xref: /freebsd/sys/contrib/ck/include/ck_stack.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*
2  * Copyright 2009-2015 Samy Al Bahra.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #ifndef CK_STACK_H
28 #define CK_STACK_H
29 
30 #include <ck_cc.h>
31 #include <ck_pr.h>
32 #include <ck_stdbool.h>
33 #include <ck_stddef.h>
34 
35 struct ck_stack_entry {
36 	struct ck_stack_entry *next;
37 };
38 typedef struct ck_stack_entry ck_stack_entry_t;
39 
40 struct ck_stack {
41 	struct ck_stack_entry *head;
42 	char *generation CK_CC_PACKED;
43 } CK_CC_ALIASED;
44 typedef struct ck_stack ck_stack_t;
45 
46 #define CK_STACK_INITIALIZER { NULL, NULL }
47 
48 #ifndef CK_F_STACK_PUSH_UPMC
49 #define CK_F_STACK_PUSH_UPMC
50 /*
51  * Stack producer operation safe for multiple unique producers and multiple consumers.
52  */
53 CK_CC_INLINE static void
54 ck_stack_push_upmc(struct ck_stack *target, struct ck_stack_entry *entry)
55 {
56 	struct ck_stack_entry *stack;
57 
58 	stack = ck_pr_load_ptr(&target->head);
59 	entry->next = stack;
60 	ck_pr_fence_store();
61 
62 	while (ck_pr_cas_ptr_value(&target->head, stack, entry, &stack) == false) {
63 		entry->next = stack;
64 		ck_pr_fence_store();
65 	}
66 
67 	return;
68 }
69 #endif /* CK_F_STACK_PUSH_UPMC */
70 
71 #ifndef CK_F_STACK_TRYPUSH_UPMC
72 #define CK_F_STACK_TRYPUSH_UPMC
73 /*
74  * Stack producer operation for multiple unique producers and multiple consumers.
75  * Returns true on success and false on failure.
76  */
77 CK_CC_INLINE static bool
78 ck_stack_trypush_upmc(struct ck_stack *target, struct ck_stack_entry *entry)
79 {
80 	struct ck_stack_entry *stack;
81 
82 	stack = ck_pr_load_ptr(&target->head);
83 	entry->next = stack;
84 	ck_pr_fence_store();
85 
86 	return ck_pr_cas_ptr(&target->head, stack, entry);
87 }
88 #endif /* CK_F_STACK_TRYPUSH_UPMC */
89 
90 #ifndef CK_F_STACK_POP_UPMC
91 #define CK_F_STACK_POP_UPMC
92 /*
93  * Stack consumer operation safe for multiple unique producers and multiple consumers.
94  */
95 CK_CC_INLINE static struct ck_stack_entry *
96 ck_stack_pop_upmc(struct ck_stack *target)
97 {
98 	struct ck_stack_entry *entry, *next;
99 
100 	entry = ck_pr_load_ptr(&target->head);
101 	if (entry == NULL)
102 		return NULL;
103 
104 	ck_pr_fence_load();
105 	next = entry->next;
106 	while (ck_pr_cas_ptr_value(&target->head, entry, next, &entry) == false) {
107 		if (entry == NULL)
108 			break;
109 
110 		ck_pr_fence_load();
111 		next = entry->next;
112 	}
113 
114 	return entry;
115 }
116 #endif
117 
118 #ifndef CK_F_STACK_TRYPOP_UPMC
119 #define CK_F_STACK_TRYPOP_UPMC
120 /*
121  * Stack production operation for multiple unique producers and multiple consumers.
122  * Returns true on success and false on failure. The value pointed to by the second
123  * argument is set to a valid ck_stack_entry_t reference if true is returned. If
124  * false is returned, then the value pointed to by the second argument is undefined.
