diff options
Diffstat (limited to 'mesalib/src/mesa/main/hash.c')
-rw-r--r-- | mesalib/src/mesa/main/hash.c | 1094 |
1 files changed, 547 insertions, 547 deletions
diff --git a/mesalib/src/mesa/main/hash.c b/mesalib/src/mesa/main/hash.c index 63f5c90fa..4b250ad54 100644 --- a/mesalib/src/mesa/main/hash.c +++ b/mesalib/src/mesa/main/hash.c @@ -1,547 +1,547 @@ -/**
- * \file hash.c
- * Generic hash table.
- *
- * Used for display lists, texture objects, vertex/fragment programs,
- * buffer objects, etc. The hash functions are thread-safe.
- *
- * \note key=0 is illegal.
- *
- * \author Brian Paul
- */
-
-/*
- * Mesa 3-D graphics library
- * Version: 6.5.1
- *
- * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-
-#include "glheader.h"
-#include "imports.h"
-#include "glapi/glthread.h"
-#include "hash.h"
-
-
-#define TABLE_SIZE 1023 /**< Size of lookup table/array */
-
-#define HASH_FUNC(K) ((K) % TABLE_SIZE)
-
-
-/**
- * An entry in the hash table.
- */
-struct HashEntry {
- GLuint Key; /**< the entry's key */
- void *Data; /**< the entry's data */
- struct HashEntry *Next; /**< pointer to next entry */
-};
-
-
-/**
- * The hash table data structure.
- */
-struct _mesa_HashTable {
- struct HashEntry *Table[TABLE_SIZE]; /**< the lookup table */
- GLuint MaxKey; /**< highest key inserted so far */
- _glthread_Mutex Mutex; /**< mutual exclusion lock */
- _glthread_Mutex WalkMutex; /**< for _mesa_HashWalk() */
- GLboolean InDeleteAll; /**< Debug check */
-};
-
-
-
-/**
- * Create a new hash table.
- *
- * \return pointer to a new, empty hash table.
- */
-struct _mesa_HashTable *
-_mesa_NewHashTable(void)
-{
- struct _mesa_HashTable *table = CALLOC_STRUCT(_mesa_HashTable);
- if (table) {
- _glthread_INIT_MUTEX(table->Mutex);
- _glthread_INIT_MUTEX(table->WalkMutex);
- }
- return table;
-}
-
-
-
-/**
- * Delete a hash table.
- * Frees each entry on the hash table and then the hash table structure itself.
- * Note that the caller should have already traversed the table and deleted
- * the objects in the table (i.e. We don't free the entries' data pointer).
- *
- * \param table the hash table to delete.
- */
-void
-_mesa_DeleteHashTable(struct _mesa_HashTable *table)
-{
- GLuint pos;
- assert(table);
- for (pos = 0; pos < TABLE_SIZE; pos++) {
- struct HashEntry *entry = table->Table[pos];
- while (entry) {
- struct HashEntry *next = entry->Next;
- if (entry->Data) {
- _mesa_problem(NULL,
- "In _mesa_DeleteHashTable, found non-freed data");
- }
- free(entry);
- entry = next;
- }
- }
- _glthread_DESTROY_MUTEX(table->Mutex);
- _glthread_DESTROY_MUTEX(table->WalkMutex);
- free(table);
-}
-
-
-
-/**
- * Lookup an entry in the hash table, without locking.
- * \sa _mesa_HashLookup
- */
-static INLINE void *
-_mesa_HashLookup_unlocked(struct _mesa_HashTable *table, GLuint key)
-{
- GLuint pos;
- const struct HashEntry *entry;
-
- assert(table);
- assert(key);
-
- pos = HASH_FUNC(key);
- entry = table->Table[pos];
- while (entry) {
- if (entry->Key == key) {
- return entry->Data;
- }
- entry = entry->Next;
- }
- return NULL;
-}
-
-
-/**
- * Lookup an entry in the hash table.
- *
- * \param table the hash table.
- * \param key the key.
