*
* Sparking support for PARALLEL_HASKELL and THREADED_RTS versions of the RTS.
*
- * The implementation uses Double-Ended Queues with lock-free access
- * (thereby often called "deque") as described in
- *
- * D.Chase and Y.Lev, Dynamic Circular Work-Stealing Deque.
- * SPAA'05, July 2005, Las Vegas, USA.
- * ACM 1-58113-986-1/05/0007
- *
- * Author: Jost Berthold MSRC 07-09/2008
- *
- * The DeQue is held as a circular array with known length. Positions
- * of top (read-end) and bottom (write-end) always increase, and the
- * array is accessed with indices modulo array-size. While this bears
- * the risk of overflow, we assume that (with 64 bit indices), a
- * program must run very long to reach that point.
- *
- * The write end of the queue (position bottom) can only be used with
- * mutual exclusion, i.e. by exactly one caller at a time. At this
- * end, new items can be enqueued using pushBottom()/newSpark(), and
- * removed using popBottom()/reclaimSpark() (the latter implying a cas
- * synchronisation with potential concurrent readers for the case of
- * just one element).
- *
- * Multiple readers can steal()/findSpark() from the read end
- * (position top), and are synchronised without a lock, based on a cas
- * of the top position. One reader wins, the others return NULL for a
- * failure.
- *
- * Both popBottom and steal also return NULL when the queue is empty.
- *
-------------------------------------------------------------------------*/
#include "PosixSource.h"
#include "Rts.h"
-#include "Storage.h"
+
#include "Schedule.h"
-#include "SchedAPI.h"
-#include "RtsFlags.h"
#include "RtsUtils.h"
-#include "ParTicky.h"
#include "Trace.h"
-
-#include "SMP.h" // for cas
-
+#include "Prelude.h"
#include "Sparks.h"
-#if defined(THREADED_RTS) || defined(PARALLEL_HASKELL)
-
-/* internal helpers ... */
-
-StgWord roundUp2(StgWord val);
-
-StgWord roundUp2(StgWord val) {
- StgWord rounded = 1;
-
- /* StgWord is unsigned anyway, only catch 0 */
- if (val == 0) {
- barf("DeQue,roundUp2: invalid size 0 requested");
- }
- /* at least 1 bit set, shift up to its place */
- do {
- rounded = rounded << 1;
- } while (0 != (val = val>>1));
- return rounded;
-}
-
-INLINE_HEADER
-rtsBool casTop(StgPtr addr, StgWord old, StgWord new);
-
-#if !defined(THREADED_RTS)
-/* missing def. in non THREADED RTS, and makes no sense anyway... */
-StgWord cas(StgPtr addr,StgWord old,StgWord new);
-StgWord cas(StgPtr addr,StgWord old,StgWord new) {
- barf("cas: not implemented without multithreading");
- old = new = *addr; /* to avoid gcc warnings */
-}
-#endif
-
-INLINE_HEADER
-rtsBool casTop(StgWord* addr, StgWord old, StgWord new) {
- StgWord res = cas((StgPtr) addr, old, new);
- return ((res == old));
-}
-
-/* or simply like this */
-#define CASTOP(addr,old,new) ((old) == cas(((StgPtr)addr),(old),(new)))
-
-/* -----------------------------------------------------------------------------
- *
- * Initialising spark pools.
- *
- * -------------------------------------------------------------------------- */
-
-/* constructor */
-SparkPool* initPool(StgWord size) {
-
- StgWord realsize;
- SparkPool *q;
-
- realsize = roundUp2(size); /* to compute modulo as a bitwise & */
-
- q = (SparkPool*) stgMallocBytes(sizeof(SparkPool), /* admin fields */
- "newSparkPool");
- q->elements = (StgClosurePtr*)
- stgMallocBytes(realsize * sizeof(StgClosurePtr), /* dataspace */
- "newSparkPool:data space");
- q->top=0;
- q->bottom=0;
- q->topBound=0; /* read by writer, updated each time top is read */
-
- q->size = realsize; /* power of 2 */
- q->moduloSize = realsize - 1; /* n % size == n & moduloSize */
-
- ASSERT_SPARK_POOL_INVARIANTS(q);
- return q;
-}
+#if defined(THREADED_RTS)
void
initSparkPools( void )
{
-#ifdef THREADED_RTS
/* walk over the capabilities, allocating a spark pool for each one */
nat i;
for (i = 0; i < n_capabilities; i++) {
- capabilities[i].sparks = initPool(RtsFlags.ParFlags.maxLocalSparks);
+ capabilities[i].sparks = newWSDeque(RtsFlags.ParFlags.maxLocalSparks);
}
-#else
- /* allocate a single spark pool */
- MainCapability->sparks = initPool(RtsFlags.ParFlags.maxLocalSparks);
-#endif
}
void
-freeSparkPool(SparkPool *pool) {
- /* should not interfere with concurrent findSpark() calls! And
- nobody should use the pointer any more. We cross our fingers...*/
- stgFree(pool->elements);
- stgFree(pool);
-}
-
-/* reclaimSpark(cap): remove a spark from the write end of the queue.
- * Returns the removed spark, and NULL if a race is lost or the pool
- * empty.
- *
- * If only one spark is left in the pool, we synchronise with
- * concurrently stealing threads by using cas to modify the top field.
- * This routine should NEVER be called by a task which does not own
- * the capability. Can this be checked here?
