varnish-cache/bin/varnishd/cache/cache_expire.c
0
/*-
1
 * Copyright (c) 2006 Verdens Gang AS
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 * Copyright (c) 2006-2011 Varnish Software AS
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 * All rights reserved.
4
 *
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 * 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
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    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
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * 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
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 * 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
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * 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_varnishd.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 an object's effective ttl time, taking req.ttl into account
64
 * if it is available.
65
 */
66
67
vtim_real
68 1835
EXP_Ttl(const struct req *req, const struct objcore *oc)
69
{
70
        vtim_dur r;
71
72 1835
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
73
74 1835
        r = oc->ttl;
75 1835
        if (req != NULL && req->d_ttl > 0. && req->d_ttl < r)
76 7
                r = req->d_ttl;
77 1835
        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
86 126
EXP_Ttl_grace(const struct req *req, const struct objcore *oc)
87
{
88
        vtim_dur g;
89
90 126
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
91
92 126
        g = oc->grace;
93 126
        if (req != NULL && req->d_grace >= 0. && req->d_grace < g)
94 3
                g = req->d_grace;
95 126
        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 1688
exp_mail_it(struct objcore *oc, uint8_t cmds)
104
{
105 1688
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
106 1688
        assert(oc->refcnt > 0);
107 1688
        AZ(cmds & OC_EF_REFD);
108
109 1688
        Lck_AssertHeld(&exphdl->mtx);
110
111 1688
        if (oc->exp_flags & OC_EF_REFD) {
112 1688
                if (!(oc->exp_flags & OC_EF_POSTED)) {
113 1688
                        if (cmds & OC_EF_REMOVE)
114 246
                                VSTAILQ_INSERT_HEAD(&exphdl->inbox,
115
                                    oc, exp_list);
116
                        else
117 1442
                                VSTAILQ_INSERT_TAIL(&exphdl->inbox,
118
                                    oc, exp_list);
119 1688
                        VSC_C_main->exp_mailed++;
120 1688
                }
121 1688
                oc->exp_flags |= cmds | OC_EF_POSTED;
122 1688
                PTOK(pthread_cond_signal(&exphdl->condvar));
123 1688
        }
124 1688
}
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 1436
EXP_RefNewObjcore(struct objcore *oc)
133
{
134 1436
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
135
136 1436
        Lck_AssertHeld(&oc->objhead->mtx);
137
138 1436
        AZ(oc->exp_flags);
139 1436
        assert(oc->refcnt >= 1);
140 1436
        oc->refcnt++;
141 1436
        oc->exp_flags |= OC_EF_REFD | OC_EF_NEW;
142 1436
}
143
144
145
146
/*--------------------------------------------------------------------
147
 * Call EXP's attention to an oc
148
 */
149
150
void
151 377
EXP_Remove(struct objcore *oc, const struct objcore *new_oc)
152
{
153
154 377
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
155 377
        CHECK_OBJ_ORNULL(new_oc, OBJCORE_MAGIC);
156
157 377
        if (oc->exp_flags & OC_EF_REFD) {
158 246
                Lck_Lock(&exphdl->mtx);
159 246
                if (new_oc != NULL)
160 71
                        VSC_C_main->n_superseded++;
161 246
                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
168 246
                        exp_mail_it(oc, OC_EF_REMOVE);
169 246
                Lck_Unlock(&exphdl->mtx);
170 246
        }
171 377
}
172
173
/*--------------------------------------------------------------------
174
 * Insert new object.
175
 *
176
 * Caller got a oc->refcnt for us.
