jsscope.c

java script test programing source code

                 ? JS_GetStringBytes(ATOM_TO_STRING(atom))
                 : "unknown";
        } else if (JSID_IS_INT(sprop->id)) {
            JS_snprintf(buf2, sizeof buf2, "%d", JSID_TO_INT(sprop->id));
            id = buf2;
        } else {
            id = "<object>";
        }
#endif

        if (sprop->attrs & JSPROP_GETTER) {
#ifdef GC_MARK_DEBUG
            JS_snprintf(buf, sizeof buf, "%s %s",
                        id, js_getter_str);
#endif
            GC_MARK(cx, JSVAL_TO_GCTHING((jsval) sprop->getter), buf);
        }
        if (sprop->attrs & JSPROP_SETTER) {
#ifdef GC_MARK_DEBUG
            JS_snprintf(buf, sizeof buf, "%s %s",
                        id, js_setter_str);
#endif
            GC_MARK(cx, JSVAL_TO_GCTHING((jsval) sprop->setter), buf);
        }
    }
#endif /* JS_HAS_GETTER_SETTER */
}

#ifdef DUMP_SCOPE_STATS

#include <stdio.h>
#include <math.h>

uint32 js_nkids_max;
uint32 js_nkids_sum;
double js_nkids_sqsum;
uint32 js_nkids_hist[11];

static void
MeterKidCount(uintN nkids)
{
    if (nkids) {
        js_nkids_sum += nkids;
        js_nkids_sqsum += (double)nkids * nkids;
        if (nkids > js_nkids_max)
            js_nkids_max = nkids;
    }
    js_nkids_hist[JS_MIN(nkids, 10)]++;
}

static void
MeterPropertyTree(JSScopeProperty *node)
{
    uintN i, nkids;
    JSScopeProperty *kids, *kid;
    PropTreeKidsChunk *chunk;

    nkids = 0;
    kids = node->kids;
    if (kids) {
        if (KIDS_IS_CHUNKY(kids)) {
            for (chunk = KIDS_TO_CHUNK(kids); chunk; chunk = chunk->next) {
                for (i = 0; i < MAX_KIDS_PER_CHUNK; i++) {
                    kid = chunk->kids[i];
                    if (!kid)
                        break;
                    MeterPropertyTree(kid);
                    nkids++;
                }
            }
        } else {
            MeterPropertyTree(kids);
            nkids = 1;
        }
    }

    MeterKidCount(nkids);
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_MeterPropertyTree(JSDHashTable *table, JSDHashEntryHdr *hdr, uint32 number,
                     void *arg)
{
    JSPropertyTreeEntry *entry = (JSPropertyTreeEntry *)hdr;

    MeterPropertyTree(entry->child);
    return JS_DHASH_NEXT;
}

static void
DumpSubtree(JSScopeProperty *sprop, int level, FILE *fp)
{
    char buf[10];
    JSScopeProperty *kids, *kid;
    PropTreeKidsChunk *chunk;
    uintN i;

    fprintf(fp, "%*sid %s g/s %p/%p slot %lu attrs %x flags %x shortid %d\n",
            level, "",
            JSID_IS_ATOM(sprop->id)
            ? JS_GetStringBytes(ATOM_TO_STRING(JSID_TO_ATOM(sprop->id)))
            : JSID_IS_OBJECT(sprop->id)
            ? js_ValueToPrintableString(cx, OBJECT_JSID_TO_JSVAL(sprop->id))
            : (JS_snprintf(buf, sizeof buf, "%ld", JSVAL_TO_INT(sprop->id)),
               buf)
            (void *) sprop->getter, (void *) sprop->setter,
            (unsigned long) sprop->slot, sprop->attrs, sprop->flags,
            sprop->shortid);
    kids = sprop->kids;
    if (kids) {
        ++level;
        if (KIDS_IS_CHUNKY(kids)) {
            chunk = KIDS_TO_CHUNK(kids);
            do {
                for (i = 0; i < MAX_KIDS_PER_CHUNK; i++) {
                    kid = chunk->kids[i];
                    if (!kid)
                        break;
                    JS_ASSERT(kid->parent == sprop);
                    DumpSubtree(kid, level, fp);
                }
            } while ((chunk = chunk->next) != NULL);
        } else {
            kid = kids;
            DumpSubtree(kid, level, fp);
        }
    }
}

