GCOV - Varnish Cache


/*-
 * Copyright (c) 2006 Verdens Gang AS
 * Copyright (c) 2006-2015 Varnish Software AS
 * All rights reserved.
 *
 * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include "config.h"

#include "cache_varnishd.h"

#include "cache_ban.h"
#include "cache_objhead.h"

#include "vtim.h"

static struct objcore oc_mark_cnt = { .magic = OBJCORE_MAGIC, };
static struct objcore oc_mark_end = { .magic = OBJCORE_MAGIC, };
static unsigned ban_batch;
static unsigned ban_generation;

pthread_cond_t  ban_lurker_cond;

void
ban_kick_lurker(void)
{

        Lck_AssertHeld(&ban_mtx);
        ban_generation++;
        PTOK(pthread_cond_signal(&ban_lurker_cond));
}

/*
 * ban_cleantail: clean the tail of the ban list up to the first ban which is
 * still referenced. For already completed bans, we update statistics
 * accordingly, but otherwise just skip the completion step and remove directly
 *
 * if an obans list is passed, we clean its tail as well
 */

static void
ban_cleantail(struct banhead_s *obans)
{
        struct ban *b, *bt;
        struct banhead_s freelist = VTAILQ_HEAD_INITIALIZER(freelist);

        /* handle the zero-length tail unprotected */
        if (VTAILQ_LAST(&ban_head, banhead_s) == VTAILQ_FIRST(&ban_head))
                return;

        Lck_Lock(&ban_mtx);
        do {
                b = VTAILQ_LAST(&ban_head, banhead_s);
                if (b != VTAILQ_FIRST(&ban_head) && b->refcount == 0) {
                        assert(VTAILQ_EMPTY(&b->objcore));
                        if (b->flags & BANS_FLAG_COMPLETED)
                                VSC_C_main->bans_completed--;
                        if (b->flags & BANS_FLAG_OBJ)
                                VSC_C_main->bans_obj--;
                        if (b->flags & BANS_FLAG_REQ)
                                VSC_C_main->bans_req--;
                        VSC_C_main->bans--;
                        VSC_C_main->bans_deleted++;
                        VTAILQ_REMOVE(&ban_head, b, list);
                        VTAILQ_INSERT_TAIL(&freelist, b, list);
                        bans_persisted_fragmentation +=
                            ban_len(b->spec);
                        VSC_C_main->bans_persisted_fragmentation =
                            bans_persisted_fragmentation;
                        ban_info_drop(b->spec, ban_len(b->spec));
                } else {
                        b = NULL;
                }
        } while (b != NULL);

        Lck_Unlock(&ban_mtx);

        /* oban order is head to tail, freelist tail to head */
        if (obans != NULL)
                bt = VTAILQ_LAST(obans, banhead_s);
        else
                bt = NULL;

        if (bt != NULL) {
                AN(obans);
                VTAILQ_FOREACH(b, &freelist, list) {
                        if (b != bt)
                                continue;
                        VTAILQ_REMOVE(obans, b, l_list);
                        bt = VTAILQ_LAST(obans, banhead_s);
                        if (bt == NULL)
                                break;
                }
        }

        VTAILQ_FOREACH_SAFE(b, &freelist, list, bt)
                BAN_Free(b);

        return;
}

/*--------------------------------------------------------------------
 * Our task here is somewhat tricky:  The canonical locking order is
 * objhead->mtx first, then ban_mtx, because that is the order which
 * makes most sense in HSH_Lookup(), but we come the other way.
 * We optimistically try to get them the other way, and get out of
 * the way if that fails, and retry again later.
 *
 * To avoid hammering on contested ocs, we first move those behind a marker
 * once. When we only have contested ocs left, we stop moving them around and
 * re-try them in order.
 */

static struct objcore *
ban_lurker_getfirst(struct vsl_log *vsl, struct ban *bt)
{
        struct objhead *oh;
        struct objcore *oc, *noc;
        int move_oc = 1;

