=== modified file 'include/my_pthread.h'
--- include/my_pthread.h	2013-07-18 14:46:57 +0000
+++ include/my_pthread.h	2013-10-05 07:31:28 +0000
@@ -447,7 +447,6 @@ typedef struct st_my_pthread_fastmutex_t
 {
   pthread_mutex_t mutex;
   uint spins;
-  uint rng_state;
 } my_pthread_fastmutex_t;
 void fastmutex_global_init(void);
 

=== modified file 'mysys/thr_mutex.c'
--- mysys/thr_mutex.c	2013-06-06 12:51:36 +0000
+++ mysys/thr_mutex.c	2013-10-05 08:33:21 +0000
@@ -865,51 +865,21 @@ int my_pthread_fastmutex_init(my_pthread
     mp->spins= MY_PTHREAD_FASTMUTEX_SPINS; 
   else
     mp->spins= 0;
-  mp->rng_state= 1;
   return pthread_mutex_init(&mp->mutex, attr); 
 }
 
-/**
-  Park-Miller random number generator. A simple linear congruential
-  generator that operates in multiplicative group of integers modulo n.
-
-  x_{k+1} = (x_k g) mod n
-
-  Popular pair of parameters: n = 2^32 − 5 = 4294967291 and g = 279470273.
-  The period of the generator is about 2^31.
-  Largest value that can be returned: 2147483646 (RAND_MAX)
-
-  Reference:
-
-  S. K. Park and K. W. Miller
-  "Random number generators: good ones are hard to find"
-  Commun. ACM, October 1988, Volume 31, No 10, pages 1192-1201.
-*/
-
-static double park_rng(my_pthread_fastmutex_t *mp)
-{
-  mp->rng_state= ((my_ulonglong)mp->rng_state * 279470273U) % 4294967291U;
-  return (mp->rng_state / 2147483647.0);
-}
 
 int my_pthread_fastmutex_lock(my_pthread_fastmutex_t *mp)
 {
-  int   res;
-  uint  i;
-  uint  maxdelay= MY_PTHREAD_FASTMUTEX_DELAY;
+  uint spins, maxdelay= MY_PTHREAD_FASTMUTEX_DELAY;
 
-  for (i= 0; i < mp->spins; i++)
+  for (spins= mp->spins; spins; spins--)
   {
-    res= pthread_mutex_trylock(&mp->mutex);
-
-    if (res == 0)
-      return 0;
-
+    int res= pthread_mutex_trylock(&mp->mutex);
     if (res != EBUSY)
       return res;
-
     mutex_delay(maxdelay);
-    maxdelay += park_rng(mp) * MY_PTHREAD_FASTMUTEX_DELAY + 1;
+    maxdelay+= MY_PTHREAD_FASTMUTEX_DELAY;
   }
   return pthread_mutex_lock(&mp->mutex);
 }