Runtime and thread_pool mostly done

include/runtime.h

@@ -1,10 +1,12 @@
 #pragma once
 
-typedef void (*system_tick_t)(int type);
+typedef void (*system_tick_t)();
 
 void runtime_init();
 void runtime_loop();
 void runtime_destroy();
 
-int runtime_callback_single(system_tick_t callback, long delay);
-int runtime_callback_many(system_tick_t callback, long period, long phase);
+void runtime_request_stop();
+
+void runtime_callback_single(system_tick_t callback, long delay);
+void runtime_callback_many(system_tick_t callback, long period, long phase);

include/systems/status.h

@@ -0,0 +1,4 @@
+#pragma once
+
+extern long status_last_tick_usec;
+extern long status_avg_tick_usec;

include/thread_pool.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <stddef.h>
+
 typedef struct thread_pool_t thread_pool_t;
 
 thread_pool_t *thread_pool_create(size_t thread_count);