- gct = saved_gct;
-}
-
-/* -----------------------------------------------------------------------------
- * Mark all nodes pointed to by sparks in the spark queues (for GC) Does an
- * implicit slide i.e. after marking all sparks are at the beginning of the
- * spark pool and the spark pool only contains sparkable closures
- * -------------------------------------------------------------------------- */
-
-#ifdef THREADED_RTS
-static void
-markSparkQueue (evac_fn evac, Capability *cap)
-{
- StgClosure **sparkp, **to_sparkp;
- nat n, pruned_sparks; // stats only
- StgSparkPool *pool;
-
- PAR_TICKY_MARK_SPARK_QUEUE_START();
-
- n = 0;
- pruned_sparks = 0;
-
- pool = &(cap->r.rSparks);
-
- ASSERT_SPARK_POOL_INVARIANTS(pool);
-
-#if defined(PARALLEL_HASKELL)
- // stats only
- n = 0;
- pruned_sparks = 0;
-#endif
-
- sparkp = pool->hd;
- to_sparkp = pool->hd;
- while (sparkp != pool->tl) {
- ASSERT(*sparkp!=NULL);
- ASSERT(LOOKS_LIKE_CLOSURE_PTR(((StgClosure *)*sparkp)));
- // ToDo?: statistics gathering here (also for GUM!)
- if (closure_SHOULD_SPARK(*sparkp)) {
- evac(sparkp);
- *to_sparkp++ = *sparkp;
- if (to_sparkp == pool->lim) {
- to_sparkp = pool->base;
- }
- n++;
- } else {
- pruned_sparks++;
- }
- sparkp++;
- if (sparkp == pool->lim) {
- sparkp = pool->base;
- }
- }
- pool->tl = to_sparkp;
-
- PAR_TICKY_MARK_SPARK_QUEUE_END(n);
-
-#if defined(PARALLEL_HASKELL)
- debugTrace(DEBUG_sched,
- "marked %d sparks and pruned %d sparks on [%x]",
- n, pruned_sparks, mytid);
-#else
- debugTrace(DEBUG_sched,
- "marked %d sparks and pruned %d sparks",
- n, pruned_sparks);
-#endif
-
- debugTrace(DEBUG_sched,
- "new spark queue len=%d; (hd=%p; tl=%p)\n",
- sparkPoolSize(pool), pool->hd, pool->tl);
-}
-#endif
-
-/* ---------------------------------------------------------------------------
- Where are the roots that we know about?
-
- - all the threads on the runnable queue
- - all the threads on the blocked queue
- - all the threads on the sleeping queue
- - all the thread currently executing a _ccall_GC
- - all the "main threads"
-
- ------------------------------------------------------------------------ */
-
-void
-GetRoots( evac_fn evac )
-{
- nat i;
- Capability *cap;
- Task *task;
-
- // Each GC thread is responsible for following roots from the
- // Capability of the same number. There will usually be the same
- // or fewer Capabilities as GC threads, but just in case there
- // are more, we mark every Capability whose number is the GC
- // thread's index plus a multiple of the number of GC threads.
- for (i = gct->thread_index; i < n_capabilities; i += n_gc_threads) {
- cap = &capabilities[i];
- evac((StgClosure **)(void *)&cap->run_queue_hd);
- evac((StgClosure **)(void *)&cap->run_queue_tl);
-#if defined(THREADED_RTS)
- evac((StgClosure **)(void *)&cap->wakeup_queue_hd);
- evac((StgClosure **)(void *)&cap->wakeup_queue_tl);
-#endif
- for (task = cap->suspended_ccalling_tasks; task != NULL;
- task=task->next) {
- debugTrace(DEBUG_sched,
- "evac'ing suspended TSO %lu", (unsigned long)task->suspended_tso->id);
- evac((StgClosure **)(void *)&task->suspended_tso);
- }
-
-#if defined(THREADED_RTS)
- markSparkQueue(evac,cap);
-#endif
- }
-
-#if !defined(THREADED_RTS)
- evac((StgClosure **)(void *)&blocked_queue_hd);
- evac((StgClosure **)(void *)&blocked_queue_tl);
- evac((StgClosure **)(void *)&sleeping_queue);
-#endif
-}
-
-/* -----------------------------------------------------------------------------
- isAlive determines whether the given closure is still alive (after
- a garbage collection) or not. It returns the new address of the
- closure if it is alive, or NULL otherwise.
-
- NOTE: Use it before compaction only!
- It untags and (if needed) retags pointers to closures.
- -------------------------------------------------------------------------- */
-
-
-StgClosure *
-isAlive(StgClosure *p)
-{
- const StgInfoTable *info;
- bdescr *bd;
- StgWord tag;
- StgClosure *q;
-
- while (1) {
- /* The tag and the pointer are split, to be merged later when needed. */
- tag = GET_CLOSURE_TAG(p);
- q = UNTAG_CLOSURE(p);
-
- ASSERT(LOOKS_LIKE_CLOSURE_PTR(q));
- info = get_itbl(q);
-
- // ignore static closures
- //
- // ToDo: for static closures, check the static link field.
- // Problem here is that we sometimes don't set the link field, eg.
- // for static closures with an empty SRT or CONSTR_STATIC_NOCAFs.
- //
- if (!HEAP_ALLOCED(q)) {
- return p;
- }
-
- // ignore closures in generations that we're not collecting.
- bd = Bdescr((P_)q);
- if (bd->gen_no > N) {
- return p;
- }
-
- // if it's a pointer into to-space, then we're done
- if (bd->flags & BF_EVACUATED) {
- return p;
- }
-
- // large objects use the evacuated flag
- if (bd->flags & BF_LARGE) {
- return NULL;
- }
-
- // check the mark bit for compacted steps
- if ((bd->flags & BF_COMPACTED) && is_marked((P_)q,bd)) {
- return p;
- }
-
- switch (info->type) {
-
- case IND:
- case IND_STATIC:
- case IND_PERM:
- case IND_OLDGEN: // rely on compatible layout with StgInd
- case IND_OLDGEN_PERM:
- // follow indirections
- p = ((StgInd *)q)->indirectee;
- continue;
-
- case EVACUATED:
- // alive!
- return ((StgEvacuated *)q)->evacuee;
-
- case TSO:
- if (((StgTSO *)q)->what_next == ThreadRelocated) {
- p = (StgClosure *)((StgTSO *)q)->link;
- continue;
- }
- return NULL;
-
- default:
- // dead.
- return NULL;
- }
- }