diff options
Diffstat (limited to 'libnetdata/dictionary')
| -rw-r--r-- | libnetdata/dictionary/dictionary.c | 42 |
1 files changed, 19 insertions, 23 deletions
diff --git a/libnetdata/dictionary/dictionary.c b/libnetdata/dictionary/dictionary.c index f03da25ab..0277e067f 100644 --- a/libnetdata/dictionary/dictionary.c +++ b/libnetdata/dictionary/dictionary.c @@ -3,10 +3,9 @@ #define DICTIONARY_INTERNALS #include "../libnetdata.h" -#include <Judy.h> // runtime flags of the dictionary - must be checked with atomics -typedef enum { +typedef enum __attribute__ ((__packed__)) { DICT_FLAG_NONE = 0, DICT_FLAG_DESTROYED = (1 << 0), // this dictionary has been destroyed } DICT_FLAGS; @@ -23,14 +22,14 @@ typedef enum { #define is_view_dictionary(dict) ((dict)->master) #define is_master_dictionary(dict) (!is_view_dictionary(dict)) -typedef enum item_options { +typedef enum __attribute__ ((__packed__)) item_options { ITEM_OPTION_NONE = 0, ITEM_OPTION_ALLOCATED_NAME = (1 << 0), // the name pointer is a STRING // IMPORTANT: This is 1-bit - to add more change ITEM_OPTIONS_BITS } ITEM_OPTIONS; -typedef enum item_flags { +typedef enum __attribute__ ((__packed__)) item_flags { ITEM_FLAG_NONE = 0, ITEM_FLAG_DELETED = (1 << 0), // this item is marked deleted, so it is not available for traversal (deleted from the index too) ITEM_FLAG_BEING_CREATED = (1 << 1), // this item is currently being created - this flag is removed when construction finishes @@ -623,7 +622,7 @@ static void dictionary_execute_delete_callback(DICTIONARY *dict, DICTIONARY_ITEM if(likely(!dict->hooks || !dict->hooks->del_callback)) return; - // We may execute the delete callback on items deleted from a view, + // We may execute delete callback on items deleted from a view, // because we may have references to it, after the master is gone // so, the shared structure will remain until the last reference is released. @@ -782,7 +781,7 @@ static void garbage_collect_pending_deletes(DICTIONARY *dict) { while(item) { examined++; - // this will cleanup + // this will clean up item_next = item->next; int rc = item_check_and_acquire_advanced(dict, item, is_view); @@ -882,7 +881,7 @@ static void item_acquire(DICTIONARY *dict, DICTIONARY_ITEM *item) { static void item_release(DICTIONARY *dict, DICTIONARY_ITEM *item) { // this function may be called without any lock on the dictionary - // or even when someone else has write lock on the dictionary + // or even when someone else has 'write' lock on the dictionary bool is_deleted; REFCOUNT refcount; @@ -934,11 +933,11 @@ static int item_check_and_acquire_advanced(DICTIONARY *dict, DICTIONARY_ITEM *it int ret = RC_ITEM_OK; + refcount = DICTIONARY_ITEM_REFCOUNT_GET(dict, item); + do { spins++; - refcount = DICTIONARY_ITEM_REFCOUNT_GET(dict, item); - if(refcount < 0) { // we can't use this item ret = RC_ITEM_IS_CURRENTLY_BEING_DELETED; @@ -953,8 +952,7 @@ static int item_check_and_acquire_advanced(DICTIONARY *dict, DICTIONARY_ITEM *it desired = refcount + 1; - } while(!__atomic_compare_exchange_n(&item->refcount, &refcount, desired, - false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); + } while(!__atomic_compare_exchange_n(&item->refcount, &refcount, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); // if ret == ITEM_OK, we acquired the item @@ -971,7 +969,7 @@ static int item_check_and_acquire_advanced(DICTIONARY *dict, DICTIONARY_ITEM *it else pointer_del(dict, item); - // mark it in our dictionary as deleted too + // mark it in our dictionary as deleted too, // this is safe to be done here, because we have got // a reference counter on item dict_item_set_deleted(dict, item); @@ -1013,11 +1011,11 @@ static inline int item_is_not_referenced_and_can_be_removed_advanced(DICTIONARY int ret = RC_ITEM_OK; + refcount = DICTIONARY_ITEM_REFCOUNT_GET(dict, item); + do { spins++; - refcount = DICTIONARY_ITEM_REFCOUNT_GET(dict, item); - if(refcount < 0) { // we can't use this item ret = RC_ITEM_IS_CURRENTLY_BEING_DELETED; @@ -1035,8 +1033,7 @@ static inline int item_is_not_referenced_and_can_be_removed_advanced(DICTIONARY ret = RC_ITEM_IS_CURRENTLY_BEING_CREATED; break; } - } while(!__atomic_compare_exchange_n(&item->refcount, &refcount, desired, - false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); + } while(!__atomic_compare_exchange_n(&item->refcount, &refcount, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); #ifdef NETDATA_INTERNAL_CHECKS if(ret == RC_ITEM_OK) @@ -1055,8 +1052,7 @@ static inline bool item_shared_release_and_check_if_it_can_be_freed(DICTIONARY * // if we can set refcount to REFCOUNT_DELETING, we can delete this item REFCOUNT links = __atomic_sub_fetch(&item->shared->links, 1, __ATOMIC_SEQ_CST); - if(links == 0 && __atomic_compare_exchange_n(&item->shared->links, &links, REFCOUNT_DELETING, - false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { + if(links == 0 && __atomic_compare_exchange_n(&item->shared->links, &links, REFCOUNT_DELETING, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { // we can delete it return true; @@ -1430,16 +1426,16 @@ static void dict_item_shared_set_deleted(DICTIONARY *dict, DICTIONARY_ITEM *item static bool dict_item_set_deleted(DICTIONARY *dict, DICTIONARY_ITEM *item) { ITEM_FLAGS expected, desired; + expected = __atomic_load_n(&item->flags, __ATOMIC_SEQ_CST); + do { - expected = __atomic_load_n(&item->flags, __ATOMIC_SEQ_CST); if (expected & ITEM_FLAG_DELETED) return false; desired = expected | ITEM_FLAG_DELETED; - } while(!__atomic_compare_exchange_n(&item->flags, &expected, desired, - false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); + } while(!__atomic_compare_exchange_n(&item->flags, &expected, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); DICTIONARY_ENTRIES_MINUS1(dict); return true; @@ -1474,7 +1470,7 @@ static inline void dict_item_free_or_mark_deleted(DICTIONARY *dict, DICTIONARY_I } // this is used by traversal functions to remove the current item -// if it is deleted and it has zero references. This will eliminate +// if it is deleted, and it has zero references. This will eliminate // the need for the garbage collector to kick-in later. // Most deletions happen during traversal, so this is a nice hack // to speed up everything! @@ -1601,7 +1597,7 @@ static DICTIONARY_ITEM *dict_item_add_or_reset_value_and_acquire(DICTIONARY *dic hashtable_inserted_item_unsafe(dict, item); // unlock the index lock, before we add it to the linked list - // DONT DO IT THE OTHER WAY AROUND - DO NOT CROSS THE LOCKS! + // DON'T DO IT THE OTHER WAY AROUND - DO NOT CROSS THE LOCKS! dictionary_index_wrlock_unlock(dict); item_linked_list_add(dict, item); |