mesa: Lock mutex around _mesa_HashLookup linked list chase.

Remove const qualifier from _mesa_HashLookup() table parameter to
avoid LOCK/UNLOCK warnings in the function body.

Signed-off-by: Brian Paul <brianp@vmware.com>

(cherry picked from commit 3094adb3caeb90124359db2356df3bf8ee94800a)

src/mesa/main/hash.c

@@ -128,7 +128,7 @@ _mesa_DeleteHashTable(struct _mesa_HashTable *table)
  * \return pointer to user's data or NULL if key not in table
  */
 void *
-_mesa_HashLookup(const struct _mesa_HashTable *table, GLuint key)
+_mesa_HashLookup(struct _mesa_HashTable *table, GLuint key)
 {
    GLuint pos;
    const struct HashEntry *entry;
@@ -137,13 +137,16 @@ _mesa_HashLookup(const struct _mesa_HashTable *table, GLuint key)
    assert(key);
 
    pos = HASH_FUNC(key);
+   _glthread_LOCK_MUTEX(table->Mutex);
    entry = table->Table[pos];
    while (entry) {
       if (entry->Key == key) {
-	 return entry->Data;
+         _glthread_UNLOCK_MUTEX(table->Mutex);
+         return entry->Data;
       }
       entry = entry->Next;
    }
+   _glthread_UNLOCK_MUTEX(table->Mutex);
    return NULL;
 }
 

src/mesa/main/hash.h

@@ -39,7 +39,7 @@ extern struct _mesa_HashTable *_mesa_NewHashTable(void);
 
 extern void _mesa_DeleteHashTable(struct _mesa_HashTable *table);
 
-extern void *_mesa_HashLookup(const struct _mesa_HashTable *table, GLuint key);
+extern void *_mesa_HashLookup(struct _mesa_HashTable *table, GLuint key);
 
 extern void _mesa_HashInsert(struct _mesa_HashTable *table, GLuint key, void *data);