GCOV - Varnish Cache


/*-
 * Copyright (c) 2006 Verdens Gang AS
 * Copyright (c) 2006-2011 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.
 *
 * We maintain a number of worker thread pools, to spread lock contention.
 *
 * Pools can be added on the fly, as a means to mitigate lock contention,
 * but can only be removed again by a restart. (XXX: we could fix that)
 *
 */

#include "config.h"

#include <stdlib.h>

#include "cache_varnishd.h"
#include "cache_pool.h"

static pthread_t                thr_pool_herder;

static struct lock              wstat_mtx;
struct lock                     pool_mtx;
static VTAILQ_HEAD(,pool)       pools = VTAILQ_HEAD_INITIALIZER(pools);

/*--------------------------------------------------------------------
 * Summing of stats into global stats counters
 */

void
Pool_Sumstat(const struct worker *wrk)
{

        Lck_Lock(&wstat_mtx);
        VSC_main_Summ_wrk(VSC_C_main, wrk->stats);
        Lck_Unlock(&wstat_mtx);
        memset(wrk->stats, 0, sizeof *wrk->stats);
}

int
Pool_TrySumstat(const struct worker *wrk)
{
        if (Lck_Trylock(&wstat_mtx))
                return (0);
        VSC_main_Summ_wrk(VSC_C_main, wrk->stats);
        Lck_Unlock(&wstat_mtx);
        memset(wrk->stats, 0, sizeof *wrk->stats);
        return (1);
}

/*--------------------------------------------------------------------
 * Facility for scheduling a task on any convenient pool.
 */

int
Pool_Task_Any(struct pool_task *task, enum task_prio prio)
{
        struct pool *pp;

        Lck_Lock(&pool_mtx);
        pp = VTAILQ_FIRST(&pools);
        if (pp != NULL) {
                VTAILQ_REMOVE(&pools, pp, list);
                VTAILQ_INSERT_TAIL(&pools, pp, list);
        }
        Lck_Unlock(&pool_mtx);
        if (pp == NULL)
                return (-1);
        // NB: When we remove pools, is there a race here ?
        return (Pool_Task(pp, task, prio));
}

/*--------------------------------------------------------------------
 * Helper function to update stats for purges under lock
 */

void
Pool_PurgeStat(unsigned nobj)
{
        Lck_Lock(&wstat_mtx);
        VSC_C_main->n_purges++;
        VSC_C_main->n_obj_purged += nobj;
        Lck_Unlock(&wstat_mtx);
}

/*--------------------------------------------------------------------
 * Special function to summ stats
 */

void v_matchproto_(task_func_t)
pool_stat_summ(struct worker *wrk, void *priv)
{
        struct VSC_main_wrk *src;
        struct pool *pp;

        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
        pp = wrk->pool;
        CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);
        AN(priv);
        src = priv;

        Lck_Lock(&wstat_mtx);
        VSC_main_Summ_wrk(VSC_C_main, src);

        Lck_Lock(&pp->mtx);
        VSC_main_Summ_pool(VSC_C_main, pp->stats);
        Lck_Unlock(&pp->mtx);
        memset(pp->stats, 0, sizeof pp->stats);

        Lck_Unlock(&wstat_mtx);
        memset(src, 0, sizeof *src);

        AZ(pp->b_stat);
        pp->b_stat = src;
}

/*--------------------------------------------------------------------
 * Add a thread pool
 */

static struct pool *
pool_mkpool(unsigned pool_no)
{
        struct pool *pp;
        int i;

        ALLOC_OBJ(pp, POOL_MAGIC);
        if (pp == NULL)
                return (NULL);
        pp->a_stat = calloc(1, sizeof *pp->a_stat);
        AN(pp->a_stat);
        pp->b_stat = calloc(1, sizeof *pp->b_stat);
        AN(pp->b_stat);
        Lck_New(&pp->mtx, lck_perpool);

        VTAILQ_INIT(&pp->idle_queue);
        VTAILQ_INIT(&pp->poolsocks);
        for (i = 0; i < TASK_QUEUE_RESERVE; i++)
                VTAILQ_INIT(&pp->queues[i]);
        PTOK(pthread_cond_init(&pp->herder_cond, NULL));
        PTOK(pthread_create(&pp->herder_thr, NULL, pool_herder, pp));

        while (VTAILQ_EMPTY(&pp->idle_queue))
                (void)usleep(10000);

