Mycorrhiza/src/myco-daemon.c

/* Copyright (C) 2016 Max Riechelmann <max.riechelmann@student.kit.edu>
   (Karlsruhe Institute of Technology)
   This library is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by the
   Free Software Foundation; either version 2.1 of the License, or (at your
   option) any later version.
   This library 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 Lesser General Public License for more
   details.
   You should have received a copy of the GNU Lesser General Public License along
   with this library; if not, write to the Free Software Foundation, Inc., 51
   Franklin St, Fifth Floor, Boston, MA 02110, USA
   */

#include "myco-daemon.h"
#include "../src/myco-memory.c"

#define DEBUG 1

myco_agent *first_agent = NULL;
myco_resource *first_resource = NULL;

myco_agent *myco_daemon_find_agent(const char *agent_name) {
    myco_agent *current_agent;
    current_agent = first_agent;
    while (current_agent != NULL) {
        if (strcmp(current_agent->name, agent_name) == 0) {
            return current_agent;
        }
        current_agent = current_agent->next;
    }
    return NULL;
}

int myco_daemon_register_agent(message msg) {
    myco_agent *current_agent;

    if (myco_daemon_find_agent(msg.agent_name) != NULL) {
        sprintf(msg.message, "ERROR: agent %s already exists\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    if (first_agent == NULL) {
        first_agent = malloc(sizeof(myco_agent));
        first_agent->next = NULL;
        first_agent->prev = NULL;
        sprintf(first_agent->name, "%s", msg.agent_name);
        first_agent->message_queue_id = msg.agent_message_queue_id;
    } else {
        current_agent = first_agent;
        while (current_agent->next != NULL) {
            current_agent = current_agent->next;
        }
        current_agent->next = malloc(sizeof(myco_agent));
        current_agent->next->prev = current_agent;
        current_agent->next->next = NULL;
        sprintf(current_agent->next->name, "%s", msg.agent_name);
        current_agent->next->message_queue_id = msg.agent_message_queue_id;
    }

    sprintf(msg.message, "SUCCESS: agent %s registered\n", msg.agent_name);
    myco_send(msg.agent_message_queue_id, msg);

    return 0;

}

int myco_daemon_unregister_agent(message msg) {
    myco_agent *current_agent;
    myco_resource *current_resource;

    current_agent = myco_daemon_find_agent(msg.agent_name);

    if ((current_resource = myco_daemon_find_resource_by_agent(msg.agent_name)) != NULL) {
        sprintf(msg.message, "ERROR: agent %s still has resource %s\n", msg.agent_name, current_resource->name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    if (current_agent == NULL) {
        sprintf(msg.message, "ERROR: agent %s could not be unregistered\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    // Element in the middle
    if (current_agent->next != NULL && current_agent->prev != NULL) {
        current_agent->prev->next = current_agent->next;
        current_agent->next->prev = current_agent->prev;
        free(current_agent);
        sprintf(msg.message, "SUCCESS: agent %s unregistered\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // First element
    if (current_agent->next != NULL && current_agent->prev == NULL) {
        first_agent = current_agent->next;
        current_agent->next->prev = NULL;
        free(current_agent);
        sprintf(msg.message, "SUCCESS: agent %s unregistered\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // Last element
    if (current_agent->next == NULL && current_agent->prev != NULL) {
        current_agent->prev->next = NULL;
        free(current_agent);
        sprintf(msg.message, "SUCCESS: agent %s unregistered\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // Only remaining
    if (current_agent->next == NULL && current_agent->prev == NULL) {
        first_agent = NULL;
        free(current_agent);
        sprintf(msg.message, "SUCCESS: agent %s unregistered\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    sprintf(msg.message, "ERROR: agent %s could not be unregistered - data structure seems to be damaged!\n", msg.agent_name);
    myco_send(msg.agent_message_queue_id, msg);

    return -1;
}

myco_resource *myco_daemon_find_resource_by_agent(const char *agent_name) {
    myco_resource *current_resource;
    current_resource = first_resource;
    while (current_resource != NULL) {
        if (strcmp(current_resource->agent, agent_name) == 0) {
            return current_resource;
        }
        current_resource = current_resource->next;
    }
    return NULL;
}

myco_resource *myco_daemon_find_resource(const char *resource_name) {
    myco_resource *current_resource;
    current_resource = first_resource;
    while (current_resource != NULL) {
        if (strcmp(current_resource->name, resource_name) == 0) {
            return current_resource;
        }
        current_resource = current_resource->next;
    }
    return NULL;
}

int myco_daemon_register_resource(message msg) {
    myco_resource *current_resource;

