From: John Hodge <tpg@portege.thepowersgang.com>
Date: Wed, 23 Sep 2009 05:01:08 +0000 (+0800)
Subject: Moved rand from arch/proc to lib.c and changed it to a LCG
X-Git-Tag: rel0.06~532
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=ef2ef0b76dca5bd5ee3b80fb7f831f89fc81f80d;p=tpg%2Facess2.git

Moved rand from arch/proc to lib.c and changed it to a LCG
---

diff --git a/Kernel/arch/x86/proc.c b/Kernel/arch/x86/proc.c
index d7af3e3d..0f9f449f 100644
--- a/Kernel/arch/x86/proc.c
+++ b/Kernel/arch/x86/proc.c
@@ -11,7 +11,6 @@
 #endif
 
 // === CONSTANTS ===
-#define	RANDOM_SEED	0xACE55052
 #define	SWITCH_MAGIC	0xFFFACE55	// There is no code in this area
 #define	DEFAULT_QUANTUM	10
 #define	DEFAULT_TICKETS	5
@@ -345,6 +344,7 @@ void Proc_SetThreadName(char *NewName)
 
 /**
  * \fn Uint Proc_MakeUserStack()
+ * \brief Creates a new user stack
  */
 Uint Proc_MakeUserStack()
 {
@@ -684,6 +684,7 @@ static tThread *Proc_int_GetPrevThread(tThread **List, tThread *Thread)
 
 /**
  * \fn void Proc_DumpThreads()
+ * \brief Dums a list of currently running threads
  */
 void Proc_DumpThreads()
 {
@@ -707,7 +708,7 @@ void Proc_DumpThreads()
 
 /**
  * \fn void Proc_Scheduler(int CPU)
- * \brief Swap current task
+ * \brief Swap current thread and clears dead threads
  */
 void Proc_Scheduler(int CPU)
 {
@@ -819,18 +820,3 @@ int Proc_GetGID()
 {
 	return gCurrentThread->GID;
 }
-
-/**
- * \fn Uint rand()
- * \brief Pseudo random number generator
- * \note Unknown effectiveness (made up on the spot)
- */
-Uint rand()
-{
-	static Uint	randomState = RANDOM_SEED;
-	Uint	ret = randomState;
-	 int	roll = randomState & 31;
-	randomState = (randomState << roll) | (randomState >> (32-roll));
-	randomState ^= 0x9A3C5E78;
-	return ret;
-}
diff --git a/Kernel/lib.c b/Kernel/lib.c
index c8a0e9f1..0dbb9b96 100644
--- a/Kernel/lib.c
+++ b/Kernel/lib.c
@@ -5,6 +5,9 @@
 #include <common.h>
 
 // === CONSTANTS ===
+#define	RANDOM_SEED	0xACE55052
+#define	RANDOM_A	0x12231ADE
+#define	RANDOM_C	0x1BADBEEF
 //                          Jan Feb Mar Apr May  Jun  Jul  Aug  Sept Oct  Nov  Dec
 const short DAYS_BEFORE[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
 #define UNIX_TO_2K	((30*365*3600*24) + (7*3600*24))	//Normal years + leap years
@@ -293,5 +296,25 @@ Sint64 timestamp(int sec, int mins, int hrs, int day, int month, int year)
 	return stamp * 1000;
 }
 
+/**
+ * \fn Uint rand()
+ * \brief Pseudo random number generator
+ * \note Unknown effectiveness (made up on the spot)
+ */
+Uint rand()
+{
+	#if 0
+	static Uint	randomState = RANDOM_SEED;
+	Uint	ret = randomState;
+	 int	roll = randomState & 31;
+	randomState = (randomState << roll) | (randomState >> (32-roll));
+	randomState ^= 0x9A3C5E78;
+	return ret;
+	#else
+	static Uint	randomState = RANDOM_SEED;
+	return randomState = (RANDOM_A*randomState + RANDOM_C) & 0xFFFFFFFF;
+	#endif
+}
+
 EXPORT(timestamp);
 EXPORT(ReadUTF8);