Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 826 insertions, 0 deletions

diff --git a/src/libs/xpcom18a4/xpcom/ds/pldhash.c b/src/libs/xpcom18a4/xpcom/ds/pldhash.c
new file mode 100644
index 00000000..74f8cd0e
--- /dev/null
+++ b/src/libs/xpcom18a4/xpcom/ds/pldhash.c
@@ -0,0 +1,826 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla JavaScript code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1999-2001
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Brendan Eich <brendan@mozilla.org> (Original Author)
+ *   Chris Waterson <waterson@netscape.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/*
+ * Double hashing implementation.
+ * GENERATED BY js/src/plify_jsdhash.sed -- DO NOT EDIT!!!
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "prbit.h"
+#include "pldhash.h"
+#include "prlog.h"     /* for PR_ASSERT */
+
+#ifdef PL_DHASHMETER
+# if defined MOZILLA_CLIENT && defined DEBUG_XXXbrendan
+#  include "nsTraceMalloc.h"
+# endif
+# define METER(x)       x
+#else
+# define METER(x)       /* nothing */
+#endif
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+# include <iprt/mem.h>
+#endif
+
+PR_IMPLEMENT(void *)
+PL_DHashAllocTable(PLDHashTable *table, PRUint32 nbytes)
+{
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+    return RTMemAlloc(nbytes);
+#else
+    return malloc(nbytes);
+#endif
+}
+
+PR_IMPLEMENT(void)
+PL_DHashFreeTable(PLDHashTable *table, void *ptr)
+{
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+    RTMemFree(ptr);
+#else
+    free(ptr);
+#endif
+}
+
+PR_IMPLEMENT(PLDHashNumber)
+PL_DHashStringKey(PLDHashTable *table, const void *key)
+{
+    PLDHashNumber h;
+    const unsigned char *s;
+
+    h = 0;
+    for (s = key; *s != '\0'; s++)
+        h = (h >> (PL_DHASH_BITS - 4)) ^ (h << 4) ^ *s;
+    return h;
+}
+
+PR_IMPLEMENT(const void *)
+PL_DHashGetKeyStub(PLDHashTable *table, PLDHashEntryHdr *entry)
+{
+    PLDHashEntryStub *stub = (PLDHashEntryStub *)entry;
+
+    return stub->key;
+}
+
+PR_IMPLEMENT(PLDHashNumber)
+PL_DHashVoidPtrKeyStub(PLDHashTable *table, const void *key)
+{
+    return (PLDHashNumber)(uintptr_t)key >> 2;
+}
+
+PR_IMPLEMENT(PRBool)
+PL_DHashMatchEntryStub(PLDHashTable *table,
+                       const PLDHashEntryHdr *entry,
+                       const void *key)
+{
+    const PLDHashEntryStub *stub = (const PLDHashEntryStub *)entry;
+
+    return stub->key == key;
+}
+
+PR_IMPLEMENT(PRBool)
+PL_DHashMatchStringKey(PLDHashTable *table,
+                       const PLDHashEntryHdr *entry,
+                       const void *key)
+{
+    const PLDHashEntryStub *stub = (const PLDHashEntryStub *)entry;
+
+    /* XXX tolerate null keys on account of sloppy Mozilla callers. */
+    return stub->key == key ||
+           (stub->key && key && strcmp(stub->key, key) == 0);
+}
+
+PR_IMPLEMENT(void)
+PL_DHashMoveEntryStub(PLDHashTable *table,
+                      const PLDHashEntryHdr *from,
+                      PLDHashEntryHdr *to)
+{
+    memcpy(to, from, table->entrySize);
+}
+
+PR_IMPLEMENT(void)
+PL_DHashClearEntryStub(PLDHashTable *table, PLDHashEntryHdr *entry)
+{
+    memset(entry, 0, table->entrySize);
+}
+
+PR_IMPLEMENT(void)
+PL_DHashFreeStringKey(PLDHashTable *table, PLDHashEntryHdr *entry)
+{
+    const PLDHashEntryStub *stub = (const PLDHashEntryStub *)entry;
+
