/**
* mds — A micro-display server
* Copyright © 2014, 2015, 2016, 2017 Mattias Andrée (maandree@kth.se)
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MDS_MDS_REGISTRY_SLAVE_H
#define MDS_MDS_REGISTRY_SLAVE_H
#include <libmdsserver/hash-table.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <pthread.h>
#include <time.h>
#include <signal.h>
#define SLAVE_T_VERSION 0
/**
* Slave information, a thread waiting for protocols to become available
*/
typedef struct slave
{
/**
* Set of protocols for which to wait that they become available
*/
hash_table_t *wait_set;
/**
* The ID of the waiting client
*/
uint64_t client;
/**
* The ID of the waiting client
*/
char *client_id;
/**
* The ID of the message that triggered the waiting
*/
char *message_id;
/**
* The slave's node in the linked list of slaves
*/
ssize_t node;
/**
* Whether the client has been closed
*/
volatile sig_atomic_t closed;
/**
* The slave thread
*/
pthread_t thread;
/**
* The time slave should die if its condition
* has not be meet at that time
*/
struct timespec dethklok;
/**
* Whether `dethklok` should apply
*/
int timed;
} slave_t;
/**
* Start a slave thread with an already created slave
*
* @param slave The slave
* @return Non-zero on error, `errno` will be set accordingly
*/
__attribute__((nonnull))
int start_created_slave(slave_t *restrict slave);
/**
* Start a slave thread
*
* @param wait_set Set of protocols for which to wait that they become available
* @param recv_client_id The ID of the waiting client
* @param recv_message_id The ID of the message that triggered the waiting
* @return Non-zero on error
*/
__attribute__((nonnull))
int start_slave(hash_table_t *restrict wait_set, const char *restrict recv_client_id,
const char *restrict recv_message_id);
/**
* Close all slaves associated with a client
*
* @param client The client's ID
*/
void close_slaves(uint64_t client);
/**
* Notify slaves that a protocol has become available
*
* @param command The protocol
* @return Non-zero on error, `ernno`will be set accordingly
*/
__attribute__((nonnull))
int advance_slaves(char *command);
/**
* Create a slave
*
* @param wait_set Set of protocols for which to wait that they become available
* @param recv_client_id The ID of the waiting client
* @param recv_message_id The ID of the message that triggered the waiting
* @return The slave, `NULL` on error, `errno` will be set accordingly
*/
__attribute__((nonnull))
slave_t *slave_create(hash_table_t *restrict wait_set, const char *restrict recv_client_id,
const char *restrict recv_message_id);
/**
* Initialise a slave
*
* @param this Memory slot in which to store the new slave information
*/
__attribute__((nonnull))
void slave_initialise(slave_t *restrict this);
/**
* Release all resources assoicated with a slave
*
* @param this The slave information
*/
void slave_destroy(slave_t *restrict this);
/**
* Calculate the buffer size need to marshal slave information
*
* @param this The slave information
* @return The number of bytes to allocate to the output buffer
*/
__attribute__((pure, nonnull))
size_t slave_marshal_size(const slave_t *restrict this);
/**
* Marshals slave information
*
* @param this The slave information
* @param data Output buffer for the marshalled data
* @return The number of bytes that have been written (everything will be written)
*/
__attribute__((nonnull))
size_t slave_marshal(const slave_t *restrict this, char *restrict data);
/**
* Unmarshals slave information
*
* @param this Memory slot in which to store the new slave information
* @param data In buffer with the marshalled data
* @return Zero on error, `errno` will be set accordingly, otherwise the
* number of read bytes. Destroy the slave information on error.
*/
__attribute__((nonnull))
size_t slave_unmarshal(slave_t *restrict this, char *restrict data);
/**
* Pretend to unmarshal slave information
*
* @param data In buffer with the marshalled data
* @return The number of read bytes
*/
__attribute__((pure, nonnull))
size_t slave_unmarshal_skip(char *restrict data);
#endif