- */
-StgClosure* reclaimSpark(Capability *cap) {
- SparkPool *deque = cap->sparks;
- /* also a bit tricky, has to avoid concurrent steal() calls by
- accessing top with cas, when there is only one element left */
- StgWord t, b;
- StgClosurePtr* pos;
- long currSize;
- StgClosurePtr removed;
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-
- b = deque->bottom;
- /* "decrement b as a test, see what happens" */
- deque->bottom = --b;
- pos = (deque->elements) + (b & (deque->moduloSize));
- t = deque->top; /* using topBound would give an *upper* bound, we
- need a lower bound. We use the real top here, but
- can update the topBound value */
- deque->topBound = t;
- currSize = b - t;
- if (currSize < 0) { /* was empty before decrementing b, set b
- consistently and abort */
- deque->bottom = t;
- return NULL;
- }
- removed = *pos;
- if (currSize > 0) { /* no danger, still elements in buffer after b-- */
- return removed;
- }
- /* otherwise, has someone meanwhile stolen the same (last) element?
- Check and increment top value to know */
- if ( !(CASTOP(&(deque->top),t,t+1)) ) {
- removed = NULL; /* no success, but continue adjusting bottom */
- }
- deque->bottom = t+1; /* anyway, empty now. Adjust bottom consistently. */
- deque->topBound = t+1; /* ...and cached top value as well */
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-
- return removed;
-}
-
-/* -----------------------------------------------------------------------------
- *
- * findSpark: find a spark on the current Capability that we can fork
- * into a thread.
- *
- * May be called by concurrent threads, which synchronise on top
- * variable. Returns a spark, or NULL if pool empty or race lost.
- *
- -------------------------------------------------------------------------- */
-
-StgClosurePtr steal(SparkPool *deque);
-
-/* steal an element from the read end. Synchronises multiple callers
- by failing with NULL return. Returns NULL when deque is empty. */
-StgClosurePtr steal(SparkPool *deque) {
- StgClosurePtr* pos;
- StgClosurePtr* arraybase;
- StgWord sz;
- StgClosurePtr stolen;
- StgWord b,t;
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-
- b = deque->bottom;
- t = deque->top;
- if (b - t <= 0 ) {
- return NULL; /* already looks empty, abort */
- }
-
- /* now access array, see pushBottom() */
- arraybase = deque->elements;
- sz = deque->moduloSize;
- pos = arraybase + (t & sz);
- stolen = *pos;
-
- /* now decide whether we have won */
- if ( !(CASTOP(&(deque->top),t,t+1)) ) {
- /* lost the race, someon else has changed top in the meantime */
- stolen = NULL;
- } /* else: OK, top has been incremented by the cas call */
-
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
- /* return NULL or stolen element */
- return stolen;
-}
-
-StgClosure *
-findSpark (Capability *cap)
+freeSparkPool (SparkPool *pool)
{
- SparkPool *deque = (cap->sparks);
- StgClosure *stolen;
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-
- do {
- /* keep trying until good spark found or pool looks empty.
- TODO is this a good idea? */
-
- stolen = steal(deque);
-
- } while ( ( !stolen /* nothing stolen*/
- || !closure_SHOULD_SPARK(stolen)) /* spark not OK */
- && !looksEmpty(deque)); /* run empty, give up */
-
- /* return stolen element */
- return stolen;
-}
-
-
-/* "guesses" whether a deque is empty. Can return false negatives in
- presence of concurrent steal() calls, and false positives in
- presence of a concurrent pushBottom().*/
-rtsBool looksEmpty(SparkPool* deque) {
- StgWord t = deque->top;
- StgWord b = deque->bottom;
- /* try to prefer false negatives by reading top first */
- return (b - t <= 0);
- /* => array is *never* completely filled, always 1 place free! */
+ freeWSDeque(pool);
}
/* -----------------------------------------------------------------------------
* -------------------------------------------------------------------------- */
void
-createSparkThread (Capability *cap, StgClosure *p)
+createSparkThread (Capability *cap)
{
StgTSO *tso;
- tso = createGenThread (cap, RtsFlags.GcFlags.initialStkSize, p);
- appendToRunQueue(cap,tso);
-}
+ tso = createIOThread (cap, RtsFlags.GcFlags.initialStkSize,
+ (StgClosure *)runSparks_closure);
-/* -----------------------------------------------------------------------------
- *
- * Create a new spark
- *
- * -------------------------------------------------------------------------- */
-
-#define DISCARD_NEW
-void pushBottom(SparkPool* deque, StgClosurePtr elem);
-
-/* enqueue an element. Should always succeed by resizing the array
- (not implemented yet, silently fails in that case). */
-void pushBottom(SparkPool* deque, StgClosurePtr elem) {
- StgWord t;
- StgClosurePtr* pos;
- StgWord sz = deque->moduloSize;
- StgWord b = deque->bottom;
+ traceEventCreateSparkThread(cap, tso->id);
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-
- /* we try to avoid reading deque->top (accessed by all) and use
- deque->topBound (accessed only by writer) instead.
- This is why we do not just call empty(deque) here.
- */
- t = deque->topBound;
- if ( b - t >= sz ) { /* nota bene: sz == deque->size - 1, thus ">=" */
- /* could be full, check the real top value in this case */
- t = deque->top;
- deque->topBound = t;
- if (b - t >= sz) { /* really no space left :-( */
- /* reallocate the array, copying the values. Concurrent steal()s
- will in the meantime use the old one and modify only top.
