fix a deadlock in atomicModifyMutVar#
[ghc-hetmet.git] / ghc / rts / PrimOps.cmm
index 3ddb2bc..2e81c1a 100644 (file)
@@ -49,7 +49,7 @@ newByteArrayzh_fast
     n = R1;
     payload_words = ROUNDUP_BYTES_TO_WDS(n);
     words = BYTES_TO_WDS(SIZEOF_StgArrWords) + payload_words;
-    "ptr" p = foreign "C" allocate(words);
+    "ptr" p = foreign "C" allocateLocal(MyCapability() "ptr",words) [];
     TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
     SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
     StgArrWords_words(p) = payload_words;
@@ -73,7 +73,7 @@ newPinnedByteArrayzh_fast
        words = words + 1;
     }
 
-    "ptr" p = foreign "C" allocatePinned(words);
+    "ptr" p = foreign "C" allocatePinned(words) [];
     TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
 
     // Again, if the ArrWords header isn't a multiple of 8 bytes, we
@@ -97,10 +97,10 @@ newArrayzh_fast
     MAYBE_GC(R2_PTR,newArrayzh_fast);
 
     words = BYTES_TO_WDS(SIZEOF_StgMutArrPtrs) + n;
-    "ptr" arr = foreign "C" allocate(words);
+    "ptr" arr = foreign "C" allocateLocal(MyCapability() "ptr",words) [];
     TICK_ALLOC_PRIM(SIZEOF_StgMutArrPtrs, WDS(n), 0);
 
-    SET_HDR(arr, stg_MUT_ARR_PTRS_info, W_[CCCS]);
+    SET_HDR(arr, stg_MUT_ARR_PTRS_DIRTY_info, W_[CCCS]);
     StgMutArrPtrs_ptrs(arr) = n;
 
     // Initialise all elements of the the array with the value in R2
@@ -126,21 +126,25 @@ unsafeThawArrayzh_fast
   // the mutable list is not easy, because the mut_list is only singly-linked).
   // 
   // So that we can tell whether a MUT_ARR_PTRS_FROZEN is on the mutable list,
-  // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0 to indicate
-  // that it is still on the mutable list.
-
+  // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0
+  // to indicate that it is still on the mutable list.
+  //
   // So, when we thaw a MUT_ARR_PTRS_FROZEN, we must cope with two cases:
   // either it is on a mut_list, or it isn't.  We adopt the convention that
-  // the mut_link field is NULL if it isn't on a mut_list, and the GC
-  // maintains this invariant.
+  // the closure type is MUT_ARR_PTRS_FROZEN0 if it is on the mutable list,
+  // and MUT_ARR_PTRS_FROZEN otherwise.  In fact it wouldn't matter if
+  // we put it on the mutable list more than once, but it would get scavenged
+  // multiple times during GC, which would be unnecessarily slow.
   //
-  if (%INFO_TYPE(%GET_STD_INFO(R1)) != HALF_W_(MUT_ARR_PTRS_FROZEN0)) {
-       foreign "C" recordMutable(R1 "ptr");
+  if (StgHeader_info(R1) != stg_MUT_ARR_PTRS_FROZEN0_info) {
+       SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
+       foreign "C" recordMutableLock(R1 "ptr") [R1];
+       // must be done after SET_INFO, because it ASSERTs closure_MUTABLE()
+       RET_P(R1);
+  } else {
+       SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
+       RET_P(R1);
   }
-
-  SET_INFO(R1,stg_MUT_ARR_PTRS_info);
-
-  RET_P(R1);
 }
 
 /* -----------------------------------------------------------------------------
@@ -155,7 +159,7 @@ newMutVarzh_fast
     ALLOC_PRIM( SIZEOF_StgMutVar, R1_PTR, newMutVarzh_fast);
 
     mv = Hp - SIZEOF_StgMutVar + WDS(1);
-    SET_HDR(mv,stg_MUT_VAR_info,W_[CCCS]);
+    SET_HDR(mv,stg_MUT_VAR_DIRTY_info,W_[CCCS]);
     StgMutVar_var(mv) = R1;
     
     RET_P(mv);
@@ -183,18 +187,18 @@ atomicModifyMutVarzh_fast
     */
 
 #if MIN_UPD_SIZE > 1
-#define THUNK_1_SIZE (SIZEOF_StgHeader + WDS(MIN_UPD_SIZE))
+#define THUNK_1_SIZE (SIZEOF_StgThunkHeader + WDS(MIN_UPD_SIZE))
 #define TICK_ALLOC_THUNK_1() TICK_ALLOC_UP_THK(WDS(1),WDS(MIN_UPD_SIZE-1))
 #else
-#define THUNK_1_SIZE (SIZEOF_StgHeader + WDS(1))
+#define THUNK_1_SIZE (SIZEOF_StgThunkHeader + WDS(1))
 #define TICK_ALLOC_THUNK_1() TICK_ALLOC_UP_THK(WDS(1),0)
 #endif
 
 #if MIN_UPD_SIZE > 2
-#define THUNK_2_SIZE (SIZEOF_StgHeader + WDS(MIN_UPD_SIZE))
+#define THUNK_2_SIZE (SIZEOF_StgThunkHeader + WDS(MIN_UPD_SIZE))
 #define TICK_ALLOC_THUNK_2() TICK_ALLOC_UP_THK(WDS(2),WDS(MIN_UPD_SIZE-2))
 #else
-#define THUNK_2_SIZE (SIZEOF_StgHeader + WDS(2))
+#define THUNK_2_SIZE (SIZEOF_StgThunkHeader + WDS(2))
 #define TICK_ALLOC_THUNK_2() TICK_ALLOC_UP_THK(WDS(2),0)
 #endif
 
@@ -202,6 +206,10 @@ atomicModifyMutVarzh_fast
 
    HP_CHK_GEN_TICKY(SIZE, R1_PTR & R2_PTR, atomicModifyMutVarzh_fast);
 
