From 60853792b2e21f4e97933fdb3ef70bdb6e514c1c Mon Sep 17 00:00:00 2001
From: Stefano Avallone <stavallo@unina.it>
Date: Wed, 14 Aug 2024 10:42:14 +0200
Subject: [PATCH] wifi: Extend EMLSR test to check that SwitchMainPhyBackDelay
 timer expires

---
 src/wifi/test/wifi-emlsr-test.cc | 39 ++++++++++++++++++++++++++++----
 src/wifi/test/wifi-emlsr-test.h  |  4 ++++
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/src/wifi/test/wifi-emlsr-test.cc b/src/wifi/test/wifi-emlsr-test.cc
index 66dd72a96..7f65bd2a7 100644
--- a/src/wifi/test/wifi-emlsr-test.cc
+++ b/src/wifi/test/wifi-emlsr-test.cc
@@ -2592,7 +2592,8 @@ EmlsrUlTxopTest::EmlsrUlTxopTest(const Params& params)
       m_countRtsframes(0),
       m_genBackoffIfTxopWithoutTx(params.genBackoffAndUseAuxPhyCca),
       m_useAuxPhyCca(params.genBackoffAndUseAuxPhyCca),
-      m_nSlotsLeftAlert(params.nSlotsLeftAlert)
+      m_nSlotsLeftAlert(params.nSlotsLeftAlert),
+      m_switchMainPhyBackDelayTimeout(params.switchMainPhyBackDelayTimeout)
 {
     m_nEmlsrStations = 1;
     m_nNonEmlsrStations = 0;
@@ -3217,6 +3218,34 @@ EmlsrUlTxopTest::CheckBlockAck(const WifiConstPsduMap& psduMap,
                                           false,
                                           false);
 
+                    if (m_switchMainPhyBackDelayTimeout)
+                    {
+                        TimeValue switchMainPhyBackDelay;
+                        m_staMacs[0]->GetEmlsrManager()->GetAttribute("SwitchMainPhyBackDelay",
+                                                                      switchMainPhyBackDelay);
+
+                        // set the NAV on all the links for enough time to make the
+                        // SwitchMainPhyBackDelay timer expire
+                        for (uint8_t id = 0; id < m_staMacs[0]->GetNLinks(); ++id)
+                        {
+                            if (!m_staMacs[0]->GetWifiPhy(id))
+                            {
+                                continue; // no PHY on this link
+                            }
+                            m_staMacs[0]->GetChannelAccessManager(id)->NotifyNavStartNow(
+                                2 * switchMainPhyBackDelay.Get());
+                        }
+                        // check that the SwitchMainPhyBackDelay timer expires
+                        Simulator::Schedule(2 * switchMainPhyBackDelay.Get() - mainPhy->GetPifs(),
+                                            [=, this]() {
+                                                CheckMainPhyTraceInfo(0,
+                                                                      "TxopNotGainedOnAuxPhyLink",
+                                                                      std::nullopt,
+                                                                      m_mainPhyId,
+                                                                      false);
+                                            });
+                    }
+
                     // events to be scheduled when main PHY finishes switching to auxiliary link
                     Simulator::Schedule(mainPhy->GetDelayUntilIdle(), [=, this]() {
                         auto nonPrimLinkId = m_staMacs[0]->GetLinkForPhy(mainPhy);
@@ -3685,7 +3714,7 @@ EmlsrUlTxopTest::CheckResults()
     // transmission is done (if the backoff expires while the main PHY is switching, a new
     // backoff is generated and, before this backoff expires, the main PHY may be requested
     // to switch to another auxiliary link; this may happen multiple times...)
-    if (!m_genBackoffIfTxopWithoutTx)
+    if (!m_genBackoffIfTxopWithoutTx && !m_switchMainPhyBackDelayTimeout)
     {
         NS_TEST_EXPECT_MSG_LT_OR_EQ(psduIt->startTx,
                                     m_5thQosFrameTxTime,
@@ -4931,7 +4960,8 @@ WifiEmlsrTestSuite::WifiEmlsrTestSuite()
                                              3,
                                              genBackoffAndUseAuxPhyCca,
                                              nSlotsLeft,
-                                             true /* putAuxPhyToSleep */}),
+                                             true, /* putAuxPhyToSleep */
+                                             false /* switchMainPhyBackDelayTimeout */}),
                         TestCase::Duration::QUICK);
             AddTestCase(new EmlsrUlTxopTest({{0, 1},
                                              40,
@@ -4940,7 +4970,8 @@ WifiEmlsrTestSuite::WifiEmlsrTestSuite()
                                              1,
                                              genBackoffAndUseAuxPhyCca,
                                              nSlotsLeft,
-                                             false /* putAuxPhyToSleep */}),
+                                             false, /* putAuxPhyToSleep */
+                                             true /* switchMainPhyBackDelayTimeout */}),
                         TestCase::Duration::QUICK);
         }
     }
diff --git a/src/wifi/test/wifi-emlsr-test.h b/src/wifi/test/wifi-emlsr-test.h
index 84d849fa0..81fac6be2 100644
--- a/src/wifi/test/wifi-emlsr-test.h
+++ b/src/wifi/test/wifi-emlsr-test.h
@@ -609,6 +609,8 @@ class EmlsrUlTxopTest : public EmlsrOperationsTestBase
         uint8_t nSlotsLeftAlert;        //!< value to set the ChannelAccessManager NSlotsLeft
                                         //!< attribute to
         bool putAuxPhyToSleep;          //!< whether aux PHYs are put to sleep during DL/UL TXOPs
+        bool switchMainPhyBackDelayTimeout; //!< whether a SwitchMainPhyBackDelay timer expires
+                                            //!< after that the main PHY moved to an aux PHY link
     };
 
     /**
@@ -714,6 +716,8 @@ class EmlsrUlTxopTest : public EmlsrOperationsTestBase
     bool m_useAuxPhyCca;                  //!< whether CCA info from aux PHY is used when
                                           //!< aux PHY is not TX capable
     uint8_t m_nSlotsLeftAlert;            //!< value for ChannelAccessManager NSlotsLeft attribute
+    bool m_switchMainPhyBackDelayTimeout; //!< whether a SwitchMainPhyBackDelay timer expires
+                                          //!< after that the main PHY moved to an aux PHY link
     std::optional<bool> m_corruptCts;     //!< whether the transmitted CTS must be corrupted
     Time m_5thQosFrameTxTime;             //!< start transmission time of the 5th QoS data frame
 };