fixing segfaults when using virtual time sampling

src/networks/model-net/dragonfly-custom.C

@@ -1004,7 +1004,7 @@ void router_custom_setup(router_state * r, tw_lp * lp)
    r->busy_time_ross_sample = (tw_stime*)calloc(p->radix, sizeof(tw_stime));
    if (g_st_model_stats)
        lp->model_types->mstat_sz = sizeof(tw_lpid) + (sizeof(int64_t) + sizeof(tw_stime)) * p->radix;
-   if (g_st_use_analysis_lps)
+   if (g_st_use_analysis_lps && g_st_model_stats)
        lp->model_types->sample_struct_sz = sizeof(struct dfly_router_sample) + (sizeof(tw_stime) + sizeof(int64_t)) * p->radix;
    r->ross_rsample.busy_time = (tw_stime*)calloc(p->radix, sizeof(tw_stime));
    r->ross_rsample.link_traffic_sample = (int64_t*)calloc(p->radix, sizeof(int64_t));

src/networks/model-net/dragonfly.c

@@ -911,7 +911,7 @@ static void router_setup(router_state * r, tw_lp * lp)
    r->busy_time_ross_sample = (tw_stime*)calloc(p->radix, sizeof(tw_stime));
    if (g_st_model_stats)
        lp->model_types->mstat_sz = sizeof(tw_lpid) + (sizeof(int64_t) + sizeof(tw_stime)) * p->radix;
-   if (g_st_use_analysis_lps)
+   if (g_st_use_analysis_lps && g_st_model_stats)
        lp->model_types->sample_struct_sz = sizeof(struct dfly_router_sample) + (sizeof(tw_stime) + sizeof(int64_t)) * p->radix;
    r->ross_rsample.busy_time = (tw_stime*)calloc(p->radix, sizeof(tw_stime));
    r->ross_rsample.link_traffic_sample = (int64_t*)calloc(p->radix, sizeof(int64_t));

src/networks/model-net/fattree.c

@@ -1172,7 +1172,7 @@ void switch_init(switch_state * r, tw_lp * lp)
   r->busy_time_sample = (tw_stime*)malloc(r->radix * sizeof(tw_stime));
 
   // ROSS Instrumentation
-  if (g_st_use_analysis_lps)
+  if (g_st_use_analysis_lps && g_st_model_stats)
     lp->model_types->sample_struct_sz = sizeof(struct fattree_switch_sample) + sizeof(int) * r->radix;
 
   rc_stack_create(&r->st);

src/networks/model-net/model-net-lp.c

@@ -146,7 +146,8 @@ void mn_event_collect(model_net_wrap_msg *m, tw_lp *lp, char *buffer, int *colle
             sub_msg = ((char*)m)+msg_offsets[((model_net_base_state*)lp->cur_state)->net_id];
             if (((model_net_base_state*)lp->cur_state)->sub_model_type)
             {
-                (((model_net_base_state*)lp->cur_state)->sub_model_type->ev_trace)(sub_msg, lp, buffer, collect_flag);
+                if (g_st_ev_trace)
+                    (((model_net_base_state*)lp->cur_state)->sub_model_type->ev_trace)(sub_msg, lp, buffer, collect_flag);
             }
             break;
         default:  // this shouldn't happen, but can help detect an issue

src/networks/model-net/slimfly.c

@@ -902,8 +902,8 @@ void slim_router_setup(router_state * r, tw_lp * lp)
     r->busy_time = (tw_stime*)malloc(p->radix * sizeof(tw_stime));
 
     // ROSS Instrumentation
-    if (g_st_use_analysis_lps)
-       lp->model_types->sample_struct_sz = sizeof(struct slimfly_router_sample) + sizeof(int) * p->radix;
+    if (g_st_use_analysis_lps && g_st_model_stats)
+        lp->model_types->sample_struct_sz = sizeof(struct slimfly_router_sample) + sizeof(int) * p->radix;
 
     rc_stack_create(&r->st);