+#if defined(THREADED_RTS)
+    foreign "C" ACQUIRE_LOCK(atomic_modify_mutvar_mutex "ptr") [R1,R2];
+#endif
+
    x = StgMutVar_var(R1);
 
    TICK_ALLOC_THUNK_2();
@@ -209,46 +217,31 @@ atomicModifyMutVarzh_fast
    z = Hp - THUNK_2_SIZE + WDS(1);
    SET_HDR(z, stg_ap_2_upd_info, W_[CCCS]);
    LDV_RECORD_CREATE(z);
-   StgClosure_payload(z,0) = R2;
-   StgClosure_payload(z,1) = x;
+   StgThunk_payload(z,0) = R2;
+   StgThunk_payload(z,1) = x;
 
    TICK_ALLOC_THUNK_1();
    CCCS_ALLOC(THUNK_1_SIZE);
    y = z - THUNK_1_SIZE;
    SET_HDR(y, stg_sel_0_upd_info, W_[CCCS]);
    LDV_RECORD_CREATE(y);
-   StgClosure_payload(y,0) = z;
+   StgThunk_payload(y,0) = z;
 
    StgMutVar_var(R1) = y;
+   foreign "C" dirty_MUT_VAR(BaseReg "ptr", R1 "ptr") [R1];
 
    TICK_ALLOC_THUNK_1();
    CCCS_ALLOC(THUNK_1_SIZE);
    r = y - THUNK_1_SIZE;
    SET_HDR(r, stg_sel_1_upd_info, W_[CCCS]);
    LDV_RECORD_CREATE(r);
-   StgClosure_payload(r,0) = z;
-
-   RET_P(r);
-}
-
-/* -----------------------------------------------------------------------------
-   Foreign Object Primitives
-   -------------------------------------------------------------------------- */
-
-mkForeignObjzh_fast
-{
-  /* R1 = ptr to foreign object,
-  */
-  W_ result;
+   StgThunk_payload(r,0) = z;
 
-  ALLOC_PRIM( SIZEOF_StgForeignObj, NO_PTRS, mkForeignObjzh_fast);
-
-  result = Hp - SIZEOF_StgForeignObj + WDS(1);
-  SET_HDR(result,stg_FOREIGN_info,W_[CCCS]);
-  StgForeignObj_data(result) = R1;
+#if defined(THREADED_RTS)
+    foreign "C" RELEASE_LOCK(atomic_modify_mutvar_mutex "ptr") [];
+#endif
 
-  /* returns (# s#, ForeignObj# #) */
-  RET_P(result);
+   RET_P(r);
 }
 
 /* -----------------------------------------------------------------------------
@@ -281,7 +274,7 @@ mkWeakzh_fast
   StgWeak_link(w)      = W_[weak_ptr_list];
   W_[weak_ptr_list]    = w;
 
-  IF_DEBUG(weak, foreign "C" fprintf(stderr,stg_weak_msg,w));
+  IF_DEBUG(weak, foreign "C" debugBelch(stg_weak_msg,w) []);
 
   RET_P(w);
 }
@@ -519,6 +512,7 @@ word64ToIntegerzh_fast
 
 /* ToDo: this is shockingly inefficient */
 
+#ifndef THREADED_RTS
 section "bss" {
   mp_tmp1:
     bits8 [SIZEOF_MP_INT];
@@ -530,101 +524,120 @@ section "bss" {
 }
 
 section "bss" {
-  result1:
+  mp_result1:
     bits8 [SIZEOF_MP_INT];
 }
 
 section "bss" {
-  result2:
+  mp_result2:
     bits8 [SIZEOF_MP_INT];
 }
+#endif
 
-#define GMP_TAKE2_RET1(name,mp_fun)                    \
-name                                                   \
-{                                                      \
-  CInt s1, s2;                                         \
-  W_ d1, d2;                                           \
-                                                       \
-  /* call doYouWantToGC() */                           \
-  MAYBE_GC(R2_PTR & R4_PTR, name);                     \
-                                                       \
-  s1 = W_TO_INT(R1);                                   \
-  d1 = R2;                                             \
-  s2 = W_TO_INT(R3);                                   \
-  d2 = R4;                                             \
-                                                       \
-  MP_INT__mp_alloc(mp_tmp1) = W_TO_INT(StgArrWords_words(d1)); \
-  MP_INT__mp_size(mp_tmp1)  = (s1);                    \
-  MP_INT__mp_d(mp_tmp1)            = BYTE_ARR_CTS(d1);         \
-  MP_INT__mp_alloc(mp_tmp2) = W_TO_INT(StgArrWords_words(d2)); \
-  MP_INT__mp_size(mp_tmp2)  = (s2);                    \
-  MP_INT__mp_d(mp_tmp2)            = BYTE_ARR_CTS(d2);         \
-                                                       \
-  foreign "C" mpz_init(result1);                       \
-                                                       \
-  /* Perform the operation */                          \
-  foreign "C" mp_fun(result1,mp_tmp1,mp_tmp2);         \
-                                                       \
-  RET_NP(TO_W_(MP_INT__mp_size(result1)),              \
-         MP_INT__mp_d(result1) - SIZEOF_StgArrWords);  \
-}
-
-#define GMP_TAKE1_RET1(name,mp_fun)                            \
-name                                                           \
-{                                                              \
-  CInt s1;                                                     \
-  W_ d1;                                                       \
-                                                               \
-  /* call doYouWantToGC() */                                   \
-  MAYBE_GC(R2_PTR, name);                                      \
-                                                               \
-  d1 = R2;                                                     \
-  s1 = W_TO_INT(R1);                                           \
-                                                               \
-  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
-  MP_INT__mp_size(mp_tmp1)     = (s1);                         \
-  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);             \
-                                                               \
-  foreign "C" mpz_init(result1);                               \
-                                                               \
-  /* Perform the operation */                                  \
-  foreign "C" mp_fun(result1,mp_tmp1);                         \
-                                                               \
-  RET_NP(TO_W_(MP_INT__mp_size(result1)),                      \
-         MP_INT__mp_d(result1) - SIZEOF_StgArrWords);          \
-}
+#ifdef THREADED_RTS
+#define FETCH_MP_TEMP(X) \
+W_ X; \
+X = BaseReg + (OFFSET_StgRegTable_r ## X);
+#else
+#define FETCH_MP_TEMP(X) /* Nothing */
+#endif
 