125  */
126 CK_CC_INLINE static bool
127 ck_stack_trypop_upmc(struct ck_stack *target, struct ck_stack_entry **r)
128 {
129 	struct ck_stack_entry *entry;
130 
131 	entry = ck_pr_load_ptr(&target->head);
132 	if (entry == NULL)
133 		return false;
134 
135 	ck_pr_fence_load();
136 	if (ck_pr_cas_ptr(&target->head, entry, entry->next) == true) {
137 		*r = entry;
138 		return true;
139 	}
140 
141 	return false;
142 }
143 #endif /* CK_F_STACK_TRYPOP_UPMC */
144 
145 #ifndef CK_F_STACK_BATCH_POP_UPMC
146 #define CK_F_STACK_BATCH_POP_UPMC
147 /*
148  * Pop all items off the stack.
149  */
150 CK_CC_INLINE static struct ck_stack_entry *
151 ck_stack_batch_pop_upmc(struct ck_stack *target)
152 {
153 	struct ck_stack_entry *entry;
154 
155 	entry = ck_pr_fas_ptr(&target->head, NULL);
156 	ck_pr_fence_load();
157 	return entry;
158 }
159 #endif /* CK_F_STACK_BATCH_POP_UPMC */
160 
161 #ifndef CK_F_STACK_PUSH_MPMC
162 #define CK_F_STACK_PUSH_MPMC
163 /*
164  * Stack producer operation safe for multiple producers and multiple consumers.
165  */
166 CK_CC_INLINE static void
167 ck_stack_push_mpmc(struct ck_stack *target, struct ck_stack_entry *entry)
168 {
169 
170 	ck_stack_push_upmc(target, entry);
171 	return;
172 }
173 #endif /* CK_F_STACK_PUSH_MPMC */
174 
175 #ifndef CK_F_STACK_TRYPUSH_MPMC
176 #define CK_F_STACK_TRYPUSH_MPMC
177 /*
178  * Stack producer operation safe for multiple producers and multiple consumers.
179  */
180 CK_CC_INLINE static bool
181 ck_stack_trypush_mpmc(struct ck_stack *target, struct ck_stack_entry *entry)
182 {
183 
184 	return ck_stack_trypush_upmc(target, entry);
185 }
186 #endif /* CK_F_STACK_TRYPUSH_MPMC */
187 
188 #ifdef CK_F_PR_CAS_PTR_2_VALUE
189 #ifndef CK_F_STACK_POP_MPMC
190 #define CK_F_STACK_POP_MPMC
191 /*
192  * Stack consumer operation safe for multiple producers and multiple consumers.
193  */
194 CK_CC_INLINE static struct ck_stack_entry *
195 ck_stack_pop_mpmc(struct ck_stack *target)
196 {
197 	struct ck_stack original, update;
198 
199 	original.generation = ck_pr_load_ptr(&target->generation);
200 	ck_pr_fence_load();
201 	original.head = ck_pr_load_ptr(&target->head);
202 	if (original.head == NULL)
203 		return NULL;
204 
205 	/* Order with respect to next pointer. */
206 	ck_pr_fence_load();
207 
208 	update.generation = original.generation + 1;
209 	update.head = original.head->next;
210 
211 	while (ck_pr_cas_ptr_2_value(target, &original, &update, &original) == false) {
212 		if (original.head == NULL)
213 			return NULL;
214 
215 		update.generation = original.generation + 1;
216 
217 		/* Order with respect to next pointer. */
218 		ck_pr_fence_load();
219 		update.head = original.head->next;
220 	}
221 
222 	return original.head;
223 }
224 #endif /* CK_F_STACK_POP_MPMC */
225 
226 #ifndef CK_F_STACK_TRYPOP_MPMC
227 #define CK_F_STACK_TRYPOP_MPMC
228 CK_CC_INLINE static bool
229 ck_stack_trypop_mpmc(struct ck_stack *target, struct ck_stack_entry **r)
230 {
231 	struct ck_stack original, update;
232 
233 	original.generation = ck_pr_load_ptr(&target->generation);
234 	ck_pr_fence_load();
235 	original.head = ck_pr_load_ptr(&target->head);
236 	if (original.head == NULL)
237 		return false;
238 
239 	update.generation = original.generation + 1;
240 	ck_pr_fence_load();
241 	update.head = original.head->next;
242 
243 	if (ck_pr_cas_ptr_2_value(target, &original, &update, &original) == true) {
244 		*r = original.head;
245 		return true;
246 	}
247 
248 	return false;
249 }
250 #endif /* CK_F_STACK_TRYPOP_MPMC */
251 #endif /* CK_F_PR_CAS_PTR_2_VALUE */
252 
253 #ifndef CK_F_STACK_BATCH_POP_MPMC
254 #define CK_F_STACK_BATCH_POP_MPMC
255 /*
256  * This is equivalent to the UP/MC version as NULL does not need a
257  * a generation count.
