vinyl-cache/bin/vinyld/cache/cache_expire.c
0
/*-
1
 * Copyright (c) 2006 Verdens Gang AS
2
 * Copyright (c) 2006-2011 Varnish Software AS
3
 * All rights reserved.
4
 *
5
 * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
6
 *
7
 * SPDX-License-Identifier: BSD-2-Clause
8
 *
9
 * Redistribution and use in source and binary forms, with or without
10
 * modification, are permitted provided that the following conditions
11
 * are met:
12
 * 1. Redistributions of source code must retain the above copyright
13
 *    notice, this list of conditions and the following disclaimer.
14
 * 2. Redistributions in binary form must reproduce the above copyright
15
 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
17
 *
18
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28
 * SUCH DAMAGE.
29
 *
30
 * LRU and object timer handling.
31
 *
32
 */
33
34
#include "config.h"
35
36
#include <stdlib.h>
37
38
#include "cache_int.h"
39
#include "cache_objhead.h"
40
41
#include "vbh.h"
42
#include "vtim.h"
43
44
struct exp_priv {
45
        unsigned                        magic;
46
#define EXP_PRIV_MAGIC                  0x9db22482
47
        /* shared */
48
        struct lock                     mtx;
49
        VSTAILQ_HEAD(,objcore)          inbox;
50
        pthread_cond_t                  condvar;
51
52
        /* owned by exp thread */
53
        struct worker                   *wrk;
54
        struct vsl_log                  vsl;
55
        struct vbh                      *heap;
56
        pthread_t                       thread;
57
};
58
59
static struct exp_priv *exphdl;
60
static int exp_shutdown = 0;
61
62
/*---------------------------------------------------------------------
63
 * Calculate the point in time when an object will become stale, taking
64
 * req.max_age into account, if available
65
 */
66
67
vtim_real
68 7757
EXP_Ttl(const struct req *req, const struct objcore *oc)
69
{
70
        vtim_dur r;
71
72 7757
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
73
74 7757
        r = oc->ttl;
75 7757
        if (req != NULL && req->d_ttl >= 0. && req->d_ttl < r)
76 25
                r = req->d_ttl;
77 7757
        return (oc->t_origin + r);
78
}
79
80
/*--------------------------------------------------------------------
81
 * Calculate an object's effective ttl+grace time, taking req.grace into
82
 * account if it is available.
83
 */
84
85
vtim_real
86 560
EXP_Ttl_grace(const struct req *req, const struct objcore *oc)
87
{
88
        vtim_dur g;
89
90 560
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
91
92 560
        g = oc->grace;
93 560
        if (req != NULL && req->d_grace >= 0. && req->d_grace < g)
94 8
                g = req->d_grace;
95 560
        return (EXP_Ttl(req, oc) + g);
96
}
97
98
/*--------------------------------------------------------------------
99
 * Post an objcore to the exp_thread's inbox.
100
 */
101
102
static void
103 7176
exp_mail_it(struct objcore *oc, uint8_t cmds)
104
{
105 7176
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
106 7176
        assert(oc->refcnt > 0);
107 7176
        AZ(cmds & OC_EF_REFD);
108
109 7176
        Lck_AssertHeld(&exphdl->mtx);
110
111 7176
        if (oc->exp_flags & OC_EF_REFD) {
112 7176
                if (!(oc->exp_flags & OC_EF_POSTED)) {
113 7176
                        if (cmds & OC_EF_REMOVE)
114 1104
                                VSTAILQ_INSERT_HEAD(&exphdl->inbox,
115
                                    oc, exp_list);
116
                        else
117 6072
                                VSTAILQ_INSERT_TAIL(&exphdl->inbox,
118
                                    oc, exp_list);
119 7176
                        VSC_C_main->exp_mailed++;
120 7176
                }
121 7176
                oc->exp_flags |= cmds | OC_EF_POSTED;
122 7176
                PTOK(pthread_cond_signal(&exphdl->condvar));
123 7176
        }
124 7176
}
125
126
/*--------------------------------------------------------------------
127
 * Setup a new ObjCore for control by expire. Should be called with the
128
 * ObjHead locked by HSH_Unbusy(/HSH_Insert) (in private access).