-#define GMP_TAKE2_RET2(name,mp_fun)                            \
-name                                                           \
-{                                                              \
-  CInt s1, s2;                                                 \
-  W_ d1, d2;                                                   \
-                                                               \
-  /* call doYouWantToGC() */                                   \
-  MAYBE_GC(R2_PTR & R4_PTR, name);                             \
-                                                               \
-  s1 = W_TO_INT(R1);                                           \
-  d1 = R2;                                                     \
-  s2 = W_TO_INT(R3);                                           \
-  d2 = R4;                                                     \
-                                                               \
-  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
-  MP_INT__mp_size(mp_tmp1)     = (s1);                         \
-  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);             \
-  MP_INT__mp_alloc(mp_tmp2)    = W_TO_INT(StgArrWords_words(d2));      \
-  MP_INT__mp_size(mp_tmp2)     = (s2);                         \
-  MP_INT__mp_d(mp_tmp2)                = BYTE_ARR_CTS(d2);             \
-                                                               \
-  foreign "C" mpz_init(result1);                               \
-  foreign "C" mpz_init(result2);                               \
-                                                               \
-  /* Perform the operation */                                  \
-  foreign "C" mp_fun(result1,result2,mp_tmp1,mp_tmp2);         \
-                                                               \
-  RET_NPNP(TO_W_(MP_INT__mp_size(result1)),                    \
-           MP_INT__mp_d(result1) - SIZEOF_StgArrWords,         \
-          TO_W_(MP_INT__mp_size(result2)),                     \
-           MP_INT__mp_d(result2) - SIZEOF_StgArrWords);                \
+#define GMP_TAKE2_RET1(name,mp_fun)                                     \
+name                                                                    \
+{                                                                       \
+  CInt s1, s2;                                                          \
+  W_ d1, d2;                                                            \
+  FETCH_MP_TEMP(mp_tmp1);                                               \
+  FETCH_MP_TEMP(mp_tmp2);                                               \
+  FETCH_MP_TEMP(mp_result1)                                             \
+  FETCH_MP_TEMP(mp_result2);                                            \
+                                                                        \
+  /* call doYouWantToGC() */                                            \
+  MAYBE_GC(R2_PTR & R4_PTR, name);                                      \
+                                                                        \
+  s1 = W_TO_INT(R1);                                                    \
+  d1 = R2;                                                              \
+  s2 = W_TO_INT(R3);                                                    \
+  d2 = R4;                                                              \
+                                                                        \
+  MP_INT__mp_alloc(mp_tmp1) = W_TO_INT(StgArrWords_words(d1));          \
+  MP_INT__mp_size(mp_tmp1)  = (s1);                                     \
+  MP_INT__mp_d(mp_tmp1)            = BYTE_ARR_CTS(d1);                         \
+  MP_INT__mp_alloc(mp_tmp2) = W_TO_INT(StgArrWords_words(d2));          \
+  MP_INT__mp_size(mp_tmp2)  = (s2);                                     \
+  MP_INT__mp_d(mp_tmp2)            = BYTE_ARR_CTS(d2);                         \
+                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                            \
+                                                                        \
+  /* Perform the operation */                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_tmp1  "ptr",mp_tmp2  "ptr") []; \
+                                                                        \
+  RET_NP(TO_W_(MP_INT__mp_size(mp_result1)),                            \
+         MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords);                \
+}
+
+#define GMP_TAKE1_RET1(name,mp_fun)                                     \
+name                                                                    \
+{                                                                       \
+  CInt s1;                                                              \
+  W_ d1;                                                                \
+  FETCH_MP_TEMP(mp_tmp1);                                               \
+  FETCH_MP_TEMP(mp_result1)                                             \
+                                                                        \
+  /* call doYouWantToGC() */                                            \
+  MAYBE_GC(R2_PTR, name);                                               \
+                                                                        \
+  d1 = R2;                                                              \
+  s1 = W_TO_INT(R1);                                                    \
+                                                                        \
+  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
+  MP_INT__mp_size(mp_tmp1)     = (s1);                                 \
+  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);                     \
+                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                            \
+                                                                        \
+  /* Perform the operation */                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_tmp1 "ptr") [];                \
+                                                                        \
+  RET_NP(TO_W_(MP_INT__mp_size(mp_result1)),                            \
+         MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords);                \
+}
+
+#define GMP_TAKE2_RET2(name,mp_fun)                                                     \
+name                                                                                    \
+{                                                                                       \
+  CInt s1, s2;                                                                          \
+  W_ d1, d2;                                                                            \
+  FETCH_MP_TEMP(mp_tmp1);                                                               \
+  FETCH_MP_TEMP(mp_tmp2);                                                               \
+  FETCH_MP_TEMP(mp_result1)                                                             \
+  FETCH_MP_TEMP(mp_result2)                                                             \
+                                                                                        \
+  /* call doYouWantToGC() */                                                            \
+  MAYBE_GC(R2_PTR & R4_PTR, name);                                                      \
+                                                                                        \
+  s1 = W_TO_INT(R1);                                                                    \
+  d1 = R2;                                                                              \
+  s2 = W_TO_INT(R3);                                                                    \
+  d2 = R4;                                                                              \
+                                                                                        \
+  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));                      \
+  MP_INT__mp_size(mp_tmp1)     = (s1);                                                 \
+  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);                                     \
+  MP_INT__mp_alloc(mp_tmp2)    = W_TO_INT(StgArrWords_words(d2));                      \
+  MP_INT__mp_size(mp_tmp2)     = (s2);                                                 \
+  MP_INT__mp_d(mp_tmp2)                = BYTE_ARR_CTS(d2);                                     \
+                                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                                               \
+  foreign "C" mpz_init(mp_result2 "ptr") [];                                               \
+                                                                                        \
+  /* Perform the operation */                                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_result2 "ptr",mp_tmp1 "ptr",mp_tmp2 "ptr") [];    \
+                                                                                        \
+  RET_NPNP(TO_W_(MP_INT__mp_size(mp_result1)),                                          \
+           MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords,                               \
+          TO_W_(MP_INT__mp_size(mp_result2)),                                          \
+           MP_INT__mp_d(mp_result2) - SIZEOF_StgArrWords);                              \
 }
 
