src_frescan/frescan_bwres.c

   1 /*!
   2  * @file frescan_bwres.c
   3  *
   4  * @brief FRESCAN bandwidth reservation layer
   5  *
   6  * This module contains function to negotiate contracts and get the
   7  * corresponding frescan sporadic servers.
   8  *
   9  * @version 0.01
  10  *
  11  * @date 1-Apr-2008
  12  *
  13  * @author Daniel Sangorrin <daniel.sangorrin@unican.es>
  14  *
  15  */
  16
  17 #include "frescan_bwres.h"
  18 #include "frescan_bwres_requests.h"
  19 #include "frescan_bwres_messages.h"
  20 #include "frescan_bwres_threads.h"
  21 #include "frescan_data.h"
  22 #include "frescan_debug.h"
  23 #include "frescan_config.h"
  24 #include "frescan_servers.h"
  25
  26 /**
  27  * frescan_bwres_init()
  28  *
  29  * Init the frescan bandwidth reservation layer
  30  */
  31
  32 int frescan_bwres_init(frescan_network_t net)
  33 {
  34         int ret;
  35         frescan_server_params_t params;
  36
  37         // TODO: server params must be configurable
  38         // TODO: initialization tree like in DTM
  39         params.values.budget = 5;
  40         params.values.period.tv_sec = 1;
  41         params.values.period.tv_nsec = 0;
  42         params.prio = FRESCAN_BWRES_NEG_MESSAGES_PRIO;
  43
  44         ret = frescan_servers_create(net, &params,
  45                                      &the_networks[net].neg_messages_ss_id);
  46         if (ret != 0) return ret;
  47
  48         ret = frescan_bwres_robjs_init(FRESCAN_REPLY_OBJECTS_MX_CEILING);
  49         if (ret != 0) return ret;
  50
  51         ret = frescan_requests_init(FRESCAN_REQUESTS_MX_CEILING);
  52         if (ret != 0) return ret;
  53
  54         ret = frescan_messages_init(net);
  55         if (ret != 0) return ret;
  56
  57         ret = frescan_manager_thread_create(net);
  58         if (ret != 0) return ret;
  59
  60         ret = frescan_acceptor_thread_create(net);
  61         if (ret != 0) return ret;
  62
  63         return 0;
  64 }
  65
  66 /**
  67  * frescan_bwres_negotiate()
  68  *
  69  * to negotiate a contract we follow the next steps:
  70  *
  71  * 1.- prepare a request
  72  * 2.- enqueue the request
  73  * 3.- wait in the reply object for a reply
  74  * 4.- return the final values and free the request
  75  *
  76  */
  77
  78 int frescan_bwres_negotiate(frescan_network_t net,
  79                             const frescan_contract_t *contract,
  80                             frescan_ss_t *id)
  81 {
  82         int ret;
  83         frescan_request_id_t   req;
  84         frescan_request_data_t *req_data;
  85         frescan_server_params_t server_params;
  86
  87         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "preparing a negotiation request\n");
  88
  89         ret = frescan_requests_alloc(&req);
  90         if (ret != 0) return ret;
  91
  92         ret = frescan_requests_get_data(req, &req_data);
  93         if (ret != 0) return ret;
  94
  95         req_data->type         = FRESCAN_REQ_NEG;
  96         req_data->req          = req;
  97         req_data->contract     = (frescan_contract_t *)contract;
  98         req_data->request_node = the_networks[net].local_node;
  99         req_data->net          = net;
 100
 101         ret = frescan_bwres_robjs_alloc(&req_data->robj, FRESCAN_BWRES_MX_PRIO);
 102         if (ret != 0) return ret;
 103
 104         // NOTE: we preallocate a server for the negotiation process
 105         server_params.values.budget = contract->min_values.budget;
 106         server_params.values.period = contract->min_values.period;
 107         server_params.prio          = contract->prio;
 108
 109         ret = frescan_servers_create(net, &server_params, &req_data->ss);
 110         if (ret != 0) return ret;
 111
 112         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "enqueue the negotiation request\n");
 113
 114         ret = frescan_requests_enqueue(req);
 115         if (ret != 0) return ret;
 116
 117         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "wait for a reply\n");
 118
 119         ret = frescan_bwres_robjs_wait(req_data->robj);
 120         if (ret != 0) return ret;
 121
 122         ret = frescan_bwres_robjs_free(req_data->robj);
 123         if (ret != 0) return ret;
 124
 125         switch (req_data->return_value) {
 126                 case FRESCAN_REQ_ACCEPTED:
 127                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation OK\n");
 128                         *id = req_data->ss;
 129                         ret = 0;
 130                         break;
 131
 132                 case FRESCAN_REQ_NOT_ACCEPTED:
 133                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation FAIL\n");
 134                         ret = frescan_servers_destroy(net, req_data->ss);
 135                         if (ret != 0) return ret;
 136                         ret = -1;
 137                         break;
 138
 139                 case FRESCAN_REQ_ERROR:
 140                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation ERROR\n");
 141                         ret = frescan_servers_destroy(net, req_data->ss);
 142                         if (ret != 0) return ret;
 143                         ret = -1;
 144                         break;
 145
 146                 default:
 147                         ERROR("return_value unknown\n");
 148                         return -1;
 149         }
 150
 151         frescan_requests_free(req);
 152
 153         return ret; // TODO: distinguish errors and failed negotiations
 154 }