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/*
* Copyright (c) 2016 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/printer.h>
#include <rtems.h>
#include <rtems/seterr.h>
#include <unistd.h>
#define PRINT_TASK_WAKE_UP RTEMS_EVENT_0
typedef struct {
rtems_chain_node node;
enum {
ACTION_WRITE,
ACTION_DRAIN
} action_kind;
union {
size_t size;
rtems_id task;
} action_data;
char data[ RTEMS_ZERO_LENGTH_ARRAY ];
} printer_task_buffer;
static void printer_task_acquire(
rtems_printer_task_context *ctx,
rtems_interrupt_lock_context *lock_context
)
{
rtems_interrupt_lock_acquire( &ctx->lock, lock_context );
}
static void printer_task_release(
rtems_printer_task_context *ctx,
rtems_interrupt_lock_context *lock_context
)
{
rtems_interrupt_lock_release( &ctx->lock, lock_context );
}
static printer_task_buffer *printer_task_get_buffer(
rtems_printer_task_context *ctx,
rtems_chain_control *chain
)
{
rtems_interrupt_lock_context lock_context;
printer_task_buffer *buffer;
printer_task_acquire( ctx, &lock_context );
buffer = (printer_task_buffer *) rtems_chain_get_unprotected( chain );
printer_task_release( ctx, &lock_context );
return buffer;
}
static void printer_task_append_buffer(
rtems_printer_task_context *ctx,
rtems_chain_control *chain,
printer_task_buffer *buffer
)
{
rtems_interrupt_lock_context lock_context;
printer_task_acquire( ctx, &lock_context );
rtems_chain_append_unprotected( chain, &buffer->node );
printer_task_release( ctx, &lock_context );
}
static int printer_task_printer( void *context, const char *fmt, va_list ap )
{
rtems_printer_task_context *ctx;
printer_task_buffer *buffer;
int n;
ctx = context;
buffer = printer_task_get_buffer( ctx, &ctx->free_buffers );
if ( buffer == NULL ) {
rtems_set_errno_and_return_minus_one( ENOMEM );
}
n = vsnprintf( &buffer->data[ 0 ], ctx->buffer_size, fmt, ap );
if ( n >= (int) ctx->buffer_size ) {
printer_task_append_buffer( ctx, &ctx->free_buffers, buffer );
rtems_set_errno_and_return_minus_one( EINVAL );
}
buffer->action_kind = ACTION_WRITE;
buffer->action_data.size = (size_t) n;
printer_task_append_buffer( ctx, &ctx->todo_buffers, buffer );
rtems_event_send( ctx->task, PRINT_TASK_WAKE_UP );
return n;
}
static void printer_task( rtems_task_argument arg )
{
rtems_printer_task_context *ctx;
int fd;
ctx = (rtems_printer_task_context *) arg;
fd = ctx->fd;
while ( true ) {
rtems_event_set unused;
printer_task_buffer *buffer;
rtems_event_receive(
PRINT_TASK_WAKE_UP,
RTEMS_EVENT_ALL | RTEMS_WAIT,
RTEMS_NO_TIMEOUT,
&unused
);
while (
( buffer = printer_task_get_buffer( ctx, &ctx->todo_buffers ) ) != NULL
) {
switch ( buffer->action_kind ) {
case ACTION_WRITE:
write( fd, &buffer->data[ 0 ], buffer->action_data.size );
printer_task_append_buffer( ctx, &ctx->free_buffers, buffer );
break;
case ACTION_DRAIN:
fsync(fd);
rtems_event_transient_send( buffer->action_data.task );
break;
}
}
}
}
int rtems_print_printer_task(
rtems_printer *printer,
rtems_printer_task_context *ctx
)
{
rtems_status_code sc;
if ( ctx->buffer_size < sizeof( printer_task_buffer ) ) {
return EINVAL;
}
sc = rtems_task_create(
rtems_build_name( 'P', 'R', 'N', 'T'),
ctx->task_priority,
ctx->task_stack_size,
RTEMS_DEFAULT_MODES,
RTEMS_DEFAULT_ATTRIBUTES,
&ctx->task
);
if ( sc != RTEMS_SUCCESSFUL ) {
return ENOMEM;
}
rtems_chain_initialize_empty( &ctx->todo_buffers );
rtems_chain_initialize(
&ctx->free_buffers,
ctx->buffer_table,
ctx->buffer_count,
ctx->buffer_size
);
ctx->buffer_size -= sizeof( printer_task_buffer );
printer->context = ctx;
printer->printer = printer_task_printer;
rtems_task_start( ctx->task, printer_task, (rtems_task_argument) ctx );
return 0;
}
void rtems_printer_task_drain( rtems_printer_task_context *ctx )
{
printer_task_buffer buffer;
rtems_chain_initialize_node( &buffer.node );
buffer.action_kind = ACTION_DRAIN;
buffer.action_data.task = rtems_task_self();
printer_task_append_buffer( ctx, &ctx->todo_buffers, &buffer );
rtems_event_send( ctx->task, PRINT_TASK_WAKE_UP );
rtems_event_transient_receive( RTEMS_WAIT, RTEMS_NO_TIMEOUT );
}
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