 GMP_TAKE2_RET1(plusIntegerzh_fast,     mpz_add)
@@ -642,17 +655,20 @@ GMP_TAKE1_RET1(complementIntegerzh_fast, mpz_com)
 GMP_TAKE2_RET2(quotRemIntegerzh_fast, mpz_tdiv_qr)
 GMP_TAKE2_RET2(divModIntegerzh_fast,  mpz_fdiv_qr)
 
+#ifndef THREADED_RTS
 section "bss" {
-  aa:  W_; // NB. aa is really an mp_limb_t
+  mp_tmp_w:  W_; // NB. mp_tmp_w is really an here mp_limb_t
 }
+#endif
 
 gcdIntzh_fast
 {
     /* R1 = the first Int#; R2 = the second Int# */
     W_ r; 
+    FETCH_MP_TEMP(mp_tmp_w);
 
-    W_[aa] = R1;
-    r = foreign "C" mpn_gcd_1(aa, 1, R2);
+    W_[mp_tmp_w] = R1;
+    r = foreign "C" mpn_gcd_1(mp_tmp_w "ptr", 1, R2) [];
 
     R1 = r;
     /* Result parked in R1, return via info-pointer at TOS */
@@ -663,7 +679,7 @@ gcdIntzh_fast
 gcdIntegerIntzh_fast
 {
     /* R1 = s1; R2 = d1; R3 = the int */
-    R1 = foreign "C" mpn_gcd_1( BYTE_ARR_CTS(R2) "ptr", R1, R3);
+    R1 = foreign "C" mpn_gcd_1( BYTE_ARR_CTS(R2) "ptr", R1, R3) [];
     
     /* Result parked in R1, return via info-pointer at TOS */
     jump %ENTRY_CODE(Sp(0));
@@ -744,7 +760,7 @@ cmpIntegerzh_fast
     up = BYTE_ARR_CTS(R2);
     vp = BYTE_ARR_CTS(R4);
 
-    cmp = foreign "C" mpn_cmp(up "ptr", vp "ptr", size);
+    cmp = foreign "C" mpn_cmp(up "ptr", vp "ptr", size) [];
 
     if (cmp == 0 :: CInt) {
        R1 = 0; 
@@ -798,14 +814,12 @@ integer2Wordzh_fast
   jump %ENTRY_CODE(Sp(0));
 }
 
-section "bss" {
-  exponent:  W_;
-}
-
 decodeFloatzh_fast
 { 
     W_ p;
     F_ arg;
+    FETCH_MP_TEMP(mp_tmp1);
+    FETCH_MP_TEMP(mp_tmp_w);
     
     /* arguments: F1 = Float# */
     arg = F1;
@@ -820,10 +834,10 @@ decodeFloatzh_fast
     MP_INT__mp_d(mp_tmp1) = BYTE_ARR_CTS(p);
     
     /* Perform the operation */
-    foreign "C" __decodeFloat(mp_tmp1,exponent,arg);
+    foreign "C" __decodeFloat(mp_tmp1 "ptr",mp_tmp_w "ptr" ,arg) [];
     
     /* returns: (Int# (expn), Int#, ByteArray#) */
-    RET_NNP(W_[exponent], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
+    RET_NNP(W_[mp_tmp_w], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
 }
 
 #define DOUBLE_MANTISSA_SIZE SIZEOF_DOUBLE
@@ -833,6 +847,8 @@ decodeDoublezh_fast
 { 
     D_ arg;
     W_ p;
+    FETCH_MP_TEMP(mp_tmp1);
+    FETCH_MP_TEMP(mp_tmp_w);
 
     /* arguments: D1 = Double# */
     arg = D1;
@@ -847,10 +863,10 @@ decodeDoublezh_fast
     MP_INT__mp_d(mp_tmp1) = BYTE_ARR_CTS(p);
 
     /* Perform the operation */
-    foreign "C" __decodeDouble(mp_tmp1,exponent,arg);
+    foreign "C" __decodeDouble(mp_tmp1 "ptr", mp_tmp_w "ptr",arg) [];
     
     /* returns: (Int# (expn), Int#, ByteArray#) */
-    RET_NNP(W_[exponent], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
+    RET_NNP(W_[mp_tmp_w], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
 }
 
 /* -----------------------------------------------------------------------------
@@ -864,9 +880,10 @@ forkzh_fast
   MAYBE_GC(R1_PTR, forkzh_fast);
 
   // create it right now, return ThreadID in R1
-  "ptr" R1 = foreign "C" createIOThread( RtsFlags_GcFlags_initialStkSize(RtsFlags), 
-                                  R1 "ptr");
-  foreign "C" scheduleThread(R1 "ptr");
+  "ptr" R1 = foreign "C" createIOThread( MyCapability() "ptr", 
+                               RtsFlags_GcFlags_initialStkSize(RtsFlags), 
+                               R1 "ptr");
+  foreign "C" scheduleThread(MyCapability() "ptr", R1 "ptr");
 
