xref: /freebsd/contrib/jemalloc/src/rtree.c (revision 8657387683946d0c03e09fe77029edfe309eeb20)
1 #define JEMALLOC_RTREE_C_
2 #include "jemalloc/internal/jemalloc_preamble.h"
3 #include "jemalloc/internal/jemalloc_internal_includes.h"
4 
5 #include "jemalloc/internal/assert.h"
6 #include "jemalloc/internal/mutex.h"
7 
8 /*
9  * Only the most significant bits of keys passed to rtree_{read,write}() are
10  * used.
11  */
12 bool
13 rtree_new(rtree_t *rtree, bool zeroed) {
14 #ifdef JEMALLOC_JET
15 	if (!zeroed) {
16 		memset(rtree, 0, sizeof(rtree_t)); /* Clear root. */
17 	}
18 #else
19 	assert(zeroed);
20 #endif
21 
22 	if (malloc_mutex_init(&rtree->init_lock, "rtree", WITNESS_RANK_RTREE,
23 	    malloc_mutex_rank_exclusive)) {
24 		return true;
25 	}
26 
27 	return false;
28 }
29 
30 static rtree_node_elm_t *
31 rtree_node_alloc_impl(tsdn_t *tsdn, rtree_t *rtree, size_t nelms) {
32 	return (rtree_node_elm_t *)base_alloc(tsdn, b0get(), nelms *
33 	    sizeof(rtree_node_elm_t), CACHELINE);
34 }
35 rtree_node_alloc_t *JET_MUTABLE rtree_node_alloc = rtree_node_alloc_impl;
36 
37 static void
38 rtree_node_dalloc_impl(tsdn_t *tsdn, rtree_t *rtree, rtree_node_elm_t *node) {
39 	/* Nodes are never deleted during normal operation. */
40 	not_reached();
41 }
42 UNUSED rtree_node_dalloc_t *JET_MUTABLE rtree_node_dalloc =
43     rtree_node_dalloc_impl;
44 
45 static rtree_leaf_elm_t *
46 rtree_leaf_alloc_impl(tsdn_t *tsdn, rtree_t *rtree, size_t nelms) {
47 	return (rtree_leaf_elm_t *)base_alloc(tsdn, b0get(), nelms *
48 	    sizeof(rtree_leaf_elm_t), CACHELINE);
49 }
50 rtree_leaf_alloc_t *JET_MUTABLE rtree_leaf_alloc = rtree_leaf_alloc_impl;
51 
52 static void
53 rtree_leaf_dalloc_impl(tsdn_t *tsdn, rtree_t *rtree, rtree_leaf_elm_t *leaf) {
54 	/* Leaves are never deleted during normal operation. */
55 	not_reached();
56 }
57 UNUSED rtree_leaf_dalloc_t *JET_MUTABLE rtree_leaf_dalloc =
58     rtree_leaf_dalloc_impl;
59 
60 #ifdef JEMALLOC_JET
61 #  if RTREE_HEIGHT > 1
62 static void
63 rtree_delete_subtree(tsdn_t *tsdn, rtree_t *rtree, rtree_node_elm_t *subtree,
64     unsigned level) {
65 	size_t nchildren = ZU(1) << rtree_levels[level].bits;
66 	if (level + 2 < RTREE_HEIGHT) {
67 		for (size_t i = 0; i < nchildren; i++) {
68 			rtree_node_elm_t *node =
69 			    (rtree_node_elm_t *)atomic_load_p(&subtree[i].child,
70 			    ATOMIC_RELAXED);
71 			if (node != NULL) {
72 				rtree_delete_subtree(tsdn, rtree, node, level +
73 				    1);
74 			}
75 		}
76 	} else {
77 		for (size_t i = 0; i < nchildren; i++) {
78 			rtree_leaf_elm_t *leaf =
79 			    (rtree_leaf_elm_t *)atomic_load_p(&subtree[i].child,
80 			    ATOMIC_RELAXED);
81 			if (leaf != NULL) {
82 				rtree_leaf_dalloc(tsdn, rtree, leaf);
83 			}
84 		}
85 	}
86 
87 	if (subtree != rtree->root) {
88 		rtree_node_dalloc(tsdn, rtree, subtree);
89 	}
90 }
91 #  endif
92 
93 void
94 rtree_delete(tsdn_t *tsdn, rtree_t *rtree) {
95 #  if RTREE_HEIGHT > 1
96 	rtree_delete_subtree(tsdn, rtree, rtree->root, 0);
97 #  endif
98 }
99 #endif
100 
101 static rtree_node_elm_t *
102 rtree_node_init(tsdn_t *tsdn, rtree_t *rtree, unsigned level,
103     atomic_p_t *elmp) {
104 	malloc_mutex_lock(tsdn, &rtree->init_lock);
105 	/*
106 	 * If *elmp is non-null, then it was initialized with the init lock
107 	 * held, so we can get by with 'relaxed' here.
