[master] fa04c3d Add a force_fresh parameter to VTP_Get

[Dag Haavi Finstad]

commit fa04c3d44d82c2617c985483d1e449a2312bda15
Author: Dag Haavi Finstad <daghf at varnish-software.com>
Date:   Mon Nov 13 16:28:27 2017 +0100

    Add a force_fresh parameter to VTP_Get
    
    Passing a nonzero value will force a fresh backend connection.

diff --git a/bin/varnishd/cache/cache_backend.c b/bin/varnishd/cache/cache_backend.c
index 31f77e9..d0fa5bb 100644
--- a/bin/varnishd/cache/cache_backend.c
+++ b/bin/varnishd/cache/cache_backend.c
@@ -112,7 +112,7 @@ vbe_dir_getfd(struct worker *wrk, struct backend *bp, struct busyobj *bo)
 	bo->htc->doclose = SC_NULL;
 
 	FIND_TMO(connect_timeout, tmod, bo, bp);
-	vtp = VTP_Get(bp->tcp_pool, tmod, wrk);
+	vtp = VTP_Get(bp->tcp_pool, tmod, wrk, 0);
 	if (vtp == NULL) {
 		VSLb(bo->vsl, SLT_FetchError,
 		     "backend %s: fail", bp->director->display_name);
diff --git a/bin/varnishd/cache/cache_tcp_pool.c b/bin/varnishd/cache/cache_tcp_pool.c
index 04ea7e2..943cdd1 100644
--- a/bin/varnishd/cache/cache_tcp_pool.c
+++ b/bin/varnishd/cache/cache_tcp_pool.c
@@ -366,7 +366,8 @@ VTP_Close(struct vtp **vtpp)
  */
 
 struct vtp *
-VTP_Get(struct tcp_pool *tp, double tmo, struct worker *wrk)
+VTP_Get(struct tcp_pool *tp, double tmo, struct worker *wrk,
+    unsigned force_fresh)
 {
 	struct vtp *vtp;
 
@@ -376,7 +377,7 @@ VTP_Get(struct tcp_pool *tp, double tmo, struct worker *wrk)
 	Lck_Lock(&tp->mtx);
 	vtp = VTAILQ_FIRST(&tp->connlist);
 	CHECK_OBJ_ORNULL(vtp, VTP_MAGIC);
-	if (vtp == NULL || vtp->state == VTP_STATE_STOLEN)
+	if (force_fresh || vtp == NULL || vtp->state == VTP_STATE_STOLEN)
 		vtp = NULL;
 	else {
 		assert(vtp->tcp_pool == tp);
diff --git a/bin/varnishd/cache/cache_tcp_pool.h b/bin/varnishd/cache/cache_tcp_pool.h
index 11b0f82..4dbc12f 100644
--- a/bin/varnishd/cache/cache_tcp_pool.h
+++ b/bin/varnishd/cache/cache_tcp_pool.h
@@ -85,7 +85,8 @@ void VTP_Recycle(const struct worker *, struct vtp **);
 	 * Recycle an open connection.
 	 */
 
-struct vtp *VTP_Get(struct tcp_pool *, double tmo, struct worker *);
+struct vtp *VTP_Get(struct tcp_pool *, double tmo, struct worker *,
+    unsigned force_fresh);
 	/*
 	 * Get a (possibly) recycled connection.
 	 */