   // switch at the earliest opportunity
   CInt[context_switch] = 1 :: CInt;
@@ -900,7 +917,7 @@ isCurrentThreadBoundzh_fast
 {
   /* no args */
   W_ r;
-  r = foreign "C" isThreadBound(CurrentTSO);
+  r = foreign "C" isThreadBound(CurrentTSO) [];
   RET_N(r);
 }
 
@@ -960,8 +977,8 @@ INFO_TABLE_RET(stg_catch_retry_frame,
 
    frame = Sp;
    trec = StgTSO_trec(CurrentTSO);
-   "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr");
-   r = foreign "C" stmCommitTransaction(trec "ptr");
+   "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
+   r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr") [];
    if (r) {
      /* Succeeded (either first branch or second branch) */
      StgTSO_trec(CurrentTSO) = outer;
@@ -971,7 +988,7 @@ INFO_TABLE_RET(stg_catch_retry_frame,
    } else {
      /* Did not commit: retry */
      W_ new_trec;
-     "ptr" new_trec = foreign "C" stmStartTransaction(outer "ptr");
+     "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
      StgTSO_trec(CurrentTSO) = new_trec;
      if (StgCatchRetryFrame_running_alt_code(frame)) {
        R1 = StgCatchRetryFrame_alt_code(frame);
@@ -1005,11 +1022,11 @@ ATOMICALLY_FRAME_ERROR(stg_atomically_frame_7_ret)
 #endif
 
 #if defined(PROFILING)
-#define ATOMICALLY_FRAME_BITMAP 7
-#define ATOMICALLY_FRAME_WORDS  4
+#define ATOMICALLY_FRAME_BITMAP 3
+#define ATOMICALLY_FRAME_WORDS  3
 #else
-#define ATOMICALLY_FRAME_BITMAP 1
-#define ATOMICALLY_FRAME_WORDS  2
+#define ATOMICALLY_FRAME_BITMAP 0
+#define ATOMICALLY_FRAME_WORDS  1
 #endif
 
 
@@ -1025,50 +1042,66 @@ INFO_TABLE_RET(stg_atomically_frame,
               stg_atomically_frame_6_ret,
               stg_atomically_frame_7_ret)
 {
-   W_ frame, trec, valid;
-   IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
+  W_ frame, trec, valid;
+  IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
 
-   frame = Sp;
-   trec = StgTSO_trec(CurrentTSO);
-   if (StgAtomicallyFrame_waiting(frame)) {
-     /* The TSO is currently waiting: should we stop waiting? */
-     valid = foreign "C" stmReWait(CurrentTSO "ptr");
-     if (valid) {
-       /* Previous attempt is still valid: no point trying again yet */
+  frame = Sp;
+  trec = StgTSO_trec(CurrentTSO);
+
+  /* The TSO is not currently waiting: try to commit the transaction */
+  valid = foreign "C" stmCommitTransaction(MyCapability() "ptr", trec "ptr");
+  if (valid) {
+    /* Transaction was valid: commit succeeded */
+    StgTSO_trec(CurrentTSO) = NO_TREC;
+    Sp = Sp + SIZEOF_StgAtomicallyFrame;
+    IF_NOT_REG_R1(Sp_adj(-1); Sp(0) = rval;)
+    jump %ENTRY_CODE(Sp(SP_OFF));
+  } else {
+    /* Transaction was not valid: try again */
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr");
+    StgTSO_trec(CurrentTSO) = trec;
+    R1 = StgAtomicallyFrame_code(frame);
+    Sp_adj(-1);
+    jump RET_LBL(stg_ap_v);
+  }
+}
+
+INFO_TABLE_RET(stg_atomically_waiting_frame,
+              ATOMICALLY_FRAME_WORDS, ATOMICALLY_FRAME_BITMAP,
+              ATOMICALLY_FRAME,
+              stg_atomically_frame_0_ret,
+              stg_atomically_frame_1_ret,
+              stg_atomically_frame_2_ret,
+              stg_atomically_frame_3_ret,
+              stg_atomically_frame_4_ret,
+              stg_atomically_frame_5_ret,
+              stg_atomically_frame_6_ret,
+              stg_atomically_frame_7_ret)
+{
+  W_ frame, trec, valid;
+  IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
+
+  frame = Sp;
+
+  /* The TSO is currently waiting: should we stop waiting? */
+  valid = foreign "C" stmReWait(MyCapability() "ptr", CurrentTSO "ptr");
+  if (valid) {
+    /* Previous attempt is still valid: no point trying again yet */
          IF_NOT_REG_R1(Sp_adj(-2);
                        Sp(1) = stg_NO_FINALIZER_closure;
                        Sp(0) = stg_ut_1_0_unreg_info;)
-       jump stg_block_noregs;
-     } else {
-       /* Previous attempt is no longer valid: try again */
-       "ptr" trec = foreign "C" stmStartTransaction(NO_TREC "ptr");
-       StgTSO_trec(CurrentTSO) = trec;
-       StgAtomicallyFrame_waiting(frame) = 0 :: CInt; /* false; */
-       R1 = StgAtomicallyFrame_code(frame);
-       Sp_adj(-1);
-       jump RET_LBL(stg_ap_v);
-     }
-   } else {
-     /* The TSO is not currently waiting: try to commit the transaction */
-     valid = foreign "C" stmCommitTransaction(trec "ptr");
-     if (valid) {
-       /* Transaction was valid: commit succeeded */
-       StgTSO_trec(CurrentTSO) = NO_TREC;
-       Sp = Sp + SIZEOF_StgAtomicallyFrame;
-       IF_NOT_REG_R1(Sp_adj(-1); Sp(0) = rval;)
-       jump %ENTRY_CODE(Sp(SP_OFF));
-     } else {
-       /* Transaction was not valid: try again */
-       "ptr" trec = foreign "C" stmStartTransaction(NO_TREC "ptr");
-       StgTSO_trec(CurrentTSO) = trec;
-       R1 = StgAtomicallyFrame_code(frame);
-       Sp_adj(-1);
-       jump RET_LBL(stg_ap_v);
-     }
-   }
+    jump stg_block_noregs;
+  } else {
+    /* Previous attempt is no longer valid: try again */
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr");
+    StgTSO_trec(CurrentTSO) = trec;
+    StgHeader_info(frame) = stg_atomically_frame_info;
+    R1 = StgAtomicallyFrame_code(frame);
+    Sp_adj(-1);
+    jump RET_LBL(stg_ap_v);
+  }
 }
 
