auto import from //depot/cupcake/@135843
diff --git a/vm/Hash.c b/vm/Hash.c
new file mode 100644
index 0000000..67a25a1
--- /dev/null
+++ b/vm/Hash.c
@@ -0,0 +1,418 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * Hash table. The dominant calls are add and lookup, with removals
+ * happening very infrequently. We use probing, and don't worry much
+ * about tombstone removal.
+ */
+#include "Dalvik.h"
+
+#include <stdlib.h>
+
+/* table load factor, i.e. how full can it get before we resize */
+//#define LOAD_NUMER 3 // 75%
+//#define LOAD_DENOM 4
+#define LOAD_NUMER 5 // 62.5%
+#define LOAD_DENOM 8
+//#define LOAD_NUMER 1 // 50%
+//#define LOAD_DENOM 2
+
+/*
+ * Compute the capacity needed for a table to hold "size" elements.
+ */
+size_t dvmHashSize(size_t size) {
+ return (size * LOAD_DENOM) / LOAD_NUMER +1;
+}
+
+
+/*
+ * Create and initialize a hash table.
+ */
+HashTable* dvmHashTableCreate(size_t initialSize, HashFreeFunc freeFunc)
+{
+ HashTable* pHashTable;
+
+ assert(initialSize > 0);
+
+ pHashTable = (HashTable*) malloc(sizeof(*pHashTable));
+ if (pHashTable == NULL)
+ return NULL;
+
+ dvmInitMutex(&pHashTable->lock);
+
+ pHashTable->tableSize = dexRoundUpPower2(initialSize);
+ pHashTable->numEntries = pHashTable->numDeadEntries = 0;
+ pHashTable->freeFunc = freeFunc;
+ pHashTable->pEntries =
+ (HashEntry*) malloc(pHashTable->tableSize * sizeof(HashEntry));
+ if (pHashTable->pEntries == NULL) {
+ free(pHashTable);
+ return NULL;
+ }
+
+ memset(pHashTable->pEntries, 0, pHashTable->tableSize * sizeof(HashEntry));
+ return pHashTable;
+}
+
+/*
+ * Clear out all entries.
+ */
+void dvmHashTableClear(HashTable* pHashTable)
+{
+ HashEntry* pEnt;
+ int i;
+
+ pEnt = pHashTable->pEntries;
+ for (i = 0; i < pHashTable->tableSize; i++, pEnt++) {
+ if (pEnt->data == HASH_TOMBSTONE) {
+ // nuke entry
+ pEnt->data = NULL;
+ } else if (pEnt->data != NULL) {
+ // call free func then nuke entry
+ if (pHashTable->freeFunc != NULL)
+ (*pHashTable->freeFunc)(pEnt->data);
+ pEnt->data = NULL;
+ }
+ }
+
+ pHashTable->numEntries = 0;
+ pHashTable->numDeadEntries = 0;
+}
+
+/*
+ * Free the table.
+ */
+void dvmHashTableFree(HashTable* pHashTable)
+{
+ if (pHashTable == NULL)
+ return;
+ dvmHashTableClear(pHashTable);
+ free(pHashTable->pEntries);
+ free(pHashTable);
+}
+
+#ifndef NDEBUG
+/*
+ * Count up the number of tombstone entries in the hash table.
+ */
+static int countTombStones(HashTable* pHashTable)
+{
+ int i, count;
+
+ for (count = i = 0; i < pHashTable->tableSize; i++) {
+ if (pHashTable->pEntries[i].data == HASH_TOMBSTONE)
+ count++;
+ }
+ return count;
+}
+#endif
+
+/*
+ * Resize a hash table. We do this when adding an entry increased the
+ * size of the table beyond its comfy limit.
+ *
+ * This essentially requires re-inserting all elements into the new storage.
+ *
+ * If multiple threads can access the hash table, the table's lock should
+ * have been grabbed before issuing the "lookup+add" call that led to the
+ * resize, so we don't have a synchronization problem here.
