[MIRROR] The profiler now starts earlier into the init process. + Documents the initialization order and pipeline (#319)

* The profiler now starts earlier into the init process. + Documents the initialization order and pipeline (#52662)

* The profiler now starts earlier into the init process.
Also documents the init pipeline and order in world/New()'s codedoc.

* better early profiler

* NEWMAN!

* The profiler now starts earlier into the init process. + Documents the initialization order and pipeline

Co-authored-by: Kyle Spier-Swenson <kyleshome@gmail.com>

code/__DEFINES/_profile.dm

@@ -0,0 +1,4 @@
+#if DM_BUILD >= 1506
+// We don't actually care about storing the output here, this is just an easy way to ensure the profile runs first.
+GLOBAL_REAL_VAR(world_init_profiler) = world.Profile(PROFILE_START)
+#endif

code/controllers/subsystem/profiler.dm

@@ -18,7 +18,7 @@ SUBSYSTEM_DEF(profiler)
 	if(CONFIG_GET(flag/auto_profile))
 		StartProfiling()
 	else
-		StopProfiling() //Stop the early start from world/New
+		StopProfiling() //Stop the early start profiler
 	return ..()
 
 /datum/controller/subsystem/profiler/fire()

code/game/world.dm

@@ -5,18 +5,28 @@ GLOBAL_VAR(restart_counter)
 /**
   * World creation
   *
-  * Here is where a round itself is actually begun and setup, lots of important config changes happen here
+  * Here is where a round itself is actually begun and setup.
   * * db connection setup
   * * config loaded from files
   * * loads admins
   * * Sets up the dynamic menu system
   * * and most importantly, calls initialize on the master subsystem, starting the game loop that causes the rest of the game to begin processing and setting up
   *
-  * Note this happens after the Master subsystem is created (as that is a global datum), this means all the subsystems exist,
-  * but they have not been Initialized at this point, only their New proc has run
   *
   * Nothing happens until something moves. ~Albert Einstein
   *
+  * For clarity, this proc gets triggered later in the initialization pipeline, it is not the first thing to happen, as it might seem.
+  *
+  * Initialization Pipeline:
+  *		Global vars are new()'ed, (including config, glob, and the master controller will also new and preinit all subsystems when it gets new()ed)
+  *		Compiled in maps are loaded (mainly centcom). all areas/turfs/objs/mobs(ATOMs) in these maps will be new()ed
+  *		world/New() (You are here)
+  *		Once world/New() returns, client's can connect.
+  *		1 second sleep
+  *		Master Controller initialization.
+  *		Subsystem initialization.
+  *			Non-compiled-in maps are maploaded, all atoms are new()ed
+  *			All atoms in both compiled and uncompiled maps are initialized()
   */
 /world/New()
 	var/extools = world.GetConfig("env", "EXTOOLS_DLL") || (world.system_type == MS_WINDOWS ? "./byond-extools.dll" : "./libbyond-extools.so")
@@ -27,11 +37,6 @@ GLOBAL_VAR(restart_counter)
 	enable_reference_tracking()
 #endif
 
-	//Early profile for auto-profiler - will be stopped on profiler init if necessary.
-#if DM_BUILD >= 1506
-	world.Profile(PROFILE_START)
-#endif
-
 	log_world("World loaded at [time_stamp()]!")
 
 	make_datum_references_lists()	//initialises global lists for referencing frequently used datums (so that we only ever do it once)

tgstation.dme

@@ -18,6 +18,7 @@
 #include "code\world.dm"
 #include "code\__DEFINES\_globals.dm"
 #include "code\__DEFINES\_helpers.dm"
+#include "code\__DEFINES\_profile.dm"
 #include "code\__DEFINES\_protect.dm"
 #include "code\__DEFINES\_tick.dm"
 #include "code\__DEFINES\access.dm"