+typedef struct _list_sched_selector_t {
+
+ /**
+ * Called before a graph is being scheduled.
+ * @param isa The isa.
+ * @param irg The graph.
+ * @return The environment pointer that is passed to all other
+ * functions in this struct.
+ */
+ void *(*init_graph)(const struct _arch_isa_t *isa, ir_graph *irg);
+
+ /**
+ * Called before scheduling starts on a block.
+ * @param env The environment.
+ * @param block The block which is to be scheduled.
+ * @return A per-block pointer that is additionally passed to select.
+ */
+ void *(*init_block)(void *env, ir_node *block);
+
+ /**
+ * The selection function.
+ * It picks one node out of the ready list to be scheduled next.
+ * The function does not have to delete the node from the ready set.
+ *
+ * @param env Some private information as returned by init_graph().
+ * @return block_env Some private information as returned by init_block().
+ * @param sched_head The schedule so far.
+ * @param curr_time The current time step which the picked node
+ * will be assigned to.
+ * @param ready_list A set containing all ready nodes. Pick one of these
+ * nodes.
+ * @return The chosen node.
+ */
+ ir_node *(*select)(void *env, void *block_env,
+ const struct list_head *sched_head,
+ int curr_time, pset *ready_set);
+
+ /**
+ * Called after a block has been scheduled.
+ * @param env The environment.
+ * @param block_env The per block environment as returned by init_block().
+ * @param block The block that has been finished.
+ */
+ void (*finish_block)(void *env, void *block_env, ir_node *block);