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/* -*- Mode: C ; c-basic-offset: 2 -*- */
/*
* LADI Session Handler (ladish)
*
* Copyright (C) 2009,2010,2011 Nedko Arnaudov <nedko@arnaudov.name>
*
**************************************************************************
* This file contains interface to the command queue
**************************************************************************
*
* LADI Session Handler is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* LADI Session Handler is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
* or write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "cmd.h"
#include "control.h"
void ladish_cqueue_init(struct ladish_cqueue * queue_ptr)
{
queue_ptr->cancel = false;
INIT_LIST_HEAD(&queue_ptr->queue);
}
void ladish_cqueue_run(struct ladish_cqueue * queue_ptr)
{
struct list_head * node_ptr;
struct ladish_command * cmd_ptr;
loop:
if (list_empty(&queue_ptr->queue))
{
return;
}
node_ptr = queue_ptr->queue.next;
cmd_ptr = list_entry(node_ptr, struct ladish_command, siblings);
ASSERT(cmd_ptr->run != NULL);
ASSERT(cmd_ptr->state == LADISH_COMMAND_STATE_PENDING || cmd_ptr->state == LADISH_COMMAND_STATE_WAITING);
if (cmd_ptr->state == LADISH_COMMAND_STATE_PENDING)
{ /* if this is a new command, put a separator so its impact is clearly visible in the log */
log_info("-------");
}
if (!cmd_ptr->run(cmd_ptr->context))
{
ladish_cqueue_clear(queue_ptr);
emit_queue_execution_halted();
return;
}
switch (cmd_ptr->state)
{
case LADISH_COMMAND_STATE_DONE:
break;
case LADISH_COMMAND_STATE_WAITING:
return;
default:
log_error("unexpected cmd state %u after run()", cmd_ptr->state);
ASSERT_NO_PASS;
ladish_cqueue_clear(queue_ptr);
emit_queue_execution_halted();
return;
}
list_del(node_ptr);
if (cmd_ptr->destructor != NULL)
{
cmd_ptr->destructor(cmd_ptr->context);
}
free(cmd_ptr);
if (queue_ptr->cancel && list_empty(&queue_ptr->queue))
{
queue_ptr->cancel = false;
}
goto loop;
}
void ladish_cqueue_cancel(struct ladish_cqueue * queue_ptr)
{
struct list_head * node_ptr;
struct ladish_command * cmd_ptr;
if (list_empty(&queue_ptr->queue))
{ /* nothing to cancel */
return;
}
node_ptr = queue_ptr->queue.next; /* current command */
cmd_ptr = list_entry(node_ptr, struct ladish_command, siblings);
if (cmd_ptr->state != LADISH_COMMAND_STATE_WAITING)
{
ladish_cqueue_clear(queue_ptr);
return;
}
/* clear all commands except currently waiting one */
while (queue_ptr->queue.next != queue_ptr->queue.prev)
{
node_ptr = queue_ptr->queue.prev;
list_del(node_ptr);
cmd_ptr = list_entry(node_ptr, struct ladish_command, siblings);
if (cmd_ptr->destructor != NULL)
{
cmd_ptr->destructor(cmd_ptr->context);
}
free(cmd_ptr);
}
queue_ptr->cancel = true;
cmd_ptr->cancel = true;
}
bool ladish_cqueue_add_command(struct ladish_cqueue * queue_ptr, struct ladish_command * cmd_ptr)
{
ASSERT(cmd_ptr->run != NULL);
if (queue_ptr->cancel)
{
return false;
}
ASSERT(cmd_ptr->state == LADISH_COMMAND_STATE_PREPARE);
cmd_ptr->state = LADISH_COMMAND_STATE_PENDING;
list_add_tail(&cmd_ptr->siblings, &queue_ptr->queue);
return true;
}
void ladish_cqueue_clear(struct ladish_cqueue * queue_ptr)
{
struct list_head * node_ptr;
struct ladish_command * cmd_ptr;
while (!list_empty(&queue_ptr->queue))
{
node_ptr = queue_ptr->queue.next;
list_del(node_ptr);
cmd_ptr = list_entry(node_ptr, struct ladish_command, siblings);
if (cmd_ptr->destructor != NULL)
{
cmd_ptr->destructor(cmd_ptr->context);
}
free(cmd_ptr);
}
queue_ptr->cancel = false;
}
void ladish_cqueue_drop_command(struct ladish_cqueue * queue_ptr)
{
struct list_head * node_ptr;
struct ladish_command * cmd_ptr;
ASSERT(!list_empty(&queue_ptr->queue)); /* there is nothing to drop */
/* remove the last command from the queue */
node_ptr = queue_ptr->queue.prev;
list_del(node_ptr);
cmd_ptr = list_entry(node_ptr, struct ladish_command, siblings);
ASSERT(cmd_ptr->run != NULL);
/* waiting commands are not supposed to be dropped */
/* commands that are not yet prepared and those that are already processed are not supposed to be in the queue */
ASSERT(cmd_ptr->state == LADISH_COMMAND_STATE_PENDING);
if (cmd_ptr->destructor != NULL)
{
cmd_ptr->destructor(cmd_ptr->context);
}
free(cmd_ptr);
}
void * ladish_command_new(size_t size)
{
struct ladish_command * cmd_ptr;
ASSERT(size >= sizeof(struct ladish_command));
cmd_ptr = malloc(size);
if (cmd_ptr == NULL)
{
log_error("malloc failed to allocate command with size %zu", size);
return NULL;
}
cmd_ptr->state = LADISH_COMMAND_STATE_PREPARE;
cmd_ptr->cancel = false;
cmd_ptr->context = cmd_ptr;
cmd_ptr->run = NULL;
cmd_ptr->destructor = NULL;
return cmd_ptr;
}
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