[project @ 1999-08-25 10:23:51 by simonmar]

Eq and Ord instances for ThreadId.

diff --git a/ghc/includes/PrimOps.h b/ghc/includes/PrimOps.h
index f4066c5..6dd2209 100644 (file)
--- a/ghc/includes/PrimOps.h
+++ b/ghc/includes/PrimOps.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: PrimOps.h,v 1.35 1999/08/24 09:36:41 simonmar Exp $
+ * $Id: PrimOps.h,v 1.36 1999/08/25 10:23:51 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -711,6 +711,8 @@ EF_(seqzh_fast);
 
 #define myThreadIdzh(t) (t = CurrentTSO)
 
+extern int cmp_thread(const StgTSO *tso1, const StgTSO *tso2);
+
 /* Hmm, I'll think about these later. */
 /* -----------------------------------------------------------------------------
    Pointer equality

diff --git a/ghc/lib/concurrent/Concurrent.lhs b/ghc/lib/concurrent/Concurrent.lhs
index c9c2240..de342c6 100644 (file)
--- a/ghc/lib/concurrent/Concurrent.lhs
+++ b/ghc/lib/concurrent/Concurrent.lhs
@@ -63,10 +63,38 @@ import PrelArr              ( ByteArray )
 import PrelPack                ( packString )
 import PrelIOBase      ( unsafePerformIO , unsafeInterleaveIO )
 import PrelBase                ( fork# )
+import PrelGHC         ( Addr#, unsafeCoerce# )
 
 infixr 0 `fork`
 \end{code}
 
+Thread Ids, specifically the instances of Eq and Ord for these things.
+The ThreadId type itself is defined in std/PrelConc.lhs.
+
+Rather than define a new primitve, we use a little helper function
+cmp_thread in the RTS.
+
+\begin{code}
+foreign import ccall "cmp_thread" unsafe cmp_thread :: Addr# -> Addr# -> Int
+-- Returns -1, 0, 1
+
+cmpThread :: ThreadId -> ThreadId -> Ordering
+cmpThread (ThreadId t1) (ThreadId t2) = 
+   case cmp_thread (unsafeCoerce# t1) (unsafeCoerce# t2) of
+      -1 -> LT
+      0  -> EQ
+      1  -> GT
+
+instance Eq ThreadId where
+   t1 == t2 = 
+      case t1 `cmpThread` t2 of
+         EQ -> True
+         _  -> False
+
+instance Ord ThreadId where
+   compare = cmpThread
+\end{code}
+
 \begin{code}
 forkIO :: IO () -> IO ThreadId
 forkIO action = IO $ \ s -> 

diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c
index 064f1e6..70df696 100644 (file)
--- a/ghc/rts/Schedule.c
+++ b/ghc/rts/Schedule.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.22 1999/06/25 09:17:58 simonmar Exp $
+ * $Id: Schedule.c,v 1.23 1999/08/25 10:23:53 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -76,6 +76,23 @@ StgTSO   *MainTSO;
 static void unblockThread(StgTSO *tso);
 
 /* -----------------------------------------------------------------------------
+ * Comparing Thread ids.
+ *
+ * This is used from STG land in the implementation of the
+ * instances of Eq/Ord for ThreadIds.
+ * -------------------------------------------------------------------------- */
+
+int cmp_thread(const StgTSO *tso1, const StgTSO *tso2) 
+{ 
+  StgThreadID id1 = tso1->id; 
+  StgThreadID id2 = tso2->id;
+ 
+  if (id1 < id2) return (-1);
+  if (id1 > id2) return 1;
+  return 0;
+}
+
+/* -----------------------------------------------------------------------------
    Create a new thread.
 
    The new thread starts with the given stack size.  Before the