- This means: we cannot safely free the old space! Can keep it
- on a free list internally here...
-
- Potential bug in combination with steal(): if array is
- replaced, it is unclear which one concurrent steal operations
- use. Must read the array base address in advance in steal().
- */
-#if defined(DISCARD_NEW)
- ASSERT_SPARK_POOL_INVARIANTS(deque);
- return; /* for now, silently fail */
-#else
- /* could make room by incrementing the top position here. In
- * this case, should use CASTOP. If this fails, someone else has
- * removed something, and new room will be available.
- */
- ASSERT_SPARK_POOL_INVARIANTS(deque);
-#endif
- }
- }
- pos = (deque->elements) + (b & sz);
- *pos = elem;
- (deque->bottom)++;
-
- ASSERT_SPARK_POOL_INVARIANTS(deque);
- return;
+ appendToRunQueue(cap,tso);
}
+/* --------------------------------------------------------------------------
+ * newSpark: create a new spark, as a result of calling "par"
+ * Called directly from STG.
+ * -------------------------------------------------------------------------- */
-/* this is called as a direct C-call from Stg => we need to keep the
- pool in a register (???) */
StgInt
newSpark (StgRegTable *reg, StgClosure *p)
{
- SparkPool *pool = (reg->rCurrentTSO->cap->sparks);
+ Capability *cap = regTableToCapability(reg);
+ SparkPool *pool = cap->sparks;
/* I am not sure whether this is the right thing to do.
* Maybe it is better to exploit the tag information
*/
p = UNTAG_CLOSURE(p);
- ASSERT_SPARK_POOL_INVARIANTS(pool);
-
if (closure_SHOULD_SPARK(p)) {
- pushBottom(pool,p);
- }
+ pushWSDeque(pool,p);
+ cap->sparks_created++;
+ } else {
+ cap->sparks_dud++;
+ }
- ASSERT_SPARK_POOL_INVARIANTS(pool);
return 1;
}
+/* -----------------------------------------------------------------------------
+ *
+ * tryStealSpark: try to steal a spark from a Capability.
+ *
+ * Returns a valid spark, or NULL if the pool was empty, and can
+ * occasionally return NULL if there was a race with another thread
+ * stealing from the same pool. In this case, try again later.
+ *
+ -------------------------------------------------------------------------- */
+StgClosure *
+tryStealSpark (Capability *cap)
+{
+ SparkPool *pool = cap->sparks;
+ StgClosure *stolen;
+
+ do {
+ stolen = stealWSDeque_(pool);
+ // use the no-loopy version, stealWSDeque_(), since if we get a
+ // spurious NULL here the caller may want to try stealing from
+ // other pools before trying again.
+ } while (stolen != NULL && !closure_SHOULD_SPARK(stolen));
+
+ return stolen;
+}
/* --------------------------------------------------------------------------
* Remove all sparks from the spark queues which should not spark any
* the spark pool only contains sparkable closures.
* -------------------------------------------------------------------------- */
-static void
+void
pruneSparkQueue (Capability *cap)
{
SparkPool *pool;
- StgClosurePtr spark, evacspark, *elements;
+ StgClosurePtr spark, tmp, *elements;
nat n, pruned_sparks; // stats only
StgWord botInd,oldBotInd,currInd; // indices in array (always < size)
-
- PAR_TICKY_MARK_SPARK_QUEUE_START();
+ const StgInfoTable *info;
n = 0;
pruned_sparks = 0;
pool = cap->sparks;
- debugTrace(DEBUG_sched,
- "markSparkQueue: current spark queue len=%d; (hd=%ld; tl=%ld)",
+ // 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_sparks,
+ "markSparkQueue: current spark queue len=%ld; (hd=%ld; tl=%ld)",
sparkPoolSize(pool), pool->bottom, pool->top);
- ASSERT_SPARK_POOL_INVARIANTS(pool);
- elements = pool->elements;
+ ASSERT_WSDEQUE_INVARIANTS(pool);
+
+ elements = (StgClosurePtr *)pool->elements;
/* We have exclusive access to the structure here, so we can reset
bottom and top counters, and prune invalid sparks. Contents are
botInd, otherwise move on */
spark = elements[currInd];
- /* if valuable work: shift inside the pool */
- if ( closure_SHOULD_SPARK(spark) ) {
- elements[botInd] = spark; // keep entry (new address)
- botInd++;
- n++;
- } else {
- pruned_sparks++; // discard spark
+ // We have to be careful here: in the parallel GC, another
+ // thread might evacuate this closure while we're looking at it,
+ // so grab the info pointer just once.
+ if (GET_CLOSURE_TAG(spark) != 0) {
+ // Tagged pointer is a value, so the spark has fizzled. It
+ // probably never happens that we get a tagged pointer in
+ // the spark pool, because we would have pruned the spark
+ // during the previous GC cycle if it turned out to be
+ // evaluated, but it doesn't hurt to have this check for
+ // robustness.