+ */
+static bool resizeHash(HashTable* pHashTable, int newSize)
+{
+ HashEntry* pNewEntries;
+ int i;
+
+ assert(countTombStones(pHashTable) == pHashTable->numDeadEntries);
+ //LOGI("before: dead=%d\n", pHashTable->numDeadEntries);
+
+ pNewEntries = (HashEntry*) calloc(newSize, sizeof(HashEntry));
+ if (pNewEntries == NULL)
+ return false;
+
+ for (i = 0; i < pHashTable->tableSize; i++) {
+ void* data = pHashTable->pEntries[i].data;
+ if (data != NULL && data != HASH_TOMBSTONE) {
+ int hashValue = pHashTable->pEntries[i].hashValue;
+ int newIdx;
+
+ /* probe for new spot, wrapping around */
+ newIdx = hashValue & (newSize-1);
+ while (pNewEntries[newIdx].data != NULL)
+ newIdx = (newIdx + 1) & (newSize-1);
+
+ pNewEntries[newIdx].hashValue = hashValue;
+ pNewEntries[newIdx].data = data;
+ }
+ }
+
+ free(pHashTable->pEntries);
+ pHashTable->pEntries = pNewEntries;
+ pHashTable->tableSize = newSize;
+ pHashTable->numDeadEntries = 0;
+
+ assert(countTombStones(pHashTable) == 0);
+ return true;
+}
+
+/*
+ * Look up an entry.
+ *
+ * We probe on collisions, wrapping around the table.
+ */
+void* dvmHashTableLookup(HashTable* pHashTable, u4 itemHash, void* item,
+ HashCompareFunc cmpFunc, bool doAdd)
+{
+ HashEntry* pEntry;
+ HashEntry* pEnd;
+ void* result = NULL;
+
+ assert(pHashTable->tableSize > 0);
+ assert(item != HASH_TOMBSTONE);
+ assert(item != NULL);
+
+ /* jump to the first entry and probe for a match */
+ pEntry = &pHashTable->pEntries[itemHash & (pHashTable->tableSize-1)];
+ pEnd = &pHashTable->pEntries[pHashTable->tableSize];
+ while (pEntry->data != NULL) {
+ if (pEntry->data != HASH_TOMBSTONE &&
+ pEntry->hashValue == itemHash &&
+ (*cmpFunc)(pEntry->data, item) == 0)
+ {
+ /* match */
+ //LOGD("+++ match on entry %d\n", pEntry - pHashTable->pEntries);
+ break;
+ }
+
+ pEntry++;
+ if (pEntry == pEnd) { /* wrap around to start */
+ if (pHashTable->tableSize == 1)
+ break; /* edge case - single-entry table */
+ pEntry = pHashTable->pEntries;
+ }
+
+ //LOGI("+++ look probing %d...\n", pEntry - pHashTable->pEntries);
+ }
+
+ if (pEntry->data == NULL) {
+ if (doAdd) {
+ pEntry->hashValue = itemHash;
+ pEntry->data = item;
+ pHashTable->numEntries++;
+
+ /*
+ * We've added an entry. See if this brings us too close to full.
+ */
+ if ((pHashTable->numEntries+pHashTable->numDeadEntries) * LOAD_DENOM
+ > pHashTable->tableSize * LOAD_NUMER)
+ {
+ if (!resizeHash(pHashTable, pHashTable->tableSize * 2)) {
+ /* don't really have a way to indicate failure */
+ LOGE("Dalvik hash resize failure\n");
+ dvmAbort();
+ }
+ /* note "pEntry" is now invalid */
+ } else {
+ //LOGW("okay %d/%d/%d\n",
+ // pHashTable->numEntries, pHashTable->tableSize,
+ // (pHashTable->tableSize * LOAD_NUMER) / LOAD_DENOM);
+ }
+
+ /* full table is bad -- search for nonexistent never halts */
+ assert(pHashTable->numEntries < pHashTable->tableSize);
+ result = item;
+ } else {
+ assert(result == NULL);
+ }
+ } else {
+ result = pEntry->data;
+ }
+
+ return result;
+}
+
+/*
+ * Remove an entry from the table.
+ *
+ * Does NOT invoke the "free" function on the item.
+ */
+bool dvmHashTableRemove(HashTable* pHashTable, u4 itemHash, void* item)
+{
+ HashEntry* pEntry;
+ HashEntry* pEnd;
+
+ assert(pHashTable->tableSize > 0);
+
+ /* jump to the first entry and probe for a match */
+ pEntry = &pHashTable->pEntries[itemHash & (pHashTable->tableSize-1)];
+ pEnd = &pHashTable->pEntries[pHashTable->tableSize];
+ while (pEntry->data != NULL) {
+ if (pEntry->data == item) {
+ //LOGI("+++ stepping on entry %d\n", pEntry - pHashTable->pEntries);
+ pEntry->data = HASH_TOMBSTONE;
+ pHashTable->numEntries--;
+ pHashTable->numDeadEntries++;
+ return true;
+ }
+
+ pEntry++;
+ if (pEntry == pEnd) { /* wrap around to start */
+ if (pHashTable->tableSize == 1)
+ break; /* edge case - single-entry table */
+ pEntry = pHashTable->pEntries;
+ }
+
+ //LOGI("+++ del probing %d...\n", pEntry - pHashTable->pEntries);
+ }
+
+ return false;
+}
+
+/*
+ * Scan every entry in the hash table and evaluate it with the specified
+ * indirect function call. If the function returns 1, remove the entry from
+ * the table.
