+ enabled[threadid] = enabled_status;
+}
+
+/**
+ * @brief Check if a Thread is currently enabled
+ *
+ * Check if a Thread is currently enabled. "Enabled" includes both
+ * THREAD_ENABLED and THREAD_SLEEP_SET.
+ * @param t The Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_enabled(const Thread *t) const
+{
+ return is_enabled(t->get_id());
+}
+
+/**
+ * @brief Check if a Thread is currently enabled
+ *
+ * Check if a Thread is currently enabled. "Enabled" includes both
+ * THREAD_ENABLED and THREAD_SLEEP_SET.
+ * @param tid The ID of the Thread to check
+ * @return True if the Thread is currently enabled
+ */
+bool Scheduler::is_enabled(thread_id_t tid) const
+{
+ int i = id_to_int(tid);
+ return (i >= enabled_len) ? false : (enabled[i] != THREAD_DISABLED);
+}
+
+/**
+ * @brief Check if a Thread is currently in the sleep set
+ * @param t The Thread to check
+ */
+bool Scheduler::is_sleep_set(const Thread *t) const
+{
+ return is_sleep_set(t->get_id());
+}
+
+bool Scheduler::is_sleep_set(thread_id_t tid) const
+{
+ int id = id_to_int(tid);
+ ASSERT(id < enabled_len);
+ return enabled[id] == THREAD_SLEEP_SET;
+}
+
+/**
+ * @brief Check if execution is stuck with no enabled threads and some sleeping
+ * thread
+ * @return True if no threads are enabled and some thread is in the sleep set;
+ * false otherwise
+ */
+bool Scheduler::all_threads_sleeping() const
+{
+ bool sleeping = false;
+ for (int i = 0;i < enabled_len;i++)
+ if (enabled[i] == THREAD_ENABLED)
+ return false;
+ else if (enabled[i] == THREAD_SLEEP_SET)
+ sleeping = true;
+ return sleeping;
+}
+
+enabled_type_t Scheduler::get_enabled(const Thread *t) const
+{
+ int id = id_to_int(t->get_id());
+ ASSERT(id < enabled_len);
+ return enabled[id];
+}
+
+/**
+ * Add a Thread to the sleep set.
+ * @param t The Thread to add
+ * A Thread is in THREAD_SLEEP_SET if it is sleeping or blocked by a wait
+ * operation that should fail spuriously (decide by fuzzer).
+ */
+void Scheduler::add_sleep(Thread *t)
+{
+ DEBUG("thread %d\n", id_to_int(t->get_id()));
+ set_enabled(t, THREAD_SLEEP_SET);
+}
+
+/**
+ * Remove a Thread from the sleep set.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_sleep(Thread *t)
+{
+ DEBUG("thread %d\n", id_to_int(t->get_id()));
+ set_enabled(t, THREAD_ENABLED);