+ pruned_sparks++;
+ cap->sparks_fizzled++;
+ } else {
+ info = spark->header.info;
+ if (IS_FORWARDING_PTR(info)) {
+ tmp = (StgClosure*)UN_FORWARDING_PTR(info);
+ /* if valuable work: shift inside the pool */
+ if (closure_SHOULD_SPARK(tmp)) {
+ elements[botInd] = tmp; // keep entry (new address)
+ botInd++;
+ n++;
+ } else {
+ pruned_sparks++; // discard spark
+ cap->sparks_fizzled++;
+ }
+ } else if (HEAP_ALLOCED(spark)) {
+ if ((Bdescr((P_)spark)->flags & BF_EVACUATED)) {
+ if (closure_SHOULD_SPARK(spark)) {
+ elements[botInd] = spark; // keep entry (new address)
+ botInd++;
+ n++;
+ } else {
+ pruned_sparks++; // discard spark
+ cap->sparks_fizzled++;
+ }
+ } else {
+ pruned_sparks++; // discard spark
+ cap->sparks_gcd++;
+ }
+ } else {
+ if (INFO_PTR_TO_STRUCT(info)->type == THUNK_STATIC) {
+ if (*THUNK_STATIC_LINK(spark) != NULL) {
+ elements[botInd] = spark; // keep entry (new address)
+ botInd++;
+ n++;
+ } else {
+ pruned_sparks++; // discard spark
+ cap->sparks_gcd++;
+ }
+ } else {
+ pruned_sparks++; // discard spark
+ cap->sparks_fizzled++;
+ }
+ }
}
+
currInd++;
// in the loop, we may reach the bounds, and instantly wrap around
pool->bottom = (oldBotInd <= botInd) ? botInd : (botInd + pool->size);
// first free place we did not use (corrected by wraparound)
- PAR_TICKY_MARK_SPARK_QUEUE_END(n);
-
- debugTrace(DEBUG_sched, "pruned %d sparks", pruned_sparks);
+ debugTrace(DEBUG_sparks, "pruned %d sparks", pruned_sparks);
- debugTrace(DEBUG_sched,
- "new spark queue len=%d; (hd=%ld; tl=%ld)",
+ debugTrace(DEBUG_sparks,
+ "new spark queue len=%ld; (hd=%ld; tl=%ld)",
sparkPoolSize(pool), pool->bottom, pool->top);
- ASSERT_SPARK_POOL_INVARIANTS(pool);
-}
-
-void
-pruneSparkQueues (void)
-{
- nat i;
- for (i = 0; i < n_capabilities; i++) {
- pruneSparkQueue(&capabilities[i]);
- }
+ ASSERT_WSDEQUE_INVARIANTS(pool);
}
/* GC for the spark pool, called inside Capability.c for all
pool = cap->sparks;
- ASSERT_SPARK_POOL_INVARIANTS(pool);
+ ASSERT_WSDEQUE_INVARIANTS(pool);
top = pool->top;
bottom = pool->bottom;
- sparkp = pool->elements;
+ sparkp = (StgClosurePtr*)pool->elements;
modMask = pool->moduloSize;
while (top < bottom) {
top++;
}
- debugTrace(DEBUG_sched,
- "traversed spark queue, len=%d; (hd=%ld; tl=%ld)",
+ debugTrace(DEBUG_sparks,
+ "traversed spark queue, len=%ld; (hd=%ld; tl=%ld)",
sparkPoolSize(pool), pool->bottom, pool->top);
}
/* ----------------------------------------------------------------------------
-
* balanceSparkPoolsCaps: takes an array of capabilities (usually: all
* capabilities) and its size. Accesses all spark pools and equally
* distributes the sparks among them.
*
* Could be called after GC, before Cap. release, from scheduler.
* -------------------------------------------------------------------------- */
-void balanceSparkPoolsCaps(nat n_caps, Capability caps[]);
+void balanceSparkPoolsCaps(nat n_caps, Capability caps[])
+ GNUC3_ATTRIBUTE(__noreturn__);
-void balanceSparkPoolsCaps(nat n_caps, Capability caps[]) {
+void balanceSparkPoolsCaps(nat n_caps STG_UNUSED,
+ Capability caps[] STG_UNUSED) {
barf("not implemented");
}
return 1;
}
-
-#endif /* PARALLEL_HASKELL || THREADED_RTS */
-
-
-/* -----------------------------------------------------------------------------
- *
- * GRAN & PARALLEL_HASKELL stuff beyond here.
- *
- * TODO "nuke" this!
