[project @ 2001-02-14 12:59:34 by simonmar]

- make putMVar block rather than raise an exception when it encounters a
  full MVar (to match the semantics in our recent paper on async excpetions).

- add tryPutMVar, a non-blocking version of putMVar.

diff --git a/ghc/compiler/prelude/primops.txt b/ghc/compiler/prelude/primops.txt
index 73d145e..1d3d99a 100644 (file)
--- a/ghc/compiler/prelude/primops.txt
+++ b/ghc/compiler/prelude/primops.txt
@@ -1,5 +1,5 @@
 -----------------------------------------------------------------------
--- $Id: primops.txt,v 1.15 2001/01/15 16:55:24 sewardj Exp $
+-- $Id: primops.txt,v 1.16 2001/02/14 12:59:35 simonmar Exp $
 --
 -- Primitive Operations
 --
@@ -1001,6 +1001,13 @@ primop  TakeMVarOp "takeMVar#" GenPrimOp
    has_side_effects = True
    out_of_line      = True
 
+primop  TryTakeMVarOp "tryTakeMVar#" GenPrimOp
+   MVar# s a -> State# s -> (# State# s, Int#, a #)
+   with
+   usage            = { mangle TryTakeMVarOp [mkM, mkP] mkM }
+   has_side_effects = True
+   out_of_line      = True
+
 primop  PutMVarOp "putMVar#" GenPrimOp
    MVar# s a -> a -> State# s -> State# s
    with
@@ -1009,18 +1016,19 @@ primop  PutMVarOp "putMVar#" GenPrimOp
    has_side_effects = True
    out_of_line      = True
 
+primop  TryPutMVarOp "tryPutMVar#" GenPrimOp
+   MVar# s a -> a -> State# s -> (# State# s, Int# #)
+   with
+   strictness       = { \ arity -> StrictnessInfo [wwPrim, wwLazy, wwPrim] False }
+   usage            = { mangle PutMVarOp [mkM, mkM, mkP] mkR }
+   has_side_effects = True
+   out_of_line      = True
+
 primop  SameMVarOp "sameMVar#" GenPrimOp
    MVar# s a -> MVar# s a -> Bool
    with
    usage = { mangle SameMVarOp [mkP, mkP] mkM }
 
-primop  TryTakeMVarOp "tryTakeMVar#" GenPrimOp
-   MVar# s a -> State# s -> (# State# s, Int#, a #)
-   with
-   usage            = { mangle TryTakeMVarOp [mkM, mkP] mkM }
-   has_side_effects = True
-   out_of_line      = True
-
 primop  IsEmptyMVarOp "isEmptyMVar#" GenPrimOp
    MVar# s a -> State# s -> (# State# s, Int# #)
    with

diff --git a/ghc/includes/PrimOps.h b/ghc/includes/PrimOps.h
index cb1aa8c..7136b7c 100644 (file)
--- a/ghc/includes/PrimOps.h
+++ b/ghc/includes/PrimOps.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: PrimOps.h,v 1.73 2001/01/24 15:37:34 simonmar Exp $
+ * $Id: PrimOps.h,v 1.74 2001/02/14 12:59:34 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2000
  *
@@ -698,9 +698,9 @@ EXTFUN_RTS(newMutVarzh_fast);
 #define isEmptyMVarzh(r,a)       r=(I_)((GET_INFO((StgMVar*)(a))) == &stg_EMPTY_MVAR_info )
 EXTFUN_RTS(newMVarzh_fast);
 EXTFUN_RTS(takeMVarzh_fast);
-EXTFUN_RTS(tryTakeMVarzh_fast);
 EXTFUN_RTS(putMVarzh_fast);
-
+EXTFUN_RTS(tryTakeMVarzh_fast);
+EXTFUN_RTS(tryPutMVarzh_fast);
 
 /* -----------------------------------------------------------------------------
    Delay/Wait PrimOps

diff --git a/ghc/lib/std/PrelGHC.hi-boot b/ghc/lib/std/PrelGHC.hi-boot
index b23a0a0..ff89ad1 100644 (file)
--- a/ghc/lib/std/PrelGHC.hi-boot
+++ b/ghc/lib/std/PrelGHC.hi-boot
@@ -46,6 +46,7 @@ __export PrelGHC
   takeMVarzh
   putMVarzh
   tryTakeMVarzh
+  tryPutMVarzh
   isEmptyMVarzh
   
