Module Name: src
Committed By: yamt
Date: Thu May 19 10:00:30 UTC 2011
Modified Files:
src/common/lib/libc/gen: radixtree.c
Log Message:
radixtree: comments
To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/common/lib/libc/gen/radixtree.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/common/lib/libc/gen/radixtree.c
diff -u src/common/lib/libc/gen/radixtree.c:1.4 src/common/lib/libc/gen/radixtree.c:1.5
--- src/common/lib/libc/gen/radixtree.c:1.4 Thu May 19 09:58:28 2011
+++ src/common/lib/libc/gen/radixtree.c Thu May 19 10:00:30 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: radixtree.c,v 1.4 2011/05/19 09:58:28 yamt Exp $ */
+/* $NetBSD: radixtree.c,v 1.5 2011/05/19 10:00:30 yamt Exp $ */
/*-
* Copyright (c)2011 YAMAMOTO Takashi,
@@ -41,7 +41,7 @@
#include <sys/cdefs.h>
#if defined(_KERNEL) || defined(_STANDALONE)
-__KERNEL_RCSID(0, "$NetBSD: radixtree.c,v 1.4 2011/05/19 09:58:28 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: radixtree.c,v 1.5 2011/05/19 10:00:30 yamt Exp $");
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/pool.h>
@@ -51,7 +51,7 @@
#include <lib/libsa/stand.h>
#endif /* defined(_STANDALONE) */
#else /* defined(_KERNEL) || defined(_STANDALONE) */
-__RCSID("$NetBSD: radixtree.c,v 1.4 2011/05/19 09:58:28 yamt Exp $");
+__RCSID("$NetBSD: radixtree.c,v 1.5 2011/05/19 10:00:30 yamt Exp $");
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
@@ -325,6 +325,25 @@
return 0;
}
+/*
+ * radix_tree_lookup_ptr:
+ *
+ * an internal helper function used for various exported functions.
+ *
+ * return the pointer to store the node for the given index.
+ *
+ * if alloc is true, try to allocate the storage. (note for _KERNEL:
+ * in that case, this function can block.) if the allocation failed or
+ * alloc is false, return NULL.
+ *
+ * if path is not NULL, fill it for the caller's investigation.
+ *
+ * if tagmask is not zero, search only for nodes with the tag set.
+ *
+ * while this function is a bit large, as it's called with some constant
+ * arguments, inlining might have benefits. anyway, a compiler will decide.
+ */
+
static inline void **
radix_tree_lookup_ptr(struct radix_tree *t, uint64_t idx,
struct radix_tree_path *path, bool alloc, const unsigned int tagmask)
@@ -336,6 +355,9 @@
const uint64_t mask = (UINT64_C(1) << RADIX_TREE_BITS_PER_HEIGHT) - 1;
struct radix_tree_node_ref *refs = NULL;
+ /*
+ * check unsupported combinations
+ */
KASSERT(tagmask == 0 || !alloc);
KASSERT(path == NULL || !alloc);
vpp = &t->t_root;