- *
- * -------------------------------------------------------------------------- */
-
-#if defined(PARALLEL_HASKELL) || defined(GRAN)
-
-static void slide_spark_pool( StgSparkPool *pool );
-
-rtsBool
-add_to_spark_queue( StgClosure *closure, StgSparkPool *pool )
-{
- if (pool->tl == pool->lim)
- slide_spark_pool(pool);
-
- if (closure_SHOULD_SPARK(closure) &&
- pool->tl < pool->lim) {
- *(pool->tl++) = closure;
-
-#if defined(PARALLEL_HASKELL)
- // collect parallel global statistics (currently done together with GC stats)
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- // debugBelch("Creating spark for %x @ %11.2f\n", closure, usertime());
- globalParStats.tot_sparks_created++;
- }
-#endif
- return rtsTrue;
- } else {
-#if defined(PARALLEL_HASKELL)
- // collect parallel global statistics (currently done together with GC stats)
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- //debugBelch("Ignoring spark for %x @ %11.2f\n", closure, usertime());
- globalParStats.tot_sparks_ignored++;
- }
-#endif
- return rtsFalse;
- }
-}
-
-static void
-slide_spark_pool( StgSparkPool *pool )
-{
- StgClosure **sparkp, **to_sparkp;
-
- sparkp = pool->hd;
- to_sparkp = pool->base;
- while (sparkp < pool->tl) {
- ASSERT(to_sparkp<=sparkp);
- ASSERT(*sparkp!=NULL);
- ASSERT(LOOKS_LIKE_GHC_INFO((*sparkp)->header.info));
-
- if (closure_SHOULD_SPARK(*sparkp)) {
- *to_sparkp++ = *sparkp++;
- } else {
- sparkp++;
- }
- }
- pool->hd = pool->base;
- pool->tl = to_sparkp;
-}
-
-void
-disposeSpark(spark)
-StgClosure *spark;
-{
-#if !defined(THREADED_RTS)
- Capability *cap;
- StgSparkPool *pool;
-
- cap = &MainRegTable;
- pool = &(cap->rSparks);
- ASSERT(pool->hd <= pool->tl && pool->tl <= pool->lim);
-#endif
- ASSERT(spark != (StgClosure *)NULL);
- /* Do nothing */
-}
-
-
-#elif defined(GRAN)
-
-/*
- Search the spark queue of the proc in event for a spark that's worth
- turning into a thread
- (was gimme_spark in the old RTS)
-*/
-void
-findLocalSpark (rtsEvent *event, rtsBool *found_res, rtsSparkQ *spark_res)
-{
- PEs proc = event->proc, /* proc to search for work */
- creator = event->creator; /* proc that requested work */
- StgClosure* node;
- rtsBool found;
- rtsSparkQ spark_of_non_local_node = NULL,
- spark_of_non_local_node_prev = NULL,
- low_priority_spark = NULL,
- low_priority_spark_prev = NULL,
- spark = NULL, prev = NULL;
-
- /* Choose a spark from the local spark queue */
- prev = (rtsSpark*)NULL;
- spark = pending_sparks_hds[proc];
- found = rtsFalse;
-
- // ToDo: check this code & implement local sparking !! -- HWL
- while (!found && spark != (rtsSpark*)NULL)
- {
- ASSERT((prev!=(rtsSpark*)NULL || spark==pending_sparks_hds[proc]) &&
- (prev==(rtsSpark*)NULL || prev->next==spark) &&
- (spark->prev==prev));
- node = spark->node;
- if (!closure_SHOULD_SPARK(node))
- {
- IF_GRAN_DEBUG(checkSparkQ,
- debugBelch("^^ pruning spark %p (node %p) in gimme_spark",
- spark, node));
-
- if (RtsFlags.GranFlags.GranSimStats.Sparks)
- DumpRawGranEvent(proc, (PEs)0, SP_PRUNED,(StgTSO*)NULL,
- spark->node, spark->name, spark_queue_len(proc));
-
- ASSERT(spark != (rtsSpark*)NULL);
- ASSERT(SparksAvail>0);
- --SparksAvail;
-
- ASSERT(prev==(rtsSpark*)NULL || prev->next==spark);
- spark = delete_from_sparkq (spark, proc, rtsTrue);
- if (spark != (rtsSpark*)NULL)
- prev = spark->prev;
- continue;
- }
- /* -- node should eventually be sparked */
- else if (RtsFlags.GranFlags.PreferSparksOfLocalNodes &&
- !IS_LOCAL_TO(PROCS(node),CurrentProc))
- {
- barf("Local sparking not yet implemented");
-
- /* Remember first low priority spark */
- if (spark_of_non_local_node==(rtsSpark*)NULL) {
- spark_of_non_local_node_prev = prev;
- spark_of_non_local_node = spark;
- }
-
- if (spark->next == (rtsSpark*)NULL) {
- /* ASSERT(spark==SparkQueueTl); just for testing */
- prev = spark_of_non_local_node_prev;
- spark = spark_of_non_local_node;
- found = rtsTrue;
- break;
- }
-
-# if defined(GRAN) && defined(GRAN_CHECK)
- /* Should never happen; just for testing
- if (spark==pending_sparks_tl) {
- debugBelch("ReSchedule: Last spark != SparkQueueTl\n");
- stg_exit(EXIT_FAILURE);
- } */
-# endif
- prev = spark;
- spark = spark->next;
- ASSERT(SparksAvail>0);
- --SparksAvail;
- continue;
- }
- else if ( RtsFlags.GranFlags.DoPrioritySparking ||
- (spark->gran_info >= RtsFlags.GranFlags.SparkPriority2) )
- {
- if (RtsFlags.GranFlags.DoPrioritySparking)
- barf("Priority sparking not yet implemented");
-
- found = rtsTrue;
- }
-#if 0
- else /* only used if SparkPriority2 is defined */
- {
- /* ToDo: fix the code below and re-integrate it */
- /* Remember first low priority spark */
- if (low_priority_spark==(rtsSpark*)NULL) {
- low_priority_spark_prev = prev;
- low_priority_spark = spark;
- }
-
- if (spark->next == (rtsSpark*)NULL) {
- /* ASSERT(spark==spark_queue_tl); just for testing */
- prev = low_priority_spark_prev;
- spark = low_priority_spark;
- found = rtsTrue; /* take low pri spark => rc is 2 */
- break;
- }
-
- /* Should never happen; just for testing
- if (spark==pending_sparks_tl) {
- debugBelch("ReSchedule: Last spark != SparkQueueTl\n");
- stg_exit(EXIT_FAILURE);
- break;
- } */
- prev = spark;
- spark = spark->next;
-
- IF_GRAN_DEBUG(pri,
- debugBelch("++ Ignoring spark of priority %u (SparkPriority=%u); node=%p; name=%u\n",
- spark->gran_info, RtsFlags.GranFlags.SparkPriority,
- spark->node, spark->name);)
- }
-#endif
- } /* while (spark!=NULL && !found) */
-
- *spark_res = spark;
- *found_res = found;
-}
-
-/*
- Turn the spark into a thread.
