Rename System::Clock::Zero to System::Clock::kZero (#11327)

#### Problem

`System::Clock::Zero` is a constants that doesn't follow the usual
convention of being named with a leading `k`.

Requested in PR #11238 review.

#### Change overview

Rename `System::Clock::Zero` to `System::Clock::kZero`.

#### Testing

CI; no changes to functionality.

examples/lock-app/esp32/main/AppTask.cpp

@@ -114,7 +114,7 @@ CHIP_ERROR AppTask::Init()
 void AppTask::AppTaskMain(void * pvParameter)
 {
     AppEvent event;
-    Clock::Timestamp lastChangeTime = Clock::Zero;
+    Clock::Timestamp lastChangeTime = Clock::kZero;
 
     CHIP_ERROR err = sAppTask.Init();
     if (err != CHIP_NO_ERROR)

examples/shell/shell_common/cmd_ping.cpp

@@ -50,7 +50,7 @@ class PingArguments
     {
         mMaxEchoCount       = 3;
         mEchoInterval       = 1000;
-        mLastEchoTime       = System::Clock::Zero;
+        mLastEchoTime       = System::Clock::kZero;
         mEchoCount          = 0;
         mEchoRespCount      = 0;
         mPayloadSize        = 32;

examples/shell/shell_common/cmd_send.cpp

@@ -47,7 +47,7 @@ class SendArguments
     {
         mProtocolId   = 0x0002;
         mMessageType  = 1;
-        mLastSendTime = System::Clock::Zero;
+        mLastSendTime = System::Clock::kZero;
         mPayloadSize  = 32;
 #if INET_CONFIG_ENABLE_TCP_ENDPOINT
         mUsingTCP = false;

src/app/EventManagement.cpp

@@ -87,7 +87,7 @@ struct EventEnvelopeContext
 
     uint16_t mFieldsToRead = 0;
     /* PriorityLevel and DeltaSystemTimestamp are there if that is not first event when putting events in report*/
-    Timestamp mDeltaSystemTime = Timestamp::System(System::Clock::Zero);
+    Timestamp mDeltaSystemTime = Timestamp::System(System::Clock::kZero);
     Timestamp mDeltaUtc        = Timestamp::UTC(0);
     PriorityLevel mPriority    = PriorityLevel::First;
     NodeId mNodeId             = 0;
@@ -855,8 +855,8 @@ void CircularEventBuffer::Init(uint8_t * apBuffer, uint32_t aBufferLength, Circu
     mPriority                  = aPriorityLevel;
     mFirstEventNumber          = 1;
     mLastEventNumber           = 0;
-    mFirstEventSystemTimestamp = Timestamp::System(System::Clock::Zero);
-    mLastEventSystemTimestamp  = Timestamp::System(System::Clock::Zero);
+    mFirstEventSystemTimestamp = Timestamp::System(System::Clock::kZero);
+    mLastEventSystemTimestamp  = Timestamp::System(System::Clock::kZero);
     mpEventNumberCounter       = nullptr;
 }
 

src/app/tests/integration/MockEvents.cpp

@@ -188,7 +188,7 @@ void MockEventGeneratorImpl::SetEventGeneratorStop()
     // This helps quit the standalone app in an orderly way without
     // spurious leaked timers.
     if (mTimeBetweenEvents != 0)
-        mpExchangeMgr->GetSessionManager()->SystemLayer()->StartTimer(chip::System::Clock::Zero, HandleNextEvent, this);
+        mpExchangeMgr->GetSessionManager()->SystemLayer()->StartTimer(chip::System::Clock::kZero, HandleNextEvent, this);
 }
 
 bool MockEventGeneratorImpl::IsEventGeneratorStopped()

src/app/tests/integration/chip_im_initiator.cpp

@@ -63,7 +63,7 @@ chip::TransportMgr<chip::Transport::UDP> gTransportManager;
 chip::Inet::IPAddress gDestAddr;
 
 // The last time a CHIP Command was attempted to be sent.
-chip::System::Clock::Timestamp gLastMessageTime = chip::System::Clock::Zero;
+chip::System::Clock::Timestamp gLastMessageTime = chip::System::Clock::kZero;
 
