
- * Copyright (C) 2013, 2016 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sched.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/irq.h>
- #include <nuttx/kmalloc.h>
- #include "sched/sched.h"
- #include "group/group.h"
- #include "environ/environ.h"
- #if defined(HAVE_TASK_GROUP) && !defined(CONFIG_DISABLE_PTHREAD)
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* Is this worth making a configuration option? */
- #define GROUP_REALLOC_MEMBERS 4
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: group_addmember
- *
- * Description:
- * Add a new member to a group.
- *
- * Input Parameters:
- * group - The task group to add the new member
- * pid - The new member
- *
- * Returned Value:
- * 0 (OK) on success; a negated errno value on failure.
- *
- * Assumptions:
- * Called during thread creation and during reparenting in a safe context.
- * No special precautions are required here.
- *
- ****************************************************************************/
- #ifdef HAVE_GROUP_MEMBERS
- static inline int group_addmember(FAR struct task_group_s *group, pid_t pid)
- {
- irqstate_t flags;
- DEBUGASSERT(group && group->tg_nmembers < UINT8_MAX);
- /* Will we need to extend the size of the array of groups? */
- if (group->tg_nmembers >= group->tg_mxmembers)
- {
- FAR pid_t *newmembers;
- unsigned int newmax;
- /* Yes... reallocate the array of members */
- newmax = group->tg_mxmembers + GROUP_REALLOC_MEMBERS;
- if (newmax > UINT8_MAX)
- {
- newmax = UINT8_MAX;
- }
- newmembers = (FAR pid_t *)
- kmm_realloc(group->tg_members, sizeof(pid_t) * newmax);
- if (!newmembers)
- {
- serr("ERROR: Failed to reallocate tg_members\n");
- return -ENOMEM;
- }
- /* Save the new number of members in the reallocated members array.
- * We need to make the following atomic because the member list
- * may be traversed from an interrupt handler (read-only).
- */
- flags = enter_critical_section();
- group->tg_members = newmembers;
- group->tg_mxmembers = newmax;
- leave_critical_section(flags);
- }
- /* Assign this new pid to the group; group->tg_nmembers will be incremented
- * by the caller.
- */
- group->tg_members[group->tg_nmembers] = pid;
- return OK;
- }
- #endif /* HAVE_GROUP_MEMBERS */
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: group_bind
- *
- * Description:
- * A thread joins the group when it is created. This is a two step process,
- * first, the group must bound to the new threads TCB. group_bind() does
- * this (at the return from group_join, things are a little unstable: The
- * group has been bound, but tg_nmembers has not yet been incremented).
- * Then, after the new thread is initialized and has a PID assigned to it,
- * group_join() is called, incrementing the tg_nmembers count on the group.
- *
- * Input Parameters:
- * tcb - The TCB of the new "child" task that need to join the group.
- *
- * Returned Value:
- * 0 (OK) on success; a negated errno value on failure.
- *
- * Assumptions:
- * - The parent task from which the group will be inherited is the task at
- * the head of the ready to run list.
- * - Called during thread creation in a safe context. No special precautions
- * are required here.
- *
- ****************************************************************************/
- int group_bind(FAR struct pthread_tcb_s *tcb)
- {
- FAR struct tcb_s *ptcb = this_task();
- DEBUGASSERT(ptcb && tcb && ptcb->group && !tcb->cmn.group);
- /* Copy the group reference from the parent to the child */
- tcb->cmn.group = ptcb->group;
- return OK;
- }
- /****************************************************************************
- * Name: group_join
- *
- * Description:
- * A thread joins the group when it is created. This is a two step process,
- * first, the group must bound to the new threads TCB. group_bind() does
- * this (at the return from group_join, things are a little unstable: The
- * group has been bound, but tg_nmembers has not yet been incremented).
- * Then, after the new thread is initialized and has a PID assigned to it,
- * group_join() is called, incrementing the tg_nmembers count on the group.
- *
- * Input Parameters:
- * tcb - The TCB of the new "child" task that need to join the group.
- *
- * Returned Value:
- * 0 (OK) on success; a negated errno value on failure.
- *
- * Assumptions:
- * - The parent task from which the group will be inherited is the task at
- * the head of the ready to run list.
- * - Called during thread creation in a safe context. No special precautions
- * are required here.
- *
- ****************************************************************************/
- int group_join(FAR struct pthread_tcb_s *tcb)
- {
- FAR struct task_group_s *group;
- #ifdef HAVE_GROUP_MEMBERS
- int ret;
- #endif
- DEBUGASSERT(tcb && tcb->cmn.group &&
- tcb->cmn.group->tg_nmembers < UINT8_MAX);
- /* Get the group from the TCB */
- group = tcb->cmn.group;
- #ifdef HAVE_GROUP_MEMBERS
- /* Add the member to the group */
- ret = group_addmember(group, tcb->cmn.pid);
- if (ret < 0)
- {
- return ret;
- }
- #endif
- group->tg_nmembers++;
- return OK;
- }
- #endif /* HAVE_TASK_GROUP && !CONFIG_DISABLE_PTHREAD */
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