#ifndef SPARKS_H
#define SPARKS_H
-#if defined(PARALLEL_HASKELL) || defined(THREADED_RTS)
-StgClosure * findSpark (Capability *cap);
-void initSparkPools (void);
-void markSparkQueue (evac_fn evac);
-void createSparkThread (Capability *cap, StgClosure *p);
-
-INLINE_HEADER void discardSparks (StgSparkPool *pool);
-INLINE_HEADER nat sparkPoolSize (StgSparkPool *pool);
-INLINE_HEADER rtsBool emptySparkPool (StgSparkPool *pool);
-
-INLINE_HEADER void discardSparksCap (Capability *cap);
-INLINE_HEADER nat sparkPoolSizeCap (Capability *cap);
-INLINE_HEADER rtsBool emptySparkPoolCap (Capability *cap);
-#endif
-
#if defined(PARALLEL_HASKELL)
-StgTSO *activateSpark (rtsSpark spark) ;
-rtsBool add_to_spark_queue( StgClosure *closure, StgSparkPool *pool );
-void markSparkQueue( void );
-nat spark_queue_len( StgSparkPool *pool );
-void disposeSpark( StgClosure *spark );
+#error Sparks.c using new internal structure, needs major overhaul!
#endif
-#if defined(GRAN)
-void findLocalSpark (rtsEvent *event, rtsBool *found_res, rtsSparkQ *spark_res);
-rtsBool activateSpark (rtsEvent *event, rtsSparkQ spark);
-rtsSpark *newSpark(StgClosure *node, nat name, nat gran_info,
- nat size_info, nat par_info, nat local);
-void add_to_spark_queue(rtsSpark *spark);
-rtsSpark *delete_from_sparkq (rtsSpark *spark, PEs p, rtsBool dispose_too);
-void disposeSpark(rtsSpark *spark);
-void disposeSparkQ(rtsSparkQ spark);
-void print_spark(rtsSpark *spark);
-void print_sparkq(PEs proc);
-void print_sparkq_stats(void);
-nat spark_queue_len(PEs proc);
-void markSparkQueue(void);
+/* typedef for SparkPool in RtsTypes.h */
+
+#if defined(THREADED_RTS)
+
+/* Spark pools: used to store pending sparks
+ * (THREADED_RTS & PARALLEL_HASKELL only)
+ * Implementation uses a DeQue to enable concurrent read accesses at
+ * the top end.
+ */
+typedef struct SparkPool_ {
+ /* Size of elements array. Used for modulo calculation: we round up
+ to powers of 2 and use the dyadic log (modulo == bitwise &) */
+ StgWord size;
+ StgWord moduloSize; /* bitmask for modulo */
+
+ /* top, index where multiple readers steal() (protected by a cas) */
+ volatile StgWord top;
+
+ /* bottom, index of next free place where one writer can push
+ elements. This happens unsynchronised. */
+ volatile StgWord bottom;
+ /* both position indices are continuously incremented, and used as
+ an index modulo the current array size. */
+
+ /* lower bound on the current top value. This is an internal
+ optimisation to avoid unnecessarily accessing the top field
+ inside pushBottom */
+ volatile StgWord topBound;
+
+ /* The elements array */
+ StgClosurePtr* elements;
+ /* Please note: the dataspace cannot follow the admin fields
+ immediately, as it should be possible to enlarge it without
+ disposing the old one automatically (as realloc would)! */
+
+} SparkPool;
+
+
+/* INVARIANTS, in this order: reasonable size,
+ topBound consistent, space pointer, space accessible to us.
+
+ NB. This is safe to use only (a) on a spark pool owned by the
+ current thread, or (b) when there's only one thread running, or no
+ stealing going on (e.g. during GC).
+*/
+#define ASSERT_SPARK_POOL_INVARIANTS(p) \
+ ASSERT((p)->size > 0); \
+ ASSERT((p)->topBound <= (p)->top); \
+ ASSERT((p)->elements != NULL); \
+ ASSERT(*((p)->elements) || 1); \
+ ASSERT(*((p)->elements - 1 + ((p)->size)) || 1);
+
+// No: it is possible that top > bottom when using reclaimSpark()
+// ASSERT((p)->bottom >= (p)->top);
+// ASSERT((p)->size > (p)->bottom - (p)->top);
+
+// Initialisation
+void initSparkPools (void);
+
+// Take a spark from the "write" end of the pool. Can be called
+// by the pool owner only.
+StgClosure* reclaimSpark(SparkPool *pool);
+
+// Returns True if the spark pool is empty (can give a false positive
+// if the pool is almost empty).
+rtsBool looksEmpty(SparkPool* deque);
+
+StgClosure * tryStealSpark (Capability *cap);
+void freeSparkPool (SparkPool *pool);
+void createSparkThread (Capability *cap);
+void traverseSparkQueue(evac_fn evac, void *user, Capability *cap);
+void pruneSparkQueue (evac_fn evac, void *user, Capability *cap);
+
+INLINE_HEADER void discardSparks (SparkPool *pool);
+INLINE_HEADER nat sparkPoolSize (SparkPool *pool);
#endif
/* -----------------------------------------------------------------------------
#if defined(PARALLEL_HASKELL) || defined(THREADED_RTS)
-INLINE_HEADER rtsBool
-emptySparkPool (StgSparkPool *pool)
-{
- return (pool->hd == pool->tl);
-}
-
-INLINE_HEADER rtsBool
-emptySparkPoolCap (Capability *cap)
-{ return emptySparkPool(&cap->r.rSparks); }
+INLINE_HEADER rtsBool
+emptySparkPool (SparkPool *pool)
+{ return looksEmpty(pool); }
INLINE_HEADER nat
-sparkPoolSize (StgSparkPool *pool)
-{
- if (pool->hd <= pool->tl) {
- return (pool->hd - pool->tl);
- } else {
- return (pool->lim - pool->hd + pool->tl - pool->base);
- }
-}
-
-INLINE_HEADER nat
-sparkPoolSizeCap (Capability *cap)
-{ return sparkPoolSize(&cap->r.rSparks); }
+sparkPoolSize (SparkPool *pool)
+{ return (pool->bottom - pool->top); }
INLINE_HEADER void
-discardSparks (StgSparkPool *pool)
+discardSparks (SparkPool *pool)
{
- pool->hd = pool->tl;
+ pool->top = pool->topBound = pool->bottom = 0;
}
-INLINE_HEADER void
-discardSparksCap (Capability *cap)
-{ return discardSparks(&cap->r.rSparks); }
-
-
-#elif defined(THREADED_RTS)
-
-INLINE_HEADER rtsBool
-emptySparkPoolCap (Capability *cap STG_UNUSED)
-{ return rtsTrue; }
-
#endif
#endif /* SPARKS_H */
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