- In GranSim this basically means scheduling a StartThread event for the
- node pointed to by the spark at some point in the future.
- (was munch_spark in the old RTS)
-*/
-rtsBool
-activateSpark (rtsEvent *event, rtsSparkQ spark)
-{
- PEs proc = event->proc, /* proc to search for work */
- creator = event->creator; /* proc that requested work */
- StgTSO* tso;
- StgClosure* node;
- rtsTime spark_arrival_time;
-
- /*
- We've found a node on PE proc requested by PE creator.
- If proc==creator we can turn the spark into a thread immediately;
- otherwise we schedule a MoveSpark event on the requesting PE
- */
-
- /* DaH Qu' yIchen */
- if (proc!=creator) {
-
- /* only possible if we simulate GUM style fishing */
- ASSERT(RtsFlags.GranFlags.Fishing);
-
- /* Message packing costs for sending a Fish; qeq jabbI'ID */
- CurrentTime[proc] += RtsFlags.GranFlags.Costs.mpacktime;
-
- if (RtsFlags.GranFlags.GranSimStats.Sparks)
- DumpRawGranEvent(proc, (PEs)0, SP_EXPORTED,
- (StgTSO*)NULL, spark->node,
- spark->name, spark_queue_len(proc));
-
- /* time of the spark arrival on the remote PE */
- spark_arrival_time = CurrentTime[proc] + RtsFlags.GranFlags.Costs.latency;
-
- new_event(creator, proc, spark_arrival_time,
- MoveSpark,
- (StgTSO*)NULL, spark->node, spark);
-
- CurrentTime[proc] += RtsFlags.GranFlags.Costs.mtidytime;
-
- } else { /* proc==creator i.e. turn the spark into a thread */
-
- if ( RtsFlags.GranFlags.GranSimStats.Global &&
- spark->gran_info < RtsFlags.GranFlags.SparkPriority2 ) {
-
- globalGranStats.tot_low_pri_sparks++;
- IF_GRAN_DEBUG(pri,
- debugBelch("++ No high priority spark available; low priority (%u) spark chosen: node=%p; name=%u\n",
- spark->gran_info,
- spark->node, spark->name));
- }
-
- CurrentTime[proc] += RtsFlags.GranFlags.Costs.threadcreatetime;
-
- node = spark->node;
-
-# if 0
- /* ToDo: fix the GC interface and move to StartThread handling-- HWL */
- if (GARBAGE COLLECTION IS NECESSARY) {
- /* Some kind of backoff needed here in case there's too little heap */
-# if defined(GRAN_CHECK) && defined(GRAN)
- if (RtsFlags.GcFlags.giveStats)
- fprintf(RtsFlags.GcFlags.statsFile,"***** vIS Qu' chen veQ boSwI'; spark=%p, node=%p; name=%u\n",
- /* (found==2 ? "no hi pri spark" : "hi pri spark"), */
- spark, node, spark->name);
-# endif
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc]+1,
- FindWork,
- (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
- barf("//// activateSpark: out of heap ; ToDo: call GarbageCollect()");
- GarbageCollect(GetRoots, rtsFalse);
- // HWL old: ReallyPerformThreadGC(TSO_HS+TSO_CTS_SIZE,rtsFalse);
- // HWL old: SAVE_Hp -= TSO_HS+TSO_CTS_SIZE;
- spark = NULL;
- return; /* was: continue; */ /* to the next event, eventually */
- }
-# endif
-
- if (RtsFlags.GranFlags.GranSimStats.Sparks)
- DumpRawGranEvent(CurrentProc,(PEs)0,SP_USED,(StgTSO*)NULL,
- spark->node, spark->name,
- spark_queue_len(CurrentProc));
-
- new_event(proc, proc, CurrentTime[proc],
- StartThread,
- END_TSO_QUEUE, node, spark); // (rtsSpark*)NULL);
-
- procStatus[proc] = Starting;
- }
-}
-
-/* -------------------------------------------------------------------------
- This is the main point where handling granularity information comes into
- play.
- ------------------------------------------------------------------------- */
-
-#define MAX_RAND_PRI 100
-
-/*
- Granularity info transformers.
- Applied to the GRAN_INFO field of a spark.
