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-rw-r--r--uts/common/fs/zfs/sys/refcount.h107
1 files changed, 107 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/sys/refcount.h b/uts/common/fs/zfs/sys/refcount.h
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef _SYS_REFCOUNT_H
+#define _SYS_REFCOUNT_H
+
+#include <sys/inttypes.h>
+#include <sys/list.h>
+#include <sys/zfs_context.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * If the reference is held only by the calling function and not any
+ * particular object, use FTAG (which is a string) for the holder_tag.
+ * Otherwise, use the object that holds the reference.
+ */
+#define FTAG ((char *)__func__)
+
+#ifdef ZFS_DEBUG
+typedef struct reference {
+ list_node_t ref_link;
+ void *ref_holder;
+ uint64_t ref_number;
+ uint8_t *ref_removed;
+} reference_t;
+
+typedef struct refcount {
+ kmutex_t rc_mtx;
+ list_t rc_list;
+ list_t rc_removed;
+ int64_t rc_count;
+ int64_t rc_removed_count;
+} refcount_t;
+
+/* Note: refcount_t must be initialized with refcount_create() */
+
+void refcount_create(refcount_t *rc);
+void refcount_destroy(refcount_t *rc);
+void refcount_destroy_many(refcount_t *rc, uint64_t number);
+int refcount_is_zero(refcount_t *rc);
+int64_t refcount_count(refcount_t *rc);
+int64_t refcount_add(refcount_t *rc, void *holder_tag);
+int64_t refcount_remove(refcount_t *rc, void *holder_tag);
+int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag);
+int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag);
+void refcount_transfer(refcount_t *dst, refcount_t *src);
+
+void refcount_init(void);
+void refcount_fini(void);
+
+#else /* ZFS_DEBUG */
+
+typedef struct refcount {
+ uint64_t rc_count;
+} refcount_t;
+
+#define refcount_create(rc) ((rc)->rc_count = 0)
+#define refcount_destroy(rc) ((rc)->rc_count = 0)
+#define refcount_destroy_many(rc, number) ((rc)->rc_count = 0)
+#define refcount_is_zero(rc) ((rc)->rc_count == 0)
+#define refcount_count(rc) ((rc)->rc_count)
+#define refcount_add(rc, holder) atomic_add_64_nv(&(rc)->rc_count, 1)
+#define refcount_remove(rc, holder) atomic_add_64_nv(&(rc)->rc_count, -1)
+#define refcount_add_many(rc, number, holder) \
+ atomic_add_64_nv(&(rc)->rc_count, number)
+#define refcount_remove_many(rc, number, holder) \
+ atomic_add_64_nv(&(rc)->rc_count, -number)
+#define refcount_transfer(dst, src) { \
+ uint64_t __tmp = (src)->rc_count; \
+ atomic_add_64(&(src)->rc_count, -__tmp); \
+ atomic_add_64(&(dst)->rc_count, __tmp); \
+}
+
+#define refcount_init()
+#define refcount_fini()
+
+#endif /* ZFS_DEBUG */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_REFCOUNT_H */