- *
- * \return pointer to user's data or NULL if key not in table
- */
-void *
-_mesa_HashLookup(struct _mesa_HashTable *table, GLuint key)
-{
- void *res;
- assert(table);
- _glthread_LOCK_MUTEX(table->Mutex);
- res = _mesa_HashLookup_unlocked(table, key);
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return res;
-}
-
-
-/**
- * Insert a key/pointer pair into the hash table.
- * If an entry with this key already exists we'll replace the existing entry.
- *
- * \param table the hash table.
- * \param key the key (not zero).
- * \param data pointer to user data.
- */
-void
-_mesa_HashInsert(struct _mesa_HashTable *table, GLuint key, void *data)
-{
- /* search for existing entry with this key */
- GLuint pos;
- struct HashEntry *entry;
-
- assert(table);
- assert(key);
-
- _glthread_LOCK_MUTEX(table->Mutex);
-
- if (key > table->MaxKey)
- table->MaxKey = key;
-
- pos = HASH_FUNC(key);
-
- /* check if replacing an existing entry with same key */
- for (entry = table->Table[pos]; entry; entry = entry->Next) {
- if (entry->Key == key) {
- /* replace entry's data */
-#if 0 /* not sure this check is always valid */
- if (entry->Data) {
- _mesa_problem(NULL, "Memory leak detected in _mesa_HashInsert");
- }
-#endif
- entry->Data = data;
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return;
- }
- }
-
- /* alloc and insert new table entry */
- entry = MALLOC_STRUCT(HashEntry);
- if (entry) {
- entry->Key = key;
- entry->Data = data;
- entry->Next = table->Table[pos];
- table->Table[pos] = entry;
- }
-
- _glthread_UNLOCK_MUTEX(table->Mutex);
-}
-
-
-
-/**
- * Remove an entry from the hash table.
- *
- * \param table the hash table.
- * \param key key of entry to remove.
- *
- * While holding the hash table's lock, searches the entry with the matching
- * key and unlinks it.
- */
-void
-_mesa_HashRemove(struct _mesa_HashTable *table, GLuint key)
-{
- GLuint pos;
- struct HashEntry *entry, *prev;
-
- assert(table);
- assert(key);
-
- /* have to check this outside of mutex lock */
- if (table->InDeleteAll) {
- _mesa_problem(NULL, "_mesa_HashRemove illegally called from "
- "_mesa_HashDeleteAll callback function");
- return;
- }
-
- _glthread_LOCK_MUTEX(table->Mutex);
-
- pos = HASH_FUNC(key);
- prev = NULL;
- entry = table->Table[pos];
- while (entry) {
- if (entry->Key == key) {
- /* found it! */
- if (prev) {
- prev->Next = entry->Next;
- }
- else {
- table->Table[pos] = entry->Next;
- }
- free(entry);
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return;
- }
- prev = entry;
- entry = entry->Next;
- }
-
- _glthread_UNLOCK_MUTEX(table->Mutex);
-}
-
-
-
-/**
- * Delete all entries in a hash table, but don't delete the table itself.
- * Invoke the given callback function for each table entry.
- *
- * \param table the hash table to delete
- * \param callback the callback function
- * \param userData arbitrary pointer to pass along to the callback
- * (this is typically a struct gl_context pointer)
- */
-void
-_mesa_HashDeleteAll(struct _mesa_HashTable *table,
- void (*callback)(GLuint key, void *data, void *userData),
- void *userData)
-{
- GLuint pos;
- ASSERT(table);
- ASSERT(callback);
- _glthread_LOCK_MUTEX(table->Mutex);
- table->InDeleteAll = GL_TRUE;
- for (pos = 0; pos < TABLE_SIZE; pos++) {
- struct HashEntry *entry, *next;
- for (entry = table->Table[pos]; entry; entry = next) {
- callback(entry->Key, entry->Data, userData);
- next = entry->Next;
- free(entry);
- }
- table->Table[pos] = NULL;
- }
- table->InDeleteAll = GL_FALSE;
- _glthread_UNLOCK_MUTEX(table->Mutex);
-}
-
-
-/**
- * Walk over all entries in a hash table, calling callback function for each.