        Lck_Lock(&ban_mtx);

        oc = VTAILQ_FIRST(&bt->objcore);
        while (1) {
                CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);

                if (oc == &oc_mark_cnt) {
                        if (VTAILQ_NEXT(oc, ban_list) == &oc_mark_end) {
                                /* done with this ban's oc list */
                                VTAILQ_REMOVE(&bt->objcore, &oc_mark_cnt,
                                    ban_list);
                                VTAILQ_REMOVE(&bt->objcore, &oc_mark_end,
                                    ban_list);
                                oc = NULL;
                                break;
                        }
                        oc = VTAILQ_NEXT(oc, ban_list);
                        CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
                        move_oc = 0;
                } else if (oc == &oc_mark_end) {
                        assert(move_oc == 0);

                        /* hold off to give lookup a chance and reiterate */
                        VSC_C_main->bans_lurker_contention++;
                        Lck_Unlock(&ban_mtx);
                        VSL_Flush(vsl, 0);
                        VTIM_sleep(cache_param->ban_lurker_holdoff);
                        Lck_Lock(&ban_mtx);

                        oc = VTAILQ_FIRST(&bt->objcore);
                        assert(oc == &oc_mark_cnt);
                        continue;
                }

                assert(oc != &oc_mark_cnt);
                assert(oc != &oc_mark_end);

                oh = oc->objhead;
                CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
                if (!Lck_Trylock(&oh->mtx)) {
                        if (oc->flags & OC_F_BUSY) {
                                Lck_Unlock(&oh->mtx);
                        } else if (oc->refcnt == 0 ||
                            oc->flags & (OC_F_DYING | OC_F_FAILED)) {
                                /*
                                 * We seize the opportunity to remove
                                 * the object completely off the ban
                                 * list, now that we have both the oh
                                 * and ban mutexes.
                                 */
                                noc = VTAILQ_NEXT(oc, ban_list);
                                VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
                                oc->ban = NULL;
                                bt->refcount--;
                                Lck_Unlock(&oh->mtx);
                                oc = noc;
                                continue;
                        } else {
                                /*
                                 * We got the lock, and the oc is not being
                                 * dismantled under our feet - grab a ref
                                 */
                                AZ(oc->flags & OC_F_BUSY);
                                oc->refcnt += 1;
                                VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
                                VTAILQ_INSERT_TAIL(&bt->objcore, oc, ban_list);
                                Lck_Unlock(&oh->mtx);
                                break;
                        }
                }

                noc = VTAILQ_NEXT(oc, ban_list);

                if (move_oc) {
                        /* contested ocs go between the two markers */
                        VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
                        VTAILQ_INSERT_BEFORE(&oc_mark_end, oc, ban_list);
                }

                oc = noc;
        }
        Lck_Unlock(&ban_mtx);
        return (oc);
}

static void
ban_lurker_test_ban(struct worker *wrk, struct vsl_log *vsl, struct ban *bt,
    struct banhead_s *obans, struct ban *bd, int kill)
{
        struct ban *bl, *bln;
        struct objcore *oc;
        unsigned tests;
        int i;
        uint64_t tested = 0, tested_tests = 0, lok = 0, lokc = 0;

        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);

        /*
         * First see if there is anything to do, and if so, insert markers
         */
        Lck_Lock(&ban_mtx);
        oc = VTAILQ_FIRST(&bt->objcore);
        if (oc != NULL) {
                VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_cnt, ban_list);
                VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_end, ban_list);
        }
        Lck_Unlock(&ban_mtx);
        if (oc == NULL)
                return;