258  */
259 CK_CC_INLINE static struct ck_stack_entry *
260 ck_stack_batch_pop_mpmc(struct ck_stack *target)
261 {
262 
263 	return ck_stack_batch_pop_upmc(target);
264 }
265 #endif /* CK_F_STACK_BATCH_POP_MPMC */
266 
267 #ifndef CK_F_STACK_PUSH_MPNC
268 #define CK_F_STACK_PUSH_MPNC
269 /*
270  * Stack producer operation safe with no concurrent consumers.
271  */
272 CK_CC_INLINE static void
273 ck_stack_push_mpnc(struct ck_stack *target, struct ck_stack_entry *entry)
274 {
275 	struct ck_stack_entry *stack;
276 
277 	entry->next = NULL;
278 	ck_pr_fence_store_atomic();
279 	stack = ck_pr_fas_ptr(&target->head, entry);
280 	ck_pr_store_ptr(&entry->next, stack);
281 	ck_pr_fence_store();
282 
283 	return;
284 }
285 #endif /* CK_F_STACK_PUSH_MPNC */
286 
287 /*
288  * Stack producer operation for single producer and no concurrent consumers.
289  */
290 CK_CC_INLINE static void
291 ck_stack_push_spnc(struct ck_stack *target, struct ck_stack_entry *entry)
292 {
293 
294 	entry->next = target->head;
295 	target->head = entry;
296 	return;
297 }
298 
299 /*
300  * Stack consumer operation for no concurrent producers and single consumer.
301  */
302 CK_CC_INLINE static struct ck_stack_entry *
303 ck_stack_pop_npsc(struct ck_stack *target)
304 {
305 	struct ck_stack_entry *n;
306 
307 	if (target->head == NULL)
308 		return NULL;
309 
310 	n = target->head;
311 	target->head = n->next;
312 
313 	return n;
314 }
315 
316 /*
317  * Pop all items off a stack.
318  */
319 CK_CC_INLINE static struct ck_stack_entry *
320 ck_stack_batch_pop_npsc(struct ck_stack *target)
321 {
322 	struct ck_stack_entry *n;
323 
324 	n = target->head;
325 	target->head = NULL;
326 
327 	return n;
328 }
329 
330 /*
331  * Stack initialization function. Guarantees initialization across processors.
332  */
333 CK_CC_INLINE static void
334 ck_stack_init(struct ck_stack *stack)
335 {
336 
337 	stack->head = NULL;
338 	stack->generation = NULL;
339 	return;
340 }
341 
342 /* Defines a container_of functions for */
343 #define CK_STACK_CONTAINER(T, M, N) CK_CC_CONTAINER(ck_stack_entry_t, T, M, N)
344 
345 #define CK_STACK_ISEMPTY(m) ((m)->head == NULL)
346 #define CK_STACK_FIRST(s)   ((s)->head)
347 #define CK_STACK_NEXT(m)    ((m)->next)
348 #define CK_STACK_FOREACH(stack, entry)				\
349 	for ((entry) = CK_STACK_FIRST(stack);			\
350 	     (entry) != NULL;					\
351 	     (entry) = CK_STACK_NEXT(entry))
352 #define CK_STACK_FOREACH_SAFE(stack, entry, T)			\
353 	for ((entry) = CK_STACK_FIRST(stack);			\
354 	     (entry) != NULL && ((T) = (entry)->next, 1);	\
355 	     (entry) = (T))
356 
357 #endif /* CK_STACK_H */
358