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      1 // SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers (at) 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 #define MAX_SLEEP 50
     26 
     27 extern unsigned int rcu_yield_active;
     28 extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
     29 
     30 #ifdef DEBUG_YIELD
     31 static inline void rcu_debug_yield_read(void)
     32 {
     33 	if (rcu_yield_active & RCU_YIELD_READ)
     34 		if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
     35 			usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
     36 }
     37 
     38 static inline void rcu_debug_yield_write(void)
     39 {
     40 	if (rcu_yield_active & RCU_YIELD_WRITE)
     41 		if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
     42 			usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
     43 }
     44 
     45 static inline void rcu_debug_yield_enable(unsigned int flags)
     46 {
     47 	rcu_yield_active |= flags;
     48 }
     49 
     50 static inline void rcu_debug_yield_disable(unsigned int flags)
     51 {
     52 	rcu_yield_active &= ~flags;
     53 }
     54 
     55 static inline void rcu_debug_yield_init(void)
     56 {
     57 	URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
     58 }
     59 #else /* DEBUG_YIELD */
     60 static inline void rcu_debug_yield_read(void)
     61 {
     62 }
     63 
     64 static inline void rcu_debug_yield_write(void)
     65 {
     66 }
     67 
     68 static inline void rcu_debug_yield_enable(
     69 		unsigned int flags __attribute__((unused)))
     70 {
     71 }
     72 
     73 static inline void rcu_debug_yield_disable(
     74 		unsigned int flags __attribute__((unused)))
     75 {
     76 }
     77 
     78 static inline void rcu_debug_yield_init(void)
     79 {
     80 }
     81 #endif
     82 
     83 #endif /* URCU_TESTS_DEBUG_YIELD_H */
     84