   -- Parallel

diff --git a/ghc/rts/Prelude.h b/ghc/rts/Prelude.h
index 48f72e4..d251340 100644 (file)
--- a/ghc/rts/Prelude.h
+++ b/ghc/rts/Prelude.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Prelude.h,v 1.14 2001/02/09 13:09:16 simonmar Exp $
+ * $Id: Prelude.h,v 1.15 2001/02/14 12:59:34 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2001
  *
@@ -67,7 +67,6 @@ extern DLL_IMPORT const StgInfoTable PrelStable_StablePtr_con_info;
 
 #define stackOverflow_closure     (&PrelIOBase_stackOverflow_closure)
 #define heapOverflow_closure      (&PrelIOBase_heapOverflow_closure)
-#define PutFullMVar_closure       (&PrelIOBase_PutFullMVar_closure)
 #define BlockedOnDeadMVar_closure (&PrelIOBase_BlockedOnDeadMVar_closure)
 #define NonTermination_closure    (&PrelIOBase_NonTermination_closure)
 

diff --git a/ghc/rts/PrimOps.hc b/ghc/rts/PrimOps.hc
index 711f538..b6d52bc 100644 (file)
--- a/ghc/rts/PrimOps.hc
+++ b/ghc/rts/PrimOps.hc
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: PrimOps.hc,v 1.71 2001/02/11 17:51:07 simonmar Exp $
+ * $Id: PrimOps.hc,v 1.72 2001/02/14 12:59:34 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2000
  *
@@ -876,6 +876,21 @@ FN_(takeMVarzh_fast)
   val = mvar->value;
   mvar->value = (StgClosure *)&stg_END_TSO_QUEUE_closure;
 
+  /* wake up the first thread on the queue
+   */
+  if (mvar->head != (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+      ASSERT(mvar->head->why_blocked == BlockedOnMVar);
+#if defined(GRAN) || defined(PAR)
+      /* ToDo: check 2nd arg (mvar) is right */
+      mvar->head = RET_STGCALL2(StgTSO *,unblockOne,mvar->head,mvar);
+#else
+      mvar->head = RET_STGCALL1(StgTSO *,unblockOne,mvar->head);
+#endif
+      if (mvar->head == (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+         mvar->tail = (StgTSO *)&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.
    */
@@ -917,6 +932,21 @@ FN_(tryTakeMVarzh_fast)
   val = mvar->value;
   mvar->value = (StgClosure *)&stg_END_TSO_QUEUE_closure;
 
+  /* wake up the first thread on the queue
+   */
+  if (mvar->head != (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+      ASSERT(mvar->head->why_blocked == BlockedOnMVar);
+#if defined(GRAN) || defined(PAR)
+      /* ToDo: check 2nd arg (mvar) is right */
+      mvar->head = RET_STGCALL2(StgTSO *,unblockOne,mvar->head,mvar);
+#else
+      mvar->head = RET_STGCALL1(StgTSO *,unblockOne,mvar->head);
+#endif
+      if (mvar->head == (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+         mvar->tail = (StgTSO *)&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.
    */
@@ -944,8 +974,21 @@ FN_(putMVarzh_fast)
 #endif
 
   if (info == &stg_FULL_MVAR_info) {
-    R1.cl = (StgClosure *)PutFullMVar_closure;
-    JMP_(raisezh_fast);
+    if (mvar->head == (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+      mvar->head = CurrentTSO;
+    } else {
+      mvar->tail->link = CurrentTSO;
+    }
+    CurrentTSO->link = (StgTSO *)&stg_END_TSO_QUEUE_closure;
+    CurrentTSO->why_blocked = BlockedOnMVar;
+    CurrentTSO->block_info.closure = (StgClosure *)mvar;
+    mvar->tail = CurrentTSO;
+
+#ifdef SMP
+    /* unlock the MVar */
+    mvar->header.info = &stg_FULL_MVAR_info;
+#endif
+    BLOCK( R1_PTR | R2_PTR, putMVarzh_fast );
   }
   
