command.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * \brief Stasis application command support.
 *
 * \author David M. Lee, II <dlee@digium.com>
 */
 
#include "asterisk.h"
 
#include "command.h"
 
#include "asterisk/lock.h"
#include "asterisk/stasis_app_impl.h"
 
struct stasis_app_command {
    ast_mutex_t lock;
    ast_cond_t condition;
    stasis_app_command_cb callback;
    void *data;
    command_data_destructor_fn data_destructor;
    int retval;
    unsigned int is_done:1;
};
 
static void command_dtor(void *obj)
{
    struct stasis_app_command *command = obj;
 
    if (command->data_destructor) {
        command->data_destructor(command->data);
    }
 
    ast_mutex_destroy(&command->lock);
    ast_cond_destroy(&command->condition);
}
 
struct stasis_app_command *command_create(
    stasis_app_command_cb callback, void *data, command_data_destructor_fn data_destructor)
{
    struct stasis_app_command *command;
 
    command = ao2_alloc(sizeof(*command), command_dtor);
    if (!command) {
        if (data_destructor) {
            data_destructor(data);
        }
        return NULL;
    }
 
    ast_mutex_init(&command->lock);
    ast_cond_init(&command->condition, 0);
    command->callback = callback;
    command->data = data;
    command->data_destructor = data_destructor;
 
    return command;
}
 
void command_complete(struct stasis_app_command *command, int retval)
{
    ast_mutex_lock(&command->lock);
    command->is_done = 1;
    command->retval = retval;
    ast_cond_signal(&command->condition);
    ast_mutex_unlock(&command->lock);
}
 
int command_join(struct stasis_app_command *command)
{
    int ret;
 
    ast_mutex_lock(&command->lock);
    while (!command->is_done) {
        ast_cond_wait(&command->condition, &command->lock);
    }
 
    ret = command->retval;
    ast_mutex_unlock(&command->lock);
 
    return ret;
}
 
void command_invoke(struct stasis_app_command *command,
    struct stasis_app_control *control, struct ast_channel *chan)
{
    int retval = command->callback(control, chan, command->data);
    if (command->data_destructor) {
        command->data_destructor(command->data);
        command->data_destructor = NULL;
    }
    command_complete(command, retval);
}
 
static void command_queue_prestart_destroy(void *obj)
{
    /* Clean up the container */
    ao2_cleanup(obj);
}
 
static const struct ast_datastore_info command_queue_prestart = {
    .type = "stasis-command-prestart-queue",
    .destroy = command_queue_prestart_destroy,
};
 
int command_prestart_queue_command(struct ast_channel *chan,
    stasis_app_command_cb command_fn, void *data, command_data_destructor_fn data_destructor)
{
    struct ast_datastore *datastore;
    struct ao2_container *command_queue;
    RAII_VAR(struct stasis_app_command *, command,
        command_create(command_fn, data, data_destructor), ao2_cleanup);
 
    if (!command) {
        return -1;
    }
 
    datastore = ast_channel_datastore_find(chan, &command_queue_prestart, NULL);
    if (datastore) {
        command_queue = datastore->data;
        ao2_link(command_queue, command);
        return 0;
    }
 
    command_queue = ao2_container_alloc_list(AO2_ALLOC_OPT_LOCK_MUTEX, 0, NULL, NULL);
    if (!command_queue) {
        return -1;
    }
 
    datastore = ast_datastore_alloc(&command_queue_prestart, NULL);
    if (!datastore) {
        ao2_cleanup(command_queue);
        return -1;
    }
    ast_channel_datastore_add(chan, datastore);
 
    datastore->data = command_queue;
    ao2_link(command_queue, command);
 
    return 0;
}
 
struct ao2_container *command_prestart_get_container(struct ast_channel *chan)
{
    struct ast_datastore *datastore = ast_channel_datastore_find(chan, &command_queue_prestart, NULL);
 
    if (!datastore) {
        return NULL;
    }
 
    return ao2_bump(datastore->data);
}