forked from Archive/PX4-Autopilot
116 lines
3.8 KiB
C
116 lines
3.8 KiB
C
/****************************************************************************
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* sched/env_share.c
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*
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* Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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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 <sched.h>
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#include <errno.h>
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#include "os_internal.h"
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#include "env_internal.h"
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Function: env_share
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*
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* Description:
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* Increment the reference count on the internal environment structure of
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* a task. This is the action that is performed when a new pthread is
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* created: The new pthread shares the environment with its parent.
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*
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* Parameters:
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* ptcb The new TCB to receive the shared environment.
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*
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* Return Value:
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* A pointer to a specified TCB's environment structure with an incremented
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* reference count.
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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_share(FAR _TCB *ptcb)
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{
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int ret = OK;
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if (!ptcb)
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{
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ret = -EINVAL;
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}
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else
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{
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FAR _TCB *parent = (FAR _TCB*)g_readytorun.head;
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environ_t *envp = parent->envp;
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/* Pre-emption must be disabled throughout the following because the
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* environment is 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 (envp)
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{
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/* Yes.. increment the reference count on the environment */
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envp->ev_crefs++;
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}
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/* Then share the environment */
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ptcb->envp = envp;
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sched_unlock();
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}
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return ret;
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}
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#endif /* CONFIG_DISABLE_ENVIRON */
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