X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=rts%2FSparks.c;h=571529afbbc31b6f8d7c2e366f4b7635b754dde2;hb=65914a2cb71caf01655b16a75b283871e2482041;hp=8f52a611699c07f6d9403a452640feaeb7e74975;hpb=17a596022d01987d5ffe7db0742aa8db267b8cc3;p=ghc-hetmet.git

diff --git a/rts/Sparks.c b/rts/Sparks.c
index 8f52a61..571529a 100644
--- a/rts/Sparks.c
+++ b/rts/Sparks.c
@@ -44,6 +44,7 @@
 #include "RtsUtils.h"
 #include "ParTicky.h"
 #include "Trace.h"
+#include "Prelude.h"
 
 #include "SMP.h" // for cas
 
@@ -201,10 +202,12 @@ steal(SparkPool *deque)
   StgClosurePtr stolen;
   StgWord b,t; 
 
-  ASSERT_SPARK_POOL_INVARIANTS(deque); 
+// Can't do this on someone else's spark pool:
+// ASSERT_SPARK_POOL_INVARIANTS(deque); 
 
   b = deque->bottom;
   t = deque->top;
+
   if (b - t <= 0 ) { 
     return NULL; /* already looks empty, abort */
   }
@@ -221,14 +224,17 @@ steal(SparkPool *deque)
       return NULL;
   }  /* else: OK, top has been incremented by the cas call */
 
-  ASSERT_SPARK_POOL_INVARIANTS(deque); 
+// Can't do this on someone else's spark pool:
+// ASSERT_SPARK_POOL_INVARIANTS(deque); 
+
   /* return stolen element */
   return stolen;
 }
 
 StgClosure *
-tryStealSpark (SparkPool *pool)
+tryStealSpark (Capability *cap)
 {
+  SparkPool *pool = cap->sparks;
   StgClosure *stolen;
 
   do { 
@@ -264,13 +270,13 @@ looksEmpty(SparkPool* deque)
  * -------------------------------------------------------------------------- */
 
 void
-createSparkThread (Capability *cap, StgClosure *p)
+createSparkThread (Capability *cap)
 {
     StgTSO *tso;
 
-    tso = createGenThread (cap, RtsFlags.GcFlags.initialStkSize, p);
+    tso = createIOThread (cap, RtsFlags.GcFlags.initialStkSize, 
+                          &base_GHCziConc_runSparks_closure);
     appendToRunQueue(cap,tso);
-    cap->sparks_converted++;
 }
 
 /* -----------------------------------------------------------------------------
@@ -387,6 +393,19 @@ pruneSparkQueue (evac_fn evac, void *user, Capability *cap)
     
     pool = cap->sparks;
     
+    // it is possible that top > bottom, indicating an empty pool.  We
+    // fix that here; this is only necessary because the loop below
+    // assumes it.
+    if (pool->top > pool->bottom)
+        pool->top = pool->bottom;
+
+    // Take this opportunity to reset top/bottom modulo the size of
+    // the array, to avoid overflow.  This is only possible because no
+    // stealing is happening during GC.
+    pool->bottom  -= pool->top & ~pool->moduloSize;
+    pool->top     &= pool->moduloSize;
+    pool->topBound = pool->top;
+
     debugTrace(DEBUG_sched,
                "markSparkQueue: current spark queue len=%d; (hd=%ld; tl=%ld)",
                sparkPoolSize(pool), pool->bottom, pool->top);