rts: Fix various data races

3 files changed, 15 insertions, 12 deletions

diff --git a/rts/Interpreter.c b/rts/Interpreter.c
index f8885cdbce..b263f749a3 100644
--- a/rts/Interpreter.c
+++ b/rts/Interpreter.c
@@ -307,7 +307,7 @@ interpretBCO (Capability* cap)
 
     LOAD_THREAD_STATE();
 
-    cap->r.rHpLim = (P_)1; // HpLim is the context-switch flag; when it
+    RELAXED_STORE(&cap->r.rHpLim, (P_)1); // HpLim is the context-switch flag; when it
                            // goes to zero we must return to the scheduler.
 
     IF_DEBUG(interpreter,
@@ -1989,7 +1989,7 @@ 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 (cap->r.rHpLim == NULL) {
+            if (RELAXED_LOAD(&cap->r.rHpLim) == NULL) {
                 Sp_subW(1); SpW(0) = (W_)&stg_enter_info;
                 RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
             }
diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm
index 60d0dc2ccc..51bb8981f7 100644
--- a/rts/PrimOps.cmm
+++ b/rts/PrimOps.cmm
@@ -1170,12 +1170,11 @@ stg_threadLabelzh ( gcptr tso )
 
 stg_threadStatuszh ( gcptr tso )
 {
-    W_ why_blocked;
-    W_ what_next;
-    W_ ret, cap, locked;
+    W_ why_blocked, what_next, flags, cap;
+    W_ ret, cap_no, locked;
 
-    what_next   = TO_W_(StgTSO_what_next(tso));
-    why_blocked = TO_W_(StgTSO_why_blocked(tso));
+    what_next   = TO_W_(RELAXED_LOAD_FIELD(StgTSO_what_next, tso));
+    why_blocked = TO_W_(RELAXED_LOAD_FIELD(StgTSO_why_blocked, tso));
     // Note: these two reads are not atomic, so they might end up
     // being inconsistent.  It doesn't matter, since we
     // only return one or the other.  If we wanted to return the
@@ -1191,15 +1190,17 @@ stg_threadStatuszh ( gcptr tso )
         }
     }
 
-    cap = TO_W_(Capability_no(StgTSO_cap(tso)));
+    cap = RELAXED_LOAD_FIELD(StgTSO_cap, tso);
+    cap_no = TO_W_(Capability_no(cap));
 
-    if ((TO_W_(StgTSO_flags(tso)) & TSO_LOCKED) != 0) {
+    flags = TO_W_(RELAXED_LOAD_FIELD(StgTSO_flags, tso));
+    if ((flags & TSO_LOCKED) != 0) {
         locked = 1;
     } else {
         locked = 0;
     }
 
-    return (ret,cap,locked);
+    return (ret,cap_no,locked);
 }
 
 /* -----------------------------------------------------------------------------
diff --git a/rts/include/Cmm.h b/rts/include/Cmm.h
index 688a5cf458..a1ea4efe92 100644
--- a/rts/include/Cmm.h
+++ b/rts/include/Cmm.h
@@ -444,9 +444,11 @@
    HP_CHK_P(bytes);                             \
    TICK_ALLOC_HEAP_NOCTR(bytes);
 
+#define RELAXED_LOAD_FIELD(fld, ptr) REP_##fld![(ptr) + SIZEOF_StgHeader + OFFSET_##fld]
+
 #define CHECK_GC()                                                      \
   (bdescr_link(CurrentNursery) == NULL ||                               \
-   generation_n_new_large_words(W_[g0]) >= TO_W_(CLong[large_alloc_lim]))
+   RELAXED_LOAD_FIELD(generation_n_new_large_words, g0) >= TO_W_(CLong[large_alloc_lim]))
 
 // allocate() allocates from the nursery, so we check to see
 // whether the nursery is nearly empty in any function that uses
@@ -695,7 +697,7 @@
    -------------------------------------------------------------------------- */
 
 #if defined(TICKY_TICKY)
-#define TICK_BUMP_BY(ctr,n) %relaxed W_[ctr] = %relaxed W_[ctr] + n
+#define TICK_BUMP_BY(ctr,n) %relaxed W_[ctr] = W_![ctr] + n
 #else
 #define TICK_BUMP_BY(ctr,n) /* nothing */
 #endif