        SES_NewPool(pp, pool_no);
        VCA_NewPool(pp);

        return (pp);
}

/*--------------------------------------------------------------------
 * This thread adjusts the number of pools to match the parameter.
 *
 * NB: This is quite silly.  The master should tell the child through
 * NB: CLI when parameters change and an appropriate call-out table
 * NB: be maintained for params which require action.
 */

static void * v_matchproto_()
pool_poolherder(void *priv)
{
        unsigned nwq;
        struct pool *pp, *ppx;
        uint64_t u;
        void *rvp;

        THR_SetName("pool_poolherder");
        THR_Init();
        (void)priv;

        nwq = 0;
        while (1) {
                if (nwq < cache_param->wthread_pools) {
                        pp = pool_mkpool(nwq);
                        if (pp != NULL) {
                                Lck_Lock(&pool_mtx);
                                VTAILQ_INSERT_TAIL(&pools, pp, list);
                                Lck_Unlock(&pool_mtx);
                                VSC_C_main->pools++;
                                nwq++;
                                continue;
                        }
                } else if (nwq > cache_param->wthread_pools &&
                                EXPERIMENT(EXPERIMENT_DROP_POOLS)) {
                        Lck_Lock(&pool_mtx);
                        pp = VTAILQ_FIRST(&pools);
                        CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);
                        VTAILQ_REMOVE(&pools, pp, list);
                        VTAILQ_INSERT_TAIL(&pools, pp, list);
                        if (!pp->die)
                                nwq--;
                        Lck_Unlock(&pool_mtx);
                        if (!pp->die) {
                                VSL(SLT_Debug, NO_VXID, "XXX Kill Pool %p", pp);
                                pp->die = 1;
                                VCA_DestroyPool(pp);
                                PTOK(pthread_cond_signal(&pp->herder_cond));
                        }
                }
                (void)sleep(1);
                u = 0;
                ppx = NULL;
                Lck_Lock(&pool_mtx);
                VTAILQ_FOREACH(pp, &pools, list) {
                        CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);

                        if (pp->die && pp->nthr == 0)
                                ppx = pp;
                        u += pp->lqueue;
                }
                if (ppx != NULL) {
                        VTAILQ_REMOVE(&pools, ppx, list);
                        PTOK(pthread_join(ppx->herder_thr, &rvp));
                        PTOK(pthread_cond_destroy(&ppx->herder_cond));
                        free(ppx->a_stat);
                        free(ppx->b_stat);
                        SES_DestroyPool(ppx);
                        Lck_Delete(&ppx->mtx);
                        FREE_OBJ(ppx);
                        VSC_C_main->pools--;
                }
                Lck_Unlock(&pool_mtx);
                VSC_C_main->thread_queue_len = u;
        }
        NEEDLESS(return (NULL));
}

/*--------------------------------------------------------------------*/
void
pan_pool(struct vsb *vsb)
{
        struct pool *pp;

        VSB_cat(vsb, "pools = {\n");
        VSB_indent(vsb, 2);
        VTAILQ_FOREACH(pp, &pools, list) {
                if (PAN_dump_struct(vsb, pp, POOL_MAGIC, "pool"))
                        continue;
                VSB_printf(vsb, "nidle = %u,\n", pp->nidle);
                VSB_printf(vsb, "nthr = %u,\n", pp->nthr);
                VSB_printf(vsb, "lqueue = %u\n", pp->lqueue);
                VSB_indent(vsb, -2);
                VSB_cat(vsb, "},\n");
        }
        VSB_indent(vsb, -2);
        VSB_cat(vsb, "},\n");
}

/*--------------------------------------------------------------------*/

void
Pool_Init(void)
{

        Lck_New(&wstat_mtx, lck_wstat);
        Lck_New(&pool_mtx, lck_wq);
        PTOK(pthread_create(&thr_pool_herder, NULL, pool_poolherder, NULL));
        while (!VSC_C_main->pools)
                (void)usleep(10000);
}