 // Count of the number of CommandRequests sent.
 uint64_t gCommandCount = 0;
@@ -703,7 +703,7 @@ int main(int argc, char * argv[])
     err = EstablishSecureSession();
     SuccessOrExit(err);
 
-    err = chip::DeviceLayer::SystemLayer().StartTimer(chip::System::Clock::Zero, CommandRequestTimerHandler, NULL);
+    err = chip::DeviceLayer::SystemLayer().StartTimer(chip::System::Clock::kZero, CommandRequestTimerHandler, NULL);
     SuccessOrExit(err);
 
     chip::DeviceLayer::PlatformMgr().RunEventLoop();

src/include/platform/internal/GenericConnectivityManagerImpl_NoWiFi.h

@@ -123,7 +123,7 @@ inline bool GenericConnectivityManagerImpl_NoWiFi<ImplClass>::_IsWiFiStationConn
 template <class ImplClass>
 inline System::Clock::Timeout GenericConnectivityManagerImpl_NoWiFi<ImplClass>::_GetWiFiStationReconnectInterval(void)
 {
-    return System::Clock::Zero;
+    return System::Clock::kZero;
 }
 
 template <class ImplClass>
@@ -181,7 +181,7 @@ inline void GenericConnectivityManagerImpl_NoWiFi<ImplClass>::_MaintainOnDemandW
 template <class ImplClass>
 inline System::Clock::Timeout GenericConnectivityManagerImpl_NoWiFi<ImplClass>::_GetWiFiAPIdleTimeout(void)
 {
-    return System::Clock::Zero;
+    return System::Clock::kZero;
 }
 
 template <class ImplClass>

src/include/platform/internal/GenericConnectivityManagerImpl_WiFi.h

@@ -109,7 +109,7 @@ class GenericConnectivityManagerImpl_WiFi
 template <class ImplClass>
 inline System::Clock::Timeout GenericConnectivityManagerImpl_WiFi<ImplClass>::_GetWiFiStationReconnectInterval()
 {
-    return System::Clock::Zero;
+    return System::Clock::kZero;
 }
 
 template <class ImplClass>
@@ -167,7 +167,7 @@ inline void GenericConnectivityManagerImpl_WiFi<ImplClass>::_MaintainOnDemandWiF
 template <class ImplClass>
 inline System::Clock::Timeout GenericConnectivityManagerImpl_WiFi<ImplClass>::_GetWiFiAPIdleTimeout()
 {
-    return System::Clock::Zero;
+    return System::Clock::kZero;
 }
 
 template <class ImplClass>

src/lib/dnssd/minimal_mdns/responders/QueryResponder.cpp

@@ -160,7 +160,7 @@ void QueryResponderBase::ClearBroadcastThrottle()
 {
     for (size_t i = 0; i < mResponderInfoSize; i++)
     {
-        mResponderInfos[i].lastMulticastTime = chip::System::Clock::Zero;
+        mResponderInfos[i].lastMulticastTime = chip::System::Clock::kZero;
     }
 }
 

src/lib/dnssd/minimal_mdns/responders/QueryResponder.h

@@ -29,9 +29,9 @@ namespace Minimal {
 /// Represents available data (replies) for mDNS queries.
 struct QueryResponderRecord
 {
-    Responder * responder                            = nullptr;                   // what response/data is available
-    bool reportService                               = false;                     // report as a service when listing dnssd services
-    chip::System::Clock::Timestamp lastMulticastTime = chip::System::Clock::Zero; // last time this record was multicast
+    Responder * responder                            = nullptr; // what response/data is available
+    bool reportService                               = false;   // report as a service when listing dnssd services
+    chip::System::Clock::Timestamp lastMulticastTime = chip::System::Clock::kZero; // last time this record was multicast
 };
 
 namespace Internal {
@@ -140,7 +140,8 @@ class QueryResponderRecordFilter
             return false;
         }
 
