--- /dev/null
+#ifndef _URCU_DEFER_STATIC_H
+#define _URCU_DEFER_STATIC_H
+
+/*
+ * urcu-defer-static.h
+ *
+ * Userspace RCU header - memory reclamation.
+ *
+ * TO BE INCLUDED ONLY IN LGPL-COMPATIBLE CODE. See urcu-defer.h for linking
+ * dynamically with the userspace rcu reclamation library.
+ *
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
+ *
+ * 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 <stdlib.h>
+#include <pthread.h>
+
+#include <compiler.h>
+#include <arch.h>
+
+
+/*
+ * Number of entries in the per-thread defer queue. Must be power of 2.
+ */
+#define DEFER_QUEUE_SIZE (1 << 12)
+#define DEFER_QUEUE_MASK (DEFER_QUEUE_SIZE - 1)
+
+/*
+ * Identify a shared load. A smp_rmc() or smp_mc() should come before the load.
+ */
+#define _LOAD_SHARED(p) ACCESS_ONCE(p)
+
+/*
+ * Load a data from shared memory, doing a cache flush if required.
+ */
+#define LOAD_SHARED(p) \
+ ({ \
+ smp_rmc(); \
+ _LOAD_SHARED(p); \
+ })
+
+/*
+ * Identify a shared store. A smp_wmc() or smp_mc() should follow the store.
+ */
+#define _STORE_SHARED(x, v) ({ ACCESS_ONCE(x) = (v); })
+
+/*
+ * Store v into x, where x is located in shared memory. Performs the required
+ * cache flush after writing. Returns v.
+ */
+#define STORE_SHARED(x, v) \
+ ({ \
+ _STORE_SHARED(x, v); \
+ smp_wmc(); \
+ (v); \
+ })
+
+/*
+ * This code section can only be included in LGPL 2.1 compatible source code.
+ * See below for the function call wrappers which can be used in code meant to
+ * be only linked with the Userspace RCU library. This comes with a small
+ * performance degradation on the read-side due to the added function calls.
+ * This is required to permit relinking with newer versions of the library.
+ */
+
+#ifdef DEBUG_RCU
+#define rcu_assert(args...) assert(args)
+#else
+#define rcu_assert(args...)
+#endif
+
+struct defer_queue {
+ unsigned long head; /* add element at head */
+ unsigned long tail; /* next element to remove at tail */
+ void **q;
+};
+
+extern struct defer_queue __thread defer_queue;
+
+extern void rcu_defer_barrier_thread(void);
+
+/*
+ * not signal-safe.
+ */
+static inline void _rcu_defer_queue(void *p)
+{
+ unsigned long head, tail;
+
+ /*
+ * Head is only modified by ourself. Tail can be modified by reclamation
+ * thread.
+ */
+ head = defer_queue.head;
+ tail = LOAD_SHARED(defer_queue.tail);
+
+ /*
+ * If queue is full, empty it ourself.
+ */
+ if (unlikely(head - tail >= DEFER_QUEUE_SIZE)) {
+ assert(head - tail == DEFER_QUEUE_SIZE);
+ rcu_defer_barrier_thread();
+ assert(head - LOAD_SHARED(defer_queue.tail) == 0);
+ }
+
+ smp_wmb(); /* Publish new pointer before write q[] */
+ _STORE_SHARED(defer_queue.q[head & DEFER_QUEUE_MASK], p);
+ smp_wmb(); /* Write q[] before head. */
+ STORE_SHARED(defer_queue.head, head + 1);
+}
+
+#endif /* _URCU_DEFER_STATIC_H */
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