Don't use a thread from the pool, backend polling is far too long-lived for

that to make sense.

We do not need a mutex for our list, all manipulation is from CLI thread.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3096 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/bin/varnishd/cache_backend_poll.c b/varnish-cache/bin/varnishd/cache_backend_poll.c
index 9125c12d28418dbfcdfd99d65b9a5fc5a0945342..3cfc08f12149b71596d1ba7f98c3fbf860b2c12b 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_backend_poll.c
+++ b/varnish-cache/bin/varnishd/cache_backend_poll.c
@@ -54,15 +54,12 @@
 #include "vrt.h"
 #include "cache_backend.h"
 
-static MTX     vbp_mtx;
-
 struct vbp_target {
        unsigned                        magic;
 #define VBP_TARGET_MAGIC               0x6b7cb656
 
        struct backend                  *backend;
        struct vrt_backend_probe        probe;
-       struct workreq                  wrq;
        int                             stop;
        int                             req_len;
        
@@ -72,6 +69,7 @@ struct vbp_target {
 #undef BITMAP
 
        VTAILQ_ENTRY(vbp_target)        list;
+       pthread_t                       thread;
 };
 
 static VTAILQ_HEAD(, vbp_target)       vbp_list =
@@ -85,7 +83,7 @@ static char default_request[] =
 static void
 dsleep(double t)
 {
-       if (t > 10.0)
+       if (t > 100.0)
                (void)sleep((int)round(t));
        else
                (void)usleep((int)round(t * 1e6));
@@ -212,20 +210,15 @@ vbp_poke(struct vbp_target *vt)
  * One thread per backend to be poked.
  */
 
-static void
-vbp_wrk_poll_backend(struct worker *w, void *priv)
+static void *
+vbp_wrk_poll_backend(void *priv)
 {
        struct vbp_target *vt;
 
-       (void)w;
        THR_SetName("backend poll");
 
        CAST_OBJ_NOTNULL(vt, priv, VBP_TARGET_MAGIC);
 
-       LOCK(&vbp_mtx);
-       VTAILQ_INSERT_TAIL(&vbp_list, vt, list);
-       UNLOCK(&vbp_mtx);
-
        /* Establish defaults (XXX: Should they go in VCC instead ?) */
        if (vt->probe.request == NULL)
                vt->probe.request = default_request;
@@ -247,14 +240,10 @@ vbp_wrk_poll_backend(struct worker *w, void *priv)
 #include "cache_backend_poll.h"
 #undef BITMAP
                vbp_poke(vt);
-               dsleep(vt->probe.interval);
+               if (!vt->stop)
+                       dsleep(vt->probe.interval);
        }
-       LOCK(&vbp_mtx);
-       VTAILQ_REMOVE(&vbp_list, vt, list);
-       UNLOCK(&vbp_mtx);
-       vt->backend->probe = NULL;
-       FREE_OBJ(vt);
-       THR_SetName("cache-worker");
+       return (NULL);
 }
 
 /*--------------------------------------------------------------------
@@ -280,7 +269,7 @@ vbp_bitmap(struct cli *cli, const char *s, uint64_t map, const char *lbl)
 /*lint -e{506} constant value boolean */
 /*lint -e{774} constant value boolean */
 static void
-vbp_health_one(struct cli *cli, struct vbp_target *vt)
+vbp_health_one(struct cli *cli, const struct vbp_target *vt)
 {
 
        cli_out(cli, "Health stats for backend %s\n",
@@ -301,6 +290,7 @@ vbp_health(struct cli *cli, const char * const *av, void *priv)
 {
        struct vbp_target *vt;
 
+       ASSERT_CLI();
        (void)av;
        (void)priv;
 
@@ -336,21 +326,32 @@ VBP_Start(struct backend *b, struct vrt_backend_probe const *p)
        vt->probe = *p;
        b->probe = vt;
 
-       vt->wrq.func = vbp_wrk_poll_backend;
-       vt->wrq.priv = vt;
-       if (WRK_Queue(&vt->wrq) == 0)
-               return;
-       assert(0 == __LINE__);
-       b->probe = NULL;
-       FREE_OBJ(vt);
+       VTAILQ_INSERT_TAIL(&vbp_list, vt, list);
+
+       AZ(pthread_create(&vt->thread, NULL, vbp_wrk_poll_backend, vt));
 }
 
 void
 VBP_Stop(struct backend *b)
 {
+       struct vbp_target *vt;
+       void *ret;
+
+       CHECK_OBJ_NOTNULL(b, BACKEND_MAGIC);
+
+       ASSERT_CLI();
        if (b->probe == NULL)
                return;
-       b->probe->stop = 1;
+       CHECK_OBJ_NOTNULL(b->probe, VBP_TARGET_MAGIC);
+       vt = b->probe;
+
+       vt->stop = 1;
+       AZ(pthread_cancel(vt->thread));
+       AZ(pthread_join(vt->thread, &ret));
+
+       VTAILQ_REMOVE(&vbp_list, vt, list);
+       b->probe = NULL;
+       FREE_OBJ(vt);
 }
 
 /*--------------------------------------------------------------------
@@ -361,7 +362,5 @@ void
 VBP_Init(void)
 {
 
-       MTX_INIT(&vbp_mtx);
-
        CLI_AddFuncs(DEBUG_CLI, debug_cmds);
 }