        while (1) {
                if (++ban_batch > cache_param->ban_lurker_batch) {
                        VTIM_sleep(cache_param->ban_lurker_sleep);
                        ban_batch = 0;
                }
                oc = ban_lurker_getfirst(vsl, bt);
                if (oc == NULL) {
                        if (tested == 0 && lokc == 0) {
                                AZ(tested_tests);
                                AZ(lok);
                                return;
                        }
                        Lck_Lock(&ban_mtx);
                        VSC_C_main->bans_lurker_tested += tested;
                        VSC_C_main->bans_lurker_tests_tested += tested_tests;
                        VSC_C_main->bans_lurker_obj_killed += lok;
                        VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
                        Lck_Unlock(&ban_mtx);
                        return;
                }
                i = 0;
                VTAILQ_FOREACH_REVERSE_SAFE(bl, obans, banhead_s, l_list, bln) {
                        if (oc->ban != bt) {
                                /*
                                 * HSH_Lookup() grabbed this oc, killed
                                 * it or tested it to top.  We're done.
                                 */
                                break;
                        }
                        if (bl->flags & BANS_FLAG_COMPLETED) {
                                /* Ban was overtaken by new (dup) ban */
                                VTAILQ_REMOVE(obans, bl, l_list);
                                continue;
                        }
                        if (kill == 1)
                                i = 1;
                        else {
                                AZ(bl->flags & BANS_FLAG_REQ);
                                tests = 0;
                                i = ban_evaluate(wrk, bl->spec, oc, NULL,
                                    &tests);
                                tested++;
                                tested_tests += tests;
                        }
                        if (i) {
                                if (kill) {
                                        VSLb(vsl, SLT_ExpBan,
                                            "%ju killed for lurker cutoff",
                                            VXID(ObjGetXID(wrk, oc)));
                                        lokc++;
                                } else {
                                        VSLb(vsl, SLT_ExpBan,
                                            "%ju banned by lurker",
                                            VXID(ObjGetXID(wrk, oc)));
                                        lok++;
                                }
                                HSH_Kill(oc);
                                break;
                        }
                }
                if (i == 0 && oc->ban == bt) {
                        Lck_Lock(&ban_mtx);
                        VSC_C_main->bans_lurker_tested += tested;
                        VSC_C_main->bans_lurker_tests_tested += tested_tests;
                        VSC_C_main->bans_lurker_obj_killed += lok;
                        VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
                        tested = tested_tests = lok = lokc = 0;
                        if (oc->ban == bt && bt != bd) {
                                bt->refcount--;
                                VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
                                oc->ban = bd;
                                bd->refcount++;
                                VTAILQ_INSERT_TAIL(&bd->objcore, oc, ban_list);
                                i = 1;
                        }
                        Lck_Unlock(&ban_mtx);
                        if (i)
                                ObjSendEvent(wrk, oc, OEV_BANCHG);
                }
                (void)HSH_DerefObjCore(wrk, &oc, 0);
        }
}

/*--------------------------------------------------------------------
 * Ban lurker thread:
 *
 * try to move ocs as far up the ban list as possible (to bd)
 *
 * BANS_FLAG_REQ bans act as barriers, for bans further down, ocs get moved to
 * them. But still all bans up to the initial bd get checked and marked
 * completed.
 */

static vtim_dur
ban_lurker_work(struct worker *wrk, struct vsl_log *vsl)
{
        struct ban *b, *bd;
        struct banhead_s obans;
        vtim_real d;
        vtim_dur dt, n;
        unsigned count = 0, cutoff = UINT_MAX;

        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);

        dt = 49.62;             // Random, non-magic
        if (cache_param->ban_lurker_sleep == 0) {
                ban_cleantail(NULL);
                return (dt);
        }
        if (cache_param->ban_cutoff > 0)
                cutoff = cache_param->ban_cutoff;

        Lck_Lock(&ban_mtx);
        b = ban_start;
        Lck_Unlock(&ban_mtx);
        d = VTIM_real() - cache_param->ban_lurker_age;
        bd = NULL;
        VTAILQ_INIT(&obans);
        for (; b != NULL; b = VTAILQ_NEXT(b, list), count++) {
                if (bd != NULL)
                        ban_lurker_test_ban(wrk, vsl, b, &obans, bd,
                            count > cutoff ? 1 : 0);
                if (b->flags & BANS_FLAG_COMPLETED)
                        continue;
                if (b->flags & BANS_FLAG_REQ && count <= cutoff) {
                        if (bd != NULL)
                                bd = VTAILQ_NEXT(b, list);
                        continue;
                }
                n = ban_time(b->spec) - d;
                if (n < 0) {
                        VTAILQ_INSERT_TAIL(&obans, b, l_list);
                        if (bd == NULL)
                                bd = b;
                } else if (n < dt) {
                        dt = n;
                }
        }

        /*
         * conceptually, all obans are now completed. Remove the tail.
         * If any bans to be completed remain after the tail is cut,
         * mark them completed
         */
        ban_cleantail(&obans);

        if (VTAILQ_FIRST(&obans) == NULL)
                return (dt);