129
 */
130
131
void
132 6048
EXP_RefNewObjcore(struct objcore *oc)
133
{
134 6048
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
135
136 6048
        Lck_AssertHeld(&oc->objhead->mtx);
137
138 6048
        AZ(oc->exp_flags);
139 6048
        assert(oc->refcnt >= 1);
140 6048
        oc->refcnt++;
141 6048
        oc->exp_flags |= OC_EF_REFD | OC_EF_NEW;
142 6048
}
143
144
145
146
/*--------------------------------------------------------------------
147
 * Call EXP's attention to an oc
148
 */
149
150
void
151 1901
EXP_Remove(struct objcore *oc, const struct objcore *new_oc)
152
{
153
154 1901
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
155 1901
        CHECK_OBJ_ORNULL(new_oc, OBJCORE_MAGIC);
156
157 1901
        if (oc->exp_flags & OC_EF_REFD) {
158 1104
                Lck_Lock(&exphdl->mtx);
159 1104
                if (new_oc != NULL)
160 300
                        VSC_C_main->n_superseded++;
161 1104
                if (oc->exp_flags & OC_EF_NEW) {
162
                        /* EXP_Insert has not been called for this object
163
                         * yet. Mark it for removal, and EXP_Insert will
164
                         * clean up once it is called. */
165 0
                        AZ(oc->exp_flags & OC_EF_POSTED);
166 0
                        oc->exp_flags |= OC_EF_REMOVE;
167 0
                } else
168 1104
                        exp_mail_it(oc, OC_EF_REMOVE);
169 1104
                Lck_Unlock(&exphdl->mtx);
170 1104
        }
171 1901
}
172
173
/*--------------------------------------------------------------------
174
 * Insert new object.
175
 *
176
 * Caller got a oc->refcnt for us.
177
 */
178
179
void
180 6048
EXP_Insert(struct worker *wrk, struct objcore *oc)
181
{
182 6048
        unsigned remove_race = 0;
183
        struct objcore *tmpoc;
184
185 6048
        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
186 6048
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
187
188 6048
        AZ(oc->flags & OC_F_BUSY);
189
190 6048
        if (!(oc->exp_flags & OC_EF_REFD))
191 0
                return;
192
193
        /* One ref held by the caller, and one that will be owned by
194
         * expiry. */
195 6048
        assert(oc->refcnt >= 2);
196
197 6048
        ObjSendEvent(wrk, oc, OEV_INSERT);
198
199 6048
        Lck_Lock(&exphdl->mtx);
200 6048
        AN(oc->exp_flags & OC_EF_NEW);
201 6048
        oc->exp_flags &= ~OC_EF_NEW;
202 6048
        AZ(oc->exp_flags & (OC_EF_INSERT | OC_EF_MOVE | OC_EF_POSTED));
203 6048
        if (oc->exp_flags & OC_EF_REMOVE) {
204
                /* We raced some other thread executing EXP_Remove */
205 0
                remove_race = 1;
206 0
                oc->exp_flags &= ~(OC_EF_REFD | OC_EF_REMOVE);
207 0
        } else
208 6048
                exp_mail_it(oc, OC_EF_INSERT | OC_EF_MOVE);
209 6048
        Lck_Unlock(&exphdl->mtx);
210
211 6048
        if (remove_race) {
212 0
                ObjSendEvent(wrk, oc, OEV_EXPIRE);
213 0
                tmpoc = oc;
214 0
                assert(oc->refcnt >= 2); /* Silence coverity */
215 0
                (void)HSH_DerefObjCore(wrk, &oc);
216 0
                AZ(oc);
217 0
                assert(tmpoc->refcnt >= 1); /* Silence coverity */
218 0
        }
219 6048
}
220
221
/*--------------------------------------------------------------------
222
 * Reduce object timers
223
 */
224
225
void
226 40
EXP_Reduce(struct objcore *oc, vtim_real now,
227
    vtim_dur ttl, vtim_dur grace, vtim_dur keep)
228
{
229
230 40
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
231 40
        assert(oc->refcnt > 0);
232
233 40
        if (!isnan(ttl) && now + ttl - oc->t_origin >= oc->ttl)
234 24
                ttl = NAN;
235 40
        if (!isnan(grace) && grace >= oc->grace)
236 8
                grace = NAN;
237 40
        if (!isnan(keep) && keep >= oc->keep)
238 4
                keep = NAN;
239
240 40
        EXP_Rearm(oc, now, ttl, grace, keep);
241 40
}
242
243
/*--------------------------------------------------------------------
