nuttx/drivers/syslog/syslog_putc.c
Xiang Xiao efd1b838e6 syslog: Add sc_write_force callback
It is used to write the log message to the channel immediately
when the log message is generated in the interrupt context, which
is faster than the normal force callback.

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2023-06-23 09:55:19 -03:00

141 lines
4.1 KiB
C

/****************************************************************************
* 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;
}