| 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_BP_H |
| 7 | #define _URCU_BP_H |
| 8 | |
| 9 | /* |
| 10 | * Userspace RCU header, "bulletproof" version. |
| 11 | * |
| 12 | * Slower RCU read-side adapted for tracing library. Does not require thread |
| 13 | * registration nor unregistration. Also signal-safe. |
| 14 | * |
| 15 | * LGPL-compatible code should include this header with : |
| 16 | * |
| 17 | * #define _LGPL_SOURCE |
| 18 | * #include <urcu.h> |
| 19 | * |
| 20 | * IBM's contributions to this file may be relicensed under LGPLv2 or later. |
| 21 | */ |
| 22 | |
| 23 | #include <stdlib.h> |
| 24 | #include <pthread.h> |
| 25 | #include <stdbool.h> |
| 26 | |
| 27 | #include <urcu/map/urcu-bp.h> |
| 28 | |
| 29 | /* |
| 30 | * Important ! |
| 31 | * |
| 32 | * Each thread containing read-side critical sections must be registered |
| 33 | * with rcu_register_thread() before calling rcu_read_lock(). |
| 34 | * rcu_unregister_thread() should be called before the thread exits. |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * See urcu/pointer.h and urcu/static/pointer.h for pointer |
| 39 | * publication headers. |
| 40 | */ |
| 41 | #include <urcu/pointer.h> |
| 42 | #include <urcu/urcu-poll.h> |
| 43 | |
| 44 | #ifdef __cplusplus |
| 45 | extern "C" { |
| 46 | #endif |
| 47 | |
| 48 | #ifdef _LGPL_SOURCE |
| 49 | |
| 50 | #include <urcu/static/urcu-bp.h> |
| 51 | |
| 52 | /* |
| 53 | * Mappings for static use of the userspace RCU library. |
| 54 | * Should only be used in LGPL-compatible code. |
| 55 | */ |
| 56 | |
| 57 | /* |
| 58 | * rcu_read_lock() |
| 59 | * rcu_read_unlock() |
| 60 | * |
| 61 | * Mark the beginning and end of a read-side critical section. |
| 62 | */ |
| 63 | #define urcu_bp_read_lock _urcu_bp_read_lock |
| 64 | #define urcu_bp_read_unlock _urcu_bp_read_unlock |
| 65 | #define urcu_bp_read_ongoing _urcu_bp_read_ongoing |
| 66 | |
| 67 | #define urcu_bp_dereference rcu_dereference |
| 68 | #define urcu_bp_cmpxchg_pointer rcu_cmpxchg_pointer |
| 69 | #define urcu_bp_xchg_pointer rcu_xchg_pointer |
| 70 | #define urcu_bp_set_pointer rcu_set_pointer |
| 71 | |
| 72 | #else /* !_LGPL_SOURCE */ |
| 73 | |
| 74 | /* |
| 75 | * library wrappers to be used by non-LGPL compatible source code. |
| 76 | * See LGPL-only urcu/static/pointer.h for documentation. |
| 77 | */ |
| 78 | |
| 79 | extern void urcu_bp_read_lock(void); |
| 80 | extern void urcu_bp_read_unlock(void); |
| 81 | extern int urcu_bp_read_ongoing(void); |
| 82 | |
| 83 | extern void *urcu_bp_dereference_sym(void *p); |
| 84 | #define urcu_bp_dereference(p) \ |
| 85 | __extension__ \ |
| 86 | ({ \ |
| 87 | __typeof__(p) _________p1 = URCU_FORCE_CAST(__typeof__(p), \ |
| 88 | urcu_bp_dereference_sym(URCU_FORCE_CAST(void *, p))); \ |
| 89 | (_________p1); \ |
| 90 | }) |
| 91 | |
| 92 | extern void *urcu_bp_cmpxchg_pointer_sym(void **p, void *old, void *_new); |
| 93 | #define urcu_bp_cmpxchg_pointer(p, old, _new) \ |
| 94 | __extension__ \ |
| 95 | ({ \ |
| 96 | __typeof__(*(p)) _________pold = (old); \ |
| 97 | __typeof__(*(p)) _________pnew = (_new); \ |