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+    RTMemFree((void *) stub->key);
+#else
+    free((void *) stub->key);
+#endif
+    memset(entry, 0, table->entrySize);
+}
+
+PR_IMPLEMENT(void)
+PL_DHashFinalizeStub(PLDHashTable *table)
+{
+}
+
+static const PLDHashTableOps stub_ops = {
+    PL_DHashAllocTable,
+    PL_DHashFreeTable,
+    PL_DHashGetKeyStub,
+    PL_DHashVoidPtrKeyStub,
+    PL_DHashMatchEntryStub,
+    PL_DHashMoveEntryStub,
+    PL_DHashClearEntryStub,
+    PL_DHashFinalizeStub,
+    NULL
+};
+
+PR_IMPLEMENT(const PLDHashTableOps *)
+PL_DHashGetStubOps(void)
+{
+    return &stub_ops;
+}
+
+PR_IMPLEMENT(PLDHashTable *)
+PL_NewDHashTable(const PLDHashTableOps *ops, void *data, PRUint32 entrySize,
+                 PRUint32 capacity)
+{
+    PLDHashTable *table;
+
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+    table = (PLDHashTable *) RTMemAlloc(sizeof *table);
+#else
+    table = (PLDHashTable *) malloc(sizeof *table);
+#endif
+    if (!table)
+        return NULL;
+    if (!PL_DHashTableInit(table, ops, data, entrySize, capacity)) {
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+        RTMemFree(table);
+#else
+        free(table);
+#endif
+        return NULL;
+    }
+    return table;
+}
+
+PR_IMPLEMENT(void)
+PL_DHashTableDestroy(PLDHashTable *table)
+{
+    PL_DHashTableFinish(table);
+#ifdef VBOX_USE_IPRT_IN_XPCOM
+    RTMemFree(table);
+#else
+    free(table);
+#endif
+}
+
+PR_IMPLEMENT(PRBool)
+PL_DHashTableInit(PLDHashTable *table, const PLDHashTableOps *ops, void *data,
+                  PRUint32 entrySize, PRUint32 capacity)
+{
+    int log2;
+    PRUint32 nbytes;
+
+#ifdef DEBUG
+    if (entrySize > 10 * sizeof(void *)) {
+        fprintf(stderr,
+                "pldhash: for the table at address %p, the given entrySize"
+                " of %lu %s favors chaining over double hashing.\n",
+                (void *)table,
+                (unsigned long) entrySize,
+                (entrySize > 16 * sizeof(void*)) ? "definitely" : "probably");
+    }
+#endif
+
+    table->ops = ops;
+    table->data = data;
+    if (capacity < PL_DHASH_MIN_SIZE)
+        capacity = PL_DHASH_MIN_SIZE;
+    log2 = PR_CeilingLog2(capacity);
+    capacity = PR_BIT(log2);
+    if (capacity >= PL_DHASH_SIZE_LIMIT)
+        return PR_FALSE;
+    table->hashShift = PL_DHASH_BITS - log2;
+    table->maxAlphaFrac = 0xC0;                 /* .75 */
+    table->minAlphaFrac = 0x40;                 /* .25 */
+    table->entrySize = entrySize;
+    table->entryCount = table->removedCount = 0;
+    table->generation = 0;
+    nbytes = capacity * entrySize;
+
+    table->entryStore = ops->allocTable(table, nbytes);
+    if (!table->entryStore)
+        return PR_FALSE;
+    memset(table->entryStore, 0, nbytes);
+    METER(memset(&table->stats, 0, sizeof table->stats));
+    return PR_TRUE;
+}
+
+/*
+ * Compute max and min load numbers (entry counts) from table params.
+ */
+#define MAX_LOAD(table, size)   (((table)->maxAlphaFrac * (size)) >> 8)
+#define MIN_LOAD(table, size)   (((table)->minAlphaFrac * (size)) >> 8)
+
+PR_IMPLEMENT(void)
+PL_DHashTableSetAlphaBounds(PLDHashTable *table,
+                            float maxAlpha,
+                            float minAlpha)
+{
+    PRUint32 size;
+
+    /*
+     * Reject obviously insane bounds, rather than trying to guess what the
+     * buggy caller intended.
