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 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) {
                        (void)Pool_TrySumstat(wrk);
                        VTIM_sleep(cache_param->ban_lurker_sleep);
                        ban_batch = 0;
                }
                oc = ban_lurker_getfirst(wrk->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(wrk->vsl, SLT_ExpBan,
                                            "%ju killed for lurker cutoff",
                                            VXID(ObjGetXID(wrk, oc)));
                                        lokc++;
                                } else {
                                        VSLb(wrk->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);
        }
}

/*--------------------------------------------------------------------
 * 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 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, 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);
        AZ(wrk->vsl);
        wrk->vsl = &vsl;

        while (!ban_shutdown) {
                dt = ban_lurker_work(wrk);
                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);
        }
        wrk->vsl = NULL;
        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	16430	ban_kick_lurker(void)
50		{
51
52	16430	Lck_AssertHeld(&ban_mtx);
53	16430	ban_generation++;
54	16430	PTOK(pthread_cond_signal(&ban_lurker_cond));
55	16430	}
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	16540	ban_cleantail(struct banhead_s *obans)
67		{
68		struct ban b, bt;
69	16540	struct banhead_s freelist = VTAILQ_HEAD_INITIALIZER(freelist);
70
71		/* handle the zero-length tail unprotected */
72	16540	if (VTAILQ_LAST(&ban_head, banhead_s) == VTAILQ_FIRST(&ban_head))
73	15084	return;
74
75	1456	Lck_Lock(&ban_mtx);
76	1456	do {
77	2032	b = VTAILQ_LAST(&ban_head, banhead_s);
78	2032	if (b != VTAILQ_FIRST(&ban_head) && b->refcount == 0) {
79	576	assert(VTAILQ_EMPTY(&b->objcore));
80	576	if (b->flags & BANS_FLAG_COMPLETED)
81	336	VSC_C_main->bans_completed--;
82	576	if (b->flags & BANS_FLAG_OBJ)
83	232	VSC_C_main->bans_obj--;
84	576	if (b->flags & BANS_FLAG_REQ)
85	168	VSC_C_main->bans_req--;
86	576	VSC_C_main->bans--;
87	576	VSC_C_main->bans_deleted++;
88	576	VTAILQ_REMOVE(&ban_head, b, list);
89	576	VTAILQ_INSERT_TAIL(&freelist, b, list);
90	576	bans_persisted_fragmentation +=
91	576	ban_len(b->spec);
92	576	VSC_C_main->bans_persisted_fragmentation =
93	576	bans_persisted_fragmentation;
94	576	ban_info_drop(b->spec, ban_len(b->spec));
95	576	} else {
96	1456	b = NULL;
97		}
98	2032	} while (b != NULL);
99
100	1456	Lck_Unlock(&ban_mtx);
101
102		/* oban order is head to tail, freelist tail to head */
103	1456	if (obans != NULL)
104	1176	bt = VTAILQ_LAST(obans, banhead_s);
105		else
106	280	bt = NULL;
107
108	1456	if (bt != NULL) {
109	72	AN(obans);
110	192	VTAILQ_FOREACH(b, &freelist, list) {
111	120	if (b != bt)
112	32	continue;
113	88	VTAILQ_REMOVE(obans, b, l_list);
114	88	bt = VTAILQ_LAST(obans, banhead_s);
115	88	if (bt == NULL)
116	0	break;
117	88	}
118	72	}
119
120	2032	VTAILQ_FOREACH_SAFE(b, &freelist, list, bt)
121	576	BAN_Free(b);
122
123	1456	return;
124	16540	}
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	312	ban_lurker_getfirst(struct vsl_log vsl, struct ban bt)
140		{
141		struct objhead *oh;
142		struct objcore oc, noc;
143	312	int move_oc = 1;
144
145	312	Lck_Lock(&ban_mtx);
146
147	312	oc = VTAILQ_FIRST(&bt->objcore);
148	312	while (1) {
149	312	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
150
151	312	if (oc == &oc_mark_cnt) {
152	136	if (VTAILQ_NEXT(oc, ban_list) == &oc_mark_end) {
153		/* done with this ban's oc list */
154	136	VTAILQ_REMOVE(&bt->objcore, &oc_mark_cnt,
155		ban_list);
156	136	VTAILQ_REMOVE(&bt->objcore, &oc_mark_end,
157		ban_list);
158	136	oc = NULL;
159	136	break;
160		}
161	0	oc = VTAILQ_NEXT(oc, ban_list);
162	0	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
163	0	move_oc = 0;
164	176	} 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	176	assert(oc != &oc_mark_cnt);