    if (myco_daemon_find_agent(msg.agent_name) == NULL) {
        sprintf(msg.message, "ERROR: agent %s does not exist\n", msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    if (myco_daemon_find_resource(msg.resource_name) != NULL) {
        sprintf(msg.message, "ERROR: resource %s already exists\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    // Insert as first element
    if (first_resource == NULL) {
        first_resource = malloc(sizeof(myco_resource));
        first_resource->next = NULL;
        first_resource->prev = NULL;
        sprintf(first_resource->name, "%s", msg.resource_name);
        sprintf(first_resource->agent, "%s", msg.agent_name);
        first_resource->pid = msg.sender_pid;
        first_resource->pointer = msg.resource_pointer;
        first_resource->size = msg.resource_size;
        first_resource->read_locked = 0;
        first_resource->transfer_locked = 1;
        first_resource->transactional = msg.resource_transactional;
        first_resource->version = 0;
    } else {
        // Insert as last element
        current_resource = first_resource;
        while (current_resource->next != NULL) {
            current_resource = current_resource->next;
        }
        current_resource->next = malloc(sizeof(myco_resource));
        current_resource->next->prev = current_resource;
        current_resource->next->next = NULL;
        sprintf(current_resource->next->name, "%s", msg.resource_name);
        sprintf(current_resource->next->agent, "%s", msg.agent_name);
        current_resource->next->pid = msg.sender_pid;
        current_resource->next->pointer = msg.resource_pointer;
        current_resource->next->size = msg.resource_size;
        current_resource->next->transfer_locked = 1;
        current_resource->next->read_locked = 0;
        current_resource->next->transactional = msg.resource_transactional;
        current_resource->next->version = 0;
    }

    sprintf(msg.message, "SUCCESS: resource %s registered\n", msg.resource_name);
    myco_send(msg.agent_message_queue_id, msg);

    return 0;
}

int myco_daemon_unregister_resource(message msg) {
    myco_resource *current_resource;

    current_resource = myco_daemon_find_resource(msg.resource_name);

    if (current_resource == NULL) {
        sprintf(msg.message, "ERROR: resource %s could not be unregistered\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return -1;
    }

    // Element in the middle
    if (current_resource->next != NULL && current_resource->prev != NULL) {
        current_resource->prev->next = current_resource->next;
        current_resource->next->prev = current_resource->prev;
        free(current_resource);
        sprintf(msg.message, "SUCCESS: resource %s unregistered\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // First element
    if (current_resource->next != NULL && current_resource->prev == NULL) {
        first_resource = current_resource->next;
        current_resource->next->prev = NULL;
        free(current_resource);
        sprintf(msg.message, "SUCCESS: resource %s unregistered\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // Last element
    if (current_resource->next == NULL && current_resource->prev != NULL) {
        current_resource->prev->next = NULL;
        free(current_resource);
        sprintf(msg.message, "SUCCESS: resource %s unregistered\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    // Only remaining
    if (current_resource->next == NULL && current_resource->prev == NULL) {
        first_resource = NULL;
        free(current_resource);
        sprintf(msg.message, "SUCCESS: resource %s unregistered\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);

        return 0;
    }

    sprintf(msg.message, "FATAL ERROR: resource %s could not be unregistered - data structure seems to be damaged!\n", msg.resource_name);
    myco_send(msg.agent_message_queue_id, msg);

    return -1;
}

int myco_daemon_request_resource(message msg) {
    myco_resource *current_resource;

    // Check if resource exists
    if ((current_resource = myco_daemon_find_resource(msg.resource_name)) == NULL) {
        sprintf(msg.message, "ERROR: resource %s does not exist\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }
    // Check if agent that requests already owns the resource
    if (strcmp(current_resource->agent, msg.agent_name) == 0) {
        sprintf(msg.message, "ERROR: resource %s already belongs to agent %s\n", msg.resource_name, msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }
    // Check if resource is transactional
    if (current_resource->transactional != RESOURCE_TRANSACTIONAL) {
        sprintf(msg.message, "ERROR: resource %s is not transactional\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }

    // TODO: Handle case where resource is on another node (another agent)

