From cdea931a51b0c5bebb37007da965635cbae74b40 Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@collectd.org>
Date: Fri, 26 Apr 2013 14:16:38 +0200
Subject: [PATCH] dns plugin: Sleep for an interval before re-trying to read
 from interface.
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Otherwise we'd just have the CPU hogging behavior shifted from libpcap
to collectd …

Github: #308
---
 src/dns.c | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/dns.c b/src/dns.c
index aea41c43..00fcff19 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -275,12 +275,47 @@ static int dns_run_pcap_loop (void)
 	return (status);
 } /* int dns_run_pcap_loop */
 
+static int dns_sleep_one_interval (void) /* {{{ */
+{
+	cdtime_t interval;
+	struct timespec ts = { 0, 0 };
+	int status = 0;
+
+	interval = plugin_get_interval ();
+	CDTIME_T_TO_TIMESPEC (interval, &ts);
+
+	while (42)
+	{
+		struct timespec rem = { 0, 0 };
+
+		status = nanosleep (&ts, &rem);
+		if (status == 0)
+			break;
+		else if ((errno == EINTR) || (errno == EAGAIN))
+		{
+			ts = rem;
+			continue;
+		}
+		else
+			break;
+	}
+
+	return (status);
+} /* }}} int dns_sleep_one_interval */
+
 static void *dns_child_loop (__attribute__((unused)) void *dummy) /* {{{ */
 {
-	int status = PCAP_ERROR_IFACE_NOT_UP;
+	int status;
 
-	while (status == PCAP_ERROR_IFACE_NOT_UP)
+	while (42)
+	{
 		status = dns_run_pcap_loop ();
+		if (status != PCAP_ERROR_IFACE_NOT_UP)
+			break;
+
+		dns_sleep_one_interval ();
+	}
+
 	if (status != PCAP_ERROR_BREAK)
 		ERROR ("dns plugin: PCAP returned error %s.",
 				pcap_statustostr (status));
-- 
2.11.0