| 98 | __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \ |
| 99 | urcu_bp_cmpxchg_pointer_sym(URCU_FORCE_CAST(void **, p), \ |
| 100 | _________pold, \ |
| 101 | _________pnew)); \ |
| 102 | (_________p1); \ |
| 103 | }) |
| 104 | |
| 105 | extern void *urcu_bp_xchg_pointer_sym(void **p, void *v); |
| 106 | #define urcu_bp_xchg_pointer(p, v) \ |
| 107 | __extension__ \ |
| 108 | ({ \ |
| 109 | __typeof__(*(p)) _________pv = (v); \ |
| 110 | __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)),\ |
| 111 | urcu_bp_xchg_pointer_sym(URCU_FORCE_CAST(void **, p), \ |
| 112 | _________pv)); \ |
| 113 | (_________p1); \ |
| 114 | }) |
| 115 | |
| 116 | extern void *urcu_bp_set_pointer_sym(void **p, void *v); |
| 117 | #define urcu_bp_set_pointer(p, v) \ |
| 118 | __extension__ \ |
| 119 | ({ \ |
| 120 | __typeof__(*(p)) _________pv = (v); \ |
| 121 | __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \ |
| 122 | urcu_bp_set_pointer_sym(URCU_FORCE_CAST(void **, p), \ |
| 123 | _________pv)); \ |
| 124 | (_________p1); \ |
| 125 | }) |
| 126 | |
| 127 | #endif /* !_LGPL_SOURCE */ |
| 128 | |
| 129 | extern void urcu_bp_synchronize_rcu(void); |
| 130 | |
| 131 | /* |
| 132 | * RCU grace period polling API. |
| 133 | */ |
| 134 | extern struct urcu_gp_poll_state urcu_bp_start_poll_synchronize_rcu(void); |
| 135 | extern bool urcu_bp_poll_state_synchronize_rcu(struct urcu_gp_poll_state state); |
| 136 | |
| 137 | /* |
| 138 | * urcu_bp_before_fork, urcu_bp_after_fork_parent and urcu_bp_after_fork_child |
| 139 | * should be called around fork() system calls when the child process is not |
| 140 | * expected to immediately perform an exec(). For pthread users, see |
| 141 | * pthread_atfork(3). |
| 142 | */ |
| 143 | extern void urcu_bp_before_fork(void); |
| 144 | extern void urcu_bp_after_fork_parent(void); |
| 145 | extern void urcu_bp_after_fork_child(void); |
| 146 | |
| 147 | /* |
| 148 | * In the bulletproof version, thread registration is performed lazily, |
| 149 | * but it can be forced by issuing an explicit urcu_bp_register_thread(). |
| 150 | */ |
| 151 | extern void urcu_bp_register_thread(void); |
| 152 | |
| 153 | /* |
| 154 | * In the bulletproof version, the following functions are no-ops. |
| 155 | */ |
| 156 | static inline void urcu_bp_unregister_thread(void) |
| 157 | { |
| 158 | } |
| 159 | |
| 160 | static inline void urcu_bp_init(void) |
| 161 | { |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * Q.S. reporting are no-ops for these URCU flavors. |
| 166 | */ |
| 167 | static inline void urcu_bp_quiescent_state(void) |
| 168 | { |
| 169 | } |
| 170 | |
| 171 | static inline void urcu_bp_thread_offline(void) |
| 172 | { |
| 173 | } |
| 174 | |
| 175 | static inline void urcu_bp_thread_online(void) |
| 176 | { |
| 177 | } |
| 178 | |
| 179 | #ifdef __cplusplus |
| 180 | } |
| 181 | #endif |
| 182 | |
| 183 | #include <urcu/call-rcu.h> |
| 184 | #include <urcu/defer.h> |
| 185 | #include <urcu/flavor.h> |
| 186 | |
| 187 | #ifndef URCU_API_MAP |
| 188 | #include <urcu/map/clear.h> |
| 189 | #endif |
| 190 | |
| 191 | #endif /* _URCU_BP_H */ |