[4.1] c6289aa Make the ban lurker sleep on a condvar so other code can wake it up.

[Lasse Karstensen]

commit c6289aaed5ccedfa6659f585626654a265c14143
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Thu Oct 22 20:34:18 2015 +0000

    Make the ban lurker sleep on a condvar so other code can wake it up.

diff --git a/bin/varnishd/cache/cache_ban.c b/bin/varnishd/cache/cache_ban.c
index 95ca144..6d66999 100644
--- a/bin/varnishd/cache/cache_ban.c
+++ b/bin/varnishd/cache/cache_ban.c
@@ -756,6 +756,7 @@ BAN_Init(void)
 	bp = BAN_Build();
 	AN(bp);
 	AZ(BAN_Commit(bp));
+	AZ(pthread_cond_init(&ban_lurker_cond, NULL));
 	Lck_Lock(&ban_mtx);
 	ban_mark_completed(VTAILQ_FIRST(&ban_head));
 	Lck_Unlock(&ban_mtx);
@@ -774,9 +775,8 @@ BAN_Shutdown(void)
 {
 	void *status;
 
-	Lck_Lock(&ban_mtx);
 	ban_shutdown = 1;
-	Lck_Unlock(&ban_mtx);
+	ban_kick_lurker();
 
 	AZ(pthread_join(ban_thread, &status));
 	AZ(status);
diff --git a/bin/varnishd/cache/cache_ban.h b/bin/varnishd/cache/cache_ban.h
index 047d0f9..100acee 100644
--- a/bin/varnishd/cache/cache_ban.h
+++ b/bin/varnishd/cache/cache_ban.h
@@ -105,6 +105,7 @@ extern struct lock ban_mtx;
 extern int ban_shutdown;
 extern struct banhead_s ban_head;
 extern struct ban * volatile ban_start;
+extern pthread_cond_t	ban_lurker_cond;
 
 void ban_mark_completed(struct ban *b);
 unsigned ban_len(const uint8_t *banspec);
@@ -114,3 +115,4 @@ int ban_evaluate(struct worker *wrk, const uint8_t *bs, struct objcore *oc,
 double ban_time(const uint8_t *banspec);
 int ban_equal(const uint8_t *bs1, const uint8_t *bs2);
 void BAN_Free(struct ban *b);
+void ban_kick_lurker(void);
diff --git a/bin/varnishd/cache/cache_ban_lurker.c b/bin/varnishd/cache/cache_ban_lurker.c
index cfcdd26..821d8c8 100644
--- a/bin/varnishd/cache/cache_ban_lurker.c
+++ b/bin/varnishd/cache/cache_ban_lurker.c
@@ -38,6 +38,18 @@
 
 static struct objcore oc_marker = { .magic = OBJCORE_MAGIC, };
 static unsigned ban_batch;
+static unsigned ban_generation;
+
+pthread_cond_t	ban_lurker_cond;
+
+void
+ban_kick_lurker(void)
+{
+	Lck_Lock(&ban_mtx);
+	ban_generation++;
+	AZ(pthread_cond_signal(&ban_lurker_cond));
+	Lck_Unlock(&ban_mtx);
+}
 
 static void
 ban_cleantail(void)
@@ -254,7 +266,10 @@ ban_lurker(struct worker *wrk, void *priv)
 		if (d <= 0.0 || !ban_lurker_work(wrk, &vsl))
 			d = 0.609;	// Random, non-magic
 		ban_cleantail();
-		VTIM_sleep(d);
+		d += VTIM_real();
+		Lck_Lock(&ban_mtx);
+		(void)Lck_CondWait(&ban_lurker_cond, &ban_mtx, d);
+		Lck_Unlock(&ban_mtx);
 	}
 	pthread_exit(0);
 	NEEDLESS_RETURN(NULL);