[nexus] stabilize srp_auto_start test (openthread#12954)

This commit stabilizes the Nexus SRP auto-start test by increasing
the synchronization wait time from 20 seconds to 30 seconds.

The test was occasionally failing in the Nexus environment because
the 20-second wait was sometimes insufficient for the SRP server
registration to fully propagate through the network data and for
the SRP client to process the update and complete its server
selection. Increasing the wait time to 30 seconds provides a more
robust buffer for these network synchronization events.

Verified by running the test 100 times in a loop without failures.

Author: jwhui

tests/nexus/test_srp_auto_start.cpp

@@ -67,7 +67,7 @@ void TestSrpAutoStart(void)
     server1.Join(client);
     server2.Join(client);
     server3.Join(client);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(server1.Get<Mle::Mle>().IsFullThreadDevice());
     VerifyOrQuit(server2.Get<Mle::Mle>().IsFullThreadDevice());
     VerifyOrQuit(server3.Get<Mle::Mle>().IsFullThreadDevice());
@@ -80,7 +80,7 @@ void TestSrpAutoStart(void)
     Log("Enable server1 with unicast address mode");
     SuccessOrQuit(server1.Get<Srp::Server>().SetAddressMode(Srp::Server::kAddressModeUnicast));
     server1.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
 
     // Check auto start mode on client and check that server1 is selected
     Log("Check auto start mode on client and check that server1 is selected");
@@ -93,28 +93,28 @@ void TestSrpAutoStart(void)
     // Disable server1 and check client is stopped/disabled.
     Log("Disable server1 and check client is stopped/disabled.");
     server1.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(!client.Get<Srp::Client>().IsRunning());
 
     // Enable server2 with unicast address mode and check client starts again.
     Log("Enable server2 with unicast address mode and check client starts again.");
     SuccessOrQuit(server2.Get<Srp::Server>().SetAddressMode(Srp::Server::kAddressModeUnicast));
     server2.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress() == server2Mleid);
 
     // Enable server1 and check that client stays with server2
     Log("Enable server1 and check that client stays with server2");
     server1.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress() == server2Mleid);
 
     // Disable server2 and check client switches to server1.
     Log("Disable server2 and check client switches to server1.");
     server2.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress() == server1Mleid);
 
@@ -123,7 +123,7 @@ void TestSrpAutoStart(void)
     SuccessOrQuit(server2.Get<Srp::Server>().SetAddressMode(Srp::Server::kAddressModeAnycast));
     SuccessOrQuit(server2.Get<Srp::Server>().SetAnycastModeSequenceNumber(1));
     server2.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
 
     VerifyOrQuit(server2.Get<Srp::Server>().GetAnycastModeSequenceNumber() == 1);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
@@ -135,7 +135,7 @@ void TestSrpAutoStart(void)
     SuccessOrQuit(server3.Get<Srp::Server>().SetAddressMode(Srp::Server::kAddressModeAnycast));
     SuccessOrQuit(server3.Get<Srp::Server>().SetAnycastModeSequenceNumber(2));
     server3.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
 
     VerifyOrQuit(server3.Get<Srp::Server>().GetAnycastModeSequenceNumber() == 2);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
@@ -145,7 +145,7 @@ void TestSrpAutoStart(void)
     // Disable server3 and check that client goes back to server2.
     Log("Disable server3 and check that client goes back to server2.");
     server3.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress().GetIid().IsAnycastServiceLocator());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetPort() == anycastPort);
@@ -155,7 +155,7 @@ void TestSrpAutoStart(void)
     Log("Enable server3 with anycast mode seq-num 0 and check that client stays with server2.");
     SuccessOrQuit(server3.Get<Srp::Server>().SetAnycastModeSequenceNumber(0));
     server3.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(server3.Get<Srp::Server>().GetAnycastModeSequenceNumber() == 0);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress().GetIid().IsAnycastServiceLocator());
@@ -164,15 +164,15 @@ void TestSrpAutoStart(void)
     // Disable server2 and check that client goes back to server3.
     Log("Disable server2 and check that client goes back to server3.");
     server2.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress().GetIid().IsAnycastServiceLocator());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetPort() == anycastPort);
 
     // Disable server3 and check that client goes back to server1 with unicast address.
     Log("Disable server3 and check that client goes back to server1 with unicast address.");
     server3.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress() == server1Mleid);
 
@@ -181,7 +181,7 @@ void TestSrpAutoStart(void)
     SuccessOrQuit(server2.Get<Srp::Server>().SetAddressMode(Srp::Server::kAddressModeAnycast));
     SuccessOrQuit(server2.Get<Srp::Server>().SetAnycastModeSequenceNumber(5));
     server2.Get<Srp::Server>().SetEnabled(true);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(server2.Get<Srp::Server>().GetAnycastModeSequenceNumber() == 5);
     VerifyOrQuit(client.Get<Srp::Client>().IsRunning());
     VerifyOrQuit(client.Get<Srp::Client>().GetServerAddress().GetAddress().GetIid().IsAnycastServiceLocator());
@@ -231,7 +231,7 @@ void TestSrpAutoStart(void)
     // Finally disable server2, and check that client is disabled.
     Log("Finally disable server2, and check that client is disabled.");
     server2.Get<Srp::Server>().SetEnabled(false);
-    nexus.AdvanceTime(20 * Time::kOneSecondInMsec);
+    nexus.AdvanceTime(30 * Time::kOneSecondInMsec);
     VerifyOrQuit(!client.Get<Srp::Client>().IsRunning());
 }