        Lck_Lock(&ban_mtx);
        VTAILQ_FOREACH(b, &obans, l_list)
                ban_mark_completed(b);
        Lck_Unlock(&ban_mtx);
        return (dt);
}

void * v_matchproto_(bgthread_t)
ban_lurker(struct worker *wrk, void *priv)
{
        struct vsl_log vsl;
        vtim_dur dt;
        unsigned gen = ban_generation + 1;

        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
        AZ(priv);

        VSL_Setup(&vsl, NULL, 0);

        while (!ban_shutdown) {
                dt = ban_lurker_work(wrk, &vsl);
                if (DO_DEBUG(DBG_LURKER))
                        VSLb(&vsl, SLT_Debug, "lurker: sleep = %lf", dt);
                Lck_Lock(&ban_mtx);
                if (gen == ban_generation) {
                        Pool_Sumstat(wrk);
                        (void)Lck_CondWaitTimeout(
                            &ban_lurker_cond, &ban_mtx, dt);
                        ban_batch = 0;
                }
                gen = ban_generation;
                Lck_Unlock(&ban_mtx);
        }
        pthread_exit(0);
        NEEDLESS(return (NULL));
}

		varnish-cache/bin/varnishd/cache/cache_ban_lurker.c
0		/*-
1		* Copyright (c) 2006 Verdens Gang AS
2		* Copyright (c) 2006-2015 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
16		* 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
21		* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
22		* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23		* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24		* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25		* 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		*/
31
32		#include "config.h"
33
34		#include "cache_varnishd.h"
35
36		#include "cache_ban.h"
37		#include "cache_objhead.h"
38
39		#include "vtim.h"
40
41		static struct objcore oc_mark_cnt = { .magic = OBJCORE_MAGIC, };
42		static struct objcore oc_mark_end = { .magic = OBJCORE_MAGIC, };
43		static unsigned ban_batch;
44		static unsigned ban_generation;
45
46		pthread_cond_t ban_lurker_cond;
47
48		void
49	48044	ban_kick_lurker(void)
50		{
51
52	48044	Lck_AssertHeld(&ban_mtx);
53	48044	ban_generation++;
54	48044	PTOK(pthread_cond_signal(&ban_lurker_cond));
55	48044	}
56
57		/*
58		* ban_cleantail: clean the tail of the ban list up to the first ban which is
59		* still referenced. For already completed bans, we update statistics
60		* accordingly, but otherwise just skip the completion step and remove directly
61		*
62		* if an obans list is passed, we clean its tail as well
63		*/
64
65		static void
66	48338	ban_cleantail(struct banhead_s *obans)
67		{
68		struct ban b, bt;
69	48338	struct banhead_s freelist = VTAILQ_HEAD_INITIALIZER(freelist);
70
71		/* handle the zero-length tail unprotected */
72	48338	if (VTAILQ_LAST(&ban_head, banhead_s) == VTAILQ_FIRST(&ban_head))
73	43838	return;
74
75	4500	Lck_Lock(&ban_mtx);
76	4500	do {
77	6250	b = VTAILQ_LAST(&ban_head, banhead_s);
78	6250	if (b != VTAILQ_FIRST(&ban_head) && b->refcount == 0) {
79	1750	assert(VTAILQ_EMPTY(&b->objcore));
80	1750	if (b->flags & BANS_FLAG_COMPLETED)
81	975	VSC_C_main->bans_completed--;
82	1750	if (b->flags & BANS_FLAG_OBJ)
83	700	VSC_C_main->bans_obj--;
84	1750	if (b->flags & BANS_FLAG_REQ)
85	525	VSC_C_main->bans_req--;
86	1750	VSC_C_main->bans--;
87	1750	VSC_C_main->bans_deleted++;
88	1750	VTAILQ_REMOVE(&ban_head, b, list);
89	1750	VTAILQ_INSERT_TAIL(&freelist, b, list);
