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_manager_thread_create(net);
  55         if (ret != 0) return ret;
  56
  57         ret = frescan_acceptor_thread_create(net);
  58         if (ret != 0) return ret;
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * frescan_bwres_negotiate()
  65  *
  66  * to negotiate a contract we follow the next steps:
  67  *
  68  * 1.- prepare a request
  69  * 2.- enqueue the request
  70  * 3.- wait in the reply object for a reply
  71  * 4.- return the final values
  72  *
  73  */
  74
  75 int frescan_bwres_negotiate(frescan_network_t net,
  76                             const frescan_contract_t *contract,
  77                             frescan_ss_t *id)
  78 {
  79         int ret, negotiation_ret;
  80         frescan_request_id_t   req;
  81         frescan_request_data_t *req_data;
  82
  83         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "preparing a negotiation request\n");
  84
  85         ret = frescan_request_alloc(&req);
  86         if (ret != 0) return ret;
  87
  88         ret = frescan_requests_get_data(req, &req_data);
  89         if (ret != 0) return ret;
  90
  91         req_data->type         = FRESCAN_REQ_NEG;
  92         req_data->req          = req;
  93         req_data->contract     = (frescan_contract_t *)contract;
  94         req_data->request_node = the_networks[net].local_node;
  95
  96         ret = frescan_bwres_robjs_alloc(&req_data->robj, FRESCAN_BWRES_MX_PRIO);
  97         if (ret != 0) return ret;
  98
  99         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "enqueue the negotiation request\n");
 100
 101         ret = frescan_requests_enqueue(req);
 102         if (ret != 0) return ret;
 103
 104         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "wait for a reply\n");
 105
 106         ret = frescan_replyobject_wait(req_data->robj);
 107         if (ret != 0) return ret;
 108
 109         ret = frescan_bwres_robjs_free(req_data->robj);
 110         if (ret != 0) return ret;
 111
 112         switch (req_data->return_value) {
 113                 case FRESCAN_REQ_ACCEPTED:
 114                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation OK\n");
 115                         *id = req_data->ss;
 116                         ret = 0;
 117                         break;
 118
 119                 case FRESCAN_REQ_NOT_ACCEPTED:
 120                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation FAIL\n");
 121                         ret = -1;
 122                         break;
 123
 124                 case FRESCAN_REQ_ERROR:
 125                         DEBUG(FRESCAN_BWRES_ENABLE_DEBUG, "negotiation ERROR\n");
 126                         ret = -1;
 127                         break;
 128
 129                 default:
 130                         ERROR("return_value unknown\n");
 131                         return -1;
 132         }
 133
 134         frescan_request_free(req);
 135
 136         return ret;
 137 }