xnu-4570.1.46.tar.gz

[apple/xnu.git] / osfmk / kern / queue.h

diff --git a/osfmk/kern/queue.h b/osfmk/kern/queue.h
index f45899ce220e4fbeeb2b40c719f49c0c8150373e..1cdcd4f1bc6cb716f8f45d0435b5753db42b0f74 100644 (file)
--- a/osfmk/kern/queue.h
+++ b/osfmk/kern/queue.h
@@ -136,7 +136,7 @@ __BEGIN_DECLS
  *             [1] remqueue
  *             [1] insque
  *             [1] remque
- *             [1] re_queue
+ *             [1] re_queue_head
  *             [1] re_queue_tail
  *             [1] movqueue
  *             [1] qe_element
@@ -197,7 +197,18 @@ struct queue_entry {
        struct queue_entry      *next;          /* next element */
        struct queue_entry      *prev;          /* previous element */
 
+#if __arm__ && (__BIGGEST_ALIGNMENT__ > 4)
+/* For the newer ARMv7k ABI where 64-bit types are 64-bit aligned, but pointers
+ * are 32-bit:
+ * Since this type is so often cast to various 64-bit aligned types
+ * aligning it to 64-bits will avoid -wcast-align without needing
+ * to disable it entirely. The impact on memory footprint should be 
+ * negligible.
+ */
+} __attribute__ ((aligned (8)));
+#else
 };
+#endif
 
 typedef struct queue_entry     *queue_t;
 typedef        struct queue_entry      queue_head_t;
@@ -520,6 +531,46 @@ re_queue_tail(queue_t que, queue_entry_t elt)
             &((elt)->field) != (head); \
             elt = _nelt, _nelt = qe_element((elt)->field.next, typeof(*(elt)), field)) \
 
+#ifdef XNU_KERNEL_PRIVATE
+
+/* Dequeue an element from head, or return NULL if the queue is empty */
+#define qe_dequeue_head(head, type, field) ({ \
+       queue_entry_t _tmp_entry = dequeue_head((head)); \
+       type *_tmp_element = (type*) NULL; \
+       if (_tmp_entry != (queue_entry_t) NULL) \
+               _tmp_element = qe_element(_tmp_entry, type, field); \
+       _tmp_element; \
+})
+
+/* Dequeue an element from tail, or return NULL if the queue is empty */
+#define qe_dequeue_tail(head, type, field) ({ \
+       queue_entry_t _tmp_entry = dequeue_tail((head)); \
+       type *_tmp_element = (type*) NULL; \
+       if (_tmp_entry != (queue_entry_t) NULL) \
+               _tmp_element = qe_element(_tmp_entry, type, field); \
+       _tmp_element; \
+})
+
+/* Peek at the first element, or return NULL if the queue is empty */
+#define qe_queue_first(head, type, field) ({ \
+       queue_entry_t _tmp_entry = queue_first((head)); \
+       type *_tmp_element = (type*) NULL; \
+       if (_tmp_entry != (queue_entry_t) head) \
+               _tmp_element = qe_element(_tmp_entry, type, field); \
+       _tmp_element; \
+})
+
+/* Peek at the last element, or return NULL if the queue is empty */
+#define qe_queue_last(head, type, field) ({ \
+       queue_entry_t _tmp_entry = queue_last((head)); \
+       type *_tmp_element = (type*) NULL; \
+       if (_tmp_entry != (queue_entry_t) head) \
+               _tmp_element = qe_element(_tmp_entry, type, field); \
+       _tmp_element; \
+})
+
+#endif /* XNU_KERNEL_PRIVATE */
+
 /*
  *     Macro:          queue_init
  *     Function:
@@ -983,11 +1034,9 @@ struct mpqueue_head {
        struct queue_entry      head;           /* header for queue */
        uint64_t                earliest_soft_deadline;
        uint64_t                count;
-#if defined(__i386__) || defined(__x86_64__)
        lck_mtx_t               lock_data;
+#if defined(__i386__) || defined(__x86_64__)
        lck_mtx_ext_t           lock_data_ext;
-#else
-       lck_spin_t              lock_data;
 #endif
 };
 
@@ -1014,7 +1063,7 @@ MACRO_END
 #define mpqueue_init(q, lck_grp, lck_attr)             \
 MACRO_BEGIN                                            \
        queue_init(&(q)->head);                         \
-        lck_spin_init(&(q)->lock_data,                 \
+        lck_mtx_init(&(q)->lock_data,                  \
                      lck_grp,                          \
                      lck_attr);                        \
 MACRO_END