| 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 | /* |
| 7 | * Userspace RCU header for LTTng-UST. Derived from liburcu |
| 8 | * "bulletproof" flavor. |
| 9 | * |
| 10 | * Slower RCU read-side adapted for tracing library. Does not require thread |
| 11 | * registration nor unregistration. Also signal-safe. |
| 12 | * |
| 13 | * LGPL-compatible code should include this header with : |
| 14 | * |
| 15 | * #define _LGPL_SOURCE |
| 16 | * #include <lttng/urcu-ust.h> |
| 17 | */ |
| 18 | |
| 19 | #ifndef _LTTNG_UST_URCU_H |
| 20 | #define _LTTNG_UST_URCU_H |
| 21 | |
| 22 | #include <stdlib.h> |
| 23 | #include <pthread.h> |
| 24 | |
| 25 | #ifdef __cplusplus |
| 26 | extern "C" { |
| 27 | #endif |
| 28 | |
| 29 | /* |
| 30 | * See lttng/urcu/pointer.h and lttng/urcu/static/pointer.h for pointer |
| 31 | * publication headers. |
| 32 | */ |
| 33 | #include <lttng/urcu/pointer.h> |
| 34 | |
| 35 | #ifdef _LGPL_SOURCE |
| 36 | |
| 37 | #include <lttng/urcu/static/urcu-ust.h> |
| 38 | |
| 39 | /* |
| 40 | * Mappings for static use of the userspace RCU library. |
| 41 | * Should only be used in LGPL-compatible code. |
| 42 | */ |
| 43 | |
| 44 | /* |
| 45 | * lttng_ust_urcu_read_lock() |
| 46 | * lttng_ust_urcu_read_unlock() |
| 47 | * |
| 48 | * Mark the beginning and end of a read-side critical section. |
| 49 | */ |
| 50 | #define lttng_ust_urcu_read_lock _lttng_ust_urcu_read_lock |
| 51 | #define lttng_ust_urcu_read_unlock _lttng_ust_urcu_read_unlock |
| 52 | #define lttng_ust_urcu_read_ongoing _lttng_ust_urcu_read_ongoing |
| 53 | |
| 54 | #else /* !_LGPL_SOURCE */ |
| 55 | |
| 56 | /* |
| 57 | * library wrappers to be used by non-LGPL compatible source code. |
| 58 | * See LGPL-only urcu/static/pointer.h for documentation. |
| 59 | */ |
| 60 | |
| 61 | extern void lttng_ust_urcu_read_lock(void); |
| 62 | extern void lttng_ust_urcu_read_unlock(void); |
| 63 | extern int lttng_ust_urcu_read_ongoing(void); |
| 64 | |
| 65 | #endif /* !_LGPL_SOURCE */ |
| 66 | |
| 67 | extern void lttng_ust_urcu_synchronize_rcu(void); |
| 68 | |
| 69 | /* |
| 70 | * lttng_ust_urcu_before_fork, lttng_ust_urcu_after_fork_parent and |
| 71 | * lttng_ust_urcu_after_fork_child should be called around fork() system |
| 72 | * calls when the child process is not expected to immediately perform |
| 73 | * an exec(). For pthread users, see pthread_atfork(3). |
| 74 | */ |
| 75 | extern void lttng_ust_urcu_before_fork(void); |
| 76 | extern void lttng_ust_urcu_after_fork_parent(void); |
| 77 | extern void lttng_ust_urcu_after_fork_child(void); |
| 78 | |
| 79 | /* |
| 80 | * In the UST version, thread registration is performed lazily, but it can be |
| 81 | * forced by issuing an explicit lttng_ust_urcu_register_thread(). |
| 82 | */ |
| 83 | extern void lttng_ust_urcu_register_thread(void); |
| 84 | |
| 85 | #ifdef __cplusplus |
| 86 | } |
| 87 | #endif |
| 88 | |
| 89 | #endif /* _LTTNG_UST_URCU_H */ |