incubator-nuttx/sched/group/group_create.c

287 lines
8.5 KiB
C

/****************************************************************************
* sched/group/group_create.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 <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/kmalloc.h>
#include <nuttx/semaphore.h>
#include <nuttx/sched.h>
#include "environ/environ.h"
#include "sched/sched.h"
#include "group/group.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Is this worth making a configuration option? */
#define GROUP_INITIAL_MEMBERS 4
/****************************************************************************
* Public Data
****************************************************************************/
#if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_ARCH_ADDRENV)
/* This is the head of a list of all group members */
FAR struct task_group_s *g_grouphead;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: group_inherit_identity
*
* Description:
* All inherit the user identity from the parent task group.
*
* Input Parameters:
* group - The new task group.
*
* Returned Value:
* None
*
* Assumptions:
* The parent of the new task is the task at the head of the assigned task
* list for the current CPU.
*
****************************************************************************/
#ifdef CONFIG_SCHED_USER_IDENTITY
static inline void group_inherit_identity(FAR struct task_group_s *group)
{
FAR struct tcb_s *rtcb = this_task();
FAR struct task_group_s *rgroup = rtcb->group;
/* Inherit the user identity from the parent task group. */
DEBUGASSERT(group != NULL);
group->tg_uid = rgroup->tg_uid;
group->tg_gid = rgroup->tg_gid;
}
#else
# define group_inherit_identity(group)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_allocate
*
* Description:
* Create and a new task group structure for the specified TCB. This
* function is called as part of the task creation sequence. The structure
* allocated and zeroed, but otherwise uninitialized. The full creation
* of the group of a two step process: (1) First, this function allocates
* group structure early in the task creation sequence in order to provide
* a group container, then (2) group_initialize() is called to set up the
* group membership.
*
* Input Parameters:
* tcb - The tcb in need of the task group.
* ttype - Type of the thread that is the parent of the group
*
* Returned Value:
* 0 (OK) on success; a negated errno value on failure.
*
* Assumptions:
* Called during task creation in a safe context. No special precautions
* are required here.
*
****************************************************************************/
int group_allocate(FAR struct task_tcb_s *tcb, uint8_t ttype)
{
FAR struct task_group_s *group;
int ret;
DEBUGASSERT(tcb && !tcb->cmn.group);
/* Allocate the group structure and assign it to the TCB */
group = (FAR struct task_group_s *)kmm_zalloc(sizeof(struct task_group_s));
if (!group)
{
return -ENOMEM;
}
#if defined(CONFIG_FILE_STREAM) && defined(CONFIG_MM_KERNEL_HEAP)
/* If this group is being created for a privileged thread, then all
* elements of the group must be created for privileged access.
*/
if ((ttype & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL)
{
group->tg_flags |= GROUP_FLAG_PRIVILEGED;
}
/* In a flat, single-heap build. The stream list is allocated with the
* group structure. But in a kernel build with a kernel allocator, it
* must be separately allocated using a user-space allocator.
*
* REVISIT: Kernel threads should not require a stream allocation. They
* should not be using C buffered I/O at all.
*/
group->tg_streamlist = (FAR struct streamlist *)
group_zalloc(group, sizeof(struct streamlist));
if (!group->tg_streamlist)
{
kmm_free(group);
return -ENOMEM;
}
#endif
/* Attach the group to the TCB */
tcb->cmn.group = group;
/* Inherit the user identity from the parent task group */
group_inherit_identity(group);
/* Duplicate the parent tasks environment */
ret = env_dup(group);
if (ret < 0)
{
#if defined(CONFIG_FILE_STREAM) && defined(CONFIG_MM_KERNEL_HEAP)
group_free(group, group->tg_streamlist);
#endif
kmm_free(group);
tcb->cmn.group = NULL;
return ret;
}
#ifndef CONFIG_DISABLE_PTHREAD
/* Initialize the pthread join semaphore */
nxsem_init(&group->tg_joinsem, 0, 1);
#endif
#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT)
/* Initialize the exit/wait semaphores
*
* This semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
nxsem_init(&group->tg_exitsem, 0, 0);
nxsem_set_protocol(&group->tg_exitsem, SEM_PRIO_NONE);
#endif
return OK;
}
/****************************************************************************
* Name: group_initialize
*
* Description:
* Add the task as the initial member of the group. The full creation of
* the group of a two step process: (1) First, this group structure is
* allocated by group_allocate() early in the task creation sequence, then
* (2) this function is called to set up the initial group membership.
*
* Input Parameters:
* tcb - The tcb in need of the task group.
*
* Returned Value:
* 0 (OK) on success; a negated errno value on failure.
*
* Assumptions:
* Called during task creation in a safe context. No special precautions
* are required here.
*
****************************************************************************/
int group_initialize(FAR struct task_tcb_s *tcb)
{
FAR struct task_group_s *group;
#if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_ARCH_ADDRENV)
irqstate_t flags;
#endif
DEBUGASSERT(tcb && tcb->cmn.group);
group = tcb->cmn.group;
#ifdef HAVE_GROUP_MEMBERS
/* Allocate space to hold GROUP_INITIAL_MEMBERS members of the group */
group->tg_members = kmm_malloc(GROUP_INITIAL_MEMBERS * sizeof(pid_t));
if (!group->tg_members)
{
kmm_free(group);
tcb->cmn.group = NULL;
return -ENOMEM;
}
/* Assign the PID of this new task as a member of the group. */
group->tg_members[0] = tcb->cmn.pid;
/* Initialize the non-zero elements of group structure and assign it to
* the tcb.
*/
group->tg_mxmembers = GROUP_INITIAL_MEMBERS; /* Number of members in allocation */
#endif
#if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_ARCH_ADDRENV)
/* Add the initialized entry to the list of groups */
flags = enter_critical_section();
group->flink = g_grouphead;
g_grouphead = group;
leave_critical_section(flags);
#endif
/* Save the ID of the main task within the group of threads. This needed
* for things like SIGCHLD. It ID is also saved in the TCB of the main
* task but is also retained in the group which may persist after the main
* task has exited.
*/
group->tg_pid = tcb->cmn.pid;
/* Mark that there is one member in the group, the main task */
group->tg_nmembers = 1;
return OK;
}