#endif /* DUMP_SCOPE_STATS */

void
js_SweepScopeProperties(JSRuntime *rt)
{
    JSArena **ap, *a;
    JSScopeProperty *limit, *sprop, *parent, *kids, *kid;
    uintN liveCount;
    PropTreeKidsChunk *chunk, *nextChunk, *freeChunk;
    uintN i;

#ifdef DUMP_SCOPE_STATS
    uint32 livePropCapacity = 0, totalLiveCount = 0;
    static FILE *logfp;
    if (!logfp)
        logfp = fopen("/tmp/proptree.stats", "a");

    MeterKidCount(rt->propertyTreeHash.entryCount);
    JS_DHashTableEnumerate(&rt->propertyTreeHash, js_MeterPropertyTree, NULL);

    {
        double mean = 0.0, var = 0.0, sigma = 0.0;
        double nodesum = rt->livePropTreeNodes;
        double kidsum = js_nkids_sum;
        if (nodesum > 0 && kidsum >= 0) {
            mean = kidsum / nodesum;
            var = nodesum * js_nkids_sqsum - kidsum * kidsum;
            if (var < 0.0 || nodesum <= 1)
                var = 0.0;
            else
                var /= nodesum * (nodesum - 1);

            /* Windows says sqrt(0.0) is "-1.#J" (?!) so we must test. */
            sigma = (var != 0.0) ? sqrt(var) : 0.0;
        }

        fprintf(logfp,
                "props %u nodes %g beta %g meankids %g sigma %g max %u",
                rt->liveScopeProps, nodesum, nodesum / rt->liveScopeProps,
                mean, sigma, js_nkids_max);
    }

    fprintf(logfp, " histogram %u %u %u %u %u %u %u %u %u %u %u",
            js_nkids_hist[0], js_nkids_hist[1],
            js_nkids_hist[2], js_nkids_hist[3],
            js_nkids_hist[4], js_nkids_hist[5],
            js_nkids_hist[6], js_nkids_hist[7],
            js_nkids_hist[8], js_nkids_hist[9],
            js_nkids_hist[10]);
    js_nkids_sum = js_nkids_max = 0;
    js_nkids_sqsum = 0;
    memset(js_nkids_hist, 0, sizeof js_nkids_hist);
#endif

    ap = &rt->propertyArenaPool.first.next;
    while ((a = *ap) != NULL) {
        limit = (JSScopeProperty *) a->avail;
        liveCount = 0;
        for (sprop = (JSScopeProperty *) a->base; sprop < limit; sprop++) {
            /* If the id is null, sprop is already on the freelist. */
            if (sprop->id == JSVAL_NULL)
                continue;

            /* If the mark bit is set, sprop is alive, so we skip it. */
            if (sprop->flags & SPROP_MARK) {
                sprop->flags &= ~SPROP_MARK;
                liveCount++;
                continue;
            }

            /* Ok, sprop is garbage to collect: unlink it from its parent. */
            freeChunk = RemovePropertyTreeChild(rt, sprop);

            /*
             * Take care to reparent all sprop's kids to their grandparent.
             * InsertPropertyTreeChild can potentially fail for two reasons:
             *
             * 1. If parent is null, insertion into the root property hash
             *    table may fail. We are forced to leave the kid out of the
             *    table (as can already happen with duplicates) but ensure
             *    that the kid's parent pointer is set to null.
             *
             * 2. If parent is non-null, allocation of a new KidsChunk can
             *    fail. To prevent this from happening, we allow sprops's own
             *    chunks to be reused by the grandparent, which removes the
             *    need for InsertPropertyTreeChild to malloc a new KidsChunk.
             *
             *    If sprop does not have chunky kids, then we rely on the
             *    RemovePropertyTreeChild call above (which removed sprop from
             *    its parent) either leaving one free entry, or else returning
             *    the now-unused chunk to us so we can reuse it.
             *
             * We also require the grandparent to have either no kids or else
             * chunky kids. A single non-chunky kid would force a new chunk to
             * be malloced in some cases (if sprop had a single non-chunky
             * kid, or a multiple of MAX_KIDS_PER_CHUNK kids). Note that
             * RemovePropertyTreeChild never converts a single-entry chunky
             * kid back to a non-chunky kid, so we are assured of correct
             * behaviour.
             */
            kids = sprop->kids;
            if (kids) {
                sprop->kids = NULL;
                parent = sprop->parent;
                /* Validate that grandparent has no kids or chunky kids. */
                JS_ASSERT(!parent || !parent->kids ||
                          KIDS_IS_CHUNKY(parent->kids));
                if (KIDS_IS_CHUNKY(kids)) {
                    chunk = KIDS_TO_CHUNK(kids);
                    do {
                        nextChunk = chunk->next;
                        chunk->next = NULL;
                        for (i = 0; i < MAX_KIDS_PER_CHUNK; i++) {
                            kid = chunk->kids[i];
                            if (!kid)
                                break;
                            JS_ASSERT(kid->parent == sprop);

