diff options
Diffstat (limited to 'qemu/include/qemu/rcu.h')
| -rw-r--r-- | qemu/include/qemu/rcu.h | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/qemu/include/qemu/rcu.h b/qemu/include/qemu/rcu.h deleted file mode 100644 index 56d3a682a..000000000 --- a/qemu/include/qemu/rcu.h +++ /dev/null @@ -1,145 +0,0 @@ -#ifndef QEMU_RCU_H -#define QEMU_RCU_H - -/* - * urcu-mb.h - * - * Userspace RCU header with explicit memory barrier. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * - * IBM's contributions to this file may be relicensed under LGPLv2 or later. - */ - -#include <glib.h> - -#include "qemu/thread.h" -#include "qemu/queue.h" -#include "qemu/atomic.h" - -#ifdef __cplusplus -extern "C" { -#endif - -/* - * Important ! - * - * Each thread containing read-side critical sections must be registered - * with rcu_register_thread() before calling rcu_read_lock(). - * rcu_unregister_thread() should be called before the thread exits. - */ - -#ifdef DEBUG_RCU -#define rcu_assert(args...) assert(args) -#else -#define rcu_assert(args...) -#endif - -/* - * Global quiescent period counter with low-order bits unused. - * Using a int rather than a char to eliminate false register dependencies - * causing stalls on some architectures. - */ -extern unsigned long rcu_gp_ctr; - -extern QemuEvent rcu_gp_event; - -struct rcu_reader_data { - /* Data used by both reader and synchronize_rcu() */ - unsigned long ctr; - bool waiting; - - /* Data used by reader only */ - unsigned depth; - - /* Data used for registry, protected by rcu_registry_lock */ - QLIST_ENTRY(rcu_reader_data) node; -}; - -extern __thread struct rcu_reader_data rcu_reader; - -static inline void rcu_read_lock(void) -{ - struct rcu_reader_data *p_rcu_reader = &rcu_reader; - unsigned ctr; - - if (p_rcu_reader->depth++ > 0) { - return; - } - - ctr = atomic_read(&rcu_gp_ctr); - atomic_xchg(&p_rcu_reader->ctr, ctr); -} - -static inline void rcu_read_unlock(void) -{ - struct rcu_reader_data *p_rcu_reader = &rcu_reader; - - assert(p_rcu_reader->depth != 0); - if (--p_rcu_reader->depth > 0) { - return; - } - - atomic_xchg(&p_rcu_reader->ctr, 0); - if (unlikely(atomic_read(&p_rcu_reader->waiting))) { - atomic_set(&p_rcu_reader->waiting, false); - qemu_event_set(&rcu_gp_event); - } -} - -extern void synchronize_rcu(void); - -/* - * Reader thread registration. - */ -extern void rcu_register_thread(void); -extern void rcu_unregister_thread(void); -extern void rcu_after_fork(void); - -struct rcu_head; -typedef void RCUCBFunc(struct rcu_head *head); - -struct rcu_head { - struct rcu_head *next; - RCUCBFunc *func; -}; - -extern void call_rcu1(struct rcu_head *head, RCUCBFunc *func); - -/* The operands of the minus operator must have the same type, - * which must be the one that we specify in the cast. - */ -#define call_rcu(head, func, field) \ - call_rcu1(({ \ - char __attribute__((unused)) \ - offset_must_be_zero[-offsetof(typeof(*(head)), field)], \ - func_type_invalid = (func) - (void (*)(typeof(head)))(func); \ - &(head)->field; \ - }), \ - (RCUCBFunc *)(func)) - -#define g_free_rcu(obj, field) \ - call_rcu1(({ \ - char __attribute__((unused)) \ - offset_must_be_zero[-offsetof(typeof(*(obj)), field)]; \ - &(obj)->field; \ - }), \ - (RCUCBFunc *)g_free); - -#ifdef __cplusplus -} -#endif - -#endif /* QEMU_RCU_H */ |