add threadStatus# primop, for querying the status of a ThreadId#

[ghc-hetmet.git] / rts / PrimOps.cmm

diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm
index a45439d..53de724 100644 (file)
--- a/rts/PrimOps.cmm
+++ b/rts/PrimOps.cmm
@@ -1034,6 +1034,39 @@ isCurrentThreadBoundzh_fast
   RET_N(r);
 }
 
+threadStatuszh_fast
+{
+    /* args: R1 :: ThreadId# */
+    W_ tso;
+    W_ why_blocked;
+    W_ what_next;
+    W_ ret;
+
+    tso = R1;
+    loop:
+      if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
+          tso = StgTSO__link(tso);
+          goto loop;
+      }
+
+    what_next   = TO_W_(StgTSO_what_next(tso));
+    why_blocked = TO_W_(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
+    // contents of block_info too, then we'd have to do some synchronisation.
+
+    if (what_next == ThreadComplete) {
+        ret = 16;  // NB. magic, matches up with GHC.Conc.threadStatus
+    } else {
+        if (what_next == ThreadKilled) {
+            ret = 17;
+        } else {
+            ret = why_blocked;
+        }
+    }
+    RET_N(ret);
+}
 
 /* -----------------------------------------------------------------------------
  * TVar primitives
@@ -1570,6 +1603,7 @@ takeMVarzh_fast
        StgTSO_block_info(CurrentTSO)  = mvar;
        StgMVar_tail(mvar) = CurrentTSO;
        
+        R1 = mvar;
        jump stg_block_takemvar;
   }
 
@@ -1697,13 +1731,14 @@ tryTakeMVarzh_fast
 
 putMVarzh_fast
 {
-    W_ mvar, info, tso;
+    W_ mvar, val, info, tso;
 
     /* args: R1 = MVar, R2 = value */
     mvar = R1;
+    val  = R2;
 
 #if defined(THREADED_RTS)
-    ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [R2];
+    ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [];
 #else
     info = GET_INFO(mvar);
 #endif
@@ -1725,6 +1760,8 @@ putMVarzh_fast
        StgTSO_block_info(CurrentTSO)  = mvar;
        StgMVar_tail(mvar) = CurrentTSO;
        
+        R1 = mvar;
+        R2 = val;
        jump stg_block_putmvar;
     }
   
@@ -1736,7 +1773,7 @@ putMVarzh_fast
 
        /* actually perform the takeMVar */
        tso = StgMVar_head(mvar);
-       PerformTake(tso, R2);
+       PerformTake(tso, val);
         if (TO_W_(StgTSO_flags(tso)) & TSO_DIRTY == 0) {
             foreign "C" dirty_TSO(MyCapability() "ptr", tso "ptr") [];
         }
@@ -1759,7 +1796,7 @@ putMVarzh_fast
     else
     {
        /* No further takes, the MVar is now full. */
-       StgMVar_value(mvar) = R2;
+       StgMVar_value(mvar) = val;
 
 #if defined(THREADED_RTS)
        unlockClosure(mvar, stg_MVAR_DIRTY_info);