Added MesaLib-7.6

1 files changed, 530 insertions, 0 deletions

diff --git a/mesalib/src/mesa/main/hash.c b/mesalib/src/mesa/main/hash.c
new file mode 100644
index 000000000..08c64568c
--- /dev/null
+++ b/mesalib/src/mesa/main/hash.c
@@ -0,0 +1,530 @@
+/**
+ * \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");
+         }
+	 _mesa_free(entry);
+	 entry = next;
+      }
+   }
+   _glthread_DESTROY_MUTEX(table->Mutex);
+   _glthread_DESTROY_MUTEX(table->WalkMutex);
+   _mesa_free(table);
+}
+
+
+
+/**
+ * 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(const 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;
+}
+
+
+
+/**
+ * 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);
+   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;
+         }
+         _mesa_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 GLcontext 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;
+         _mesa_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 GLcontext 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(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