From 4e05dd63f94a25b6c2fc23df376c0e1501b55941 Mon Sep 17 00:00:00 2001
From: pigeons <pigeons@protonmail.com>
Date: Tue, 25 Jul 2017 19:48:21 -0400
Subject: [PATCH] Fixes timer id collision (#29437)

The list of active timers timer_id_dict identifies timers by their numerical id as a string. However this was done using embedded expressions inside the string, which calls num2text with a default of 6 significant figures. This means anything at or above 1 million is expressed in scientific notation.

"timer[1000000]" -> "timer1e+06"
"timer[1000001]" -> "timer1e+06"

Calling num2text manually with 8 significant figures kicks the collision problem down the road to 2^24 (16 million).

nextid is now selectively incremented and is looped back to 1 when reaching the 2^24 threshold.
Also now includes collision checking.
---
 code/controllers/subsystem/timer.dm | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/code/controllers/subsystem/timer.dm b/code/controllers/subsystem/timer.dm
index daf7dc2ca9d..5696fa09e72 100644
--- a/code/controllers/subsystem/timer.dm
+++ b/code/controllers/subsystem/timer.dm
@@ -1,5 +1,6 @@
 #define BUCKET_LEN (world.fps*1*60) //how many ticks should we keep in the bucket. (1 minutes worth)
 #define BUCKET_POS(timer) (round((timer.timeToRun - SStimer.head_offset) / world.tick_lag) + 1)
+#define TIMER_ID_MAX (2**24) //max float with integer precision
 
 SUBSYSTEM_DEF(timer)
 	name = "Timer"
@@ -225,18 +226,23 @@ SUBSYSTEM_DEF(timer)
 	var/static/nextid = 1
 
 /datum/timedevent/New(datum/callback/callBack, timeToRun, flags, hash)
-	id = nextid++
+	id = TIMER_ID_NULL
 	src.callBack = callBack
 	src.timeToRun = timeToRun
 	src.flags = flags
 	src.hash = hash
 	
-	name = "Timer: [id]: TTR: [timeToRun], Flags: [jointext(bitfield2list(flags, list("TIMER_UNIQUE", "TIMER_OVERRIDE", "TIMER_CLIENT_TIME", "TIMER_STOPPABLE", "TIMER_NO_HASH_WAIT")), ", ")], callBack: \ref[callBack], callBack.object: [callBack.object]\ref[callBack.object]([getcallingtype()]), callBack.delegate:[callBack.delegate]([callBack.arguments ? callBack.arguments.Join(", ") : ""])"
-	
 	if (flags & TIMER_UNIQUE)
 		SStimer.hashes[hash] = src
 	if (flags & TIMER_STOPPABLE)
-		SStimer.timer_id_dict["timerid[id]"] = src
+		do
+			if (nextid >= TIMER_ID_MAX)
+				nextid = 1
+			id = nextid++
+		while(SStimer.timer_id_dict["timerid" + num2text(id, 8)])
+		SStimer.timer_id_dict["timerid" + num2text(id, 8)] = src
+
+	name = "Timer: " + num2text(id, 8) + ", TTR: [timeToRun], Flags: [jointext(bitfield2list(flags, list("TIMER_UNIQUE", "TIMER_OVERRIDE", "TIMER_CLIENT_TIME", "TIMER_STOPPABLE", "TIMER_NO_HASH_WAIT")), ", ")], callBack: \ref[callBack], callBack.object: [callBack.object]\ref[callBack.object]([getcallingtype()]), callBack.delegate:[callBack.delegate]([callBack.arguments ? callBack.arguments.Join(", ") : ""])"
 
 	if (callBack.object != GLOBAL_PROC)
 		LAZYADD(callBack.object.active_timers, src)
@@ -297,7 +303,7 @@ SUBSYSTEM_DEF(timer)
 	callBack = null
 
 	if (flags & TIMER_STOPPABLE)
-		SStimer.timer_id_dict -= "timerid[id]"
+		SStimer.timer_id_dict -= "timerid" + num2text(id, 8)
 
 	if (flags & TIMER_CLIENT_TIME)
 		SStimer.clienttime_timers -= src
@@ -378,9 +384,7 @@ SUBSYSTEM_DEF(timer)
 		timeToRun = REALTIMEOFDAY + wait
 
 	var/datum/timedevent/timer = new(callback, timeToRun, flags, hash)
-	if (flags & TIMER_STOPPABLE)
-		return timer.id
-	return TIMER_ID_NULL
+	return timer.id 
 
 /proc/deltimer(id)
 	if (!id)
@@ -391,6 +395,7 @@ SUBSYSTEM_DEF(timer)
 		if (istype(id, /datum/timedevent))
 			qdel(id)
 			return TRUE
+	//id is string
 	var/datum/timedevent/timer = SStimer.timer_id_dict["timerid[id]"]
 	if (timer && !timer.spent)
 		qdel(timer)