+ *
+ * Does NOT invoke the "free" function on the item.
+ *
+ * Returning values other than 0 or 1 will abort the routine.
+ */
+int dvmHashForeachRemove(HashTable* pHashTable, HashForeachRemoveFunc func)
+{
+ int i, val;
+
+ for (i = 0; i < pHashTable->tableSize; i++) {
+ HashEntry* pEnt = &pHashTable->pEntries[i];
+
+ if (pEnt->data != NULL && pEnt->data != HASH_TOMBSTONE) {
+ val = (*func)(pEnt->data);
+ if (val == 1) {
+ pEnt->data = HASH_TOMBSTONE;
+ pHashTable->numEntries--;
+ pHashTable->numDeadEntries++;
+ }
+ else if (val != 0) {
+ return val;
+ }
+ }
+ }
+ return 0;
+}
+
+
+/*
+ * Execute a function on every entry in the hash table.
+ *
+ * If "func" returns a nonzero value, terminate early and return the value.
+ */
+int dvmHashForeach(HashTable* pHashTable, HashForeachFunc func, void* arg)
+{
+ int i, val;
+
+ for (i = 0; i < pHashTable->tableSize; i++) {
+ HashEntry* pEnt = &pHashTable->pEntries[i];
+
+ if (pEnt->data != NULL && pEnt->data != HASH_TOMBSTONE) {
+ val = (*func)(pEnt->data, arg);
+ if (val != 0)
+ return val;
+ }
+ }
+
+ return 0;
+}
+
+
+/*
+ * Look up an entry, counting the number of times we have to probe.
+ *
+ * Returns -1 if the entry wasn't found.
+ */
+static int countProbes(HashTable* pHashTable, u4 itemHash, const void* item,
+ HashCompareFunc cmpFunc)
+{
+ HashEntry* pEntry;
+ HashEntry* pEnd;
+ int count = 0;
+
+ assert(pHashTable->tableSize > 0);
+ assert(item != HASH_TOMBSTONE);
+ assert(item != NULL);
+
+ /* jump to the first entry and probe for a match */
+ pEntry = &pHashTable->pEntries[itemHash & (pHashTable->tableSize-1)];
+ pEnd = &pHashTable->pEntries[pHashTable->tableSize];
+ while (pEntry->data != NULL) {
+ if (pEntry->data != HASH_TOMBSTONE &&
+ pEntry->hashValue == itemHash &&
+ (*cmpFunc)(pEntry->data, item) == 0)
+ {
+ /* match */
+ break;
+ }
+
+ pEntry++;
+ if (pEntry == pEnd) { /* wrap around to start */
+ if (pHashTable->tableSize == 1)
+ break; /* edge case - single-entry table */
+ pEntry = pHashTable->pEntries;
+ }
+
+ count++;
+ }
+ if (pEntry->data == NULL)
+ return -1;
+
+ return count;
+}
+
+/*
+ * Evaluate the amount of probing required for the specified hash table.
+ *
+ * We do this by running through all entries in the hash table, computing
+ * the hash value and then doing a lookup.
+ *
+ * The caller should lock the table before calling here.
+ */
+void dvmHashTableProbeCount(HashTable* pHashTable, HashCalcFunc calcFunc,
+ HashCompareFunc cmpFunc)
+{
+ int numEntries, minProbe, maxProbe, totalProbe;
+ HashIter iter;
+
+ numEntries = maxProbe = totalProbe = 0;
+ minProbe = 65536*32767;
+
+ for (dvmHashIterBegin(pHashTable, &iter); !dvmHashIterDone(&iter);
+ dvmHashIterNext(&iter))
+ {
+ const void* data = (const void*)dvmHashIterData(&iter);
+ int count;
+
+ count = countProbes(pHashTable, (*calcFunc)(data), data, cmpFunc);
+
+ numEntries++;
+
+ if (count < minProbe)
+ minProbe = count;
+ if (count > maxProbe)
+ maxProbe = count;
+ totalProbe += count;
+ }
+
+ LOGI("Probe: min=%d max=%d, total=%d in %d (%d), avg=%.3f\n",
+ minProbe, maxProbe, totalProbe, numEntries, pHashTable->tableSize,
+ (float) totalProbe / (float) numEntries);
+}