+     */
+    PR_ASSERT(0.5 <= maxAlpha && maxAlpha < 1 && 0 <= minAlpha);
+    if (maxAlpha < 0.5 || 1 <= maxAlpha || minAlpha < 0)
+        return;
+
+    /*
+     * Ensure that at least one entry will always be free.  If maxAlpha at
+     * minimum size leaves no entries free, reduce maxAlpha based on minimum
+     * size and the precision limit of maxAlphaFrac's fixed point format.
+     */
+    PR_ASSERT(PL_DHASH_MIN_SIZE - (maxAlpha * PL_DHASH_MIN_SIZE) >= 1);
+    if (PL_DHASH_MIN_SIZE - (maxAlpha * PL_DHASH_MIN_SIZE) < 1) {
+        maxAlpha = (float)
+                   (PL_DHASH_MIN_SIZE - PR_MAX(PL_DHASH_MIN_SIZE / 256, 1))
+                   / PL_DHASH_MIN_SIZE;
+    }
+
+    /*
+     * Ensure that minAlpha is strictly less than half maxAlpha.  Take care
+     * not to truncate an entry's worth of alpha when storing in minAlphaFrac
+     * (8-bit fixed point format).
+     */
+    PR_ASSERT(minAlpha < maxAlpha / 2);
+    if (minAlpha >= maxAlpha / 2) {
+        size = PL_DHASH_TABLE_SIZE(table);
+        minAlpha = (size * maxAlpha - PR_MAX(size / 256, 1)) / (2 * size);
+    }
+
+    table->maxAlphaFrac = (uint8)(maxAlpha * 256);
+    table->minAlphaFrac = (uint8)(minAlpha * 256);
+}
+
+/*
+ * Double hashing needs the second hash code to be relatively prime to table
+ * size, so we simply make hash2 odd.
+ */
+#define HASH1(hash0, shift)         ((hash0) >> (shift))
+#define HASH2(hash0,log2,shift)     ((((hash0) << (log2)) >> (shift)) | 1)
+
+/*
+ * Reserve keyHash 0 for free entries and 1 for removed-entry sentinels.  Note
+ * that a removed-entry sentinel need be stored only if the removed entry had
+ * a colliding entry added after it.  Therefore we can use 1 as the collision
+ * flag in addition to the removed-entry sentinel value.  Multiplicative hash
+ * uses the high order bits of keyHash, so this least-significant reservation
+ * should not hurt the hash function's effectiveness much.
+ *
+ * If you change any of these magic numbers, also update PL_DHASH_ENTRY_IS_LIVE
+ * in pldhash.h.  It used to be private to pldhash.c, but then became public to
+ * assist iterator writers who inspect table->entryStore directly.