- * Note: we use a separate mutex in this function to avoid a recursive
- * locking deadlock (in case the callback calls _mesa_HashRemove()) and to
- * prevent multiple threads/contexts from getting tangled up.
- * A lock-less version of this function could be used when the table will
- * not be modified.
- * \param table the hash table to walk
- * \param callback the callback function
- * \param userData arbitrary pointer to pass along to the callback
- * (this is typically a struct gl_context pointer)
- */
-void
-_mesa_HashWalk(const struct _mesa_HashTable *table,
- void (*callback)(GLuint key, void *data, void *userData),
- void *userData)
-{
- /* cast-away const */
- struct _mesa_HashTable *table2 = (struct _mesa_HashTable *) table;
- GLuint pos;
- ASSERT(table);
- ASSERT(callback);
- _glthread_LOCK_MUTEX(table2->WalkMutex);
- for (pos = 0; pos < TABLE_SIZE; pos++) {
- struct HashEntry *entry, *next;
- for (entry = table->Table[pos]; entry; entry = next) {
- /* save 'next' pointer now in case the callback deletes the entry */
- next = entry->Next;
- callback(entry->Key, entry->Data, userData);
- }
- }
- _glthread_UNLOCK_MUTEX(table2->WalkMutex);
-}
-
-
-/**
- * Return the key of the "first" entry in the hash table.
- * While holding the lock, walks through all table positions until finding
- * the first entry of the first non-empty one.
- *
- * \param table the hash table
- * \return key for the "first" entry in the hash table.
- */
-GLuint
-_mesa_HashFirstEntry(struct _mesa_HashTable *table)
-{
- GLuint pos;
- assert(table);
- _glthread_LOCK_MUTEX(table->Mutex);
- for (pos = 0; pos < TABLE_SIZE; pos++) {
- if (table->Table[pos]) {
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return table->Table[pos]->Key;
- }
- }
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return 0;
-}
-
-
-/**
- * Given a hash table key, return the next key. This is used to walk
- * over all entries in the table. Note that the keys returned during
- * walking won't be in any particular order.
- * \return next hash key or 0 if end of table.
- */
-GLuint
-_mesa_HashNextEntry(const struct _mesa_HashTable *table, GLuint key)
-{
- const struct HashEntry *entry;
- GLuint pos;
-
- assert(table);
- assert(key);
-
- /* Find the entry with given key */
- pos = HASH_FUNC(key);
- for (entry = table->Table[pos]; entry ; entry = entry->Next) {
- if (entry->Key == key) {
- break;
- }
- }
-
- if (!entry) {
- /* the given key was not found, so we can't find the next entry */
- return 0;
- }
-
- if (entry->Next) {
- /* return next in linked list */
- return entry->Next->Key;
- }
- else {
- /* look for next non-empty table slot */
- pos++;
- while (pos < TABLE_SIZE) {
- if (table->Table[pos]) {
- return table->Table[pos]->Key;
- }
- pos++;
- }
- return 0;
- }
-}
-
-
-/**
- * Dump contents of hash table for debugging.
- *
- * \param table the hash table.
- */
-void
-_mesa_HashPrint(const struct _mesa_HashTable *table)
-{
- GLuint pos;
- assert(table);
- for (pos = 0; pos < TABLE_SIZE; pos++) {
- const struct HashEntry *entry = table->Table[pos];
- while (entry) {
- _mesa_debug(NULL, "%u %p\n", entry->Key, entry->Data);
- entry = entry->Next;
- }
- }
-}
-
-
-
-/**
- * Find a block of adjacent unused hash keys.
- *
- * \param table the hash table.
- * \param numKeys number of keys needed.
- *
- * \return Starting key of free block or 0 if failure.
- *
- * If there are enough free keys between the maximum key existing in the table
- * (_mesa_HashTable::MaxKey) and the maximum key possible, then simply return
- * the adjacent key. Otherwise do a full search for a free key block in the
- * allowable key range.
