From 17e92e4b1902206ecb8459a86a4f7cfbf246d887 Mon Sep 17 00:00:00 2001
From: cxl <cxl@f0d560ea-af0d-0410-9eb7-867de7ffcac7>
Date: Wed, 7 Aug 2013 11:40:10 +0000
Subject: [PATCH] Core: Random now fork safe

git-svn-id: svn://ultimatepp.org/upp/trunk@6236 f0d560ea-af0d-0410-9eb7-867de7ffcac7
---
 uppsrc/Core/Random.cpp                 | 21 +++++++++++++--------
 uppsrc/Core/Util.h                     |  1 -
 uppsrc/Core/src.tpp/MathUtil$en-us.tpp |  9 +--------
 3 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/uppsrc/Core/Random.cpp b/uppsrc/Core/Random.cpp
index ec1061449..01bd3a2f0 100644
--- a/uppsrc/Core/Random.cpp
+++ b/uppsrc/Core/Random.cpp
@@ -58,6 +58,9 @@ struct MTrand {
 	dword mt[N];
 	int   mti;         /* mti==N+1 means mt[N] is not initialized */
 	dword mag01[2];
+#ifdef PLATFORM_POSIX
+	int   pid;
+#endif
 	
 	void seed();
 	void init_genrand(dword s);
@@ -160,6 +163,9 @@ MTrand::MTrand()
 	mag01[0] = 0;
 	mag01[1] = MATRIX_A;
 	seed();
+#ifdef PLATFORM_POSIX
+	pid = getpid();
+#endif
 }
 
 void MTrand::seed()
@@ -192,14 +198,6 @@ thread__ MTrand *sRng;
 thread__ byte    sRb[sizeof(MTrand)];
 #endif
 
-void SeedRandom()
-{
-	if(!sRng) {
-		sRng = new(sRb) MTrand;
-	}
-	sRng->seed();
-}
-
 void SeedRandom(dword *seed, int len){
 	if(!sRng) {
 		sRng = new(sRb) MTrand;
@@ -219,6 +217,13 @@ dword Random()
 	if(!sRng) {
 		sRng = new(sRb) MTrand;
 	}
+#ifdef PLATFORM_POSIX // Be fork safe...
+	int pid = getpid();
+	if(sRng->pid != pid) {
+		sRng->seed();
+		sRng->pid = pid;
+	}
+#endif
 	return sRng->genrand();
 }
 
diff --git a/uppsrc/Core/Util.h b/uppsrc/Core/Util.h
index f9db5bfeb..0d7b621b5 100644
--- a/uppsrc/Core/Util.h
+++ b/uppsrc/Core/Util.h
@@ -296,7 +296,6 @@ qword  Random64();
 qword  Random64(qword n);
 double Randomf();
 
-void  SeedRandom();
 void  SeedRandom(dword *seed,int len);
 void  SeedRandom(dword seed = 0);
 
diff --git a/uppsrc/Core/src.tpp/MathUtil$en-us.tpp b/uppsrc/Core/src.tpp/MathUtil$en-us.tpp
index 9ee6d15d3..adb744eeb 100644
--- a/uppsrc/Core/src.tpp/MathUtil$en-us.tpp
+++ b/uppsrc/Core/src.tpp/MathUtil$en-us.tpp
@@ -95,14 +95,7 @@ d],[@(0.0.255) int]_[*@3 len])&]
 [s5;:SeedRandom`(dword`): [@(0.0.255) void]_[* SeedRandom]([_^dword^ dword]_[*@3 seed]_`=_[@3 0
 ])&]
 [s2;%% Seeds random with single value [%-*@3 seed]. This is good to 
-get always the same sequence of numbers (for the same seed)&]
-[s3; &]
-[s4; &]
-[s5;:SeedRandom`(`): [@(0.0.255) void]_[* SeedRandom]()&]
-[s2; Seeds random from the host platform randomness sources. Note 
-that this is done by default by random number generator, there 
-is no need to call this function unless you are doing something 
-special.&]
+get always the same sequence of numbers (for the same seed).&]
 [s3;%% &]
 [s4; &]
 [s5;:ZeroArray`(x`): [* ZeroArray]([*@3 x])&]