+ */
+#define COLLISION_FLAG              ((PLDHashNumber) 1)
+#define MARK_ENTRY_FREE(entry)      ((entry)->keyHash = 0)
+#define MARK_ENTRY_REMOVED(entry)   ((entry)->keyHash = 1)
+#define ENTRY_IS_REMOVED(entry)     ((entry)->keyHash == 1)
+#define ENTRY_IS_LIVE(entry)        PL_DHASH_ENTRY_IS_LIVE(entry)
+#define ENSURE_LIVE_KEYHASH(hash0)  if (hash0 < 2) hash0 -= 2; else (void)0
+
+/* Match an entry's keyHash against an unstored one computed from a key. */
+#define MATCH_ENTRY_KEYHASH(entry,hash0) \
+    (((entry)->keyHash & ~COLLISION_FLAG) == (hash0))
+
+/* Compute the address of the indexed entry in table. */
+#define ADDRESS_ENTRY(table, index) \
+    ((PLDHashEntryHdr *)((table)->entryStore + (index) * (table)->entrySize))
+
+PR_IMPLEMENT(void)
+PL_DHashTableFinish(PLDHashTable *table)
+{
+    char *entryAddr, *entryLimit;
+    PRUint32 entrySize;
+    PLDHashEntryHdr *entry;
+
+#ifdef DEBUG_XXXbrendan
+    static FILE *dumpfp = NULL;
+    if (!dumpfp) dumpfp = fopen("/tmp/pldhash.bigdump", "w");
+    if (dumpfp) {
+#ifdef MOZILLA_CLIENT
+        NS_TraceStack(1, dumpfp);
+#endif
+        PL_DHashTableDumpMeter(table, NULL, dumpfp);
+        fputc('\n', dumpfp);
+    }
+#endif
+
+    /* Call finalize before clearing entries, so it can enumerate them. */
+    table->ops->finalize(table);
+
+    /* Clear any remaining live entries. */
+    entryAddr = table->entryStore;
+    entrySize = table->entrySize;
+    entryLimit = entryAddr + PL_DHASH_TABLE_SIZE(table) * entrySize;
+    while (entryAddr < entryLimit) {
+        entry = (PLDHashEntryHdr *)entryAddr;
+        if (ENTRY_IS_LIVE(entry)) {
+            METER(table->stats.removeEnums++);
+            table->ops->clearEntry(table, entry);
+        }
+        entryAddr += entrySize;
+    }
+
+    /* Free entry storage last. */
+    table->ops->freeTable(table, table->entryStore);
+}
+
+static PLDHashEntryHdr * PL_DHASH_FASTCALL
+SearchTable(PLDHashTable *table, const void *key, PLDHashNumber keyHash,
+            PLDHashOperator op)
+{
+    PLDHashNumber hash1, hash2;
+    int hashShift, sizeLog2;
+    PLDHashEntryHdr *entry, *firstRemoved;
+    PLDHashMatchEntry matchEntry;
+    PRUint32 sizeMask;
+
+    METER(table->stats.searches++);
+    PR_ASSERT(!(keyHash & COLLISION_FLAG));
+
+    /* Compute the primary hash address. */
+    hashShift = table->hashShift;
+    hash1 = HASH1(keyHash, hashShift);
+    entry = ADDRESS_ENTRY(table, hash1);
+
+    /* Miss: return space for a new entry. */
+    if (PL_DHASH_ENTRY_IS_FREE(entry)) {
+        METER(table->stats.misses++);
+        return entry;
+    }
+
+    /* Hit: return entry. */
+    matchEntry = table->ops->matchEntry;
+    if (MATCH_ENTRY_KEYHASH(entry, keyHash) && matchEntry(table, entry, key)) {
+        METER(table->stats.hits++);
+        return entry;
+    }
+
+    /* Collision: double hash. */
+    sizeLog2 = PL_DHASH_BITS - table->hashShift;
+    hash2 = HASH2(keyHash, sizeLog2, hashShift);
+    sizeMask = PR_BITMASK(sizeLog2);
+
+    /* Save the first removed entry pointer so PL_DHASH_ADD can recycle it. */
+    if (ENTRY_IS_REMOVED(entry)) {
+        firstRemoved = entry;
+    } else {
+        firstRemoved = NULL;
+        if (op == PL_DHASH_ADD)
+            entry->keyHash |= COLLISION_FLAG;
+    }
+
+    for (;;) {
+        METER(table->stats.steps++);
+        hash1 -= hash2;
+        hash1 &= sizeMask;
+
+        entry = ADDRESS_ENTRY(table, hash1);
+        if (PL_DHASH_ENTRY_IS_FREE(entry)) {
+            METER(table->stats.misses++);
+            return (firstRemoved && op == PL_DHASH_ADD) ? firstRemoved : entry;