- */
-GLuint
-_mesa_HashFindFreeKeyBlock(struct _mesa_HashTable *table, GLuint numKeys)
-{
- const GLuint maxKey = ~((GLuint) 0);
- _glthread_LOCK_MUTEX(table->Mutex);
- if (maxKey - numKeys > table->MaxKey) {
- /* the quick solution */
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return table->MaxKey + 1;
- }
- else {
- /* the slow solution */
- GLuint freeCount = 0;
- GLuint freeStart = 1;
- GLuint key;
- for (key = 1; key != maxKey; key++) {
- if (_mesa_HashLookup_unlocked(table, key)) {
- /* darn, this key is already in use */
- freeCount = 0;
- freeStart = key+1;
- }
- else {
- /* this key not in use, check if we've found enough */
- freeCount++;
- if (freeCount == numKeys) {
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return freeStart;
- }
- }
- }
- /* cannot allocate a block of numKeys consecutive keys */
- _glthread_UNLOCK_MUTEX(table->Mutex);
- return 0;
- }
-}
-
-
-#if 0 /* debug only */
-
-/**
- * Test walking over all the entries in a hash table.
- */
-static void
-test_hash_walking(void)
-{
- struct _mesa_HashTable *t = _mesa_NewHashTable();
- const GLuint limit = 50000;
- GLuint i;
-
- /* create some entries */
- for (i = 0; i < limit; i++) {
- GLuint dummy;
- GLuint k = (rand() % (limit * 10)) + 1;
- while (_mesa_HashLookup(t, k)) {
- /* id already in use, try another */
- k = (rand() % (limit * 10)) + 1;
- }
- _mesa_HashInsert(t, k, &dummy);
- }
-
- /* walk over all entries */
- {
- GLuint k = _mesa_HashFirstEntry(t);
- GLuint count = 0;
- while (k) {
- GLuint knext = _mesa_HashNextEntry(t, k);
- assert(knext != k);
- _mesa_HashRemove(t, k);
- count++;
- k = knext;
- }
- assert(count == limit);
- k = _mesa_HashFirstEntry(t);
- assert(k==0);
- }
-
- _mesa_DeleteHashTable(t);
-}
-
-
-void
-_mesa_test_hash_functions(void)
-{
- int a, b, c;
- struct _mesa_HashTable *t;
-
- t = _mesa_NewHashTable();
- _mesa_HashInsert(t, 501, &a);
- _mesa_HashInsert(t, 10, &c);
- _mesa_HashInsert(t, 0xfffffff8, &b);
- /*_mesa_HashPrint(t);*/
-
- assert(_mesa_HashLookup(t,501));
- assert(!_mesa_HashLookup(t,1313));
- assert(_mesa_HashFindFreeKeyBlock(t, 100));
-
- _mesa_DeleteHashTable(t);
-
- test_hash_walking();
-}
-
-#endif
+/** + * \file hash.c + * Generic hash table. + * + * Used for display lists, texture objects, vertex/fragment programs, + * buffer objects, etc. The hash functions are thread-safe. + * + * \note key=0 is illegal. + * + * \author Brian Paul + */ + +/* + * Mesa 3-D graphics library + * Version: 6.5.1 + * + * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +#include "glheader.h" +#include "imports.h" +#include "glapi/glthread.h" +#include "hash.h" + + +#define TABLE_SIZE 1023 /**< Size of lookup table/array */ + +#define HASH_FUNC(K) ((K) % TABLE_SIZE) + + +/** + * An entry in the hash table. + */ +struct HashEntry { + GLuint Key; /**< the entry's key */ + void *Data; /**< the entry's data */ + struct HashEntry *Next; /**< pointer to next entry */ +}; + + +/** + * The hash table data structure. + */ +struct _mesa_HashTable { + struct HashEntry *Table[TABLE_SIZE]; /**< the lookup table */ + GLuint MaxKey; /**< highest key inserted so far */ + _glthread_Mutex Mutex; /**< mutual exclusion lock */ + _glthread_Mutex WalkMutex; /**< for _mesa_HashWalk() */ + GLboolean InDeleteAll; /**< Debug check */ +}; + + + +/** + * Create a new hash table. + * + * \return pointer to a new, empty hash table. + */ +struct _mesa_HashTable * +_mesa_NewHashTable(void) +{ + struct _mesa_HashTable *table = CALLOC_STRUCT(_mesa_HashTable); + if (table) { + _glthread_INIT_MUTEX(table->Mutex); + _glthread_INIT_MUTEX(table->WalkMutex); + } + return