Implement the cooling period before objhead's are deleted in the

critbit hasher.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3457 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/bin/varnishd/cache_hash.c b/varnish-cache/bin/varnishd/cache_hash.c
index e756f814e345035776e5fcec7b488976c7ac2873..083027fbdfb56e3349383f719f5b6f150f40d2de 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_hash.c
+++ b/varnish-cache/bin/varnishd/cache_hash.c
@@ -262,7 +262,6 @@ HSH_Lookup(struct sess *sp)
        HSH_Prealloc(sp);
        if (params->hash_sha256) {
                SHA256_Final(sp->wrk->nobjhead->digest, sp->wrk->sha256ctx);
-               sp->wrk->nobjhead->digest_len = 32;
                /* WSP(sp, SLT_Debug, "SHA256: <%.32s>", sha256); */
        }
        

diff --git a/varnish-cache/bin/varnishd/hash_critbit.c b/varnish-cache/bin/varnishd/hash_critbit.c
index a328dc268754f7b629bbece947992f490e48a377..5b178229bf285b9ed6986c7f5435d75e869a52af 100644 (file)
--- a/varnish-cache/bin/varnishd/hash_critbit.c
+++ b/varnish-cache/bin/varnishd/hash_critbit.c
@@ -30,6 +30,8 @@
  * A Crit Bit tree based hash
  */
 
+#define PHK    1
+
 #include "config.h"
 
 #include <pthread.h>
@@ -42,6 +44,8 @@
 
 static struct lock hcb_mtx;
 
+static VTAILQ_HEAD(,objhead)   laylow = VTAILQ_HEAD_INITIALIZER(laylow);
+
 /**********************************************************************
  * Table for finding out how many bits two bytes have in common,
  * counting from the MSB towards the LSB.
@@ -160,7 +164,7 @@ hcb_crit_bit(const struct objhead *oh1, const struct objhead *oh2, struct hcb_y
 {
        unsigned u, r;
 
-       for (u = 0; u < oh1->digest_len && oh1->digest[u] == oh2->digest[u]; u++)
+       for (u = 0; u < DIGEST_LEN && oh1->digest[u] == oh2->digest[u]; u++)
                ;
        r = hcb_bits(oh1->digest[u], oh2->digest[u]);
        y->ptr = u;
@@ -190,7 +194,7 @@ hcb_insert(struct hcb_root *root, struct objhead *oh, int has_lock)
 
        while(hcb_is_y(*p)) {
                y = hcb_l_y(*p);
-               if (y->ptr > oh->digest_len)
+               if (y->ptr > DIGEST_LEN)
                        s = 0;
                else
                        s = (oh->digest[y->ptr] & y->bitmask) != 0;
@@ -203,8 +207,7 @@ hcb_insert(struct hcb_root *root, struct objhead *oh, int has_lock)
 
        /* We found a node, does it match ? */
        oh2 = hcb_l_node(*p);
-       if (oh2->digest_len == oh->digest_len &&
-           !memcmp(oh2->digest, oh->digest, oh->digest_len))
+       if (!memcmp(oh2->digest, oh->digest, DIGEST_LEN))
                return (oh2);
 
        if (!has_lock)
@@ -227,7 +230,7 @@ hcb_insert(struct hcb_root *root, struct objhead *oh, int has_lock)
                y = hcb_l_y(*p);
                if (y->critbit > y2->critbit)
                        break;
-               if (y->ptr > oh->digest_len)
+               if (y->ptr > DIGEST_LEN)
                        s = 0;
                else
                        s = (oh->digest[y->ptr] & y->bitmask) != 0;
@@ -259,7 +262,7 @@ hcb_delete(struct hcb_root *r, struct objhead *oh)
        y = NULL;
        while(hcb_is_y(*p)) {
                y = hcb_l_y(*p);
-               if (y->ptr > oh->digest_len)
+               if (y->ptr > DIGEST_LEN)
                        s = 0;
                else
                        s = (oh->digest[y->ptr] & y->bitmask) != 0;
@@ -291,7 +294,7 @@ dumptree(uintptr_t p, int indent, FILE *fd)
        if (hcb_is_node(p)) {
                oh = hcb_l_node(p);
                fprintf(fd, "%*.*sN %u %u r%d <%02x%02x%02x...> <%s>\n",
-                   indent, indent, "", oh->digest_len, indent / 2,
+                   indent, indent, "", DIGEST_LEN, indent / 2,
                    oh->refcnt,
                    oh->digest[0], oh->digest[1], oh->digest[2],
                    oh->hash);
@@ -317,14 +320,51 @@ dump(const struct hcb_root *root, FILE *fd)
 }
 