108 	 */
109 	rtree_node_elm_t *node = atomic_load_p(elmp, ATOMIC_RELAXED);
110 	if (node == NULL) {
111 		node = rtree_node_alloc(tsdn, rtree, ZU(1) <<
112 		    rtree_levels[level].bits);
113 		if (node == NULL) {
114 			malloc_mutex_unlock(tsdn, &rtree->init_lock);
115 			return NULL;
116 		}
117 		/*
118 		 * Even though we hold the lock, a later reader might not; we
119 		 * need release semantics.
120 		 */
121 		atomic_store_p(elmp, node, ATOMIC_RELEASE);
122 	}
123 	malloc_mutex_unlock(tsdn, &rtree->init_lock);
124 
125 	return node;
126 }
127 
128 static rtree_leaf_elm_t *
129 rtree_leaf_init(tsdn_t *tsdn, rtree_t *rtree, atomic_p_t *elmp) {
130 	malloc_mutex_lock(tsdn, &rtree->init_lock);
131 	/*
132 	 * If *elmp is non-null, then it was initialized with the init lock
133 	 * held, so we can get by with 'relaxed' here.
134 	 */
135 	rtree_leaf_elm_t *leaf = atomic_load_p(elmp, ATOMIC_RELAXED);
136 	if (leaf == NULL) {
137 		leaf = rtree_leaf_alloc(tsdn, rtree, ZU(1) <<
138 		    rtree_levels[RTREE_HEIGHT-1].bits);
139 		if (leaf == NULL) {
140 			malloc_mutex_unlock(tsdn, &rtree->init_lock);
141 			return NULL;
142 		}
143 		/*
144 		 * Even though we hold the lock, a later reader might not; we
145 		 * need release semantics.
146 		 */
147 		atomic_store_p(elmp, leaf, ATOMIC_RELEASE);
148 	}
149 	malloc_mutex_unlock(tsdn, &rtree->init_lock);
150 
151 	return leaf;
152 }
153 
154 static bool
155 rtree_node_valid(rtree_node_elm_t *node) {
156 	return ((uintptr_t)node != (uintptr_t)0);
157 }
158 
159 static bool
160 rtree_leaf_valid(rtree_leaf_elm_t *leaf) {
161 	return ((uintptr_t)leaf != (uintptr_t)0);
162 }
163 
164 static rtree_node_elm_t *
165 rtree_child_node_tryread(rtree_node_elm_t *elm, bool dependent) {
166 	rtree_node_elm_t *node;
167 
168 	if (dependent) {
169 		node = (rtree_node_elm_t *)atomic_load_p(&elm->child,
170 		    ATOMIC_RELAXED);
171 	} else {
172 		node = (rtree_node_elm_t *)atomic_load_p(&elm->child,
173 		    ATOMIC_ACQUIRE);
174 	}
175 
176 	assert(!dependent || node != NULL);
177 	return node;
178 }
179 
180 static rtree_node_elm_t *
181 rtree_child_node_read(tsdn_t *tsdn, rtree_t *rtree, rtree_node_elm_t *elm,
182     unsigned level, bool dependent) {
183 	rtree_node_elm_t *node;
184 
185 	node = rtree_child_node_tryread(elm, dependent);
186 	if (!dependent && unlikely(!rtree_node_valid(node))) {
187 		node = rtree_node_init(tsdn, rtree, level + 1, &elm->child);
188 	}
189 	assert(!dependent || node != NULL);
190 	return node;
191 }
192 
193 static rtree_leaf_elm_t *
194 rtree_child_leaf_tryread(rtree_node_elm_t *elm, bool dependent) {
195 	rtree_leaf_elm_t *leaf;
196 
197 	if (dependent) {
198 		leaf = (rtree_leaf_elm_t *)atomic_load_p(&elm->child,
199 		    ATOMIC_RELAXED);
200 	} else {
201 		leaf = (rtree_leaf_elm_t *)atomic_load_p(&elm->child,
202 		    ATOMIC_ACQUIRE);
203 	}
204 
205 	assert(!dependent || leaf != NULL);
206 	return leaf;
207 }
208 
209 static rtree_leaf_elm_t *
210 rtree_child_leaf_read(tsdn_t *tsdn, rtree_t *rtree, rtree_node_elm_t *elm,
211     unsigned level, bool dependent) {
212 	rtree_leaf_elm_t *leaf;
213 
214 	leaf = rtree_child_leaf_tryread(elm, dependent);
215 	if (!dependent && unlikely(!rtree_leaf_valid(leaf))) {
216 		leaf = rtree_leaf_init(tsdn, rtree, &elm->child);
217 	}
218 	assert(!dependent || leaf != NULL);
219 	return leaf;