                            /*
                             * Clear a space in the kids array for possible
                             * re-use by InsertPropertyTreeChild.
                             */
                            chunk->kids[i] = NULL;
                            if (!InsertPropertyTreeChild(rt, parent, kid,
                                                         chunk)) {
                                /*
                                 * This can happen only if we failed to add an
                                 * entry to the root property hash table.
                                 */
                                JS_ASSERT(!parent);
                                kid->parent = NULL;
                            }
                        }
                        if (!chunk->kids[0]) {
                            /* The chunk wasn't reused, so we must free it. */
                            DestroyPropTreeKidsChunk(rt, chunk);
                        }
                    } while ((chunk = nextChunk) != NULL);
                } else {
                    kid = kids;
                    if (!InsertPropertyTreeChild(rt, parent, kid, freeChunk)) {
                        /*
                         * This can happen only if we failed to add an entry
                         * to the root property hash table.
                         */
                        JS_ASSERT(!parent);
                        kid->parent = NULL;
                    }
                }
            }

            if (freeChunk && !freeChunk->kids[0]) {
                /* The chunk wasn't reused, so we must free it. */
                DestroyPropTreeKidsChunk(rt, freeChunk);
            }

            /* Clear id so we know (above) that sprop is on the freelist. */
            sprop->id = JSVAL_NULL;
            FREENODE_INSERT(rt->propertyFreeList, sprop);
            JS_RUNTIME_UNMETER(rt, livePropTreeNodes);
        }

        /* If a contains no live properties, return it to the malloc heap. */
        if (liveCount == 0) {
            for (sprop = (JSScopeProperty *) a->base; sprop < limit; sprop++)
                FREENODE_REMOVE(sprop);
            JS_ARENA_DESTROY(&rt->propertyArenaPool, a, ap);
        } else {
#ifdef DUMP_SCOPE_STATS
            livePropCapacity += limit - (JSScopeProperty *) a->base;
            totalLiveCount += liveCount;
#endif
            ap = &a->next;
        }
    }

#ifdef DUMP_SCOPE_STATS
    fprintf(logfp, " arenautil %g%%\n",
            (totalLiveCount * 100.0) / livePropCapacity);
    fflush(logfp);
#endif

#ifdef DUMP_PROPERTY_TREE
    {
        FILE *dumpfp = fopen("/tmp/proptree.dump", "w");
        if (dumpfp) {
            JSPropertyTreeEntry *pte, *end;

            pte = (JSPropertyTreeEntry *) rt->propertyTreeHash.entryStore;
            end = pte + JS_DHASH_TABLE_SIZE(&rt->propertyTreeHash);
            while (pte < end) {
                if (pte->child)
                    DumpSubtree(pte->child, 0, dumpfp);
                pte++;
            }
            fclose(dumpfp);
        }
    }
#endif
}

JSBool
js_InitPropertyTree(JSRuntime *rt)
{
    if (!JS_DHashTableInit(&rt->propertyTreeHash, &PropertyTreeHashOps, NULL,
                           sizeof(JSPropertyTreeEntry), JS_DHASH_MIN_SIZE)) {
        rt->propertyTreeHash.ops = NULL;
        return JS_FALSE;
    }
    JS_InitArenaPool(&rt->propertyArenaPool, "properties",
                     256 * sizeof(JSScopeProperty), sizeof(void *));
    return JS_TRUE;
}

void
js_FinishPropertyTree(JSRuntime *rt)
{
    if (rt->propertyTreeHash.ops) {
        JS_DHashTableFinish(&rt->propertyTreeHash);
        rt->propertyTreeHash.ops = NULL;
    }
    JS_FinishArenaPool(&rt->propertyArenaPool);
}