177
 */
178
179
void
180 2214
EXP_Insert(struct worker *wrk, struct objcore *oc)
181
{
182 2214
        unsigned remove_race = 0;
183
        struct objcore *tmpoc;
184
185 2214
        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
186 2214
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
187
188 2214
        AZ(oc->flags & OC_F_BUSY);
189
190 2214
        if (!(oc->exp_flags & OC_EF_REFD))
191 778
                return;
192
193
        /* One ref held by the caller, and one that will be owned by
194
         * expiry. */
195 1436
        assert(oc->refcnt >= 2);
196
197 1436
        ObjSendEvent(wrk, oc, OEV_INSERT);
198
199 1436
        Lck_Lock(&exphdl->mtx);
200 1436
        AN(oc->exp_flags & OC_EF_NEW);
201 1436
        oc->exp_flags &= ~OC_EF_NEW;
202 1436
        AZ(oc->exp_flags & (OC_EF_INSERT | OC_EF_MOVE | OC_EF_POSTED));
203 1436
        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 1436
                exp_mail_it(oc, OC_EF_INSERT | OC_EF_MOVE);
209 1436
        Lck_Unlock(&exphdl->mtx);
210
211 1436
        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, 0);
216 0
                AZ(oc);
217 0
                assert(tmpoc->refcnt >= 1); /* Silence coverity */
218 0
        }
219 2214
}
220
221
/*--------------------------------------------------------------------
222
 * Reduce object timers
223
 */
224
225
void
226 10
EXP_Reduce(struct objcore *oc, vtim_real now,
227
    vtim_dur ttl, vtim_dur grace, vtim_dur keep)
228
{
229
230 10
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
231 10
        assert(oc->refcnt > 0);
232
233 10
        if (!isnan(ttl) && now + ttl - oc->t_origin >= oc->ttl)
234 6
                ttl = NAN;
235 10
        if (!isnan(grace) && grace >= oc->grace)
236 2
                grace = NAN;
237 10
        if (!isnan(keep) && keep >= oc->keep)
238 1
                keep = NAN;
239
240 10
        EXP_Rearm(oc, now, ttl, grace, keep);
241 10
}
242
243
/*--------------------------------------------------------------------
244
 * We have changed one or more of the object timers, tell the exp_thread
245
 *
246
 */
247
248
void
249 10
EXP_Rearm(struct objcore *oc, vtim_real now,
250
    vtim_dur ttl, vtim_dur grace, vtim_dur keep)
251
{
252
        vtim_real when;
253
254 10
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
255 10
        assert(oc->refcnt > 0);
256
257 10
        if (!(oc->exp_flags & OC_EF_REFD))
258 0
                return;
259
260 10
        if (!isnan(ttl))
261 4
                oc->ttl = now + ttl - oc->t_origin;
262 10
        if (!isnan(grace))
263 2
                oc->grace = grace;
264 10
        if (!isnan(keep))
265 2
                oc->keep = keep;
266
267 10
        when = EXP_WHEN(oc);
268
269 20
        VSL(SLT_ExpKill, NO_VXID, "EXP_Rearm p=%p E=%.6f e=%.6f f=0x%x", oc,
270 10
            oc->timer_when, when, oc->flags);
271
272 10
        if (when < oc->t_origin || when < oc->timer_when) {
273 6
                Lck_Lock(&exphdl->mtx);
274 6
                if (oc->exp_flags & OC_EF_NEW) {
275
                        /* EXP_Insert has not been called yet, do nothing
276
                         * as the initial insert will execute the move
277
                         * operation. */
278 0
                } else
279 6
                        exp_mail_it(oc, OC_EF_MOVE);
280 6
                Lck_Unlock(&exphdl->mtx);
281 6
        }
282 10
}
283
284
/*--------------------------------------------------------------------
285
 * Handle stuff in the inbox
286
 */
287
288
static void
289 1688
exp_inbox(struct exp_priv *ep, struct objcore *oc, unsigned flags, double now)
290
{
291
292 1688
        CHECK_OBJ_NOTNULL(ep, EXP_PRIV_MAGIC);
293 1688
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
294 1688
        assert(oc->refcnt > 0);
295
296 3376
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_Inbox flg=%x p=%p e=%.6f f=0x%x",
297 1688
            flags, oc, oc->timer_when, oc->flags);
298
299 1688
        if (flags & OC_EF_REMOVE) {
300 246
                if (!(flags & OC_EF_INSERT)) {
301 246
                        assert(oc->timer_idx != VBH_NOIDX);
302 246
                        VBH_delete(ep->heap, oc->timer_idx);
303 246
                }
304 246
                assert(oc->timer_idx == VBH_NOIDX);
305 246
                assert(oc->refcnt > 0);
306 246
                AZ(oc->exp_flags);
307 492
                VSLb(&ep->vsl, SLT_ExpKill, "EXP_Removed x=%ju t=%.0f h=%jd",
308 246
                    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now,
309 246
                    (intmax_t)oc->hits);
310 246
                ObjSendEvent(ep->wrk, oc, OEV_EXPIRE);
311 246
                (void)HSH_DerefObjCore(ep->wrk, &oc, 0);
312 246
                return;
313
        }
314
315 1442
        if (flags & OC_EF_MOVE) {
316 1442
                oc->timer_when = EXP_WHEN(oc);
317 1442
                ObjSendEvent(ep->wrk, oc, OEV_TTLCHG);
318 1442
        }
319
320 2884
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_When p=%p e=%.6f f=0x%x", oc,
321 1442
            oc->timer_when, flags);
322
323
        /*
324
         * XXX: There are some pathological cases here, were we
325
         * XXX: insert or move an expired object, only to find out
326
         * XXX: the next moment and rip them out again.