+        }
+
+        if (MATCH_ENTRY_KEYHASH(entry, keyHash) &&
+            matchEntry(table, entry, key)) {
+            METER(table->stats.hits++);
+            return entry;
+        }
+
+        if (ENTRY_IS_REMOVED(entry)) {
+            if (!firstRemoved)
+                firstRemoved = entry;
+        } else {
+            if (op == PL_DHASH_ADD)
+                entry->keyHash |= COLLISION_FLAG;
+        }
+    }
+
+    /* NOTREACHED */
+    return NULL;
+}
+
+static PRBool
+ChangeTable(PLDHashTable *table, int deltaLog2)
+{
+    int oldLog2, newLog2;
+    PRUint32 oldCapacity, newCapacity;
+    char *newEntryStore, *oldEntryStore, *oldEntryAddr;
+    PRUint32 entrySize, i, nbytes;
+    PLDHashEntryHdr *oldEntry, *newEntry;
+    PLDHashGetKey getKey;
+    PLDHashMoveEntry moveEntry;
+
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+    PR_ASSERT(table->generation != PR_UINT32_MAX);
+    if (table->generation == PR_UINT32_MAX)
+        return PR_FALSE;
+#endif
+
+    /* Look, but don't touch, until we succeed in getting new entry store. */
+    oldLog2 = PL_DHASH_BITS - table->hashShift;
+    newLog2 = oldLog2 + deltaLog2;
+    oldCapacity = PR_BIT(oldLog2);
+    newCapacity = PR_BIT(newLog2);
+    if (newCapacity >= PL_DHASH_SIZE_LIMIT)
+        return PR_FALSE;
+    entrySize = table->entrySize;
+    nbytes = newCapacity * entrySize;
+
+    newEntryStore = table->ops->allocTable(table, nbytes);
+    if (!newEntryStore)
+        return PR_FALSE;
+
+    /* We can't fail from here on, so update table parameters. */
+    table->hashShift = PL_DHASH_BITS - newLog2;
+    table->removedCount = 0;
+    table->generation++;
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+    if (table->generation == PR_UINT32_MAX)
+        table->generation++;
+#endif
+
+    /* Assign the new entry store to table. */
+    memset(newEntryStore, 0, nbytes);
+    oldEntryAddr = oldEntryStore = table->entryStore;
+    table->entryStore = newEntryStore;
+    getKey = table->ops->getKey;
+    moveEntry = table->ops->moveEntry;
+
+    /* Copy only live entries, leaving removed ones behind. */
+    for (i = 0; i < oldCapacity; i++) {
+        oldEntry = (PLDHashEntryHdr *)oldEntryAddr;
+        if (ENTRY_IS_LIVE(oldEntry)) {
+            oldEntry->keyHash &= ~COLLISION_FLAG;
+            newEntry = SearchTable(table, getKey(table, oldEntry),
+                                   oldEntry->keyHash, PL_DHASH_ADD);
+            PR_ASSERT(PL_DHASH_ENTRY_IS_FREE(newEntry));
+            moveEntry(table, oldEntry, newEntry);
+            newEntry->keyHash = oldEntry->keyHash;
+        }
+        oldEntryAddr += entrySize;
+    }
+
+    table->ops->freeTable(table, oldEntryStore);
+    return PR_TRUE;
+}
+
+PR_IMPLEMENT(PLDHashEntryHdr *) PL_DHASH_FASTCALL
+PL_DHashTableOperate(PLDHashTable *table, const void *key, PLDHashOperator op)
+{
+    PLDHashNumber keyHash;
+    PLDHashEntryHdr *entry;
+    PRUint32 size;
+    int deltaLog2;
+
+    keyHash = table->ops->hashKey(table, key);
+    keyHash *= PL_DHASH_GOLDEN_RATIO;
+
+    /* Avoid 0 and 1 hash codes, they indicate free and removed entries. */
+    ENSURE_LIVE_KEYHASH(keyHash);
+    keyHash &= ~COLLISION_FLAG;
+
+    switch (op) {
+      case PL_DHASH_LOOKUP:
+        METER(table->stats.lookups++);
+        entry = SearchTable(table, key, keyHash, op);
+        break;
+
+      case PL_DHASH_ADD:
+        /*
+         * If alpha is >= .75, grow or compress the table.  If key is already
+         * in the table, we may grow once more than necessary, but only if we
+         * are on the edge of being overloaded.