244
 * We have changed one or more of the object timers, tell the exp_thread
245
 *
246
 */
247
248
static inline void
249 40
apply_timers(struct objcore *oc, vtim_real now,
250
    vtim_dur ttl, vtim_dur grace, vtim_dur keep)
251
{
252 40
        if (!isnan(ttl))
253 16
                oc->ttl = now + ttl - oc->t_origin;
254 40
        if (!isnan(grace))
255 8
                oc->grace = grace;
256 40
        if (!isnan(keep))
257 8
                oc->keep = keep;
258 40
}
259
260
void
261 40
EXP_Rearm(struct objcore *oc, vtim_real now,
262
    vtim_dur ttl, vtim_dur grace, vtim_dur keep)
263
{
264
        vtim_real when;
265
266 40
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
267 40
        assert(oc->refcnt > 0);
268
269 40
        if (oc->flags & OC_F_BUSY) {
270 0
                struct objhead *oh = oc->objhead;
271
                uint8_t flags;
272
273 0
                Lck_Lock(&oh->mtx);
274 0
                flags = oc->flags;
275 0
                if (flags & OC_F_BUSY)
276 0
                        apply_timers(oc, now, ttl, grace, keep);
277 0
                Lck_Unlock(&oh->mtx);
278 0
                if (flags & OC_F_BUSY)
279 0
                        return;
280 0
        }
281
282 40
        if (!(oc->exp_flags & OC_EF_REFD))
283 0
                return;
284
285 40
        apply_timers(oc, now, ttl, grace, keep);
286
287 40
        when = EXP_WHEN(oc);
288
289 80
        VSL(SLT_ExpKill, NO_VXID, "EXP_Rearm p=%p E=%.6f e=%.6f f=0x%x", oc,
290 40
            oc->timer_when, when, oc->flags);
291
292 40
        if (when < oc->t_origin || when < oc->timer_when) {
293 24
                Lck_Lock(&exphdl->mtx);
294 24
                if (oc->exp_flags & OC_EF_NEW) {
295
                        /* EXP_Insert has not been called yet, do nothing
296
                         * as the initial insert will execute the move
297
                         * operation. */
298 0
                } else
299 24
                        exp_mail_it(oc, OC_EF_MOVE);
300 24
                Lck_Unlock(&exphdl->mtx);
301 24
        }
302 40
}
303
304
/*--------------------------------------------------------------------
305
 * Handle stuff in the inbox
306
 */
307
308
static void
309 7176
exp_inbox(struct exp_priv *ep, struct objcore *oc, unsigned flags, vtim_real now)
310
{
311
312 7176
        CHECK_OBJ_NOTNULL(ep, EXP_PRIV_MAGIC);
313 7176
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
314 7176
        assert(oc->refcnt > 0);
315
316 14352
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_Inbox flg=%x p=%p e=%.6f f=0x%x",
317 7176
            flags, oc, oc->timer_when, oc->flags);
318
319 7176
        if (flags & OC_EF_REMOVE) {
320 1104
                if (!(flags & OC_EF_INSERT)) {
321 1104
                        assert(oc->timer_idx != VBH_NOIDX);
322 1104
                        VBH_delete(ep->heap, oc->timer_idx);
323 1104
                }
324 1104
                assert(oc->timer_idx == VBH_NOIDX);
325 1104
                assert(oc->refcnt > 0);
326 1104
                AZ(oc->exp_flags);
327 2208
                VSLb(&ep->vsl, SLT_ExpKill, "EXP_Removed x=%ju t=%.0f h=%jd",
328 1104
                    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now,
329 1104
                    (intmax_t)oc->hits);
330 1104
                ObjSendEvent(ep->wrk, oc, OEV_EXPIRE);
331 1104
                (void)HSH_DerefObjCore(ep->wrk, &oc);
332 1104
                return;
333
        }
334
335 6072
        if (flags & OC_EF_MOVE) {
336 6072
                oc->timer_when = EXP_WHEN(oc);
337 6072
                ObjSendEvent(ep->wrk, oc, OEV_TTLCHG);
338 6072
        }
339
340 12144
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_When p=%p e=%.6f f=0x%x", oc,
341 6072
            oc->timer_when, flags);
342
343
        /*
344
         * XXX: There are some pathological cases here, were we
345
         * XXX: insert or move an expired object, only to find out
346
         * XXX: the next moment and rip them out again.
