#endif
#if defined(THREADED_RTS)
-rtsBool
-stealWork (Capability *cap)
+StgClosure *
+findSpark (Capability *cap)
{
/* use the normal Sparks.h interface (internally modified to enable
concurrent stealing)
rtsBool retry;
nat i = 0;
+ // first try to get a spark from our own pool.
+ // We should be using reclaimSpark(), because it works without
+ // needing any atomic instructions:
+ // spark = reclaimSpark(cap->sparks);
+ // However, measurements show that this makes at least one benchmark
+ // slower (prsa) and doesn't affect the others.
+ spark = tryStealSpark(cap);
+ if (spark != NULL) {
+ cap->sparks_converted++;
+ return spark;
+ }
+
+ if (n_capabilities == 1) { return NULL; } // makes no sense...
+
debugTrace(DEBUG_sched,
"cap %d: Trying to steal work from other capabilities",
cap->no);
- if (n_capabilities == 1) { return rtsFalse; } // makes no sense...
-
do {
retry = rtsFalse;
if (emptySparkPoolCap(robbed)) // nothing to steal here
continue;
- spark = tryStealSpark(robbed->sparks);
+ spark = tryStealSpark(robbed);
if (spark == NULL && !emptySparkPoolCap(robbed)) {
// we conflicted with another thread while trying to steal;
// try again later.
debugTrace(DEBUG_sched,
"cap %d: Stole a spark from capability %d",
cap->no, robbed->no);
-
- createSparkThread(cap,spark);
- return rtsTrue;
+ cap->sparks_converted++;
+ return spark;
}
// otherwise: no success, try next one
}
} while (retry);
debugTrace(DEBUG_sched, "No sparks stolen");
- return rtsFalse;
+ return NULL;
+}
+
+// Returns True if any spark pool is non-empty at this moment in time
+// The result is only valid for an instant, of course, so in a sense
+// is immediately invalid, and should not be relied upon for
+// correctness.
+rtsBool
+anySparks (void)
+{
+ nat i;
+
+ for (i=0; i < n_capabilities; i++) {
+ if (!emptySparkPoolCap(&capabilities[i])) {
+ return rtsTrue;
+ }
+ }
+ return rtsFalse;
}
#endif