+         */
+        size = PL_DHASH_TABLE_SIZE(table);
+        if (table->entryCount + table->removedCount >= MAX_LOAD(table, size)) {
+            /* Compress if a quarter or more of all entries are removed. */
+            if (table->removedCount >= size >> 2) {
+                METER(table->stats.compresses++);
+                deltaLog2 = 0;
+            } else {
+                METER(table->stats.grows++);
+                deltaLog2 = 1;
+            }
+
+            /*
+             * Grow or compress table, returning null if ChangeTable fails and
+             * falling through might claim the last free entry.
+             */
+            if (!ChangeTable(table, deltaLog2) &&
+                table->entryCount + table->removedCount == size - 1) {
+                METER(table->stats.addFailures++);
+                return NULL;
+            }
+        }
+
+        /*
+         * Look for entry after possibly growing, so we don't have to add it,
+         * then skip it while growing the table and re-add it after.
+         */
+        entry = SearchTable(table, key, keyHash, op);
+        if (!ENTRY_IS_LIVE(entry)) {
+            /* Initialize the entry, indicating that it's no longer free. */
+            METER(table->stats.addMisses++);
+            if (ENTRY_IS_REMOVED(entry)) {
+                METER(table->stats.addOverRemoved++);
+                table->removedCount--;
+                keyHash |= COLLISION_FLAG;
+            }
+            if (table->ops->initEntry &&
+                !table->ops->initEntry(table, entry, key)) {
+                /* We haven't claimed entry yet; fail with null return. */
+                memset(entry + 1, 0, table->entrySize - sizeof *entry);
+                return NULL;
+            }
+            entry->keyHash = keyHash;
+            table->entryCount++;
+        }
+        METER(else table->stats.addHits++);
+        break;
+
+      case PL_DHASH_REMOVE:
+        entry = SearchTable(table, key, keyHash, op);
+        if (ENTRY_IS_LIVE(entry)) {
+            /* Clear this entry and mark it as "removed". */
+            METER(table->stats.removeHits++);
+            PL_DHashTableRawRemove(table, entry);
+
+            /* Shrink if alpha is <= .25 and table isn't too small already. */
+            size = PL_DHASH_TABLE_SIZE(table);
+            if (size > PL_DHASH_MIN_SIZE &&
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+            /** @todo This is where IPC screws up, avoid the assertion in ChangeTable until it's fixed. */
+                table->generation != PR_UINT32_MAX &&
+#endif
+                table->entryCount <= MIN_LOAD(table, size)) {
+                METER(table->stats.shrinks++);
+                (void) ChangeTable(table, -1);
+            }
+        }
+        METER(else table->stats.removeMisses++);
+        entry = NULL;
+        break;
+
+      default:
+        PR_ASSERT(0);
+        entry = NULL;
+    }
+
+    return entry;
+}
+
+PR_IMPLEMENT(void)
+PL_DHashTableRawRemove(PLDHashTable *table, PLDHashEntryHdr *entry)
+{
+    PLDHashNumber keyHash;      /* load first in case clearEntry goofs it */
+
+    PR_ASSERT(PL_DHASH_ENTRY_IS_LIVE(entry));
+    keyHash = entry->keyHash;
+    table->ops->clearEntry(table, entry);
+    if (keyHash & COLLISION_FLAG) {
+        MARK_ENTRY_REMOVED(entry);
+        table->removedCount++;
+    } else {
+        METER(table->stats.removeFrees++);
+        MARK_ENTRY_FREE(entry);
+    }
+    table->entryCount--;
+}
+
+PR_IMPLEMENT(PRUint32)
+PL_DHashTableEnumerate(PLDHashTable *table, PLDHashEnumerator etor, void *arg)
+{
+    char *entryAddr, *entryLimit;
+    PRUint32 i, capacity, entrySize;
+    PRBool didRemove;
+    PLDHashEntryHdr *entry;
+    PLDHashOperator op;
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+    PRUint32 generation;
+
+    /*
+     * The hack! Set generation to PR_UINT32_MAX during the enumeration so
+     * we can prevent ChangeTable from being called.
