[4.1] 65f62a3 Add a read/write lock for VCL temperature

[Dridi Boukelmoune]

commit 65f62a3f9ac5f3136bd1ab308b82cfef94c991ca
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Tue Aug 30 20:31:34 2016 +0200

    Add a read/write lock for VCL temperature

diff --git a/bin/varnishd/cache/cache_vcl.c b/bin/varnishd/cache/cache_vcl.c
index 234238b..a2d90eb 100644
--- a/bin/varnishd/cache/cache_vcl.c
+++ b/bin/varnishd/cache/cache_vcl.c
@@ -34,6 +34,7 @@
 #include "config.h"
 
 #include <dlfcn.h>
+#include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -68,6 +69,7 @@ struct vcl {
 	unsigned		busy;
 	unsigned		discard;
 	const char		*temp;
+	pthread_rwlock_t	temp_rwl;
 	VTAILQ_HEAD(,backend)	backend_list;
 	VTAILQ_HEAD(,vclref)	ref_list;
 };
@@ -323,6 +325,7 @@ VCL_Open(const char *fn, struct vsb *msg)
 	}
 	ALLOC_OBJ(vcl, VCL_MAGIC);
 	AN(vcl);
+	AZ(pthread_rwlock_init(&vcl->temp_rwl, NULL));
 	vcl->dlh = dlh;
 	vcl->conf = cnf;
 	return (vcl);
@@ -337,6 +340,7 @@ VCL_Close(struct vcl **vclp)
 	vcl = *vclp;
 	*vclp = NULL;
 	AZ(dlclose(vcl->dlh));
+	AZ(pthread_rwlock_destroy(&vcl->temp_rwl));
 	FREE_OBJ(vcl);
 }