From 9e0c884820c5ac931bf35cbcd8838b357de8924f Mon Sep 17 00:00:00 2001
From: Ondrej Fabry <ofabry@cisco.com>
Date: Tue, 20 Sep 2022 21:28:10 +0200
Subject: [PATCH] Disable default reply timeout

This commit allows disabling reply timeout by setting it to 0 and sets this as a default value.

Signed-off-by: Ondrej Fabry <ofabry@cisco.com>
---
 api/api.go         |  5 +++--
 core/channel.go    | 12 +++++++++---
 core/connection.go |  2 +-
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/api/api.go b/api/api.go
index c4f069fa..9b1d4bbc 100644
--- a/api/api.go
+++ b/api/api.go
@@ -86,8 +86,9 @@ type Channel interface {
 	// buffer is full, the notifications will not be delivered into it.
 	SubscribeNotification(notifChan chan Message, event Message) (SubscriptionCtx, error)
 
-	// SetReplyTimeout sets the timeout for replies from VPP. It represents the maximum time the API waits for a reply
-	// from VPP before returning an error.
+	// SetReplyTimeout sets the timeout for replies from VPP. It represents the maximum time the client waits for a reply
+	// from VPP before returning a timeout error. Setting the reply timeout to 0 disables it. The initial reply timeout is
+	//set to the value of core.DefaultReplyTimeout.
 	SetReplyTimeout(timeout time.Duration)
 
 	// CheckCompatibility checks the compatiblity for the given messages.
diff --git a/core/channel.go b/core/channel.go
index b82dab61..93370797 100644
--- a/core/channel.go
+++ b/core/channel.go
@@ -259,6 +259,8 @@ func (sub *subscriptionCtx) Unsubscribe() error {
 	return fmt.Errorf("subscription for %q not found", sub.event.GetMessageName())
 }
 
+const maxInt64 = 1<<63 - 1
+
 // receiveReplyInternal receives a reply from the reply channel into the provided msg structure.
 func (ch *Channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (lastReplyReceived bool, err error) {
 	if msg == nil {
@@ -276,7 +278,11 @@ func (ch *Channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (last
 		}
 	}
 
-	timer := time.NewTimer(ch.replyTimeout)
+	timeout := ch.replyTimeout
+	if timeout <= 0 {
+		timeout = maxInt64
+	}
+	timer := time.NewTimer(timeout)
 	for {
 		select {
 		// blocks until a reply comes to ReplyChan or until timeout expires
@@ -295,8 +301,8 @@ func (ch *Channel) receiveReplyInternal(msg api.Message, expSeqNum uint16) (last
 			log.WithFields(logrus.Fields{
 				"expSeqNum": expSeqNum,
 				"channel":   ch.id,
-			}).Debugf("timeout (%v) waiting for reply: %s", ch.replyTimeout, msg.GetMessageName())
-			err = fmt.Errorf("no reply received within the timeout period %s", ch.replyTimeout)
+			}).Debugf("timeout (%v) waiting for reply: %s", timeout, msg.GetMessageName())
+			err = fmt.Errorf("no reply received within the timeout period %s", timeout)
 			return false, err
 		}
 	}
diff --git a/core/connection.go b/core/connection.go
index 5607de33..6d1a6435 100644
--- a/core/connection.go
+++ b/core/connection.go
@@ -47,7 +47,7 @@ var (
 	HealthCheckProbeInterval = time.Second            // default health check probe interval
 	HealthCheckReplyTimeout  = time.Millisecond * 250 // timeout for reply to a health check probe
 	HealthCheckThreshold     = 2                      // number of failed health checks until the error is reported
-	DefaultReplyTimeout      = time.Second            // default timeout for replies from VPP
+	DefaultReplyTimeout      = time.Duration(0)       // default timeout for replies from VPP is disabled
 )
 
 // ConnectionState represents the current state of the connection to VPP.