-*/
-STATIC_INLINE nat ID(nat x) { return(x); };
-STATIC_INLINE nat INV(nat x) { return(-x); };
-STATIC_INLINE nat IGNORE(nat x) { return (0); };
-STATIC_INLINE nat RAND(nat x) { return ((random() % MAX_RAND_PRI) + 1); }
-
-/* NB: size_info and par_info are currently unused (what a shame!) -- HWL */
-rtsSpark *
-newSpark(node,name,gran_info,size_info,par_info,local)
-StgClosure *node;
-nat name, gran_info, size_info, par_info, local;
-{
- nat pri;
- rtsSpark *newspark;
-
- pri = RtsFlags.GranFlags.RandomPriorities ? RAND(gran_info) :
- RtsFlags.GranFlags.InversePriorities ? INV(gran_info) :
- RtsFlags.GranFlags.IgnorePriorities ? IGNORE(gran_info) :
- ID(gran_info);
-
- if ( RtsFlags.GranFlags.SparkPriority!=0 &&
- pri<RtsFlags.GranFlags.SparkPriority ) {
- IF_GRAN_DEBUG(pri,
- debugBelch(",, NewSpark: Ignoring spark of priority %u (SparkPriority=%u); node=%#x; name=%u\n",
- pri, RtsFlags.GranFlags.SparkPriority, node, name));
- return ((rtsSpark*)NULL);
- }
-
- newspark = (rtsSpark*) stgMallocBytes(sizeof(rtsSpark), "NewSpark");
- newspark->prev = newspark->next = (rtsSpark*)NULL;
- newspark->node = node;
- newspark->name = (name==1) ? CurrentTSO->gran.sparkname : name;
- newspark->gran_info = pri;
- newspark->global = !local; /* Check that with parAt, parAtAbs !!*/
-
- if (RtsFlags.GranFlags.GranSimStats.Global) {
- globalGranStats.tot_sparks_created++;
- globalGranStats.sparks_created_on_PE[CurrentProc]++;
- }
-
- return(newspark);
-}
-
-void
-disposeSpark(spark)
-rtsSpark *spark;
-{
- ASSERT(spark!=NULL);
- stgFree(spark);
-}
-
-void
-disposeSparkQ(spark)
-rtsSparkQ spark;
-{
- if (spark==NULL)
- return;
-
- disposeSparkQ(spark->next);
-
-# ifdef GRAN_CHECK
- if (SparksAvail < 0) {
- debugBelch("disposeSparkQ: SparksAvail<0 after disposing sparkq @ %p\n", &spark);
- print_spark(spark);
- }
-# endif
-
- stgFree(spark);
-}
-
-/*
- With PrioritySparking add_to_spark_queue performs an insert sort to keep
- the spark queue sorted. Otherwise the spark is just added to the end of
- the queue.
-*/
-
-void
-add_to_spark_queue(spark)
-rtsSpark *spark;
-{
- rtsSpark *prev = NULL, *next = NULL;
- nat count = 0;
- rtsBool found = rtsFalse;
-
- if ( spark == (rtsSpark *)NULL ) {
- return;
- }
-
- if (RtsFlags.GranFlags.DoPrioritySparking && (spark->gran_info != 0) ) {
- /* Priority sparking is enabled i.e. spark queues must be sorted */
-
- for (prev = NULL, next = pending_sparks_hd, count=0;
- (next != NULL) &&
- !(found = (spark->gran_info >= next->gran_info));
- prev = next, next = next->next, count++)
- {}
-
- } else { /* 'utQo' */
- /* Priority sparking is disabled */
-
- found = rtsFalse; /* to add it at the end */
-
- }
-
- if (found) {
- /* next points to the first spark with a gran_info smaller than that
- of spark; therefore, add spark before next into the spark queue */
- spark->next = next;
- if ( next == NULL ) {
- pending_sparks_tl = spark;
- } else {
- next->prev = spark;
- }
- spark->prev = prev;
- if ( prev == NULL ) {
- pending_sparks_hd = spark;
- } else {
- prev->next = spark;
- }
- } else { /* (RtsFlags.GranFlags.DoPrioritySparking && !found) || !DoPrioritySparking */
- /* add the spark at the end of the spark queue */
- spark->next = NULL;
- spark->prev = pending_sparks_tl;
- if (pending_sparks_hd == NULL)
- pending_sparks_hd = spark;
- else
- pending_sparks_tl->next = spark;
- pending_sparks_tl = spark;
- }
- ++SparksAvail;
-
- /* add costs for search in priority sparking */
- if (RtsFlags.GranFlags.DoPrioritySparking) {
- CurrentTime[CurrentProc] += count * RtsFlags.GranFlags.Costs.pri_spark_overhead;
- }
-
- IF_GRAN_DEBUG(checkSparkQ,
- debugBelch("++ Spark stats after adding spark %p (node %p) to queue on PE %d",
- spark, spark->node, CurrentProc);
- print_sparkq_stats());
-
-# if defined(GRAN_CHECK)
- if (RtsFlags.GranFlags.Debug.checkSparkQ) {
- for (prev = NULL, next = pending_sparks_hd;
- (next != NULL);
- prev = next, next = next->next)
- {}
- if ( (prev!=NULL) && (prev!=pending_sparks_tl) )
- debugBelch("SparkQ inconsistency after adding spark %p: (PE %u) pending_sparks_tl (%p) not end of queue (%p)\n",
- spark,CurrentProc,
- pending_sparks_tl, prev);
- }
-# endif
-
-# if defined(GRAN_CHECK)
- /* Check if the sparkq is still sorted. Just for testing, really! */
- if ( RtsFlags.GranFlags.Debug.checkSparkQ &&
- RtsFlags.GranFlags.Debug.pri ) {
- rtsBool sorted = rtsTrue;
- rtsSpark *prev, *next;
-
- if (pending_sparks_hd == NULL ||
- pending_sparks_hd->next == NULL ) {
- /* just 1 elem => ok */
- } else {
- for (prev = pending_sparks_hd,
- next = pending_sparks_hd->next;
- (next != NULL) ;
- prev = next, next = next->next) {
- sorted = sorted &&
- (prev->gran_info >= next->gran_info);
- }
- }
- if (!sorted) {
- debugBelch("ghuH: SPARKQ on PE %d is not sorted:\n",
- CurrentProc);
- print_sparkq(CurrentProc);
- }
- }
-# endif
-}
-
-nat
-spark_queue_len(proc)
-PEs proc;
-{
- rtsSpark *prev, *spark; /* prev only for testing !! */
- nat len;
-
- for (len = 0, prev = NULL, spark = pending_sparks_hds[proc];
- spark != NULL;
- len++, prev = spark, spark = spark->next)
- {}
-
-# if defined(GRAN_CHECK)
- if ( RtsFlags.GranFlags.Debug.checkSparkQ )
- if ( (prev!=NULL) && (prev!=pending_sparks_tls[proc]) )
- debugBelch("ERROR in spark_queue_len: (PE %u) pending_sparks_tl (%p) not end of queue (%p)\n",
- proc, pending_sparks_tls[proc], prev);
-# endif
-
- return (len);
-}
-
-/*
- Take spark out of the spark queue on PE p and nuke the spark. Adjusts
- hd and tl pointers of the spark queue. Returns a pointer to the next
- spark in the queue.