    // If on same node, send information
    msg.sender_pid = current_resource->pid; 
    msg.resource_size = current_resource->size;
    msg.resource_pointer = current_resource->pointer;
    sprintf(msg.message, "SUCCESS: resource found on same node, sending information\n");
    myco_send(msg.agent_message_queue_id, msg);

    msg = myco_receive(msg.agent_message_queue_id);
    if (strcmp(msg.message, "RESOURCE GRANTED") == 0) {
        // Transfer ownership of resource to agent
        sprintf(current_resource->agent, "%s", msg.agent_name);
        current_resource->pid = msg.sender_pid;
        current_resource->pointer = msg.resource_pointer;
    } else {
        fprintf(stderr, "ERROR: myco_daemon_request: %s\n", strerror(errno));
        return -1;
    }

    return 0;
}

int myco_daemon_request_list(message msg, pid_t pid) {
    myco_resource *current_resource;
    current_resource = first_resource;
    char *resource_pointer;
    char tmp[64];
    int resource_size = 0;
    if (current_resource == NULL) {
        sprintf(msg.message, "ERROR: no resources\n");
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }
    while (current_resource != NULL) {
        resource_size += strlen(current_resource->name) + strlen(current_resource->agent) + strlen("1");
        resource_size += strlen("(,,,);");
        resource_size += 22;
        current_resource = current_resource->next;
    }

    resource_pointer = malloc(resource_size);
    memset(resource_pointer, 0, resource_size);

    current_resource = first_resource;
    while (current_resource != NULL) {
        strcat(resource_pointer, current_resource->name);
        strcat(resource_pointer, "(");
        strcat(resource_pointer, current_resource->agent);
        strcat(resource_pointer, ",");
        sprintf(tmp, "%d", current_resource->size);
        strcat(resource_pointer, tmp);
        strcat(resource_pointer, ",");
        sprintf(tmp, "%p", current_resource->pointer);
        strcat(resource_pointer, tmp);
        strcat(resource_pointer, ",");
        sprintf(tmp, "%d", current_resource->read_locked);
        strcat(resource_pointer, tmp);
        strcat(resource_pointer, ",");
        sprintf(tmp, "%d", current_resource->transfer_locked);
        strcat(resource_pointer, tmp);
        strcat(resource_pointer, ",");
        if (current_resource->transactional) {
            strcat(resource_pointer, "1");
        } else {
            strcat(resource_pointer, "0");
        }
        strcat(resource_pointer, ");");
        current_resource = current_resource->next;
    }

    msg.sender_pid = pid;
    msg.resource_size = resource_size;
    msg.resource_pointer = (void *)resource_pointer;
    sprintf(msg.message, "SUCCESS: sending resource list\n");
    myco_send(msg.agent_message_queue_id, msg);

    msg = myco_receive(msg.agent_message_queue_id);
    if (strcmp(msg.message, "RESOURCE LIST GRANTED") == 0) {
        free(resource_pointer);
    } else {
        fprintf(stderr, "ERROR: resource list was not granted: %s\n", strerror(errno));
        free(resource_pointer);
        return -1;
    }

    return 0;
}

int myco_daemon_write_remote_resource(message msg, int force) {
    myco_resource *current_resource;

    // Check if resource exists
    if ((current_resource = myco_daemon_find_resource(msg.resource_name)) == NULL) {
        sprintf(msg.message, "ERROR: resource %s does not exist\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }

    if (force == 1) {
        sprintf(msg.message, "SUCCESS: forcing to overwrite resource %s, sending information\n", msg.resource_name);
        msg.resource_pointer = current_resource->pointer;
        msg.resource_size = current_resource->size;
        msg.sender_pid = current_resource->pid;
        myco_send(msg.agent_message_queue_id, msg);
        return 0;
    } else {
        if (current_resource->version > msg.version) {
            sprintf(msg.message, "ERROR: resource %s is newer than your copied version\n", msg.resource_name);
            myco_send(msg.agent_message_queue_id, msg);
            return -1;
        } else {
            sprintf(msg.message, "SUCCESS: version updated, sending information for resource %s\n", msg.resource_name);
            msg.resource_pointer = current_resource->pointer;
            msg.resource_size = current_resource->size;
            msg.sender_pid = current_resource->pid;
            myco_send(msg.agent_message_queue_id, msg);
            current_resource->version += 1;
            myco_send(msg.agent_message_queue_id, msg);
            return 0;
        }
    }
}

int myco_daemon_read_remote_resource(message msg) {
    myco_resource *current_resource;

    // Check if resource exists
    if ((current_resource = myco_daemon_find_resource(msg.resource_name)) == NULL) {
        sprintf(msg.message, "ERROR: resource %s does not exist\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }
    // Check if agent that requests already owns the resource
    if (strcmp(current_resource->agent, msg.agent_name) == 0) {
        sprintf(msg.message, "ERROR: resource %s already belongs to agent %s\n", msg.resource_name, msg.agent_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }

    // TODO: Handle case where resource is on another node (another agent)

    // If on same node, send information
    msg.sender_pid = current_resource->pid; 
    msg.resource_size = current_resource->size;
    msg.resource_pointer = current_resource->pointer;
    sprintf(msg.message, "SUCCESS: resource found on same node, sending information\n");
    myco_send(msg.agent_message_queue_id, msg);

    msg = myco_receive(msg.agent_message_queue_id);
    if (strcmp(msg.message, "RESOURCE READ") == 0) {