table; +} + + + +/** + * Delete a hash table. + * Frees each entry on the hash table and then the hash table structure itself. + * Note that the caller should have already traversed the table and deleted + * the objects in the table (i.e. We don't free the entries' data pointer). + * + * \param table the hash table to delete. + */ +void +_mesa_DeleteHashTable(struct _mesa_HashTable *table) +{ + GLuint pos; + assert(table); + for (pos = 0; pos < TABLE_SIZE; pos++) { + struct HashEntry *entry = table->Table[pos]; + while (entry) { + struct HashEntry *next = entry->Next; + if (entry->Data) { + _mesa_problem(NULL, + "In _mesa_DeleteHashTable, found non-freed data"); + } + free(entry); + entry = next; + } + } + _glthread_DESTROY_MUTEX(table->Mutex); + _glthread_DESTROY_MUTEX(table->WalkMutex); + free(table); +} + + + +/** + * Lookup an entry in the hash table, without locking. + * \sa _mesa_HashLookup + */ +static inline void * +_mesa_HashLookup_unlocked(struct _mesa_HashTable *table, GLuint key) +{ + GLuint pos; + const struct HashEntry *entry; + + assert(table); + assert(key); + + pos = HASH_FUNC(key); + entry = table->Table[pos]; + while (entry) { + if (entry->Key == key) { + return entry->Data; + } + entry = entry->Next; + } + return NULL; +} + + +/** + * Lookup an entry in the hash table. + * + * \param table the hash table. + * \param key the key. + * + * \return pointer to user's data or NULL if key not in table + */ +void * +_mesa_HashLookup(struct _mesa_HashTable *table, GLuint key) +{ + void *res; + assert(table); + _glthread_LOCK_MUTEX(table->Mutex); + res = _mesa_HashLookup_unlocked(table, key); + _glthread_UNLOCK_MUTEX(table->Mutex); + return res; +} + + +/** + * Insert a key/pointer pair into the hash table. + * If an entry with this key already exists we'll replace the existing entry. + * + * \param table the hash table. + * \param key the key (not zero). + * \param data pointer to user data. + */ +void +_mesa_HashInsert(struct _mesa_HashTable *table, GLuint key, void *data) +{ + /* search for existing entry with this key */ + GLuint pos; + struct HashEntry *entry; + + assert(table); + assert(key); + + _glthread_LOCK_MUTEX(table->Mutex); + + if (key > table->MaxKey) + table->MaxKey = key; + + pos = HASH_FUNC(key); + + /* check if replacing an existing entry with same key */ + for (entry = table->Table[pos]; entry; entry = entry->Next) { + if (entry->Key == key) { + /* replace entry's data */ +#if 0 /* not sure this check is always valid */ + if (entry->Data) { + _mesa_problem(NULL, "Memory leak detected in _mesa_HashInsert"); + } +#endif + entry->Data = data; + _glthread_UNLOCK_MUTEX(table->Mutex); + return; + } + } + + /* alloc and insert new table entry */ + entry = MALLOC_STRUCT(HashEntry); + if (entry) { + entry->Key = key; + entry->Data = data; + entry->Next = table->Table[pos]; + table->Table[pos] = entry; + } + + _glthread_UNLOCK_MUTEX(table->Mutex); +} + + + +/** + * Remove an entry from the hash table. + * + * \param table the hash table. + * \param key key of entry to remove. + * + * While holding the hash table's lock, searches the entry with the matching + * key and unlinks it. + */ +void +_mesa_HashRemove(struct _mesa_HashTable *table, GLuint key) +{ + GLuint pos; + struct HashEntry *entry, *prev; + + assert(table); + assert(key); + + /* have to check this outside of mutex lock */ + if (table->InDeleteAll) { + _mesa_problem(NULL, "_mesa_HashRemove illegally called from " + "_mesa_HashDeleteAll callback function"); + return; + } + + _glthread_LOCK_MUTEX(table->Mutex); + + pos = HASH_FUNC(key); + prev = NULL; + entry = table->Table[pos]; + while (entry) { + if (entry->Key == key) { + /* found it! */ + if (prev) { + prev->Next = entry->Next; + } + else { + table->Table[pos] = entry->Next; + } + free(entry); + _glthread_UNLOCK_MUTEX(table->Mutex); + return; + } + prev = entry; + entry = entry->Next; + } + + _glthread_UNLOCK_MUTEX(table->Mutex); +} + + + +/** + * Delete all entries in a hash table, but don't delete the table itself. + * Invoke the given callback function for each table entry. + * + * \param table the hash table to delete + * \param callback the callback function + * \param userData arbitrary pointer to pass along to the callback + * (this is typically a struct gl_context pointer) + */ +void +_mesa_HashDeleteAll(struct _mesa_HashTable *table, + void (*callback)(GLuint key, void *data, void *userData), + void *userData) +{ + GLuint pos; + ASSERT(table); + ASSERT(callback); + _glthread_LOCK_MUTEX(table->Mutex); + table->InDeleteAll = GL_TRUE; + for (pos = 0; pos < TABLE_SIZE; pos++) { + struct HashEntry *entry, *next; + for (entry = table->Table[pos]; entry; entry = next) { + callback(entry->Key, entry->Data, userData); + next = entry->Next; + free(entry); + } + table->Table[pos] = NULL; + } + table->InDeleteAll = GL_FALSE; + _glthread_UNLOCK_MUTEX(table->Mutex); +} + + +/** + * Walk over all entries in a hash table, calling callback function for each. + * Note: we use a separate mutex in this function to avoid a recursive + * locking deadlock (in case the callback calls _mesa_HashRemove()) and to + * prevent multiple threads/contexts from getting tangled up. + * A lock-less version of this function could be used when the table will + * not be modified. + * \param table the hash table to walk + * \param callback the callback function + * \param userData arbitrary pointer to pass along to the callback + * (this is typically a struct gl_context pointer) + */ +void +_mesa_HashWalk(const struct _mesa_HashTable *table, + void (*callback)(GLuint key, void *data, void *userData), + void *userData) +{ + /* cast-away const */ + struct _mesa_HashTable *table2 = (struct _mesa_HashTable *) table; + GLuint pos; + ASSERT(table); + ASSERT(callback); + _glthread_LOCK_MUTEX(table2->WalkMutex); + for (pos = 0; pos < TABLE_SIZE; pos++) { + struct HashEntry *entry, *next; + for (entry = table->Table[pos]; entry; entry = next) { + /* save 'next' pointer now in case the callback deletes the entry */ + next = entry->Next; + callback(entry->Key, entry->Data, userData); + } + } + _glthread_UNLOCK_MUTEX(table2->WalkMutex); +} + + +/** + * Return the key of the "first" entry in the hash table. + * While holding the lock, walks through all table positions until finding + * the first entry of the first non-empty one. + * + * \param table the hash table + * \return key for the "first" entry in the hash table. + */ +GLuint +_mesa_HashFirstEntry(struct _mesa_HashTable *table) +{ + GLuint pos; + assert(table); + _glthread_LOCK_MUTEX(table->Mutex); + for (pos = 0; pos < TABLE_SIZE; pos++) { + if (table->Table[pos]) { + _glthread_UNLOCK_MUTEX(table->Mutex); + return table->Table[pos]->Key; + } + } + _glthread_UNLOCK_MUTEX(table->Mutex); + return 0; +} + + +/** + * Given a hash table key, return the next key. This is used to walk + * over all entries in the table. Note that the keys returned during + * walking won't be in any particular order. + * \return next hash key or 0 if end of table. + */ +GLuint +_mesa_HashNextEntry(const struct _mesa_HashTable *table, GLuint key) +{ + const struct HashEntry *entry; + GLuint