Replace rand() implementation - fixes threading lockups

[tpg/acess2.git] / Kernel / lib.c

diff --git a/Kernel/lib.c b/Kernel/lib.c
index cab15b3..2ce5c98 100644 (file)
--- a/Kernel/lib.c
+++ b/Kernel/lib.c
@@ -8,7 +8,7 @@
 #define        RANDOM_SEED     0xACE55052
 #define        RANDOM_A        0x00731ADE
 #define        RANDOM_C        12345
-#define        RANDOM_SPRUCE   0xf12b02b
+#define        RANDOM_SPRUCE   0xf12b039
 //                          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
@@ -66,9 +66,6 @@ EXPORT(CheckMem);
 EXPORT(ModUtil_LookupString);
 EXPORT(ModUtil_SetIdent);
 
-// === GLOBALS ===
-static Uint    giRandomState = RANDOM_SEED;
-
 // === CODE ===
 /**
  * \brief Convert a string into an integer
@@ -679,12 +676,27 @@ Sint64 timestamp(int sec, int mins, int hrs, int day, int month, int year)
  */
 Uint rand(void)
 {
-       Uint    old = giRandomState;
+       #if 0
+       static Uint     state = RANDOM_SEED;
+       Uint    old = state;
        // Get the next state value
-       giRandomState = (RANDOM_A*giRandomState + RANDOM_C) & 0xFFFFFFFF;
+       giRandomState = (RANDOM_A*state + RANDOM_C);
        // Check if it has changed, and if it hasn't, change it
-       if(giRandomState == old)        giRandomState += RANDOM_SPRUCE;
-       return giRandomState;
+       if(state == old)        state += RANDOM_SPRUCE;
+       return state;
+       #else
+       // http://en.wikipedia.org/wiki/Xorshift
+       // 2010-10-03
+       static Uint32   x = 123456789;
+       static Uint32   y = 362436069;
+       static Uint32   z = 521288629;
+       static Uint32   w = 88675123; 
+       Uint32  t;
+ 
+       t = x ^ (x << 11);
+       x = y; y = z; z = w;
+       return w = w ^ (w >> 19) ^ t ^ (t >> 8); 
+       #endif
 }
 
 /* *