+     *
+     * This happens during ipcDConnectService::OnClientStateChange()
+     * / ipcDConnectService::DeleteInstance() now when running
+     * java clienttest list hostinfo and vboxwebsrv crashes. It's quite
+     * likely that the IPC code isn't following the rules here, but it
+     * looks more difficult to fix that just hacking this hash code.
+     */
+    generation = table->generation;
+    table->generation = PR_UINT32_MAX;
+#endif /* VBOX */
+    entryAddr = table->entryStore;
+    entrySize = table->entrySize;
+    capacity = PL_DHASH_TABLE_SIZE(table);
+    entryLimit = entryAddr + capacity * entrySize;
+    i = 0;
+    didRemove = PR_FALSE;
+    while (entryAddr < entryLimit) {
+        entry = (PLDHashEntryHdr *)entryAddr;
+        if (ENTRY_IS_LIVE(entry)) {
+            op = etor(table, entry, i++, arg);
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+            PR_ASSERT(table->generation == PR_UINT32_MAX);
+#endif
+            if (op & PL_DHASH_REMOVE) {
+                METER(table->stats.removeEnums++);
+                PL_DHashTableRawRemove(table, entry);
+                didRemove = PR_TRUE;
+            }
+            if (op & PL_DHASH_STOP)
+                break;
+        }
+        entryAddr += entrySize;
+    }
+#ifdef VBOX /* HACK ALERT! generation == PR_UINT32_MAX during enumeration. */
+    table->generation = generation;
+#endif
+
+    /*
+     * Shrink or compress if a quarter or more of all entries are removed, or
+     * if the table is underloaded according to the configured minimum alpha,
+     * and is not minimal-size already.  Do this only if we removed above, so
+     * non-removing enumerations can count on stable table->entryStore until
+     * the next non-lookup-Operate or removing-Enumerate.
+     */
+    if (didRemove &&
+        (table->removedCount >= capacity >> 2 ||
+         (capacity > PL_DHASH_MIN_SIZE &&
+          table->entryCount <= MIN_LOAD(table, capacity)))) {
+        METER(table->stats.enumShrinks++);
+        capacity = table->entryCount;
+        capacity += capacity >> 1;
+        if (capacity < PL_DHASH_MIN_SIZE)
+            capacity = PL_DHASH_MIN_SIZE;
+        (void) ChangeTable(table,
+                           PR_CeilingLog2(capacity)
+                           - (PL_DHASH_BITS - table->hashShift));
+    }
+    return i;
+}
+
+#ifdef PL_DHASHMETER
+#include <math.h>
+
+PR_IMPLEMENT(void)
+PL_DHashTableDumpMeter(PLDHashTable *table, PLDHashEnumerator dump, FILE *fp)
+{
+    char *entryAddr;
+    PRUint32 entrySize, entryCount;
+    int hashShift, sizeLog2;
+    PRUint32 i, tableSize, sizeMask, chainLen, maxChainLen, chainCount;
+    PLDHashNumber hash1, hash2, saveHash1, maxChainHash1, maxChainHash2;
+    double sqsum, mean, variance, sigma;
+    PLDHashEntryHdr *entry, *probe;
+
+    entryAddr = table->entryStore;
+    entrySize = table->entrySize;
+    hashShift = table->hashShift;
+    sizeLog2 = PL_DHASH_BITS - hashShift;
+    tableSize = PL_DHASH_TABLE_SIZE(table);
+    sizeMask = PR_BITMASK(sizeLog2);
+    chainCount = maxChainLen = 0;
+    hash2 = 0;
+    sqsum = 0;
+
+    for (i = 0; i < tableSize; i++) {
+        entry = (PLDHashEntryHdr *)entryAddr;
+        entryAddr += entrySize;
+        if (!ENTRY_IS_LIVE(entry))
+            continue;
+        hash1 = HASH1(entry->keyHash & ~COLLISION_FLAG, hashShift);
+        saveHash1 = hash1;
+        probe = ADDRESS_ENTRY(table, hash1);
+        chainLen = 1;
+        if (probe == entry) {
+            /* Start of a (possibly unit-length) chain. */