90	1750	bans_persisted_fragmentation +=
91	1750	ban_len(b->spec);
92	1750	VSC_C_main->bans_persisted_fragmentation =
93	1750	bans_persisted_fragmentation;
94	1750	ban_info_drop(b->spec, ban_len(b->spec));
95	1750	} else {
96	4500	b = NULL;
97		}
98	6250	} while (b != NULL);
99
100	4500	Lck_Unlock(&ban_mtx);
101
102		/* oban order is head to tail, freelist tail to head */
103	4500	if (obans != NULL)
104	3625	bt = VTAILQ_LAST(obans, banhead_s);
105		else
106	875	bt = NULL;
107
108	4500	if (bt != NULL) {
109	175	AN(obans);
110	225	VTAILQ_FOREACH(b, &freelist, list) {
111	50	if (b != bt)
112	25	continue;
113	25	VTAILQ_REMOVE(obans, b, l_list);
114	25	bt = VTAILQ_LAST(obans, banhead_s);
115	25	if (bt == NULL)
116	0	break;
117	25	}
118	175	}
119
120	6250	VTAILQ_FOREACH_SAFE(b, &freelist, list, bt)
121	1750	BAN_Free(b);
122
123	4500	return;
124	48338	}
125
126		/*--------------------------------------------------------------------
127		* Our task here is somewhat tricky: The canonical locking order is
128		* objhead->mtx first, then ban_mtx, because that is the order which
129		* makes most sense in HSH_Lookup(), but we come the other way.
130		* We optimistically try to get them the other way, and get out of
131		* the way if that fails, and retry again later.
132		*
133		* To avoid hammering on contested ocs, we first move those behind a marker
134		* once. When we only have contested ocs left, we stop moving them around and
135		* re-try them in order.
136		*/
137
138		static struct objcore *
139	850	ban_lurker_getfirst(struct vsl_log vsl, struct ban bt)
140		{
141		struct objhead *oh;
142		struct objcore oc, noc;
143	850	int move_oc = 1;
144
145	850	Lck_Lock(&ban_mtx);
146
147	850	oc = VTAILQ_FIRST(&bt->objcore);
148	850	while (1) {
149	850	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
150
151	850	if (oc == &oc_mark_cnt) {
152	375	if (VTAILQ_NEXT(oc, ban_list) == &oc_mark_end) {
153		/* done with this ban's oc list */
154	375	VTAILQ_REMOVE(&bt->objcore, &oc_mark_cnt,
155		ban_list);
156	375	VTAILQ_REMOVE(&bt->objcore, &oc_mark_end,
157		ban_list);
158	375	oc = NULL;
159	375	break;
160		}
161	0	oc = VTAILQ_NEXT(oc, ban_list);
162	0	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
163	0	move_oc = 0;
164	475	} else if (oc == &oc_mark_end) {
165	0	assert(move_oc == 0);
166
167		/* hold off to give lookup a chance and reiterate */
168	0	VSC_C_main->bans_lurker_contention++;
169	0	Lck_Unlock(&ban_mtx);
170	0	VSL_Flush(vsl, 0);
171	0	VTIM_sleep(cache_param->ban_lurker_holdoff);
172	0	Lck_Lock(&ban_mtx);
173
174	0	oc = VTAILQ_FIRST(&bt->objcore);
175	0	assert(oc == &oc_mark_cnt);
176	0	continue;
177		}
178
179	475	assert(oc != &oc_mark_cnt);
180	475	assert(oc != &oc_mark_end);
181
182	475	oh = oc->objhead;
183	475	CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
184	475	if (!Lck_Trylock(&oh->mtx)) {
185	475	if (oc->flags & OC_F_BUSY) {
186	0	Lck_Unlock(&oh->mtx);
187	475	} else if (oc->refcnt == 0 \|\|
188	475	oc->flags & (OC_F_DYING \| OC_F_FAILED)) {
189		/*
190		* We seize the opportunity to remove
191		* the object completely off the ban
192		* list, now that we have both the oh
193		* and ban mutexes.
194		*/
195	0	noc = VTAILQ_NEXT(oc, ban_list);
196	0	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
197	0	oc->ban = NULL;
198	0	bt->refcount--;
199	0	Lck_Unlock(&oh->mtx);
200	0	oc = noc;
201	0	continue;
202		} else {
203		/*