pos; + + assert(table); + assert(key); + + /* Find the entry with given key */ + pos = HASH_FUNC(key); + for (entry = table->Table[pos]; entry ; entry = entry->Next) { + if (entry->Key == key) { + break; + } + } + + if (!entry) { + /* the given key was not found, so we can't find the next entry */ + return 0; + } + + if (entry->Next) { + /* return next in linked list */ + return entry->Next->Key; + } + else { + /* look for next non-empty table slot */ + pos++; + while (pos < TABLE_SIZE) { + if (table->Table[pos]) { + return table->Table[pos]->Key; + } + pos++; + } + return 0; + } +} + + +/** + * Dump contents of hash table for debugging. + * + * \param table the hash table. + */ +void +_mesa_HashPrint(const struct _mesa_HashTable *table) +{ + GLuint pos; + assert(table); + for (pos = 0; pos < TABLE_SIZE; pos++) { + const struct HashEntry *entry = table->Table[pos]; + while (entry) { + _mesa_debug(NULL, "%u %p\n", entry->Key, entry->Data); + entry = entry->Next; + } + } +} + + + +/** + * Find a block of adjacent unused hash keys. + * + * \param table the hash table. + * \param numKeys number of keys needed. + * + * \return Starting key of free block or 0 if failure. + * + * If there are enough free keys between the maximum key existing in the table + * (_mesa_HashTable::MaxKey) and the maximum key possible, then simply return + * the adjacent key. Otherwise do a full search for a free key block in the + * allowable key range. + */ +GLuint +_mesa_HashFindFreeKeyBlock(struct _mesa_HashTable *table, GLuint numKeys) +{ + const GLuint maxKey = ~((GLuint) 0); + _glthread_LOCK_MUTEX(table->Mutex); + if (maxKey - numKeys > table->MaxKey) { + /* the quick solution */ + _glthread_UNLOCK_MUTEX(table->Mutex); + return table->MaxKey + 1; + } + else { + /* the slow solution */ + GLuint freeCount = 0; + GLuint freeStart = 1; + GLuint key; + for (key = 1; key != maxKey; key++) { + if (_mesa_HashLookup_unlocked(table, key)) { + /* darn, this key is already in use */ + freeCount = 0; + freeStart = key+1; + } + else { + /* this key not in use, check if we've found enough */ + freeCount++; + if (freeCount == numKeys) { + _glthread_UNLOCK_MUTEX(table->Mutex); + return freeStart; + } + } + } + /* cannot allocate a block of numKeys consecutive keys */ + _glthread_UNLOCK_MUTEX(table->Mutex); + return 0; + } +} + + +#if 0 /* debug only */ + +/** + * Test walking over all the entries in a hash table. + */ +static void +test_hash_walking(void) +{ + struct _mesa_HashTable *t = _mesa_NewHashTable(); + const GLuint limit = 50000; + GLuint i; + + /* create some entries */ + for (i = 0; i < limit; i++) { + GLuint dummy; + GLuint k = (rand() % (limit * 10)) + 1; + while (_mesa_HashLookup(t, k)) { + /* id already in use, try another */ + k = (rand() % (limit * 10)) + 1; + } + _mesa_HashInsert(t, k, &dummy); + } + + /* walk over all entries */ + { + GLuint k = _mesa_HashFirstEntry(t); + GLuint count = 0; + while (k) { + GLuint knext = _mesa_HashNextEntry(t, k); + assert(knext != k); + _mesa_HashRemove(t, k); + count++; + k = knext; + } + assert(count == limit); + k = _mesa_HashFirstEntry(t); + assert(k==0); + } + + _mesa_DeleteHashTable(t); +} + + +void +_mesa_test_hash_functions(void) +{ + int a, b, c; + struct _mesa_HashTable *t; + + t = _mesa_NewHashTable(); + _mesa_HashInsert(t, 501, &a); + _mesa_HashInsert(t, 10, &c); + _mesa_HashInsert(t, 0xfffffff8, &b); + /*_mesa_HashPrint(t);*/ + + assert(_mesa_HashLookup(t,501)); + assert(!_mesa_HashLookup(t,1313)); + assert(_mesa_HashFindFreeKeyBlock(t, 100)); + + _mesa_DeleteHashTable(t); + + test_hash_walking(); +} + +#endif |