327
         */
328
329 1442
        if (flags & OC_EF_INSERT) {
330 1436
                assert(oc->timer_idx == VBH_NOIDX);
331 1436
                VBH_insert(exphdl->heap, oc);
332 1436
                assert(oc->timer_idx != VBH_NOIDX);
333 1442
        } else if (flags & OC_EF_MOVE) {
334 6
                assert(oc->timer_idx != VBH_NOIDX);
335 6
                VBH_reorder(exphdl->heap, oc->timer_idx);
336 6
                assert(oc->timer_idx != VBH_NOIDX);
337 6
        } else {
338 0
                WRONG("Objcore state wrong in inbox");
339
        }
340 1688
}
341
342
/*--------------------------------------------------------------------
343
 * Expire stuff from the binheap
344
 */
345
346
static vtim_real
347 5210
exp_expire(struct exp_priv *ep, vtim_real now)
348
{
349
        struct objcore *oc;
350
351 5210
        CHECK_OBJ_NOTNULL(ep, EXP_PRIV_MAGIC);
352
353 5210
        oc = VBH_root(ep->heap);
354 5210
        if (oc == NULL)
355 2169
                return (now + 355. / 113.);
356 6082
        VSLb(&ep->vsl, SLT_ExpKill, "EXP_Inspect p=%p e=%.6f f=0x%x", oc,
357 3041
            oc->timer_when - now, oc->flags);
358
359 3041
        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
360
361
        /* Ready ? */
362 3041
        if (oc->timer_when > now)
363 2916
                return (oc->timer_when);
364
365 125
        VSC_C_main->n_expired++;
366
367 125
        Lck_Lock(&ep->mtx);
368 125
        if (oc->exp_flags & OC_EF_POSTED) {
369 0
                oc->exp_flags |= OC_EF_REMOVE;
370 0
                oc = NULL;
371 0
        } else {
372 125
                oc->exp_flags &= ~OC_EF_REFD;
373
        }
374 125
        Lck_Unlock(&ep->mtx);
375 125
        if (oc != NULL) {
376 125
                if (!(oc->flags & OC_F_DYING))
377 125
                        HSH_Kill(oc);
378
379
                /* Remove from binheap */
380 125
                assert(oc->timer_idx != VBH_NOIDX);
381 125
                VBH_delete(ep->heap, oc->timer_idx);
382 125
                assert(oc->timer_idx == VBH_NOIDX);
383
384 125
                CHECK_OBJ_NOTNULL(oc->objhead, OBJHEAD_MAGIC);
385 250
                VSLb(&ep->vsl, SLT_ExpKill, "EXP_Expired x=%ju t=%.0f h=%jd",
386 125
                    VXID(ObjGetXID(ep->wrk, oc)), EXP_Ttl(NULL, oc) - now,
387 125
                    (intmax_t)oc->hits);
388 125
                ObjSendEvent(ep->wrk, oc, OEV_EXPIRE);
389 125
                (void)HSH_DerefObjCore(ep->wrk, &oc, 0);
390 125
        }
391 125
        return (0);
392 5210
}
393
394
/*--------------------------------------------------------------------
395
 * This thread monitors the root of the binary heap and whenever an
396
 * object expires, accounting also for graceability, it is killed.