180	176	assert(oc != &oc_mark_end);
181
182	176	oh = oc->objhead;
183	176	CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
184	176	if (!Lck_Trylock(&oh->mtx)) {
185	176	if (oc->flags & OC_F_BUSY) {
186	0	Lck_Unlock(&oh->mtx);
187	176	} else if (oc->refcnt == 0 \|\|
188	176	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	176	AZ(oc->flags & OC_F_BUSY);
208	176	oc->refcnt += 1;
209	176	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
210	176	VTAILQ_INSERT_TAIL(&bt->objcore, oc, ban_list);
211	176	Lck_Unlock(&oh->mtx);
212	176	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	312	Lck_Unlock(&ban_mtx);
227	312	return (oc);
228		}
229
230		static void
231	280	ban_lurker_test_ban(struct worker wrk, 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	280	uint64_t tested = 0, tested_tests = 0, lok = 0, lokc = 0;
239
240	280	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
241
242		/*
243		* First see if there is anything to do, and if so, insert markers
244		*/
245	280	Lck_Lock(&ban_mtx);
246	280	oc = VTAILQ_FIRST(&bt->objcore);
247	280	if (oc != NULL) {
248	136	VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_cnt, ban_list);
249	136	VTAILQ_INSERT_TAIL(&bt->objcore, &oc_mark_end, ban_list);
250	136	}
251	280	Lck_Unlock(&ban_mtx);
252	280	if (oc == NULL)
253	144	return;
254
255	312	while (1) {
256	312	if (++ban_batch > cache_param->ban_lurker_batch) {
257	0	(void)Pool_TrySumstat(wrk);
258	0	VTIM_sleep(cache_param->ban_lurker_sleep);
259	0	ban_batch = 0;
260	0	}
261	312	oc = ban_lurker_getfirst(wrk->vsl, bt);
262	312	if (oc == NULL) {
263	136	if (tested == 0 && lokc == 0) {
264	56	AZ(tested_tests);
265	56	AZ(lok);
266	56	return;
267		}
268	80	Lck_Lock(&ban_mtx);
269	80	VSC_C_main->bans_lurker_tested += tested;
270	80	VSC_C_main->bans_lurker_tests_tested += tested_tests;
271	80	VSC_C_main->bans_lurker_obj_killed += lok;
272	80	VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
273	80	Lck_Unlock(&ban_mtx);
274	80	return;
275		}
276	176	i = 0;
277	344	VTAILQ_FOREACH_REVERSE_SAFE(bl, obans, banhead_s, l_list, bln) {
278	288	if (oc->ban != bt) {
279		/*
280		* HSH_Lookup() grabbed this oc, killed
281		* it or tested it to top. We're done.
282		*/
283	0	break;
284		}
285	288	if (bl->flags & BANS_FLAG_COMPLETED) {
286		/* Ban was overtaken by new (dup) ban */
287	0	VTAILQ_REMOVE(obans, bl, l_list);
288	0	continue;
289		}
290	288	if (kill == 1)
291	24	i = 1;
292		else {
293	264	AZ(bl->flags & BANS_FLAG_REQ);
294	264	tests = 0;
295	264	i = ban_evaluate(wrk, bl->spec, oc, NULL,
296		&tests);
297	264	tested++;
298	264	tested_tests += tests;
299		}
300	288	if (i) {
301	120	if (kill) {
302	48	VSLb(wrk->vsl, SLT_ExpBan,
303		"%ju killed for lurker cutoff",
304	24	VXID(ObjGetXID(wrk, oc)));
305	24	lokc++;
306	24	} else {
307	192	VSLb(wrk->vsl, SLT_ExpBan,
308		"%ju banned by lurker",
309	96	VXID(ObjGetXID(wrk, oc)));
310	96	lok++;
311		}
312	120	HSH_Kill(oc);
313	120	break;
314		}
315	168	}
316	176	if (i == 0 && oc->ban == bt) {
317	56	Lck_Lock(&ban_mtx);
318	56	VSC_C_main->bans_lurker_tested += tested;
319	56	VSC_C_main->bans_lurker_tests_tested += tested_tests;
320	56	VSC_C_main->bans_lurker_obj_killed += lok;
321	56	VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
322	56	tested = tested_tests = lok = lokc = 0;
323	56	if (oc->ban == bt && bt != bd) {
324	40	bt->refcount--;
325	40	VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
326	40	oc->ban = bd;
327	40	bd->refcount++;
328	40	VTAILQ_INSERT_TAIL(&bd->objcore, oc, ban_list);
329	40	i = 1;
330	40	}
331	56	Lck_Unlock(&ban_mtx);
332	56	if (i)
333	40	ObjSendEvent(wrk, oc, OEV_BANCHG);
334	56	}
335	176	(void)HSH_DerefObjCore(wrk, &oc);
336		}
337	280	}
338
339		/*--------------------------------------------------------------------
340		* Ban lurker thread:
341		*
342		* try to move ocs as far up the ban list as possible (to bd)
343		*
344		* BANS_FLAG_REQ bans act as barriers, for bans further down, ocs get moved to
345		* them. But still all bans up to the initial bd get checked and marked
346		* completed.