204		* We got the lock, and the oc is not being
205		* dismantled under our feet - grab a ref
206		*/
207	475	AZ(oc->flags & OC_F_BUSY);
208	475	oc->refcnt += 1;
209	475	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
210	475	VTAILQ_INSERT_TAIL(&bt->objcore, oc, ban_list);
211	475	Lck_Unlock(&oh->mtx);
212	475	break;
213		}
214	0	}
215
216	0	noc = VTAILQ_NEXT(oc, ban_list);
217
218	0	if (move_oc) {
219		/* contested ocs go between the two markers */
220	0	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
221	0	VTAILQ_INSERT_BEFORE(&oc_mark_end, oc, ban_list);
222	0	}
223
224	0	oc = noc;
225		}
226	850	Lck_Unlock(&ban_mtx);
227	850	return (oc);
228		}
229
230		static void
231	525	ban_lurker_test_ban(struct worker wrk, struct vsl_log vsl, struct ban *bt,
232		struct banhead_s obans, struct ban bd, int kill)
233		{
234		struct ban bl, bln;
235		struct objcore *oc;
236		unsigned tests;
237		int i;
238	525	uint64_t tested = 0, tested_tests = 0, lok = 0, lokc = 0;
239
240	525	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
241
242		/*
243		* First see if there is anything to do, and if so, insert markers
244		*/
245	525	Lck_Lock(&ban_mtx);
246	525	oc = VTAILQ_FIRST(&bt->objcore);
247	525	if (oc != NULL) {
248	375	VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_cnt, ban_list);
249	375	VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_end, ban_list);
250	375	}
251	525	Lck_Unlock(&ban_mtx);
252	525	if (oc == NULL)
253	150	return;
254
255	850	while (1) {
256	850	if (++ban_batch > cache_param->ban_lurker_batch) {
257	0	VTIM_sleep(cache_param->ban_lurker_sleep);
258	0	ban_batch = 0;
259	0	}
260	850	oc = ban_lurker_getfirst(vsl, bt);
261	850	if (oc == NULL) {
262	375	if (tested == 0 && lokc == 0) {
263	125	AZ(tested_tests);
264	125	AZ(lok);
265	125	return;
266		}
267	250	Lck_Lock(&ban_mtx);
268	250	VSC_C_main->bans_lurker_tested += tested;
269	250	VSC_C_main->bans_lurker_tests_tested += tested_tests;
270	250	VSC_C_main->bans_lurker_obj_killed += lok;
271	250	VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
272	250	Lck_Unlock(&ban_mtx);
273	250	return;
274		}
275	475	i = 0;
276	700	VTAILQ_FOREACH_REVERSE_SAFE(bl, obans, banhead_s, l_list, bln) {
277	575	if (oc->ban != bt) {
278		/*
279		* HSH_Lookup() grabbed this oc, killed
280		* it or tested it to top. We're done.
281		*/
282	0	break;
283		}
284	575	if (bl->flags & BANS_FLAG_COMPLETED) {
285		/* Ban was overtaken by new (dup) ban */
286	0	VTAILQ_REMOVE(obans, bl, l_list);
287	0	continue;
288		}
289	575	if (kill == 1)
290	75	i = 1;
291		else {
292	500	AZ(bl->flags & BANS_FLAG_REQ);
293	500	tests = 0;
294	500	i = ban_evaluate(wrk, bl->spec, oc, NULL,
295		&tests);
296	500	tested++;
297	500	tested_tests += tests;
298		}
299	575	if (i) {
300	350	if (kill) {
301	150	VSLb(vsl, SLT_ExpBan,
302		"%ju killed for lurker cutoff",
303	75	VXID(ObjGetXID(wrk, oc)));
304	75	lokc++;
305	75	} else {
306	550	VSLb(vsl, SLT_ExpBan,
307		"%ju banned by lurker",
308	275	VXID(ObjGetXID(wrk, oc)));
309	275	lok++;
310		}
311	350	HSH_Kill(oc);
312	350	break;
313		}
314	225	}
315	475	if (i == 0 && oc->ban == bt) {
316	125	Lck_Lock(&ban_mtx);
317	125	VSC_C_main->bans_lurker_tested += tested;
318	125	VSC_C_main->bans_lurker_tests_tested += tested_tests;
319	125	VSC_C_main->bans_lurker_obj_killed += lok;
320	125	VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
321	125	tested = tested_tests = lok = lokc = 0;