397
 */
398
399
static int v_matchproto_(vbh_cmp_t)
400 1321
object_cmp(void *priv, const void *a, const void *b)
401
{
402
        const struct objcore *aa, *bb;
403
404 1321
        (void)priv;
405 1321
        CAST_OBJ_NOTNULL(aa, a, OBJCORE_MAGIC);
406 1321
        CAST_OBJ_NOTNULL(bb, b, OBJCORE_MAGIC);
407 1321
        return (aa->timer_when < bb->timer_when);
408
}
409
410
static void v_matchproto_(vbh_update_t)
411 2763
object_update(void *priv, void *p, unsigned u)
412
{
413
        struct objcore *oc;
414
415 2763
        (void)priv;
416 2763
        CAST_OBJ_NOTNULL(oc, p, OBJCORE_MAGIC);
417 2763
        oc->timer_idx = u;
418 2763
}
419
420
static void * v_matchproto_(bgthread_t)
421 935
exp_thread(struct worker *wrk, void *priv)
422
{
423
        struct objcore *oc;
424 935
        vtim_real t = 0, tnext = 0;
425
        struct exp_priv *ep;
426 935
        unsigned flags = 0;
427
428 935
        CAST_OBJ_NOTNULL(ep, priv, EXP_PRIV_MAGIC);
429 935
        ep->wrk = wrk;
430 935
        VSL_Setup(&ep->vsl, NULL, 0);
431 935
        AZ(wrk->vsl);
432 935
        wrk->vsl = &ep->vsl;
433 935
        ep->heap = VBH_new(NULL, object_cmp, object_update);
434 935
        AN(ep->heap);
435 7833
        while (exp_shutdown == 0) {
436
437 6898
                Lck_Lock(&ep->mtx);
438 6898
                oc = VSTAILQ_FIRST(&ep->inbox);
439 6898
                CHECK_OBJ_ORNULL(oc, OBJCORE_MAGIC);
440 6898
                if (oc != NULL) {
441 1688
                        assert(oc->refcnt >= 1);
442 1688
                        VSTAILQ_REMOVE(&ep->inbox, oc, objcore, exp_list);
443 1688
                        VSC_C_main->exp_received++;
444 1688
                        tnext = 0;
445 1688
                        flags = oc->exp_flags;
446 1688
                        if (flags & OC_EF_REMOVE)
447 246
                                oc->exp_flags = 0;
448
                        else
449 1442
                                oc->exp_flags &= OC_EF_REFD;
450 6898
                } else if (tnext > t) {
451 2599
                        VSL_Flush(&ep->vsl, 0);
452 2599
                        Pool_Sumstat(wrk);
453 2599
                        (void)Lck_CondWaitUntil(&ep->condvar, &ep->mtx, tnext);
454 2599
                }
455 6898
                Lck_Unlock(&ep->mtx);
456
457 6898
                t = VTIM_real();
458
459 6898
                if (oc != NULL)
460 1688
                        exp_inbox(ep, oc, flags, t);
461
                else
462 5210
                        tnext = exp_expire(ep, t);
463
        }
464 935
        wrk->vsl = NULL;
465 935
        return (NULL);
466
}
467
468
/*--------------------------------------------------------------------*/
469
470
void
471 935
EXP_Init(void)
472
{
473
        struct exp_priv *ep;
474
        pthread_t pt;
475
476 935
        ALLOC_OBJ(ep, EXP_PRIV_MAGIC);
477 935
        AN(ep);
478
479 935
        Lck_New(&ep->mtx, lck_exp);
480 935
        PTOK(pthread_cond_init(&ep->condvar, NULL));
481 935
        VSTAILQ_INIT(&ep->inbox);
482 935
        WRK_BgThread(&pt, "cache-exp", exp_thread, ep);
483 935
        ep->thread = pt;
484 935
        exphdl = ep;
485 935
}
486
487
void
488 923
EXP_Shutdown(void)
489
{
490 923
        struct exp_priv *ep = exphdl;
491
        void *status;
492
493 923
        Lck_Lock(&ep->mtx);
494 923
        exp_shutdown = 1;
495 923
        PTOK(pthread_cond_signal(&ep->condvar));
496 923
        Lck_Unlock(&ep->mtx);
497
498 923
        AN(ep->thread);
499 923
        PTOK(pthread_join(ep->thread, &status));
500 923
        AZ(status);
501 923
        memset(&ep->thread, 0, sizeof ep->thread);
502
503
        /* XXX could cleanup more - not worth it for now */
504 923
}