 
+/**********************************************************************/
+
+#define COOL_DURATION  15              /* seconds */
+
+static void *
+hcb_cleaner(void *priv)
+{
+       struct objhead *oh, *oh2;
+       struct hcb_y *y;
+
+       THR_SetName("hcb_cleaner");
+       (void)priv;
+       while (1) {
+               sleep(1);
+               Lck_Lock(&hcb_mtx);
+               VTAILQ_FOREACH_SAFE(oh, &laylow, coollist, oh2) {
+                       if (oh->hash != NULL) {
+                               free(oh->hash);
+                               oh->hash = NULL;
+                       }
+                       y = (void *)&oh->u;
+                       if (y->leaf[0] || y->leaf[1])
+                               continue;
+                       if (++oh->refcnt > COOL_DURATION) {
+                               VTAILQ_REMOVE(&laylow, oh, coollist);
+                               if (PHK)
+                                       fprintf(stderr, "OH %p is cold enough\n", oh);
+                               free(oh);
+                               VSL_stats->n_objecthead--;
+                       }
+               }
+               Lck_Unlock(&hcb_mtx);
+       }
+}
+
 /**********************************************************************/
 
 static void
 hcb_start(void)
 {
        struct objhead *oh = NULL;
+       pthread_t tp;
 
        (void)oh;
+       AZ(pthread_create(&tp, NULL, hcb_cleaner, NULL));
        assert(params->hash_sha256);
        assert(sizeof(struct hcb_y) <= sizeof(oh->u));
        memset(&hcb_root, 0, sizeof hcb_root);
@@ -336,7 +376,6 @@ static int
 hcb_deref(struct objhead *oh)
 {
        int r;
-       struct hcb_y *y;
 
        r = 1;
        CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
@@ -344,16 +383,11 @@ hcb_deref(struct objhead *oh)
        if (--oh->refcnt == 0) {
                Lck_Lock(&hcb_mtx);
                hcb_delete(&hcb_root, oh);
-               y = (void*)&oh->u;
-               if (y->leaf[0] == 0 && y->leaf[1] == 0)
-                       r = 0;
-               else {
-                       /* XXX: on waiting list */
-               }
+               VTAILQ_INSERT_TAIL(&laylow, oh, coollist);
                Lck_Unlock(&hcb_mtx);
        }
        Lck_Unlock(&oh->mtx);
-       if (0) {
+       if (PHK) {
                fprintf(stderr, "%s %d %d <%s>\n", __func__, __LINE__, r, oh->hash);
                dump(&hcb_root, stderr);
        }
@@ -391,7 +425,7 @@ hcb_lookup(const struct sess *sp, struct objhead *noh)
        oh =  hcb_insert(&hcb_root, noh, 1);
        if (oh == noh) {
                VSL_stats->hcb_insert++;
-               if (0) {
+               if (PHK) {
                        fprintf(stderr, "%s %d\n", __func__, __LINE__);
                        dump(&hcb_root, stderr);
                }
@@ -400,7 +434,7 @@ hcb_lookup(const struct sess *sp, struct objhead *noh)
                noh->hash = NULL;
                noh->hashlen = 0;
                VSL_stats->hcb_lock++;
-               if (0) {
+               if (PHK) {
                        fprintf(stderr, "%s %d\n", __func__, __LINE__);
                        dump(&hcb_root, stderr);
                }

diff --git a/varnish-cache/bin/varnishd/hash_slinger.h b/varnish-cache/bin/varnishd/hash_slinger.h
index 90f55af558a85908815ac613ab6004c983284df9..81dfcf1fdbef5bdee261514b26e76fb47afe850b 100644 (file)
--- a/varnish-cache/bin/varnishd/hash_slinger.h
+++ b/varnish-cache/bin/varnishd/hash_slinger.h
@@ -64,6 +64,9 @@ void HSH_Prepare(struct sess *sp, unsigned hashcount);
 
 
 #ifdef VARNISH_CACHE_CHILD
+
+#define DIGEST_LEN             32
+
 struct objhead {
        unsigned                magic;
 #define OBJHEAD_MAGIC          0x1b96615d
@@ -73,9 +76,13 @@ struct objhead {
        VTAILQ_HEAD(,object)    objects;
        char                    *hash;
        unsigned                hashlen;
-       unsigned char           digest[32];
-       unsigned char           digest_len;
-       VTAILQ_HEAD(, sess)     waitinglist;
+       unsigned char           digest[DIGEST_LEN];
+       union {
+               VTAILQ_HEAD(, sess)     __u_waitinglist;
+               VTAILQ_ENTRY(objhead)   __u_coollist;
+       } __u;
+#define waitinglist __u.__u_waitinglist
+#define coollist __u.__u_coollist
 
        /*----------------------------------------------------
         * The fields below are for the sole private use of