-
 // STM catch frame --------------------------------------------------------------
 
 #define CATCH_STM_FRAME_ENTRY_TEMPLATE(label,ret)          \
@@ -1134,20 +1167,29 @@ atomicallyzh_fast
   W_ old_trec;
   W_ new_trec;
   
+  // stmStartTransaction may allocate
+  MAYBE_GC (R1_PTR, atomicallyzh_fast); 
+
   /* Args: R1 = m :: STM a */
   STK_CHK_GEN(SIZEOF_StgAtomicallyFrame + WDS(1), R1_PTR, atomicallyzh_fast);
 
+  old_trec = StgTSO_trec(CurrentTSO);
+
+  /* Nested transactions are not allowed; raise an exception */
+  if (old_trec != NO_TREC) {
+     R1 = GHCziIOBase_NestedAtomically_closure;
+     jump raisezh_fast;
+  }
+
   /* Set up the atomically frame */
   Sp = Sp - SIZEOF_StgAtomicallyFrame;
   frame = Sp;
 
   SET_HDR(frame,stg_atomically_frame_info, W_[CCCS]);
-  StgAtomicallyFrame_waiting(frame) = 0 :: CInt; // False
   StgAtomicallyFrame_code(frame) = R1;
 
   /* Start the memory transcation */
-  old_trec = StgTSO_trec(CurrentTSO);
-  "ptr" new_trec = foreign "C" stmStartTransaction(old_trec "ptr");
+  "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", old_trec "ptr");
   StgTSO_trec(CurrentTSO) = new_trec;
 
   /* Apply R1 to the realworld token */
@@ -1183,13 +1225,16 @@ catchRetryzh_fast
   W_ new_trec;
   W_ trec;
 
+  // stmStartTransaction may allocate
+  MAYBE_GC (R1_PTR & R2_PTR, catchRetryzh_fast); 
+
   /* Args: R1 :: STM a */
   /* Args: R2 :: STM a */
   STK_CHK_GEN(SIZEOF_StgCatchRetryFrame + WDS(1), R1_PTR & R2_PTR, catchRetryzh_fast);
 
   /* Start a nested transaction within which to run the first code */
   trec = StgTSO_trec(CurrentTSO);
-  "ptr" new_trec = foreign "C" stmStartTransaction(trec "ptr");
+  "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", trec "ptr");
   StgTSO_trec(CurrentTSO) = new_trec;
 
   /* Set up the catch-retry frame */
@@ -1232,7 +1277,7 @@ retry_pop_stack:
     ASSERT(outer != NO_TREC);
     if (!StgCatchRetryFrame_running_alt_code(frame)) {
       // Retry in the first code: try the alternative
-      "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+      "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr");
       StgTSO_trec(CurrentTSO) = trec;
       StgCatchRetryFrame_running_alt_code(frame) = 1 :: CInt; // true;
       R1 = StgCatchRetryFrame_alt_code(frame);
@@ -1242,9 +1287,11 @@ retry_pop_stack:
       // Retry in the alternative code: propagate
       W_ other_trec;
       other_trec = StgCatchRetryFrame_first_code_trec(frame);
-      r = foreign "C" stmMergeForWaiting(trec "ptr", other_trec "ptr");
+      r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", other_trec "ptr");
       if (r) {
-        r = foreign "C" stmCommitTransaction(trec "ptr");
+        r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr");
+      } else {
+        foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr");
       }
       if (r) {
         // Merge between siblings succeeded: commit it back to enclosing transaction
@@ -1254,7 +1301,7 @@ retry_pop_stack:
         goto retry_pop_stack;
       } else {
         // Merge failed: we musn't propagate the retry.  Try both paths again.
-        "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+        "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr");
         StgCatchRetryFrame_first_code_trec(frame) = trec;
         StgCatchRetryFrame_running_alt_code(frame) = 0 :: CInt; // false;
         StgTSO_trec(CurrentTSO) = trec;
@@ -1268,19 +1315,20 @@ retry_pop_stack:
   // We've reached the ATOMICALLY_FRAME: attempt to wait 
   ASSERT(frame_type == ATOMICALLY_FRAME);
   ASSERT(outer == NO_TREC);
-  r = foreign "C" stmWait(CurrentTSO "ptr", trec "ptr");
+  r = foreign "C" stmWait(MyCapability() "ptr", CurrentTSO "ptr", trec "ptr");
   if (r) {
     // Transaction was valid: stmWait put us on the TVars' queues, we now block
-    StgAtomicallyFrame_waiting(frame) = 1 :: CInt; // true
+    StgHeader_info(frame) = stg_atomically_waiting_frame_info;
     Sp = frame;
     // Fix up the stack in the unregisterised case: the return convention is different.
     IF_NOT_REG_R1(Sp_adj(-2); 
                  Sp(1) = stg_NO_FINALIZER_closure;
                  Sp(0) = stg_ut_1_0_unreg_info;)
-    jump stg_block_noregs;
+    R3 = trec; // passing to stmWaitUnblock()
+    jump stg_block_stmwait;
   } else {
     // Transaction was not valid: retry immediately
-    "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr");
     StgTSO_trec(CurrentTSO) = trec;
     R1 = StgAtomicallyFrame_code(frame);
     Sp = frame;
@@ -1293,15 +1341,13 @@ retry_pop_stack:
 newTVarzh_fast
 {
   W_ tv;
+  W_ new_value;
 
