incubator-nuttx/drivers/syslog/syslog_putc.c

116 lines
4.0 KiB
C

/****************************************************************************
* drivers/syslog/syslog_putc.c
*
* Copyright (C) 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 <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include <nuttx/syslog/syslog.h>
#include "syslog.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: syslog_putc
*
* Description:
* This is the low-level system logging interface.
*
* Input Parameters:
* ch - The character to add to the SYSLOG (must be positive).
*
* Returned Value:
* On success, the character is echoed back to the caller. A negated
* errno value is returned on any failure.
*
****************************************************************************/
int syslog_putc(int ch)
{
DEBUGASSERT(g_syslog_channel != NULL);
/* Is this an attempt to do SYSLOG output from an interrupt handler? */
if (up_interrupt_context() || sched_idletask())
{
#if defined(CONFIG_SYSLOG_INTBUFFER)
if (up_interrupt_context())
{
/* Buffer the character in the interrupt buffer. The interrupt buffer
* will be flushed before the next normal, non-interrupt SYSLOG output.
*/
return syslog_add_intbuffer(ch);
}
else
#endif
{
/* Force the character to the SYSLOG device immediately (if possible).
* This means that the interrupt data may not be in synchronization
* with output data that may have been buffered by sc_putc().
*/
DEBUGASSERT(g_syslog_channel->sc_force != NULL);
return g_syslog_channel->sc_force(ch);
}
}
else
{
DEBUGASSERT(g_syslog_channel->sc_putc != NULL);
#ifdef CONFIG_SYSLOG_INTBUFFER
/* Flush any characters that may have been added to the interrupt
* buffer.
*/
syslog_flush_intbuffer(g_syslog_channel, false);
#endif
return g_syslog_channel->sc_putc(ch);
}
}