rt: Make some runtime calls work outside of task context

Author: brson

src/rt/rust_builtin.cpp

@@ -124,8 +124,7 @@ vec_reserve_shared_actual(type_desc* ty, rust_vec_box** vp,
 extern "C" CDECL void
 vec_reserve_shared(type_desc* ty, rust_vec_box** vp,
                    size_t n_elts) {
-    rust_task *task = rust_get_current_task();
-    reserve_vec_exact(task, vp, n_elts * ty->size);
+    reserve_vec_exact(vp, n_elts * ty->size);
 }
 
 extern "C" CDECL size_t
@@ -445,9 +444,8 @@ void tm_to_rust_tm(tm* in_tm, rust_tm* out_tm, int32_t gmtoff,
     out_tm->tm_nsec = nsec;
 
     if (zone != NULL) {
-        rust_task *task = rust_get_current_task();
         size_t size = strlen(zone);
-        reserve_vec_exact(task, &out_tm->tm_zone, size + 1);
+        reserve_vec_exact(&out_tm->tm_zone, size + 1);
         memcpy(out_tm->tm_zone->body.data, zone, size);
         out_tm->tm_zone->body.fill = size + 1;
         out_tm->tm_zone->body.data[size] = '\0';

src/rt/rust_upcall.cpp

@@ -118,7 +118,12 @@ extern "C" CDECL void
 upcall_fail(char const *expr,
             char const *file,
             size_t line) {
-    rust_task *task = rust_get_current_task();
+    rust_task *task = rust_try_get_current_task();
+    if (task == NULL) {
+        // NOTE: Need to think about what to do here
+        printf("failure outside of a task");
+        abort();
+    }
     s_fail_args args = {task,expr,file,line};
     UPCALL_SWITCH_STACK(task, &args, upcall_s_fail);
 }

src/rt/rust_util.h

@@ -67,11 +67,12 @@ inline void reserve_vec_exact_shared(rust_task* task, rust_vec_box** vpp,
     }
 }
 
-inline void reserve_vec_exact(rust_task* task, rust_vec_box** vpp,
+inline void reserve_vec_exact(rust_vec_box** vpp,
                               size_t size) {
     if (size > (*vpp)->body.alloc) {
-        *vpp = (rust_vec_box*)task->kernel
-            ->realloc(*vpp, size + sizeof(rust_vec_box));
+        rust_exchange_alloc exchange_alloc;
+        *vpp = (rust_vec_box*)exchange_alloc
+            .realloc(*vpp, size + sizeof(rust_vec_box));
         (*vpp)->body.alloc = size;
     }
 }