322	125	if (oc->ban == bt && bt != bd) {
323	75	bt->refcount--;
324	75	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
325	75	oc->ban = bd;
326	75	bd->refcount++;
327	75	VTAILQ_INSERT_TAIL(&bd->objcore, oc, ban_list);
328	75	i = 1;
329	75	}
330	125	Lck_Unlock(&ban_mtx);
331	125	if (i)
332	75	ObjSendEvent(wrk, oc, OEV_BANCHG);
333	125	}
334	475	(void)HSH_DerefObjCore(wrk, &oc, 0);
335		}
336	525	}
337
338		/*--------------------------------------------------------------------
339		* Ban lurker thread:
340		*
341		* try to move ocs as far up the ban list as possible (to bd)
342		*
343		* BANS_FLAG_REQ bans act as barriers, for bans further down, ocs get moved to
344		* them. But still all bans up to the initial bd get checked and marked
345		* completed.
346		*/
347
348		static vtim_dur
349	48338	ban_lurker_work(struct worker wrk, struct vsl_log vsl)
350		{
351		struct ban b, bd;
352		struct banhead_s obans;
353		vtim_real d;
354		vtim_dur dt, n;
355	48338	unsigned count = 0, cutoff = UINT_MAX;
356
357	48338	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
358
359	48338	dt = 49.62; // Random, non-magic
360	48338	if (cache_param->ban_lurker_sleep == 0) {
361	1250	ban_cleantail(NULL);
362	1250	return (dt);
363		}
364	47088	if (cache_param->ban_cutoff > 0)
365	350	cutoff = cache_param->ban_cutoff;
366
367	47088	Lck_Lock(&ban_mtx);
368	47088	b = ban_start;
369	47088	Lck_Unlock(&ban_mtx);
370	47088	d = VTIM_real() - cache_param->ban_lurker_age;
371	47088	bd = NULL;
372	47088	VTAILQ_INIT(&obans);
373	104426	for (; b != NULL; b = VTAILQ_NEXT(b, list), count++) {
374	57338	if (bd != NULL)
375	1050	ban_lurker_test_ban(wrk, vsl, b, &obans, bd,
376	525	count > cutoff ? 1 : 0);
377	57338	if (b->flags & BANS_FLAG_COMPLETED)
378	46563	continue;
379	10775	if (b->flags & BANS_FLAG_REQ && count <= cutoff) {
380	2275	if (bd != NULL)
381	125	bd = VTAILQ_NEXT(b, list);
382	2275	continue;
383		}
384	8500	n = ban_time(b->spec) - d;
385	8500	if (n < 0) {
386	400	VTAILQ_INSERT_TAIL(&obans, b, l_list);
387	400	if (bd == NULL)
388	200	bd = b;
389	8500	} else if (n < dt) {
390	600	dt = n;
391	600	}
392	8500	}
393
394		/*
395		* conceptually, all obans are now completed. Remove the tail.
396		* If any bans to be completed remain after the tail is cut,
397		* mark them completed
398		*/
399	47088	ban_cleantail(&obans);
400
401	47088	if (VTAILQ_FIRST(&obans) == NULL)
402	46888	return (dt);
403
404	200	Lck_Lock(&ban_mtx);
405	575	VTAILQ_FOREACH(b, &obans, l_list)
406	375	ban_mark_completed(b);
407	200	Lck_Unlock(&ban_mtx);
408	200	return (dt);
409	48338	}
410
411		void * v_matchproto_(bgthread_t)
412	22144	ban_lurker(struct worker wrk, void priv)
413		{
414		struct vsl_log vsl;
415		vtim_dur dt;
416	22144	unsigned gen = ban_generation + 1;
417
418	22144	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
419	22144	AZ(priv);
420
421	22144	VSL_Setup(&vsl, NULL, 0);
422
423	70238	while (!ban_shutdown) {
424	48094	dt = ban_lurker_work(wrk, &vsl);
425	48094	if (DO_DEBUG(DBG_LURKER))
426	725	VSLb(&vsl, SLT_Debug, "lurker: sleep = %lf", dt);
427	48094	Lck_Lock(&ban_mtx);
428	48094	if (gen == ban_generation) {
429	26194	Pool_Sumstat(wrk);
430	26194	(void)Lck_CondWaitTimeout(
431	26194	&ban_lurker_cond, &ban_mtx, dt);
432	26194	ban_batch = 0;
433	26194	}
434	48094	gen = ban_generation;
435	48094	Lck_Unlock(&ban_mtx);
436		}
437	22144	pthread_exit(0);
438		NEEDLESS(return (NULL));
439		}