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-rw-r--r--src/basic/prioq.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/src/basic/prioq.c b/src/basic/prioq.c
index b89888be0..d55b348c2 100644
--- a/src/basic/prioq.c
+++ b/src/basic/prioq.c
@@ -19,6 +19,16 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+/*
+ * Priority Queue
+ * The prioq object implements a priority queue. That is, it orders objects by
+ * their priority and allows O(1) access to the object with the highest
+ * priority. Insertion and removal are Θ(log n). Optionally, the caller can
+ * provide a pointer to an index which will be kept up-to-date by the prioq.
+ *
+ * The underlying algorithm used in this implementation is a Heap.
+ */
+
#include "util.h"
#include "prioq.h"
@@ -101,7 +111,7 @@ static unsigned shuffle_up(Prioq *q, unsigned idx) {
k = (idx-1)/2;
- if (q->compare_func(q->items[k].data, q->items[idx].data) < 0)
+ if (q->compare_func(q->items[k].data, q->items[idx].data) <= 0)
break;
swap(q, idx, k);