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 #define RCU_YIELD_READ  (1 << 0)
  35 #define RCU_YIELD_WRITE (1 << 1)
  36
  37 /*
  38  * Updates with RCU_SIGNAL are much slower. Account this in the delay.
  39  */
  40 #ifdef RCU_SIGNAL
  41 /* maximum sleep delay, in us */
  42 #define MAX_SLEEP 30000
  43 #else
  44 #define MAX_SLEEP 50
  45 #endif
  46
  47 extern unsigned int rcu_yield_active;
  48 extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
  49
  50 #ifdef DEBUG_YIELD
  51 static inline void rcu_debug_yield_read(void)
  52 {
  53         if (rcu_yield_active & RCU_YIELD_READ)
  54                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  55                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  56 }
  57
  58 static inline void rcu_debug_yield_write(void)
  59 {
  60         if (rcu_yield_active & RCU_YIELD_WRITE)
  61                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  62                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  63 }
  64
  65 static inline void rcu_debug_yield_enable(unsigned int flags)
  66 {
  67         rcu_yield_active |= flags;
  68 }
  69
  70 static inline void rcu_debug_yield_disable(unsigned int flags)
  71 {
  72         rcu_yield_active &= ~flags;
  73 }
  74
  75 static inline void rcu_debug_yield_init(void)
  76 {
  77         URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
  78 }
  79 #else /* DEBUG_YIELD */
  80 static inline void rcu_debug_yield_read(void)
  81 {
  82 }
  83
  84 static inline void rcu_debug_yield_write(void)
  85 {
  86 }
  87
  88 static inline void rcu_debug_yield_enable(unsigned int flags)
  89 {
  90 }
  91
  92 static inline void rcu_debug_yield_disable(unsigned int flags)
  93 {
  94 }
  95
  96 static inline void rcu_debug_yield_init(void)
  97 {
  98 }
  99 #endif
 100
 101 #endif /* URCU_TESTS_DEBUG_YIELD_H */