| 1 | #ifndef _URCU_LFSTACK_H |
| 2 | #define _URCU_LFSTACK_H |
| 3 | |
| 4 | /* |
| 5 | * lfstack.h |
| 6 | * |
| 7 | * Userspace RCU library - Lock-Free Stack |
| 8 | * |
| 9 | * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 10 | * |
| 11 | * This library is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU Lesser General Public |
| 13 | * License as published by the Free Software Foundation; either |
| 14 | * version 2.1 of the License, or (at your option) any later version. |
| 15 | * |
| 16 | * This library is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 19 | * Lesser General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU Lesser General Public |
| 22 | * License along with this library; if not, write to the Free Software |
| 23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 24 | */ |
| 25 | |
| 26 | #ifdef __cplusplus |
| 27 | extern "C" { |
| 28 | #endif |
| 29 | |
| 30 | struct cds_lfs_node { |
| 31 | struct cds_lfs_node *next; |
| 32 | }; |
| 33 | |
| 34 | struct cds_lfs_stack { |
| 35 | struct cds_lfs_node *head; |
| 36 | }; |
| 37 | |
| 38 | #ifdef _LGPL_SOURCE |
| 39 | |
| 40 | #include <urcu/static/lfstack.h> |
| 41 | |
| 42 | #define cds_lfs_node_init _cds_lfs_node_init |
| 43 | #define cds_lfs_init _cds_lfs_init |
| 44 | #define cds_lfs_push _cds_lfs_push |
| 45 | #define cds_lfs_pop _cds_lfs_pop |
| 46 | |
| 47 | #else /* !_LGPL_SOURCE */ |
| 48 | |
| 49 | extern void cds_lfs_node_init(struct cds_lfs_node *node); |
| 50 | extern void cds_lfs_init(struct cds_lfs_stack *s); |
| 51 | |
| 52 | /* |
| 53 | * cds_lfs_push: push a node into the stack. |
| 54 | * |
| 55 | * Does not require any synchronization with other push nor pop. |
| 56 | * |
| 57 | * Returns 0 if the stack was empty prior to adding the node. |
| 58 | * Returns non-zero otherwise. |
| 59 | */ |
| 60 | extern int cds_lfs_push(struct cds_lfs_stack *s, |
| 61 | struct cds_lfs_node *node); |
| 62 | |
| 63 | /* |
| 64 | * cds_lfs_pop: pop a node from the stack. |
| 65 | * |
| 66 | * Returns NULL if stack is empty. |
| 67 | * |
| 68 | * cds_lfs_pop needs to be synchronized using one of the following |
| 69 | * techniques: |
| 70 | * |
| 71 | * 1) Calling cds_lfs_pop under rcu read lock critical section. The |
| 72 | * caller must wait for a grace period to pass before freeing the |
| 73 | * returned node or modifying the cds_lfs_node structure. |
| 74 | * 2) Using mutual exclusion (e.g. mutexes) to protect cds_lfs_pop |
| 75 | * callers. |
| 76 | * 3) Ensuring that only ONE thread can call cds_lfs_pop(). |
| 77 | * (multi-provider/single-consumer scheme). |
| 78 | */ |
| 79 | extern struct cds_lfs_node *cds_lfs_pop(struct cds_lfs_stack *s); |
| 80 | |
| 81 | #endif /* !_LGPL_SOURCE */ |
| 82 | |
| 83 | #ifdef __cplusplus |
| 84 | } |
| 85 | #endif |
| 86 | |
| 87 | #endif /* _URCU_LFSTACK_H */ |