nuttx/drivers/syslog/syslog_putc.c

141 lines
4.1 KiB
C
Raw Normal View History

/****************************************************************************
* drivers/syslog/syslog_putc.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 <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)
{
int i;
/* 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().
*/
for (i = 0; i < CONFIG_SYSLOG_MAX_CHANNELS; i++)
{
FAR struct syslog_channel_s *channel = g_syslog_channel[i];
if (channel == NULL)
{
break;
}
if (channel->sc_ops->sc_force != NULL)
{
channel->sc_ops->sc_force(channel, ch);
}
else
{
char tmp = ch;
DEBUGASSERT(channel->sc_ops->sc_write_force != NULL);
channel->sc_ops->sc_write_force(channel, &tmp, 1);
}
}
}
}
else
{
#ifdef CONFIG_SYSLOG_INTBUFFER
/* Flush any characters that may have been added to the interrupt
* buffer.
*/
syslog_flush_intbuffer(false);
#endif
for (i = 0; i < CONFIG_SYSLOG_MAX_CHANNELS; i++)
{
FAR struct syslog_channel_s *channel = g_syslog_channel[i];
if (channel == NULL)
{
break;
}
if (channel->sc_ops->sc_putc != NULL)
{
channel->sc_ops->sc_putc(channel, ch);
}
else
{
char tmp = ch;
DEBUGASSERT(channel->sc_ops->sc_write != NULL);
channel->sc_ops->sc_write(channel, &tmp, 1);
}
}
}
return ch;
}