Move the context_switch flag into the Capability

[ghc-hetmet.git] / rts / Interpreter.c

diff --git a/rts/Interpreter.c b/rts/Interpreter.c
index ab59533..4324f7f 100644 (file)
--- a/rts/Interpreter.c
+++ b/rts/Interpreter.c
@@ -63,6 +63,7 @@
     SpLim = cap->r.rCurrentTSO->stack + RESERVED_STACK_WORDS;
 
 #define SAVE_STACK_POINTERS                    \
+    ASSERT(Sp > SpLim); \
     cap->r.rCurrentTSO->sp = Sp
 
 #define RETURN_TO_SCHEDULER(todo,retcode)      \
@@ -549,6 +550,16 @@ do_apply:
                goto defer_apply_to_sched;
            }
 
+            // Stack check: we're about to unpack the PAP onto the
+            // stack.  The (+1) is for the (arity < n) case, where we
+            // also need space for an extra info pointer.
+            if (Sp - (pap->n_args + 1) < SpLim) {
+                Sp -= 2;
+                Sp[1] = (W_)tagged_obj;
+                Sp[0] = (W_)&stg_enter_info;
+                RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
+            }
+
            Sp++;
            arity = pap->arity;
            ASSERT(arity > 0);
@@ -1270,7 +1281,7 @@ run_BCO:
            // context switching: sometimes the scheduler can invoke
            // the interpreter with context_switch == 1, particularly
            // if the -C0 flag has been given on the cmd line.
-           if (context_switch) {
+           if (cap->context_switch) {
                Sp--; Sp[0] = (W_)&stg_enter_info;
                RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
            }