125 lines
3.7 KiB
C
125 lines
3.7 KiB
C
/****************************************************************************
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* sched/environ/env_dup.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#ifndef CONFIG_DISABLE_ENVIRON
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#include <sys/types.h>
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#include <sched.h>
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#include <string.h>
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#include <errno.h>
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#include <nuttx/kmalloc.h>
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#include "sched/sched.h"
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#include "environ/environ.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: env_dup
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*
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* Description:
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* Copy the internal environment structure of a task. This is the action
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* that is performed when a new task is created: The new task has a
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* private, exact duplicate of the parent task's environment.
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*
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* Input Parameters:
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* group - The child task group to receive the newly allocated copy of the
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* parent task groups environment structure.
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*
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* Returned Value:
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* zero on success
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*
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* Assumptions:
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* Not called from an interrupt handler.
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*
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****************************************************************************/
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int env_dup(FAR struct task_group_s *group)
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{
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FAR struct tcb_s *ptcb = this_task();
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FAR char *envp = NULL;
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size_t envlen;
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int ret = OK;
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DEBUGASSERT(group != NULL && ptcb != NULL && ptcb->group != NULL);
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/* Pre-emption must be disabled throughout the following because the
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* environment may be shared.
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*/
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sched_lock();
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/* Does the parent task have an environment? */
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if (ptcb->group != NULL && ptcb->group->tg_envp != NULL)
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{
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/* Yes.. The parent task has an environment allocation. */
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envlen = ptcb->group->tg_envsize;
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envp = NULL;
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/* A special case is that the parent has an "empty" environment
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* allocation, i.e., there is an allocation in place but it
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* contains no variable definitions and, hence, envlen == 0.
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*/
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if (envlen > 0)
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{
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/* There is an environment, duplicate it */
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envp = (FAR char *)kumm_malloc(envlen);
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if (envp == NULL)
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{
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/* The parent's environment can not be inherited due to a
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* failure in the allocation of the child environment.
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*/
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envlen = 0;
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ret = -ENOMEM;
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}
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else
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{
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/* Duplicate the parent environment. */
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memcpy(envp, ptcb->group->tg_envp, envlen);
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}
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}
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/* Save the size and child environment allocation. */
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group->tg_envsize = envlen;
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group->tg_envp = envp;
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}
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sched_unlock();
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return ret;
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}
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#endif /* CONFIG_DISABLE_ENVIRON */
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