   mvar->value = R2.cl;
@@ -955,10 +998,8 @@ FN_(putMVarzh_fast)
    */
   if (mvar->head != (StgTSO *)&stg_END_TSO_QUEUE_closure) {
     ASSERT(mvar->head->why_blocked == BlockedOnMVar);
-#if defined(GRAN)
-    mvar->head = RET_STGCALL2(StgTSO *,unblockOne,mvar->head,mvar);
-#elif defined(PAR)
-    // ToDo: check 2nd arg (mvar) is right
+#if defined(GRAN) || defined(PAR)
+    /* ToDo: check 2nd arg (mvar) is right */
     mvar->head = RET_STGCALL2(StgTSO *,unblockOne,mvar->head,mvar);
 #else
     mvar->head = RET_STGCALL1(StgTSO *,unblockOne,mvar->head);
@@ -976,6 +1017,59 @@ FN_(putMVarzh_fast)
   FE_
 }
 
+FN_(tryPutMVarzh_fast)
+{
+  StgMVar *mvar;
+  const StgInfoTable *info;
+
+  FB_
+  /* args: R1 = MVar, R2 = value */
+
+  mvar = (StgMVar *)R1.p;
+
+#ifdef SMP
+  info = LOCK_CLOSURE(mvar);
+#else
+  info = GET_INFO(mvar);
+#endif
+
+  if (info == &stg_FULL_MVAR_info) {
+
+#ifdef SMP
+    /* unlock the MVar */
+    mvar->header.info = &stg_FULL_MVAR_info;
+#endif
+
+    /* HACK: we need a pointer to pass back, so we abuse NO_FINALIZER_closure */
+    RET_N(0);
+  }
+  
+  mvar->value = R2.cl;
+
+  /* wake up the first thread on the queue, it will continue with the
+   * takeMVar operation and mark the MVar empty again.
+   */
+  if (mvar->head != (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+    ASSERT(mvar->head->why_blocked == BlockedOnMVar);
+#if defined(GRAN) || defined(PAR)
+    /* ToDo: check 2nd arg (mvar) is right */
+    mvar->head = RET_STGCALL2(StgTSO *,unblockOne,mvar->head,mvar);
+#else
+    mvar->head = RET_STGCALL1(StgTSO *,unblockOne,mvar->head);
+#endif
+    if (mvar->head == (StgTSO *)&stg_END_TSO_QUEUE_closure) {
+      mvar->tail = (StgTSO *)&stg_END_TSO_QUEUE_closure;
+    }
+  }
+
+  /* unlocks the MVar in the SMP case */
+  SET_INFO(mvar,&stg_FULL_MVAR_info);
+
+  /* ToDo: yield here for better communication performance? */
+  RET_N(1);
+  FE_
+}
+
 /* -----------------------------------------------------------------------------
    Stable pointer primitives
    -------------------------------------------------------------------------  */

diff --git a/ghc/tests/concurrent/should_run/conc026.hs b/ghc/tests/concurrent/should_run/conc026.hs
new file mode 100644 (file)
index 0000000..ba86bf4
--- /dev/null
+++ b/ghc/tests/concurrent/should_run/conc026.hs
@@ -0,0 +1,8 @@
+-- test for blocking putMVar
+
+import Concurrent
+
+main = do
+  m <- newMVar ()
+  forkIO (threadDelay 100000 >> takeMVar m)
+  putMVar m ()  

diff --git a/ghc/tests/concurrent/should_run/conc027.hs b/ghc/tests/concurrent/should_run/conc027.hs
new file mode 100644 (file)
index 0000000..71e956e
--- /dev/null
+++ b/ghc/tests/concurrent/should_run/conc027.hs
@@ -0,0 +1,9 @@
+
+import Concurrent
+
+main = do
+  m <- newEmptyMVar
+  end <- newEmptyMVar
+  forkIO (sequence_ [ putMVar m () | _ <- [1 .. 10000] ])
+  forkIO (sequence_ [ takeMVar m   | _ <- [1 .. 10000] ] >> putMVar end ())
+  takeMVar end