Scheduler now uses btime, and other improvements

code/__defines/btime.dm

@@ -0,0 +1,18 @@
+// Comment this out if the external btime library is unavailable
+#define PRECISE_TIMER_AVAILABLE
+
+#ifdef PRECISE_TIMER_AVAILABLE
+var/global/__btime__libName = "btime.[world.system_type==MS_WINDOWS?"dll":"so"]"
+#define TimeOfHour (__extern__timeofhour)
+#define __extern__timeofhour text2num(call(__btime__libName, "gettime")())
+/hook/startup/proc/checkbtime()
+	try
+		// This will always return 1 unless the btime library cannot be accessed
+		if(TimeOfHour || 1) return 1
+	catch(var/exception/e)
+		log_to_dd("PRECISE_TIMER_AVAILABLE is defined in btime.dm, but calling the btime library failed: [e]")
+		log_to_dd("This is a fatal error. The world will now shut down.")
+		del(world)
+#else
+#define TimeOfHour (world.timeofday % 36000)
+#endif

code/__defines/process_scheduler.dm

@@ -0,0 +1,20 @@
+// Process status defines
+#define PROCESS_STATUS_IDLE 1
+#define PROCESS_STATUS_QUEUED 2
+#define PROCESS_STATUS_RUNNING 3
+#define PROCESS_STATUS_MAYBE_HUNG 4
+#define PROCESS_STATUS_PROBABLY_HUNG 5
+#define PROCESS_STATUS_HUNG 6
+
+// Process time thresholds
+#define PROCESS_DEFAULT_HANG_WARNING_TIME 	300 // 30 seconds
+#define PROCESS_DEFAULT_HANG_ALERT_TIME 	600 // 60 seconds
+#define PROCESS_DEFAULT_HANG_RESTART_TIME 	900 // 90 seconds
+#define PROCESS_DEFAULT_SCHEDULE_INTERVAL 	50  // 50 ticks
+#define PROCESS_DEFAULT_SLEEP_INTERVAL		8	// 2 ticks
+#define PROCESS_DEFAULT_CPU_THRESHOLD		90  // 90%
+
+// SCHECK macros
+// This references src directly to work around a weird bug with try/catch
+#define SCHECK_EVERY(this_many_calls) if(++src.calls_since_last_scheck >= this_many_calls) sleepCheck()
+#define SCHECK SCHECK_EVERY(50)