   /* Args: R1 = initialisation value */
 
-  ALLOC_PRIM( SIZEOF_StgTVar, R1_PTR, newTVarzh_fast);
-  tv = Hp - SIZEOF_StgTVar + WDS(1);
-  SET_HDR(tv,stg_TVAR_info,W_[CCCS]);
-  StgTVar_current_value(tv) = R1;
-  StgTVar_first_wait_queue_entry(tv) = stg_END_STM_WAIT_QUEUE_closure;
-    
+  MAYBE_GC (R1_PTR, newTVarzh_fast); 
+  new_value = R1;
+  "ptr" tv = foreign "C" stmNewTVar(MyCapability() "ptr", new_value "ptr");
   RET_P(tv);
 }
 
@@ -1317,7 +1363,7 @@ readTVarzh_fast
   MAYBE_GC (R1_PTR, readTVarzh_fast); // Call to stmReadTVar may allocate
   trec = StgTSO_trec(CurrentTSO);
   tvar = R1;
-  "ptr" result = foreign "C" stmReadTVar(trec "ptr", tvar "ptr");
+  "ptr" result = foreign "C" stmReadTVar(MyCapability() "ptr", trec "ptr", tvar "ptr") [];
 
   RET_P(result);
 }
@@ -1336,7 +1382,7 @@ writeTVarzh_fast
   trec = StgTSO_trec(CurrentTSO);
   tvar = R1;
   new_value = R2;
-  foreign "C" stmWriteTVar(trec "ptr", tvar "ptr", new_value "ptr");
+  foreign "C" stmWriteTVar(MyCapability() "ptr", trec "ptr", tvar "ptr", new_value "ptr") [];
 
   jump %ENTRY_CODE(Sp(0));
 }
@@ -1416,7 +1462,6 @@ newMVarzh_fast
     StgTSO_sp(tso) = StgTSO_sp(tso) + WDS(3);  \
     lval = W_[StgTSO_sp(tso) - WDS(1)];
 
-
 takeMVarzh_fast
 {
     W_ mvar, val, info, tso;
@@ -1424,7 +1469,11 @@ takeMVarzh_fast
     /* args: R1 = MVar closure */
     mvar = R1;
 
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#else
     info = GET_INFO(mvar);
+#endif
 
     /* If the MVar is empty, put ourselves on its blocking queue,
      * and wait until we're woken up.
@@ -1459,26 +1508,34 @@ takeMVarzh_fast
 
 #if defined(GRAN) || defined(PAR)
       /* ToDo: check 2nd arg (mvar) is right */
-      "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar),mvar);
+      "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar),mvar) [];
       StgMVar_head(mvar) = tso;
 #else
-      "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr");
+      "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", 
+                                        StgMVar_head(mvar) "ptr") [];
       StgMVar_head(mvar) = tso;
 #endif
+
       if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
          StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
       }
+
+#if defined(THREADED_RTS)
+      foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#endif
       RET_P(val);
   } 
   else
   {
       /* No further putMVars, MVar is now empty */
-      
-      /* do this last... we might have locked the MVar in the SMP case,
-       * and writing the info pointer will unlock it.
-       */
-      SET_INFO(mvar,stg_EMPTY_MVAR_info);
       StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
+#if defined(THREADED_RTS)
+      foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#else
+      SET_INFO(mvar,stg_EMPTY_MVAR_info);
+#endif
+
       RET_P(val);
   }
 }
@@ -1492,9 +1549,16 @@ tryTakeMVarzh_fast
 
     mvar = R1;
 
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#else
     info = GET_INFO(mvar);
+#endif
 
     if (info == stg_EMPTY_MVAR_info) {
+#if defined(THREADED_RTS)
+        foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#endif
        /* HACK: we need a pointer to pass back, 
         * so we abuse NO_FINALIZER_closure
         */
@@ -1505,6 +1569,7 @@ tryTakeMVarzh_fast
     val = StgMVar_value(mvar);
 
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
+
        /* There are putMVar(s) waiting... 
         * wake up the first thread on the queue
         */
@@ -1516,26 +1581,30 @@ tryTakeMVarzh_fast
 
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr", mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr", mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr",
+                                          StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
        if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
+#if defined(THREADED_RTS)
+        foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#endif
     }
     else 
     {
        /* No further putMVars, MVar is now empty */
        StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
-       
-       /* do this last... we might have locked the MVar in the SMP case,
-        * and writing the info pointer will unlock it.
-        */
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#else
        SET_INFO(mvar,stg_EMPTY_MVAR_info);
+#endif
     }
     
     RET_NP(1, val);
@@ -1549,7 +1618,11 @@ putMVarzh_fast
     /* args: R1 = MVar, R2 = value */
     mvar = R1;
 
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#else
     info = GET_INFO(mvar);
+#endif
 
     if (info == stg_FULL_MVAR_info) {
        if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
@@ -1566,6 +1639,7 @@ putMVarzh_fast
     }
   
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
+
        /* There are takeMVar(s) waiting: wake up the first one
         */
        ASSERT(StgTSO_why_blocked(StgMVar_head(mvar)) == BlockedOnMVar::I16);
@@ -1576,10 +1650,10 @@ putMVarzh_fast
       
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr",mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr",mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
@@ -1587,14 +1661,21 @@ putMVarzh_fast
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
 