-*/
-rtsSpark *
-delete_from_sparkq (spark, p, dispose_too) /* unlink and dispose spark */
-rtsSpark *spark;
-PEs p;
-rtsBool dispose_too;
-{
- rtsSpark *new_spark;
-
- if (spark==NULL)
- barf("delete_from_sparkq: trying to delete NULL spark\n");
-
-# if defined(GRAN_CHECK)
- if ( RtsFlags.GranFlags.Debug.checkSparkQ ) {
- debugBelch("## |%p:%p| (%p)<-spark=%p->(%p) <-(%p)\n",
- pending_sparks_hd, pending_sparks_tl,
- spark->prev, spark, spark->next,
- (spark->next==NULL ? 0 : spark->next->prev));
- }
-# endif
-
- if (spark->prev==NULL) {
- /* spark is first spark of queue => adjust hd pointer */
- ASSERT(pending_sparks_hds[p]==spark);
- pending_sparks_hds[p] = spark->next;
- } else {
- spark->prev->next = spark->next;
- }
- if (spark->next==NULL) {
- ASSERT(pending_sparks_tls[p]==spark);
- /* spark is first spark of queue => adjust tl pointer */
- pending_sparks_tls[p] = spark->prev;
- } else {
- spark->next->prev = spark->prev;
- }
- new_spark = spark->next;
-
-# if defined(GRAN_CHECK)
- if ( RtsFlags.GranFlags.Debug.checkSparkQ ) {
- debugBelch("## |%p:%p| (%p)<-spark=%p->(%p) <-(%p); spark=%p will be deleted NOW \n",
- pending_sparks_hd, pending_sparks_tl,
- spark->prev, spark, spark->next,
- (spark->next==NULL ? 0 : spark->next->prev), spark);
- }
-# endif
-
- if (dispose_too)
- disposeSpark(spark);
-
- return new_spark;
-}
-
-/* Mark all nodes pointed to by sparks in the spark queues (for GC) */
-void
-markSparkQueue(void)
-{
- StgClosure *MarkRoot(StgClosure *root); // prototype
- PEs p;
- rtsSpark *sp;
-
- for (p=0; p<RtsFlags.GranFlags.proc; p++)
- for (sp=pending_sparks_hds[p]; sp!=NULL; sp=sp->next) {
- ASSERT(sp->node!=NULL);
- ASSERT(LOOKS_LIKE_GHC_INFO(sp->node->header.info));
- // ToDo?: statistics gathering here (also for GUM!)
- sp->node = (StgClosure *)MarkRoot(sp->node);
- }
-
- IF_DEBUG(gc,
- debugBelch("markSparkQueue: spark statistics at start of GC:");
- print_sparkq_stats());
-}
-
-void
-print_spark(spark)
-rtsSpark *spark;
-{
- char str[16];
-
- if (spark==NULL) {
- debugBelch("Spark: NIL\n");
- return;
- } else {
- sprintf(str,
- ((spark->node==NULL) ? "______" : "%#6lx"),
- stgCast(StgPtr,spark->node));
-
- debugBelch("Spark: Node %8s, Name %#6x, Global %5s, Creator %5x, Prev %6p, Next %6p\n",
- str, spark->name,
- ((spark->global)==rtsTrue?"True":"False"), spark->creator,
- spark->prev, spark->next);
- }
-}
-
-void
-print_sparkq(proc)
-PEs proc;
-// rtsSpark *hd;
-{
- rtsSpark *x = pending_sparks_hds[proc];
-
- debugBelch("Spark Queue of PE %d with root at %p:\n", proc, x);
- for (; x!=(rtsSpark*)NULL; x=x->next) {
- print_spark(x);
- }
-}
-
-/*
- Print a statistics of all spark queues.
-*/
-void
-print_sparkq_stats(void)
-{
- PEs p;
-
- debugBelch("SparkQs: [");
- for (p=0; p<RtsFlags.GranFlags.proc; p++)
- debugBelch(", PE %d: %d", p, spark_queue_len(p));
- debugBelch("\n");
-}
-
-#endif
+#endif /* THREADED_RTS */
projects / ghc-hetmet.git / blobdiff