#include "glheader.h"
#include "imports.h"
-#include "glthread.h"
+#include "glapi/glthread.h"
#include "hash.h"
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 */
};
struct _mesa_HashTable *table = CALLOC_STRUCT(_mesa_HashTable);
if (table) {
_glthread_INIT_MUTEX(table->Mutex);
+ _glthread_INIT_MUTEX(table->WalkMutex);
}
return table;
}
_mesa_problem(NULL,
"In _mesa_DeleteHashTable, found non-freed data");
}
- _mesa_free(entry);
+ free(entry);
entry = next;
}
}
_glthread_DESTROY_MUTEX(table->Mutex);
- _mesa_free(table);
+ _glthread_DESTROY_MUTEX(table->WalkMutex);
+ 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
+ * Lookup an entry in the hash table, without locking.
+ * \sa _mesa_HashLookup
*/
-void *
-_mesa_HashLookup(const struct _mesa_HashTable *table, GLuint key)
+static INLINE void *
+_mesa_HashLookup_unlocked(struct _mesa_HashTable *table, GLuint key)
{
GLuint pos;
const struct HashEntry *entry;
entry = table->Table[pos];
while (entry) {
if (entry->Key == key) {
- return entry->Data;
+ return entry->Data;
}
entry = entry->Next;
}
}
+/**
+ * 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.
/* 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;
+ if (entry) {
+ entry->Key = key;
+ entry->Data = data;
+ entry->Next = table->Table[pos];
+ table->Table[pos] = entry;
+ }
_glthread_UNLOCK_MUTEX(table->Mutex);
}
else {
table->Table[pos] = entry->Next;
}
- _mesa_free(entry);
+ free(entry);
_glthread_UNLOCK_MUTEX(table->Mutex);
return;
}
* \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)
+ * (this is typically a struct gl_context pointer)
*/
void
_mesa_HashDeleteAll(struct _mesa_HashTable *table,
for (entry = table->Table[pos]; entry; entry = next) {
callback(entry->Key, entry->Data, userData);
next = entry->Next;
- _mesa_free(entry);
+ free(entry);
}
table->Table[pos] = NULL;
}
/**
* 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)
+ * (this is typically a struct gl_context pointer)
*/
void
_mesa_HashWalk(const struct _mesa_HashTable *table,
GLuint pos;
ASSERT(table);
ASSERT(callback);
- _glthread_UNLOCK_MUTEX(table2->Mutex);
+ _glthread_LOCK_MUTEX(table2->WalkMutex);
for (pos = 0; pos < TABLE_SIZE; pos++) {
- struct HashEntry *entry;
- for (entry = table->Table[pos]; entry; entry = entry->Next) {
+ 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->Mutex);
+ _glthread_UNLOCK_MUTEX(table2->WalkMutex);
}
GLuint freeStart = 1;
GLuint key;
for (key = 1; key != maxKey; key++) {
- if (_mesa_HashLookup(table, key)) {
+ if (_mesa_HashLookup_unlocked(table, key)) {
/* darn, this key is already in use */
freeCount = 0;
freeStart = key+1;