Format to dynamically handle default DL SCHED algo

openair2/LAYER2/MAC/mac.h

@@ -1274,6 +1274,19 @@ typedef struct {
   int length;
 } contig_rbs_t;
 
+/**
+ * definition of a scheduling algorithm implementation used in the
+ * default scheduler
+ */
+typedef struct {
+  char *name;
+  void *(*setup)(void);
+  void (*unset)(void **);
+  int (*run)(
+      module_id_t, int, int, int, UE_list_t *, int, int, uint8_t *, void *);
+  void *data;
+} default_sched_dl_algo_t;
+
 /*! \brief eNB common channels */
 typedef struct {
   int physCellId;
@@ -1432,6 +1445,8 @@ typedef struct eNB_MAC_INST_s {
   UE_free_list_t UE_free_list;
   /// for scheduling selection
   SCHEDULER_MODES scheduler_mode;
+  /// scheduling algorithm used in default scheduler
+  default_sched_dl_algo_t dl_algo;
 
   int32_t puSch10xSnr;
   int32_t puCch10xSnr;

openair2/LAYER2/MAC/main.c

@@ -128,7 +128,11 @@ void mac_top_init_eNB(void)
     }
 
     mac[i]->if_inst = IF_Module_init(i);
-
+    char *s = "round_robin_dl";
+    void *d = dlsym(NULL, s);
+    AssertFatal(d, "%s(): no scheduler algo '%s' found\n", __func__, s);
+    mac[i]->dl_algo = *(default_sched_dl_algo_t *) d;
+    mac[i]->dl_algo.data = mac[i]->dl_algo.setup();
     init_UE_info(&mac[i]->UE_info);
     init_slice_info(&mac[i]->slice_info);
   }

openair2/LAYER2/MAC/pre_processor.c

@@ -69,15 +69,26 @@ int get_rbg_size_last(module_id_t Mod_id, int CC_id) {
     return RBGsize;
 }
 
-int g_start_ue_dl = -1;
-int round_robin_dl(module_id_t Mod_id,
-                   int CC_id,
-                   int frame,
-                   int subframe,
-                   UE_list_t *UE_list,
-                   int max_num_ue,
-                   int n_rbg_sched,
-                   uint8_t *rbgalloc_mask) {
+void *rr_dl_setup(void) {
+  void *data = malloc(sizeof(int));
+  *(int *) data = 0;
+  AssertFatal(data, "could not allocate data in %s()\n", __func__);
+  return data;
+}
+void rr_dl_unset(void **data) {
+  if (*data)
+    free(*data);
+  *data = NULL;
+}
+int rr_dl_run(module_id_t Mod_id,
+              int CC_id,
+              int frame,
+              int subframe,
+              UE_list_t *UE_list,
+              int max_num_ue,
+              int n_rbg_sched,
+              uint8_t *rbgalloc_mask,
+              void *data) {
   DevAssert(UE_list->head >= 0);
   DevAssert(n_rbg_sched > 0);
   const int N_RBG = to_rbg(RC.mac[Mod_id]->common_channels[CC_id].mib->message.dl_Bandwidth);
@@ -91,10 +102,10 @@ int round_robin_dl(module_id_t Mod_id,
 
   /* just start with the UE after the one we had last time. If it does not
    * exist, this will start at the head */
-  int g_start_ue_dl = data;
-  g_start_ue_dl = next_ue_list_looped(UE_list, g_start_ue_dl);
+  int *start_ue = data;
+  *start_ue = next_ue_list_looped(UE_list, *start_ue);
 
-  int UE_id = g_start_ue_dl;
+  int UE_id = *start_ue;
   UE_list_t UE_sched;
   int *cur_UE = &UE_sched.head;
   // Allocate retransmissions, and mark UEs with new transmissions
@@ -163,7 +174,7 @@ int round_robin_dl(module_id_t Mod_id,
 
 skip_ue:
     UE_id = next_ue_list_looped(UE_list, UE_id);
-  } while (UE_id != g_start_ue_dl);
+  } while (UE_id != *start_ue);
   *cur_UE = -1; // mark end
 
   if (UE_sched.head < 0)
@@ -217,6 +228,14 @@ skip_ue:
 
   return n_rbg_sched;
 }
+default_sched_dl_algo_t round_robin_dl = {
+  .name  = "round_robin_dl",
+  .setup = rr_dl_setup,
+  .unset = rr_dl_unset,
+  .run   = rr_dl_run,
+  .data  = NULL
+};
+
 
 // This function stores the downlink buffer for all the logical channels
 void
@@ -306,8 +325,9 @@ dlsch_scheduler_pre_processor(module_id_t Mod_id,
                               int CC_id,
                               frame_t frameP,
                               sub_frame_t subframeP) {
-  UE_info_t *UE_info = &RC.mac[Mod_id]->UE_info;
-  const int N_RBG = to_rbg(RC.mac[Mod_id]->common_channels[CC_id].mib->message.dl_Bandwidth);
+  eNB_MAC_INST *mac = RC.mac[Mod_id];
+  UE_info_t *UE_info = &mac->UE_info;
+  const int N_RBG = to_rbg(mac->common_channels[CC_id].mib->message.dl_Bandwidth);
   const int RBGsize = get_min_rb_unit(Mod_id, CC_id);
 
   store_dlsch_buffer(Mod_id, CC_id, frameP, subframeP);
@@ -364,7 +384,7 @@ dlsch_scheduler_pre_processor(module_id_t Mod_id,
   if (UE_to_sched.head < 0)
     return;
 
-  uint8_t *vrb_map = RC.mac[Mod_id]->common_channels[CC_id].vrb_map;
+  uint8_t *vrb_map = mac->common_channels[CC_id].vrb_map;
   uint8_t rbgalloc_mask[N_RBG_MAX];
   int n_rbg_sched = 0;
   for (int i = 0; i < N_RBG; i++) {
@@ -376,14 +396,15 @@ dlsch_scheduler_pre_processor(module_id_t Mod_id,
     n_rbg_sched += rbgalloc_mask[i];
   }
 
-  round_robin_dl(Mod_id,
-                 CC_id,
-                 frameP,
-                 subframeP,
-                 &UE_to_sched,
-                 4, // max_num_ue
-                 n_rbg_sched,
-                 rbgalloc_mask);
+  mac->dl_algo.run(Mod_id,
+                   CC_id,
+                   frameP,
+                   subframeP,
+                   &UE_to_sched,
+                   4, // max_num_ue
+                   n_rbg_sched,
+                   rbgalloc_mask,
+                   mac->dl_algo.data);
 
   // the following block is meant for validation of the pre-processor to check
   // whether all UE allocations are non-overlapping and is not necessary for