    } else {
        fprintf(stderr, "ERROR: myco_daemon_reead_remote: %s\n", strerror(errno));
        return -1;
    }

    return 0;
}

int myco_daemon_lock_resource(message msg) {
    myco_resource *current_resource;
    current_resource = myco_daemon_find_resource(msg.resource_name);

    if (current_resource != NULL && current_resource->transfer_locked == 1 && strcmp(current_resource->agent, msg.agent_name) == 0) {
        current_resource->read_locked = 1;
        sprintf(msg.message, "SUCCESS: resource %s locked\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return 0;
    } else {
        sprintf(msg.message, "ERROR: resource %s could not be locked\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }
}

int myco_daemon_release_resource(message msg) {
    myco_resource *current_resource;
    current_resource = myco_daemon_find_resource(msg.resource_name);

    if (current_resource != NULL && strcmp(current_resource->agent, msg.agent_name) == 0) {
        current_resource->transfer_locked = 0;
        sprintf(msg.message, "SUCCESS: resource %s released\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return 0;
    } else {
        sprintf(msg.message, "ERROR: resource %s could not be released\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }

}

int myco_daemon_unlock_resource(message msg) {
    myco_resource *current_resource;
    current_resource = myco_daemon_find_resource(msg.resource_name);

    if (current_resource != NULL && current_resource->transfer_locked == 1 && strcmp(current_resource->agent, msg.agent_name) == 0) {
        current_resource->read_locked = 0;
        sprintf(msg.message, "SUCCESS: resource %s unlocked\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return 0;
    } else {
        sprintf(msg.message, "ERROR: resource %s could not be locked\n", msg.resource_name);
        myco_send(msg.agent_message_queue_id, msg);
        return -1;
    }

}

int myco_daemon_start(pid) {
    int daemon_message_queue_id;
    message msg = {0};

    // Create message queue
    daemon_message_queue_id = myco_create_global_message_queue();
    if (daemon_message_queue_id < 0) {
        fprintf(stderr, "ERROR: Message queue could not be created. %s\n", strerror(errno));
        return -1;
    }

    // Receive messages
    while (1) {
        msg = myco_receive(daemon_message_queue_id);
        if (DEBUG) {
            printf("%d, %s, %s, %s, %p, %d, %d, %d, %d\n", msg.agent_message_queue_id, msg.agent_name, msg.message, \
                    msg.resource_name, msg.resource_pointer, msg.resource_size, msg.resource_transactional, msg.sender_pid, msg.version);
        }
        if (msg.message == NULL) {
            fprintf(stderr, "FATAL ERROR: No message could be received. %s\n", strerror(errno));
            return -1;
        } else {
            if (strcmp(msg.message, "REGISTER AGENT") == 0) {
                myco_daemon_register_agent(msg);
            }
            if (strcmp(msg.message, "UNREGISTER AGENT") == 0) {
                myco_daemon_unregister_agent(msg);
            }
            if (strcmp(msg.message, "REGISTER RESOURCE") == 0) {
                myco_daemon_register_resource(msg);
            }
            if (strcmp(msg.message, "UNREGISTER RESOURCE") == 0) {
                myco_daemon_unregister_resource(msg);
            }
            if (strcmp(msg.message, "REQUEST RESOURCE") == 0) {
                myco_daemon_request_resource(msg);
            }
            if (strcmp(msg.message, "REQUEST LIST") == 0) {
                myco_daemon_request_list(msg, pid);
            }
            if (strcmp(msg.message, "WRITE REMOTE RESOURCE") == 0) {
                myco_daemon_write_remote_resource(msg, 0);
            }
            if (strcmp(msg.message, "FORCE WRITE REMOTE RESOURCE") == 0) {
                myco_daemon_write_remote_resource(msg, 1);
            }
            if (strcmp(msg.message, "READ REMOTE RESOURCE") == 0) {
                myco_daemon_read_remote_resource(msg);
            }
            if (strcmp(msg.message, "LOCK RESOURCE") == 0) {
                myco_daemon_lock_resource(msg);
            }
            if (strcmp(msg.message, "UNLOCK RESOURCE") == 0) {
                myco_daemon_unlock_resource(msg);
            }
            if (strcmp(msg.message, "RELEASE RESOURCE") == 0) {
                myco_daemon_release_resource(msg);
            }
        } 
    }

    if (myco_remove_message_queue(daemon_message_queue_id) == -1) {
        fprintf(stderr, "FATAL ERROR: could not remove message queue %d\n", daemon_message_queue_id);
        return -1;
    }


    return EXIT_SUCCESS;
}

// TODO: Communication with indexserver