220 }
221 
222 rtree_leaf_elm_t *
223 rtree_leaf_elm_lookup_hard(tsdn_t *tsdn, rtree_t *rtree, rtree_ctx_t *rtree_ctx,
224     uintptr_t key, bool dependent, bool init_missing) {
225 	rtree_node_elm_t *node;
226 	rtree_leaf_elm_t *leaf;
227 #if RTREE_HEIGHT > 1
228 	node = rtree->root;
229 #else
230 	leaf = rtree->root;
231 #endif
232 
233 	if (config_debug) {
234 		uintptr_t leafkey = rtree_leafkey(key);
235 		for (unsigned i = 0; i < RTREE_CTX_NCACHE; i++) {
236 			assert(rtree_ctx->cache[i].leafkey != leafkey);
237 		}
238 		for (unsigned i = 0; i < RTREE_CTX_NCACHE_L2; i++) {
239 			assert(rtree_ctx->l2_cache[i].leafkey != leafkey);
240 		}
241 	}
242 
243 #define RTREE_GET_CHILD(level) {					\
244 		assert(level < RTREE_HEIGHT-1);				\
245 		if (level != 0 && !dependent &&				\
246 		    unlikely(!rtree_node_valid(node))) {		\
247 			return NULL;					\
248 		}							\
249 		uintptr_t subkey = rtree_subkey(key, level);		\
250 		if (level + 2 < RTREE_HEIGHT) {				\
251 			node = init_missing ?				\
252 			    rtree_child_node_read(tsdn, rtree,		\
253 			    &node[subkey], level, dependent) :		\
254 			    rtree_child_node_tryread(&node[subkey],	\
255 			    dependent);					\
256 		} else {						\
257 			leaf = init_missing ?				\
258 			    rtree_child_leaf_read(tsdn, rtree,		\
259 			    &node[subkey], level, dependent) :		\
260 			    rtree_child_leaf_tryread(&node[subkey],	\
261 			    dependent);					\
262 		}							\
263 	}
264 	/*
265 	 * Cache replacement upon hard lookup (i.e. L1 & L2 rtree cache miss):
266 	 * (1) evict last entry in L2 cache; (2) move the collision slot from L1
267 	 * cache down to L2; and 3) fill L1.
268 	 */
269 #define RTREE_GET_LEAF(level) {						\
270 		assert(level == RTREE_HEIGHT-1);			\
271 		if (!dependent && unlikely(!rtree_leaf_valid(leaf))) {	\
272 			return NULL;					\
273 		}							\
274 		if (RTREE_CTX_NCACHE_L2 > 1) {				\
275 			memmove(&rtree_ctx->l2_cache[1],		\
276 			    &rtree_ctx->l2_cache[0],			\
277 			    sizeof(rtree_ctx_cache_elm_t) *		\
278 			    (RTREE_CTX_NCACHE_L2 - 1));			\
279 		}							\
280 		size_t slot = rtree_cache_direct_map(key);		\
281 		rtree_ctx->l2_cache[0].leafkey =			\
282 		    rtree_ctx->cache[slot].leafkey;			\
283 		rtree_ctx->l2_cache[0].leaf =				\
284 		    rtree_ctx->cache[slot].leaf;			\
285 		uintptr_t leafkey = rtree_leafkey(key);			\
286 		rtree_ctx->cache[slot].leafkey = leafkey;		\
287 		rtree_ctx->cache[slot].leaf = leaf;			\
288 		uintptr_t subkey = rtree_subkey(key, level);		\
289 		return &leaf[subkey];					\
290 	}
291 	if (RTREE_HEIGHT > 1) {
292 		RTREE_GET_CHILD(0)
293 	}
294 	if (RTREE_HEIGHT > 2) {
295 		RTREE_GET_CHILD(1)
296 	}
297 	if (RTREE_HEIGHT > 3) {
298 		for (unsigned i = 2; i < RTREE_HEIGHT-1; i++) {
299 			RTREE_GET_CHILD(i)
300 		}
301 	}
302 	RTREE_GET_LEAF(RTREE_HEIGHT-1)
303 #undef RTREE_GET_CHILD
304 #undef RTREE_GET_LEAF
305 	not_reached();
306 }
307 
308 void
309 rtree_ctx_data_init(rtree_ctx_t *ctx) {
310 	for (unsigned i = 0; i < RTREE_CTX_NCACHE; i++) {
311 		rtree_ctx_cache_elm_t *cache = &ctx->cache[i];
312 		cache->leafkey = RTREE_LEAFKEY_INVALID;
313 		cache->leaf = NULL;
314 	}
315 	for (unsigned i = 0; i < RTREE_CTX_NCACHE_L2; i++) {
316 		rtree_ctx_cache_elm_t *cache = &ctx->l2_cache[i];
317 		cache->leafkey = RTREE_LEAFKEY_INVALID;
318 		cache->leaf = NULL;
319 	}
320 }
321