tests/common/debug-yield.h

   1 #ifndef URCU_TESTS_DEBUG_YIELD_H
   2 #define URCU_TESTS_DEBUG_YIELD_H
   3
   4 /*
   5  * debug-yield.h
   6  *
   7  * Userspace RCU library tests - Debugging header
   8  *
   9  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2.1 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this library; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  25  *
  26  * IBM's contributions to this file may be relicensed under LGPLv2 or later.
  27  */
  28
  29 #include <sched.h>
  30 #include <time.h>
  31 #include <pthread.h>
  32 #include <unistd.h>
  33
  34 #include <compat-rand.h>
  35
  36 #define RCU_YIELD_READ  (1 << 0)
  37 #define RCU_YIELD_WRITE (1 << 1)
  38
  39 /*
  40  * Updates with RCU_SIGNAL are much slower. Account this in the delay.
  41  */
  42 #ifdef RCU_SIGNAL
  43 /* maximum sleep delay, in us */
  44 #define MAX_SLEEP 30000
  45 #else
  46 #define MAX_SLEEP 50
  47 #endif
  48
  49 extern unsigned int rcu_yield_active;
  50 extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
  51
  52 #ifdef DEBUG_YIELD
  53 static inline void rcu_debug_yield_read(void)
  54 {
  55         if (rcu_yield_active & RCU_YIELD_READ)
  56                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  57                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  58 }
  59
  60 static inline void rcu_debug_yield_write(void)
  61 {
  62         if (rcu_yield_active & RCU_YIELD_WRITE)
  63                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  64                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  65 }
  66
  67 static inline void rcu_debug_yield_enable(unsigned int flags)
  68 {
  69         rcu_yield_active |= flags;
  70 }
  71
  72 static inline void rcu_debug_yield_disable(unsigned int flags)
  73 {
  74         rcu_yield_active &= ~flags;
  75 }
  76
  77 static inline void rcu_debug_yield_init(void)
  78 {
  79         URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
  80 }
  81 #else /* DEBUG_YIELD */
  82 static inline void rcu_debug_yield_read(void)
  83 {
  84 }
  85
  86 static inline void rcu_debug_yield_write(void)
  87 {
  88 }
  89
  90 static inline void rcu_debug_yield_enable(
  91                 unsigned int flags __attribute__((unused)))
  92 {
  93 }
  94
  95 static inline void rcu_debug_yield_disable(
  96                 unsigned int flags __attribute__((unused)))
  97 {
  98 }
  99
 100 static inline void rcu_debug_yield_init(void)
 101 {
 102 }
 103 #endif
 104
 105 #endif /* URCU_TESTS_DEBUG_YIELD_H */