		varnish-cache/bin/varnishd/cache/cache_pool.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
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		* We maintain a number of worker thread pools, to spread lock contention.
31		*
32		* Pools can be added on the fly, as a means to mitigate lock contention,
33		* but can only be removed again by a restart. (XXX: we could fix that)
34		*
35		*/
36
37		#include "config.h"
38
39		#include <stdlib.h>
40
41		#include "cache_varnishd.h"
42		#include "cache_pool.h"
43
44		static pthread_t thr_pool_herder;
45
46		static struct lock wstat_mtx;
47		struct lock pool_mtx;
48		static VTAILQ_HEAD(,pool) pools = VTAILQ_HEAD_INITIALIZER(pools);
49
50		/*--------------------------------------------------------------------
51		* Summing of stats into global stats counters
52		*/
53
54		void
55	133388	Pool_Sumstat(const struct worker *wrk)
56		{
57
58	133388	Lck_Lock(&wstat_mtx);
59	133388	VSC_main_Summ_wrk(VSC_C_main, wrk->stats);
60	133388	Lck_Unlock(&wstat_mtx);
61	133388	memset(wrk->stats, 0, sizeof *wrk->stats);
62	133388	}
63
64		int
65	0	Pool_TrySumstat(const struct worker *wrk)
66		{
67	0	if (Lck_Trylock(&wstat_mtx))
68	0	return (0);
69	0	VSC_main_Summ_wrk(VSC_C_main, wrk->stats);
70	0	Lck_Unlock(&wstat_mtx);
71	0	memset(wrk->stats, 0, sizeof *wrk->stats);
72	0	return (1);
73	0	}
74
75		/*--------------------------------------------------------------------
76		* Facility for scheduling a task on any convenient pool.
77		*/
78
79		int
80	4796	Pool_Task_Any(struct pool_task *task, enum task_prio prio)
81		{
82		struct pool *pp;
83
84	4796	Lck_Lock(&pool_mtx);
85	4796	pp = VTAILQ_FIRST(&pools);
86	4796	if (pp != NULL) {
87	4796	VTAILQ_REMOVE(&pools, pp, list);
88	4796	VTAILQ_INSERT_TAIL(&pools, pp, list);
89	4796	}
90	4796	Lck_Unlock(&pool_mtx);
91	4796	if (pp == NULL)
92	0	return (-1);
93		// NB: When we remove pools, is there a race here ?
94	4796	return (Pool_Task(pp, task, prio));
95	4796	}
96
97		/*--------------------------------------------------------------------
98		* Helper function to update stats for purges under lock
99		*/
100
101		void
102	275	Pool_PurgeStat(unsigned nobj)
103		{
104	275	Lck_Lock(&wstat_mtx);
105	275	VSC_C_main->n_purges++;
106	275	VSC_C_main->n_obj_purged += nobj;
107	275	Lck_Unlock(&wstat_mtx);
108	275	}
109
110		/*--------------------------------------------------------------------
111		* Special function to summ stats
112		*/
113
114		void v_matchproto_(task_func_t)
115	115465	pool_stat_summ(struct worker wrk, void priv)
116		{
117		struct VSC_main_wrk *src;
118		struct pool *pp;
119
120	115465	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
121	115465	pp = wrk->pool;
122	115465	CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);
123	115465	AN(priv);
124	115465	src = priv;
125
126	115465	Lck_Lock(&wstat_mtx);
127	115465	VSC_main_Summ_wrk(VSC_C_main, src);
128
129	115465	Lck_Lock(&pp->mtx);
130	115465	VSC_main_Summ_pool(VSC_C_main, pp->stats);
131	115465	Lck_Unlock(&pp->mtx);
132	115465	memset(pp->stats, 0, sizeof pp->stats);
133
134	115465	Lck_Unlock(&wstat_mtx);
135	115465	memset(src, 0, sizeof *src);
136
137	115465	AZ(pp->b_stat);
138	115465	pp->b_stat = src;
139	115465	}
140
141		/*--------------------------------------------------------------------
142		* Add a thread pool
143		*/
144
145		static struct pool *
146	43944	pool_mkpool(unsigned pool_no)
147		{
148		struct pool *pp;
149		int i;
150
151	43944	ALLOC_OBJ(pp, POOL_MAGIC);
152	43944	if (pp == NULL)
153	0	return (NULL);
154	43944	pp->a_stat = calloc(1, sizeof *pp->a_stat);
155	43944	AN(pp->a_stat);
156	43944	pp->b_stat = calloc(1, sizeof *pp->b_stat);
157	43944	AN(pp->b_stat);
158	43944	Lck_New(&pp->mtx, lck_perpool);
159
