More scheduling and probabilisticity

1 files changed, 22 insertions, 0 deletions

diff --git a/src/schedule.c b/src/schedule.c
index e746a7f..dda08f3 100644
--- a/src/schedule.c
+++ b/src/schedule.c
@@ -1,6 +1,10 @@
 // Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
 // SPDX-License-Identifier: MIT
 
+#include <math.h>
+#include <time.h>
+#include <stdlib.h>
+
 #include <schedule.h>
 #include <lib/pqueue.h>
 #include <parse.h>
@@ -25,8 +29,26 @@ static void set_pos(void *a, size_t position)
 	(void)position;
 }
 
+// skewed random number generator
+// prefers smaller numbers
+static size_t choose_position(void)
+{
+	size_t size = pqueue_size(queue);
+	return size - (size_t)sqrt(((size_t)rand() % (size_t)pow(size, 2)));
+}
+
+void schedule(void)
+{
+	while (pqueue_size(queue) > 0) {
+		size_t position = choose_position();
+		struct term *term = pqueue_pop_at(queue, position);
+		// TODO: reduce term
+	}
+}
+
 void schedule_init(void)
 {
+	srand(time(0));
 	queue = map_to_pqueue(cmp_pri, get_pri, set_pos);
 }