#include "glheader.h"
#include "imports.h"
-#include "glthread.h"
+#include "glapi/glthread.h"
#include "hash.h"
/**
* An entry in the hash table.
- *
- * This struct is private to this file.
*/
struct HashEntry {
GLuint Key; /**< the entry's key */
struct HashEntry *Next; /**< pointer to next entry */
};
+
/**
* The hash table data structure.
- *
- * This is an opaque types (it's not defined in hash.h file).
*/
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.
*
struct _mesa_HashTable *table = CALLOC_STRUCT(_mesa_HashTable);
if (table) {
_glthread_INIT_MUTEX(table->Mutex);
+ _glthread_INIT_MUTEX(table->WalkMutex);
}
return table;
}
void
_mesa_DeleteHashTable(struct _mesa_HashTable *table)
{
- GLuint i;
+ GLuint pos;
assert(table);
- for (i = 0; i < TABLE_SIZE; i++) {
- struct HashEntry *entry = table->Table[i];
+ for (pos = 0; pos < TABLE_SIZE; pos++) {
+ struct HashEntry *entry = table->Table[pos];
while (entry) {
struct HashEntry *next = entry->Next;
- FREE(entry);
+ if (entry->Data) {
+ _mesa_problem(NULL,
+ "In _mesa_DeleteHashTable, found non-freed data");
+ }
+ free(entry);
entry = next;
}
}
_glthread_DESTROY_MUTEX(table->Mutex);
- 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.
table->MaxKey = key;
pos = HASH_FUNC(key);
- entry = table->Table[pos];
- while (entry) {
+
+ /* 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;
}
- entry = entry->Next;
}
/* 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;
}
- 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 pos;
assert(table);
_glthread_LOCK_MUTEX(table->Mutex);
- for (pos=0; pos < TABLE_SIZE; pos++) {
+ for (pos = 0; pos < TABLE_SIZE; pos++) {
if (table->Table[pos]) {
_glthread_UNLOCK_MUTEX(table->Mutex);
return table->Table[pos]->Key;
/* Find the entry with given key */
pos = HASH_FUNC(key);
- entry = table->Table[pos];
- while (entry) {
+ for (entry = table->Table[pos]; entry ; entry = entry->Next) {
if (entry->Key == key) {
break;
}
- entry = entry->Next;
}
if (!entry) {
- /* the key was not found, we can't find next entry */
+ /* the given key was not found, so we can't find the next entry */
return 0;
}
void
_mesa_HashPrint(const struct _mesa_HashTable *table)
{
- GLuint i;
+ GLuint pos;
assert(table);
- for (i=0;i<TABLE_SIZE;i++) {
- const struct HashEntry *entry = table->Table[i];
+ 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;
GLuint
_mesa_HashFindFreeKeyBlock(struct _mesa_HashTable *table, GLuint numKeys)
{
- GLuint maxKey = ~((GLuint) 0);
+ const GLuint maxKey = ~((GLuint) 0);
_glthread_LOCK_MUTEX(table->Mutex);
if (maxKey - numKeys > table->MaxKey) {
/* the quick solution */
GLuint freeCount = 0;
GLuint freeStart = 1;
GLuint key;
- for (key=1; key!=maxKey; key++) {
- if (_mesa_HashLookup(table, 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;
}
+/**
+ * Return the number of entries in the hash table.
+ */
+GLuint
+_mesa_HashNumEntries(const struct _mesa_HashTable *table)
+{
+ GLuint pos, count = 0;
+
+ for (pos = 0; pos < TABLE_SIZE; pos++) {
+ const struct HashEntry *entry;
+ for (entry = table->Table[pos]; entry; entry = entry->Next) {
+ count++;
+ }
+ }
+
+ return count;
+}
+
+
+
#if 0 /* debug only */
/**
projects / mesa.git / blobdiff