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#endif
        jump %ENTRY_CODE(Sp(0));
     }
     else
     {
        /* No further takes, the MVar is now full. */
        StgMVar_value(mvar) = R2;
-       /* unlocks the MVar in the SMP case */
+
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#else
        SET_INFO(mvar,stg_FULL_MVAR_info);
+#endif
        jump %ENTRY_CODE(Sp(0));
     }
     
@@ -1609,13 +1690,21 @@ tryPutMVarzh_fast
     /* args: R1 = MVar, R2 = value */
     mvar = R1;
 
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#else
     info = GET_INFO(mvar);
+#endif
 
     if (info == stg_FULL_MVAR_info) {
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#endif
        RET_N(0);
     }
   
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
+
        /* There are takeMVar(s) waiting: wake up the first one
         */
        ASSERT(StgTSO_why_blocked(StgMVar_head(mvar)) == BlockedOnMVar::I16);
@@ -1626,10 +1715,10 @@ tryPutMVarzh_fast
       
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr",mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr",mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
@@ -1637,17 +1726,23 @@ tryPutMVarzh_fast
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
 
-       jump %ENTRY_CODE(Sp(0));
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#endif
     }
     else
     {
        /* No further takes, the MVar is now full. */
        StgMVar_value(mvar) = R2;
-       /* unlocks the MVar in the SMP case */
+
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#else
        SET_INFO(mvar,stg_FULL_MVAR_info);
-       jump %ENTRY_CODE(Sp(0));
+#endif
     }
     
+    RET_N(1);
     /* ToDo: yield afterward for better communication performance? */
 }
 
@@ -1662,18 +1757,18 @@ makeStableNamezh_fast
 
     ALLOC_PRIM( SIZEOF_StgStableName, R1_PTR, makeStableNamezh_fast );
   
-    index = foreign "C" lookupStableName(R1 "ptr");
+    index = foreign "C" lookupStableName(R1 "ptr") [];
 
     /* Is there already a StableName for this heap object?
-     *  stable_ptr_table is an array of snEntry structs.
+     *  stable_ptr_table is a pointer to an array of snEntry structs.
      */
-    if ( snEntry_sn_obj(stable_ptr_table + index*SIZEOF_snEntry) == NULL ) {
+    if ( snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry) == NULL ) {
        sn_obj = Hp - SIZEOF_StgStableName + WDS(1);
        SET_HDR(sn_obj, stg_STABLE_NAME_info, W_[CCCS]);
        StgStableName_sn(sn_obj) = index;
-       snEntry_sn_obj(stable_ptr_table + index*SIZEOF_snEntry) = sn_obj;
+       snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry) = sn_obj;
     } else {
-       sn_obj = snEntry_sn_obj(stable_ptr_table + index*SIZEOF_snEntry);
+       sn_obj = snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry);
     }
     
     RET_P(sn_obj);
@@ -1685,7 +1780,7 @@ makeStablePtrzh_fast
     /* Args: R1 = a */
     W_ sp;
     MAYBE_GC(R1_PTR, makeStablePtrzh_fast);
-    "ptr" sp = foreign "C" getStablePtr(R1 "ptr");
+    "ptr" sp = foreign "C" getStablePtr(R1 "ptr") [];
     RET_N(sp);
 }
 
@@ -1694,7 +1789,7 @@ deRefStablePtrzh_fast
     /* Args: R1 = the stable ptr */
     W_ r, sp;
     sp = R1;
-    r = snEntry_addr(stable_ptr_table + sp*SIZEOF_snEntry);
+    r = snEntry_addr(W_[stable_ptr_table] + sp*SIZEOF_snEntry);
     RET_P(r);
 }
 
@@ -1789,7 +1884,7 @@ waitReadzh_fast
     /* args: R1 */
 #ifdef THREADED_RTS
     foreign "C" barf("waitRead# on threaded RTS");
-#endif
+#else
 
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnRead::I16;
@@ -1798,6 +1893,7 @@ waitReadzh_fast
     // threaded RTS anyway.
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_noregs;
+#endif
 }
 
 waitWritezh_fast
@@ -1805,7 +1901,7 @@ waitWritezh_fast
     /* args: R1 */
 #ifdef THREADED_RTS
     foreign "C" barf("waitWrite# on threaded RTS");
-#endif
+#else
 
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnWrite::I16;
@@ -1814,6 +1910,7 @@ waitWritezh_fast
     // threaded RTS anyway.
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_noregs;
+#endif
 }
 
 
@@ -1829,7 +1926,7 @@ delayzh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("delay# on threaded RTS");
-#endif
+#else
 
     /* args: R1 (microsecond delay amount) */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
@@ -1879,6 +1976,7 @@ while:
     }
     jump stg_block_noregs;
 #endif
+#endif /* !THREADED_RTS */
 }
 
 
@@ -1891,7 +1989,7 @@ asyncReadzh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("asyncRead# on threaded RTS");
-#endif
+#else
 
     /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
@@ -1907,6 +2005,7 @@ asyncReadzh_fast
     StgTSO_block_info(CurrentTSO)  = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 
 STRING(stg_asyncWritezh_malloc_str, "asyncWritezh_fast")
@@ -1917,7 +2016,7 @@ asyncWritezh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("asyncWrite# on threaded RTS");
-#endif
+#else
 
     /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
@@ -1933,6 +2032,7 @@ asyncWritezh_fast
     StgTSO_block_info(CurrentTSO)  = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 
 STRING(stg_asyncDoProczh_malloc_str, "asyncDoProczh_fast")
@@ -1941,6 +2041,10 @@ asyncDoProczh_fast
     W_ ares;
     CInt reqID;
 
+#ifdef THREADED_RTS
+    foreign "C" barf("asyncDoProc# on threaded RTS");
+#else
+
     /* args: R1 = proc, R2 = param */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnDoProc::I16;
@@ -1955,6 +2059,7 @@ asyncDoProczh_fast
     StgTSO_block_info(CurrentTSO) = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 #endif