Change CLI cmd debug.xid to set the next XID to be used, rather than "one less...

Change CLI cmd debug.xid to set the next XID to be used, rather than "one less than the next XID to be used"

bin/varnishd/cache/cache_main.c

@@ -179,7 +179,7 @@ THR_Init(void)
  * zero vxid, in order to reserve that for "unassociated" VSL records.
  */
 
-static uint64_t vxid_base;
+static uint64_t vxid_base = 1;
 static uint32_t vxid_chunk = 32768;
 static struct lock vxid_lock;
 
@@ -193,18 +193,20 @@ VXID_Get(const struct worker *wrk, uint32_t mask)
 	CHECK_OBJ_NOTNULL(wrk->wpriv, WORKER_PRIV_MAGIC);
 	v = wrk->wpriv->vxid_pool;
 	AZ(mask & VSL_IDENTMASK);
-	do {
-		if (v->count == 0) {
-			Lck_Lock(&vxid_lock);
-			v->next = vxid_base;
-			v->count = vxid_chunk;
-			vxid_base = (vxid_base + v->count) & VSL_IDENTMASK;
-			Lck_Unlock(&vxid_lock);
-		}
-		v->count--;
-		v->next++;
-	} while (v->next == 0);
+	while (v->count == 0 || v->next >= VSL_CLIENTMARKER) {
+		Lck_Lock(&vxid_lock);
+		v->next = vxid_base;
+		v->count = vxid_chunk;
+		vxid_base += v->count;
+		if (vxid_base >= VSL_CLIENTMARKER)
+			vxid_base = 1;
+		Lck_Unlock(&vxid_lock);
+	}
+	v->count--;
+	assert(v->next > 0);
+	assert(v->next < VSL_CLIENTMARKER);
 	retval.vxid = v->next | mask;
+	v->next++;
 	return (retval);
 }
 

bin/varnishtest/tests/p00000.vtc

@@ -43,7 +43,7 @@ varnish v1 -cliok "debug.persistent s0 sync"
 varnish v1 -stop
 
 varnish v1 -start
-varnish v1 -cliok "debug.xid 1999"
+varnish v1 -cliok "debug.xid 2000"
 
 client c1 {
 	txreq -url "/"

bin/varnishtest/tests/p00004.vtc

@@ -39,7 +39,7 @@ varnish v1 -expect n_object == 2
 
 varnish v1 -stop
 varnish v1 -start
-varnish v1 -cliok "debug.xid 1999"
+varnish v1 -cliok "debug.xid 2000"
 
 varnish v1 -expect n_vampireobject == 2
 varnish v1 -expect n_object == 0

bin/varnishtest/tests/p00006.vtc

@@ -38,7 +38,7 @@ server s1 -wait
 
 varnish v1 -stop
 varnish v1 -start
-varnish v1 -cliok "debug.xid 1999"
+varnish v1 -cliok "debug.xid 2000"
 
 varnish v1 -expect n_vampireobject == 2
 

bin/varnishtest/tests/r01762.vtc

@@ -36,7 +36,7 @@ varnish v1 -cliok "param.set debug +syncvsl"
 varnish v1 -cliok "debug.xid 1073741823"
 
 logexpect l1 -v v1 -g request -T 2 {
-	expect 0 1	Begin		"req 0"
+	expect 0 1	Begin		"req 107374182"
 	expect * =	ReqStart
 	expect 0 =	ReqMethod	GET
 	expect 0 =	ReqURL		/
@@ -80,7 +80,7 @@ varnish v1 -cliok "param.set debug +syncvsl"
 varnish v1 -cliok "debug.xid 1073741823"
 
 logexpect l1 -v v1 -g request {
-	expect 0 1	Begin		"req 0"
+	expect 0 1	Begin		"req 1073741823"
 	expect * =	ReqStart
 	expect 0 =	ReqMethod	GET
 	expect 0 =	ReqURL		/

bin/varnishtest/vtc_varnish.c

@@ -620,7 +620,7 @@ varnish_start(struct varnish *v)
 	wait_running(v);
 	free(resp);
 	resp = NULL;
-	u = varnish_ask_cli(v, "debug.xid 999", &resp);
+	u = varnish_ask_cli(v, "debug.xid 1000", &resp);
 	if (vtc_error)
 		return;
 	if (u != CLIS_OK)

doc/changes.rst

@@ -35,6 +35,9 @@ release process.
 Varnish Cache NEXT (2023-03-15)
 ===============================
 
+* The ``debug.xid`` CLI command now sets the next XID to be used,
+  rather than "one less than the next XID to be used"
+
 ================================
 Varnish Cache 7.2.0 (2022-09-15)
 ================================