tests/common/debug-yield.h

   1 // SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 // SPDX-FileCopyrightText: 2009 Paul E. McKenney, IBM Corporation.
   3 //
   4 // SPDX-License-Identifier: LGPL-2.1-or-later
   5
   6 #ifndef URCU_TESTS_DEBUG_YIELD_H
   7 #define URCU_TESTS_DEBUG_YIELD_H
   8
   9 /*
  10  * Userspace RCU library tests - Debugging header
  11  *
  12  * IBM's contributions to this file may be relicensed under LGPLv2 or later.
  13  */
  14
  15 #include <sched.h>
  16 #include <time.h>
  17 #include <pthread.h>
  18 #include <unistd.h>
  19
  20 #include <compat-rand.h>
  21
  22 #define RCU_YIELD_READ  (1 << 0)
  23 #define RCU_YIELD_WRITE (1 << 1)
  24
  25 /*
  26  * Updates with RCU_SIGNAL are much slower. Account this in the delay.
  27  */
  28 #ifdef RCU_SIGNAL
  29 /* maximum sleep delay, in us */
  30 #define MAX_SLEEP 30000
  31 #else
  32 #define MAX_SLEEP 50
  33 #endif
  34
  35 extern unsigned int rcu_yield_active;
  36 extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
  37
  38 #ifdef DEBUG_YIELD
  39 static inline void rcu_debug_yield_read(void)
  40 {
  41         if (rcu_yield_active & RCU_YIELD_READ)
  42                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  43                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  44 }
  45
  46 static inline void rcu_debug_yield_write(void)
  47 {
  48         if (rcu_yield_active & RCU_YIELD_WRITE)
  49                 if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
  50                         usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
  51 }
  52
  53 static inline void rcu_debug_yield_enable(unsigned int flags)
  54 {
  55         rcu_yield_active |= flags;
  56 }
  57
  58 static inline void rcu_debug_yield_disable(unsigned int flags)
  59 {
  60         rcu_yield_active &= ~flags;
  61 }
  62
  63 static inline void rcu_debug_yield_init(void)
  64 {
  65         URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
  66 }
  67 #else /* DEBUG_YIELD */
  68 static inline void rcu_debug_yield_read(void)
  69 {
  70 }
  71
  72 static inline void rcu_debug_yield_write(void)
  73 {
  74 }
  75
  76 static inline void rcu_debug_yield_enable(
  77                 unsigned int flags __attribute__((unused)))
  78 {
  79 }
  80
  81 static inline void rcu_debug_yield_disable(
  82                 unsigned int flags __attribute__((unused)))
  83 {
  84 }
  85
  86 static inline void rcu_debug_yield_init(void)
  87 {
  88 }
  89 #endif
  90
  91 #endif /* URCU_TESTS_DEBUG_YIELD_H */