+            chainCount++;
+        } else {
+            hash2 = HASH2(entry->keyHash & ~COLLISION_FLAG, sizeLog2,
+                          hashShift);
+            do {
+                chainLen++;
+                hash1 -= hash2;
+                hash1 &= sizeMask;
+                probe = ADDRESS_ENTRY(table, hash1);
+            } while (probe != entry);
+        }
+        sqsum += chainLen * chainLen;
+        if (chainLen > maxChainLen) {
+            maxChainLen = chainLen;
+            maxChainHash1 = saveHash1;
+            maxChainHash2 = hash2;
+        }
+    }
+
+    entryCount = table->entryCount;
+    if (entryCount && chainCount) {
+        mean = (double)entryCount / chainCount;
+        variance = chainCount * sqsum - entryCount * entryCount;
+        if (variance < 0 || chainCount == 1)
+            variance = 0;
+        else
+            variance /= chainCount * (chainCount - 1);
+        sigma = sqrt(variance);
+    } else {
+        mean = sigma = 0;
+    }
+
+    fprintf(fp, "Double hashing statistics:\n");
+    fprintf(fp, "    table size (in entries): %u\n", tableSize);
+    fprintf(fp, "          number of entries: %u\n", table->entryCount);
+    fprintf(fp, "  number of removed entries: %u\n", table->removedCount);
+    fprintf(fp, "         number of searches: %u\n", table->stats.searches);
+    fprintf(fp, "             number of hits: %u\n", table->stats.hits);
+    fprintf(fp, "           number of misses: %u\n", table->stats.misses);
+    fprintf(fp, "      mean steps per search: %g\n", table->stats.searches ?
+                                                     (double)table->stats.steps
+                                                     / table->stats.searches :
+                                                     0.);
+    fprintf(fp, "     mean hash chain length: %g\n", mean);
+    fprintf(fp, "         standard deviation: %g\n", sigma);
+    fprintf(fp, "  maximum hash chain length: %u\n", maxChainLen);
+    fprintf(fp, "          number of lookups: %u\n", table->stats.lookups);
+    fprintf(fp, " adds that made a new entry: %u\n", table->stats.addMisses);
+    fprintf(fp, "adds that recycled removeds: %u\n", table->stats.addOverRemoved);
+    fprintf(fp, "   adds that found an entry: %u\n", table->stats.addHits);
+    fprintf(fp, "               add failures: %u\n", table->stats.addFailures);
+    fprintf(fp, "             useful removes: %u\n", table->stats.removeHits);
+    fprintf(fp, "            useless removes: %u\n", table->stats.removeMisses);
+    fprintf(fp, "removes that freed an entry: %u\n", table->stats.removeFrees);
+    fprintf(fp, "  removes while enumerating: %u\n", table->stats.removeEnums);
+    fprintf(fp, "            number of grows: %u\n", table->stats.grows);
+    fprintf(fp, "          number of shrinks: %u\n", table->stats.shrinks);
+    fprintf(fp, "       number of compresses: %u\n", table->stats.compresses);
+    fprintf(fp, "number of enumerate shrinks: %u\n", table->stats.enumShrinks);
+
+    if (dump && maxChainLen && hash2) {
+        fputs("Maximum hash chain:\n", fp);
+        hash1 = maxChainHash1;
+        hash2 = maxChainHash2;
+        entry = ADDRESS_ENTRY(table, hash1);
+        i = 0;
+        do {
+            if (dump(table, entry, i++, fp) != PL_DHASH_NEXT)
+                break;
+            hash1 -= hash2;
+            hash1 &= sizeMask;
+            entry = ADDRESS_ENTRY(table, hash1);
+        } while (PL_DHASH_ENTRY_IS_BUSY(entry));
+    }
+}
+#endif /* PL_DHASHMETER */