160	43944	VTAILQ_INIT(&pp->idle_queue);
161	43944	VTAILQ_INIT(&pp->poolsocks);
162	263664	for (i = 0; i < TASK_QUEUE_RESERVE; i++)
163	219720	VTAILQ_INIT(&pp->queues[i]);
164	43944	PTOK(pthread_cond_init(&pp->herder_cond, NULL));
165	43944	PTOK(pthread_create(&pp->herder_thr, NULL, pool_herder, pp));
166
167	87888	while (VTAILQ_EMPTY(&pp->idle_queue))
168	43944	(void)usleep(10000);
169
170	43944	SES_NewPool(pp, pool_no);
171	43944	VCA_NewPool(pp);
172
173	43944	return (pp);
174	43944	}
175
176		/*--------------------------------------------------------------------
177		* This thread adjusts the number of pools to match the parameter.
178		*
179		* NB: This is quite silly. The master should tell the child through
180		* NB: CLI when parameters change and an appropriate call-out table
181		* NB: be maintained for params which require action.
182		*/
183
184		static void * v_matchproto_()
185	0	pool_poolherder(void *priv)
186		{
187		unsigned nwq;
188		struct pool pp, ppx;
189		uint64_t u;
190		void *rvp;
191
192	0	THR_SetName("pool_poolherder");
193	0	THR_Init();
194	0	(void)priv;
195
196	0	nwq = 0;
197	42183	while (1) {
198	86127	if (nwq < cache_param->wthread_pools) {
199	43944	pp = pool_mkpool(nwq);
200	43944	if (pp != NULL) {
201	43944	Lck_Lock(&pool_mtx);
202	43944	VTAILQ_INSERT_TAIL(&pools, pp, list);
203	43944	Lck_Unlock(&pool_mtx);
204	43944	VSC_C_main->pools++;
205	43944	nwq++;
206	43944	continue;
207		}
208	42183	} else if (nwq > cache_param->wthread_pools &&
209	50	EXPERIMENT(EXPERIMENT_DROP_POOLS)) {
210	50	Lck_Lock(&pool_mtx);
211	50	pp = VTAILQ_FIRST(&pools);
212	50	CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);
213	50	VTAILQ_REMOVE(&pools, pp, list);
214	50	VTAILQ_INSERT_TAIL(&pools, pp, list);
215	50	if (!pp->die)
216	50	nwq--;
217	50	Lck_Unlock(&pool_mtx);
218	50	if (!pp->die) {
219	50	VSL(SLT_Debug, NO_VXID, "XXX Kill Pool %p", pp);
220	50	pp->die = 1;
221	50	VCA_DestroyPool(pp);
222	50	PTOK(pthread_cond_signal(&pp->herder_cond));
223	50	}
224	50	}
225	42183	(void)sleep(1);
226	42183	u = 0;
227	42183	ppx = NULL;
228	42183	Lck_Lock(&pool_mtx);
229	80293	VTAILQ_FOREACH(pp, &pools, list) {
230	38110	CHECK_OBJ_NOTNULL(pp, POOL_MAGIC);
231
232	38110	if (pp->die && pp->nthr == 0)
233	50	ppx = pp;
234	38110	u += pp->lqueue;
235	38110	}
236	42183	if (ppx != NULL) {
237	50	VTAILQ_REMOVE(&pools, ppx, list);
238	50	PTOK(pthread_join(ppx->herder_thr, &rvp));
239	50	PTOK(pthread_cond_destroy(&ppx->herder_cond));
240	50	free(ppx->a_stat);
241	50	free(ppx->b_stat);
242	50	SES_DestroyPool(ppx);
243	50	Lck_Delete(&ppx->mtx);
244	50	FREE_OBJ(ppx);
245	50	VSC_C_main->pools--;
246	50	}
247	42183	Lck_Unlock(&pool_mtx);
248	42183	VSC_C_main->thread_queue_len = u;
249		}
250		NEEDLESS(return (NULL));
251		}
252
253		/--------------------------------------------------------------------/
254		void
255	297	pan_pool(struct vsb *vsb)
256		{
257		struct pool *pp;
258
259	297	VSB_cat(vsb, "pools = {\n");
260	297	VSB_indent(vsb, 2);
261	891	VTAILQ_FOREACH(pp, &pools, list) {
262	594	if (PAN_dump_struct(vsb, pp, POOL_MAGIC, "pool"))
263	0	continue;
264	594	VSB_printf(vsb, "nidle = %u,\n", pp->nidle);
265	594	VSB_printf(vsb, "nthr = %u,\n", pp->nthr);
266	594	VSB_printf(vsb, "lqueue = %u\n", pp->lqueue);
267	594	VSB_indent(vsb, -2);
268	594	VSB_cat(vsb, "},\n");
269	594	}
270	297	VSB_indent(vsb, -2);
271	297	VSB_cat(vsb, "},\n");
272	297	}
273
274		/--------------------------------------------------------------------/
275
276		void
277	22197	Pool_Init(void)
278		{
279
280	22197	Lck_New(&wstat_mtx, lck_wstat);
281	22197	Lck_New(&pool_mtx, lck_wq);
282	22197	PTOK(pthread_create(&thr_pool_herder, NULL, pool_poolherder, NULL));
283	66588	while (!VSC_C_main->pools)
284	44391	(void)usleep(10000);
285	22197	}