347
         */
348
349 6072
        if (flags & OC_EF_INSERT) {
350 6048
                assert(oc->timer_idx == VBH_NOIDX);
351 6048
                VBH_insert(exphdl->heap, oc);
352 6048
                assert(oc->timer_idx != VBH_NOIDX);
353 6072
        } else if (flags & OC_EF_MOVE) {
354 24
                assert(oc->timer_idx != VBH_NOIDX);
355 24
                VBH_reorder(exphdl->heap, oc->timer_idx);
356 24
                assert(oc->timer_idx != VBH_NOIDX);
357 24
        } else {
358 0
                WRONG("Objcore state wrong in inbox");
359
        }
360 7176
}
361
362
/*--------------------------------------------------------------------
363
 * Expire stuff from the binheap
364
 */
365
366
static vtim_real
367 22028
exp_expire(struct exp_priv *ep, vtim_real now)
368
{
369
        struct objcore *oc;
370
371 22028
        CHECK_OBJ_NOTNULL(ep, EXP_PRIV_MAGIC);
372
373 22028
        oc = VBH_root(ep->heap);
374 22028
        if (oc == NULL)
375 9198
                return (now + 355. / 113.);
376 25660
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_Inspect p=%p e=%.6f f=0x%x", oc,
377 12830
            oc->timer_when - now, oc->flags);
378
379 12830
        CHECK_OBJ(oc, OBJCORE_MAGIC);
380
381
        /* Ready ? */
382 12830
        if (oc->timer_when > now)
383 12273
                return (oc->timer_when);
384
385 557
        VSC_C_main->n_expired++;
386
387 557
        Lck_Lock(&ep->mtx);
388 557
        if (oc->exp_flags & OC_EF_POSTED) {
389 0
                oc->exp_flags |= OC_EF_REMOVE;
390 0
                oc = NULL;
391 0
        } else {
392 557
                oc->exp_flags &= ~OC_EF_REFD;
393
        }
394 557
        Lck_Unlock(&ep->mtx);
395 557
        if (oc != NULL) {
396 557
                if (!(oc->flags & OC_F_DYING))
397 557
                        HSH_Kill(oc);
398
399
                /* Remove from binheap */
400 557
                assert(oc->timer_idx != VBH_NOIDX);
401 557
                VBH_delete(ep->heap, oc->timer_idx);
402 557
                assert(oc->timer_idx == VBH_NOIDX);
403
404 557
                CHECK_OBJ_NOTNULL(oc->objhead, OBJHEAD_MAGIC);
405 1114
                VSLb(&ep->vsl, SLT_ExpKill, "EXP_Expired x=%ju t=%.0f h=%jd",
406 557
                    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now,
407 557
                    (intmax_t)oc->hits);
408 557
                ObjSendEvent(ep->wrk, oc, OEV_EXPIRE);
409 557
                (void)HSH_DerefObjCore(ep->wrk, &oc);
410 557
        }
411 557
        return (0);
412 22028
}
413
414
/*--------------------------------------------------------------------
415
 * This thread monitors the root of the binary heap and whenever an
416
 * object expires, accounting also for graceability, it is killed.
