16e8906ed5
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@141 42af7a65-404d-4744-a932-0658087f49c3
105 lines
3.4 KiB
C
105 lines
3.4 KiB
C
/************************************************************
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* get_errno_ptr.c
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*
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* Copyright (C) 2007 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 Gregory Nutt 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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#include <sched.h>
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#include <errno.h>
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#include <nuttx/arch.h>
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#include "os_internal.h"
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#undef get_errno_ptr
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/************************************************************
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* Private Data
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************************************************************/
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static int g_irqerrno;
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/************************************************************
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* Public Functions
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************************************************************/
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/************************************************************
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* Function: get_errno_ptr
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*
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* Description:
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* Return a pointer to the thread specific errno.
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*
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* Parameters:
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* None
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*
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* Return Value:
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* A pointer to the per-thread errno variable.
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*
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* Assumptions:
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*
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************************************************************/
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FAR int *get_errno_ptr(void)
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{
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/* Check if this function was called from an interrupt
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* handler. In that case, we have to do things a little
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* differently.
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*/
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if (up_interrupt_context())
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{
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/* Yes, we were called from an interrupt handler. Do
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* not permit access to the errno in the TCB of the
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* interrupt task. Instead, use a separate errno just
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* for interrupt handlers. Of course, this would have
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* to change if we ever wanted to support nested
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* interrupts.
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*/
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return &g_irqerrno;
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}
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else
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{
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/* We were called from the normal tasking context. Return
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* a reference to the thread-private errno in the TCB.
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*/
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FAR _TCB *ptcb = (FAR _TCB*)g_readytorun.head;
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return &ptcb->errno;
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}
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}
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