347		*/
348
349		static vtim_dur
350	16540	ban_lurker_work(struct worker *wrk)
351		{
352		struct ban b, bd;
353		struct banhead_s obans;
354		vtim_real d;
355		vtim_dur dt, n;
356	16540	unsigned count = 0, cutoff = UINT_MAX;
357
358	16540	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
359
360	16540	dt = 49.62; // Random, non-magic
361	16540	if (cache_param->ban_lurker_sleep == 0) {
362	400	ban_cleantail(NULL);
363	400	return (dt);
364		}
365	16140	if (cache_param->ban_cutoff > 0)
366	112	cutoff = cache_param->ban_cutoff;
367
368	16140	Lck_Lock(&ban_mtx);
369	16140	b = ban_start;
370	16140	Lck_Unlock(&ban_mtx);
371	16140	d = VTIM_real() - cache_param->ban_lurker_age;
372	16140	bd = NULL;
373	16140	VTAILQ_INIT(&obans);
374	36456	for (; b != NULL; b = VTAILQ_NEXT(b, list), count++) {
375	20316	if (bd != NULL)
376	560	ban_lurker_test_ban(wrk, b, &obans, bd,
377	280	count > cutoff ? 1 : 0);
378	20316	if (b->flags & BANS_FLAG_COMPLETED)
379	16204	continue;
380	4112	if (b->flags & BANS_FLAG_REQ && count <= cutoff) {
381	736	if (bd != NULL)
382	40	bd = VTAILQ_NEXT(b, list);
383	736	continue;
384		}
385	3376	n = ban_time(b->spec) - d;
386	3376	if (n < 0) {
387	224	VTAILQ_INSERT_TAIL(&obans, b, l_list);
388	224	if (bd == NULL)
389	80	bd = b;
390	3376	} else if (n < dt) {
391	200	dt = n;
392	200	}
393	3376	}
394
395		/*
396		* conceptually, all obans are now completed. Remove the tail.
397		* If any bans to be completed remain after the tail is cut,
398		* mark them completed
399		*/
400	16140	ban_cleantail(&obans);
401
402	16140	if (VTAILQ_FIRST(&obans) == NULL)
403	16060	return (dt);
404
405	80	Lck_Lock(&ban_mtx);
406	216	VTAILQ_FOREACH(b, &obans, l_list)
407	136	ban_mark_completed(b);
408	80	Lck_Unlock(&ban_mtx);
409	80	return (dt);
410	16540	}
411
412		void * v_matchproto_(bgthread_t)
413	7614	ban_lurker(struct worker wrk, void priv)
414		{
415		struct vsl_log vsl;
416		vtim_dur dt;
417	7614	unsigned gen = ban_generation + 1;
418
419	7614	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
420	7614	AZ(priv);
421
422	7614	VSL_Setup(&vsl, NULL, 0);
423	7614	AZ(wrk->vsl);
424	7614	wrk->vsl = &vsl;
425
426	24068	while (!ban_shutdown) {
427	16454	dt = ban_lurker_work(wrk);
428	16454	if (DO_DEBUG(DBG_LURKER))
429	232	VSLb(&vsl, SLT_Debug, "lurker: sleep = %lf", dt);
430	16454	Lck_Lock(&ban_mtx);
431	16454	if (gen == ban_generation) {
432	8926	Pool_Sumstat(wrk);
433	8926	(void)Lck_CondWaitTimeout(
434	8926	&ban_lurker_cond, &ban_mtx, dt);
435	8926	ban_batch = 0;
436	8926	}
437	16454	gen = ban_generation;
438	16454	Lck_Unlock(&ban_mtx);
439		}
440	7614	wrk->vsl = NULL;
441	7614	pthread_exit(0);
442		NEEDLESS(return (NULL));
443		}