rpc: Add APIs for direct triggering of keepalive timer

Add virKeepAliveTimeout and virKeepAliveTrigger APIs that can be used to
set poll timeouts and trigger keepalive timer. virKeepAliveTrigger
checks if it is called to early and does nothing in that case.
(cherry picked from commit 28c75382)

src/rpc/virkeepalive.c

@@ -45,6 +45,7 @@ struct _virKeepAlive {
     unsigned int count;
     unsigned int countToDeath;
     time_t lastPacketReceived;
+    time_t intervalStart;
     int timer;
 
     virNetMessagePtr response;
@@ -158,8 +159,11 @@ virKeepAliveTimerInternal(virKeepAlivePtr ka,
 {
     time_t now = time(NULL);
 
-    if (now - ka->lastPacketReceived < ka->interval - 1) {
-        int timeout = ka->interval - (now - ka->lastPacketReceived);
+    if (ka->interval <= 0 || ka->intervalStart == 0)
+        return false;
+
+    if (now - ka->intervalStart < ka->interval) {
+        int timeout = ka->interval - (now - ka->intervalStart);
         virEventUpdateTimeout(ka->timer, timeout * 1000);
         return false;
     }
@@ -179,6 +183,7 @@ virKeepAliveTimerInternal(virKeepAlivePtr ka,
         return true;
     } else {
         ka->countToDeath--;
+        ka->intervalStart = now;
         *msg = virKeepAliveMessage(KEEPALIVE_PROC_PING);
         virEventUpdateTimeout(ka->timer, ka->interval * 1000);
         return false;
@@ -335,6 +340,7 @@ virKeepAliveStart(virKeepAlivePtr ka,
     int ret = -1;
     time_t delay;
     int timeout;
+    time_t now;
 
     virKeepAliveLock(ka);
 
@@ -365,11 +371,13 @@ virKeepAliveStart(virKeepAlivePtr ka,
           "ka=%p client=%p interval=%d count=%u",
           ka, ka->client, interval, count);
 
-    delay = time(NULL) - ka->lastPacketReceived;
+    now = time(NULL);
+    delay = now - ka->lastPacketReceived;
     if (delay > ka->interval)
         timeout = 0;
     else
         timeout = ka->interval - delay;
+    ka->intervalStart = now - (ka->interval - timeout);
     ka->timer = virEventAddTimeout(timeout * 1000, virKeepAliveTimer,
                                    ka, virKeepAliveTimerFree);
     if (ka->timer < 0)
@@ -427,6 +435,51 @@ virKeepAliveStopSending(virKeepAlivePtr ka)
 }
 
 
+int
+virKeepAliveTimeout(virKeepAlivePtr ka)
+{
+    int timeout;
+
+    if (!ka)
+        return -1;
+
+    virKeepAliveLock(ka);
+
+    if (ka->interval <= 0 || ka->intervalStart == 0) {
+        timeout = -1;
+    } else {
+        timeout = ka->interval - (time(NULL) - ka->intervalStart);
+        if (timeout < 0)
+            timeout = 0;
+    }
+
+    virKeepAliveUnlock(ka);
+
+    if (timeout < 0)
+        return -1;
+    else
+        return timeout * 1000;
+}
+
+
+bool
+virKeepAliveTrigger(virKeepAlivePtr ka,
+                    virNetMessagePtr *msg)
+{
+    bool dead;
+
+    *msg = NULL;
+    if (!ka)
+        return false;
+
+    virKeepAliveLock(ka);
+    dead = virKeepAliveTimerInternal(ka, msg);
+    virKeepAliveUnlock(ka);
+
+    return dead;
+}
+
+
 bool
 virKeepAliveCheckMessage(virKeepAlivePtr ka,
                          virNetMessagePtr msg)
@@ -442,7 +495,7 @@ virKeepAliveCheckMessage(virKeepAlivePtr ka,
     virKeepAliveLock(ka);
 
     ka->countToDeath = ka->count;
-    ka->lastPacketReceived = time(NULL);
+    ka->lastPacketReceived = ka->intervalStart = time(NULL);
 
     if (msg->header.prog == KEEPALIVE_PROGRAM &&
         msg->header.vers == KEEPALIVE_PROTOCOL_VERSION &&

src/rpc/virkeepalive.h

@@ -51,6 +51,9 @@ int virKeepAliveStart(virKeepAlivePtr ka,
 void virKeepAliveStop(virKeepAlivePtr ka);
 void virKeepAliveStopSending(virKeepAlivePtr ka);
 
+int virKeepAliveTimeout(virKeepAlivePtr ka);
+bool virKeepAliveTrigger(virKeepAlivePtr ka,
+                         virNetMessagePtr *msg);
 bool virKeepAliveCheckMessage(virKeepAlivePtr ka,
                               virNetMessagePtr msg);