417
 */
418
419
static int v_matchproto_(vbh_cmp_t)
420 5285
object_cmp(void *priv, const void *a, const void *b)
421
{
422
        const struct objcore *aa, *bb;
423
424 5285
        (void)priv;
425 5285
        CAST_OBJ_NOTNULL(aa, a, OBJCORE_MAGIC);
426 5285
        CAST_OBJ_NOTNULL(bb, b, OBJCORE_MAGIC);
427 5285
        return (aa->timer_when < bb->timer_when);
428
}
429
430
static void v_matchproto_(vbh_update_t)
431 11517
object_update(void *priv, void *p, unsigned u)
432
{
433
        struct objcore *oc;
434
435 11517
        (void)priv;
436 11517
        CAST_OBJ_NOTNULL(oc, p, OBJCORE_MAGIC);
437 11517
        oc->timer_idx = u;
438 11517
}
439
440
static void * v_matchproto_(bgthread_t)
441 3892
exp_thread(struct worker *wrk, void *priv)
442
{
443
        struct objcore *oc;
444 3892
        vtim_real t = 0, tnext = 0;
445
        struct exp_priv *ep;
446 3892
        unsigned flags = 0;
447
448 3892
        CAST_OBJ_NOTNULL(ep, priv, EXP_PRIV_MAGIC);
449 3892
        ep->wrk = wrk;
450 3892
        VSL_Alloc(&ep->vsl);
451 3892
        AZ(wrk->vsl);
452 3892
        wrk->vsl = &ep->vsl;
453 3892
        ep->heap = VBH_new(NULL, object_cmp, object_update);
454 3892
        AN(ep->heap);
455 33096
        while (exp_shutdown == 0) {
456
457 29204
                Lck_Lock(&ep->mtx);
458 29204
                oc = VSTAILQ_FIRST(&ep->inbox);
459 29204
                CHECK_OBJ_ORNULL(oc, OBJCORE_MAGIC);
460 29204
                if (oc != NULL) {
461 7176
                        assert(oc->refcnt >= 1);
462 7176
                        assert(oc->exp_flags & OC_EF_POSTED);
463 7176
                        VSTAILQ_REMOVE(&ep->inbox, oc, objcore, exp_list);
464 7176
                        VSC_C_main->exp_received++;
465 7176
                        tnext = 0;
466 7176
                        flags = oc->exp_flags;
467 7176
                        if (flags & OC_EF_REMOVE)
468 1104
                                oc->exp_flags = 0;
469
                        else
470 6072
                                oc->exp_flags &= OC_EF_REFD;
471 29204
                } else if (tnext > t) {
472 10984
                        VSL_Flush(&ep->vsl, 0);
473 10984
                        Pool_Sumstat(wrk);
474 10984
                        (void)Lck_CondWaitUntil(&ep->condvar, &ep->mtx, tnext);
475 10984
                }
476 29204
                Lck_Unlock(&ep->mtx);
477
478 29204
                t = VTIM_real();
479
480 29204
                if (oc != NULL)
481 7176
                        exp_inbox(ep, oc, flags, t);
482
                else
483 22028
                        tnext = exp_expire(ep, t);
484
        }
485 3892
        wrk->vsl = NULL;
486 3892
        VSL_Free(&ep->vsl);
487 3892
        return (NULL);
488
}
489
490
/*--------------------------------------------------------------------*/
491
492
void
493 3892
EXP_Init(void)
494
{
495
        struct exp_priv *ep;
496
        pthread_t pt;
497
498 3892
        ALLOC_OBJ(ep, EXP_PRIV_MAGIC);
499 3892
        AN(ep);
500
501 3892
        Lck_New(&ep->mtx, lck_exp);
502 3892
        PTOK(pthread_cond_init(&ep->condvar, NULL));
503 3892
        VSTAILQ_INIT(&ep->inbox);
504 3892
        WRK_BgThread(&pt, "cache-exp", exp_thread, ep);
505 3892
        ep->thread = pt;
506 3892
        exphdl = ep;
507 3892
}
508
509
void
510 3848
EXP_Shutdown(void)
511
{
512 3848
        struct exp_priv *ep = exphdl;
513
        void *status;
514
515 3848
        Lck_Lock(&ep->mtx);
516 3848
        exp_shutdown = 1;
517 3848
        PTOK(pthread_cond_signal(&ep->condvar));
518 3848
        Lck_Unlock(&ep->mtx);
519
520 3848
        AN(ep->thread);
521 3848
        PTOK(pthread_join(ep->thread, &status));
522 3848
        AZ(status);
523 3848
        memset(&ep->thread, 0, sizeof ep->thread);
524
525
        /* XXX could cleanup more - not worth it for now */
526 3848
}