-        if ((mIncludeOnlyMulticastBefore > chip::System::Clock::Zero) && (record->lastMulticastTime >= mIncludeOnlyMulticastBefore))
+        if ((mIncludeOnlyMulticastBefore > chip::System::Clock::kZero) &&
+            (record->lastMulticastTime >= mIncludeOnlyMulticastBefore))
         {
             return false;
         }
@@ -156,7 +157,7 @@ class QueryResponderRecordFilter
 private:
     bool mIncludeAdditionalRepliesOnly                         = false;
     ReplyFilter * mReplyFilter                                 = nullptr;
-    chip::System::Clock::Timestamp mIncludeOnlyMulticastBefore = chip::System::Clock::Zero;
+    chip::System::Clock::Timestamp mIncludeOnlyMulticastBefore = chip::System::Clock::kZero;
 };
 
 /// Iterates over an array of QueryResponderRecord items, providing only 'valid' ones, where

src/messaging/ExchangeContext.cpp

@@ -124,7 +124,7 @@ CHIP_ERROR ExchangeContext::SendMessage(Protocols::Id protocolId, uint8_t msgTyp
         SetResponseExpected(true);
 
         // Arm the response timer if a timeout has been specified.
-        if (mResponseTimeout > System::Clock::Zero)
+        if (mResponseTimeout > System::Clock::kZero)
         {
             CHIP_ERROR err = StartResponseTimer();
             if (err != CHIP_NO_ERROR)

src/messaging/ReliableMessageMgr.cpp

@@ -59,7 +59,7 @@ void ReliableMessageMgr::Init(chip::System::Layer * systemLayer, SessionManager
 {
     mSystemLayer        = systemLayer;
     mTimeStampBase      = System::SystemClock().GetMonotonicTimestamp();
-    mCurrentTimerExpiry = System::Clock::Zero;
+    mCurrentTimerExpiry = System::Clock::kZero;
 }
 
 void ReliableMessageMgr::Shutdown()
@@ -448,7 +448,7 @@ void ReliableMessageMgr::StartTimer()
             // If the tick boundary has expired in the past (delayed processing of event due to other system activity),
             // expire the timer immediately
             System::Clock::Timestamp now         = System::SystemClock().GetMonotonicTimestamp();
-            System::Clock::Timeout timerArmValue = (timerExpiry > now) ? timerExpiry - now : System::Clock::Zero;
+            System::Clock::Timeout timerArmValue = (timerExpiry > now) ? timerExpiry - now : System::Clock::kZero;
 
 #if defined(RMP_TICKLESS_DEBUG)
             ChipLogDetail(ExchangeManager, "ReliableMessageMgr::StartTimer set timer for %" PRIu32 " ms",

src/messaging/tests/echo/echo_requester.cpp

@@ -62,7 +62,7 @@ chip::TransportMgr<chip::Transport::TCP<kMaxTcpActiveConnectionCount, kMaxTcpPen
 chip::Inet::IPAddress gDestAddr;
 
 // The last time a CHIP Echo was attempted to be sent.
-chip::System::Clock::Timestamp gLastEchoTime = chip::System::Clock::Zero;
+chip::System::Clock::Timestamp gLastEchoTime = chip::System::Clock::kZero;
 
 // Count of the number of EchoRequests sent.
 uint64_t gEchoCount = 0;
@@ -263,7 +263,7 @@ int main(int argc, char * argv[])
     // Arrange to get a callback whenever an Echo Response is received.
     gEchoClient.SetEchoResponseReceived(HandleEchoResponseReceived);
 
-    err = chip::DeviceLayer::SystemLayer().StartTimer(chip::System::Clock::Zero, EchoTimerHandler, NULL);
+    err = chip::DeviceLayer::SystemLayer().StartTimer(chip::System::Clock::kZero, EchoTimerHandler, NULL);
     SuccessOrExit(err);
 
     chip::DeviceLayer::PlatformMgr().RunEventLoop();

src/platform/Ameba/ConnectivityManagerImpl.cpp

@@ -129,7 +129,7 @@ void ConnectivityManagerImpl::_StopOnDemandWiFiAP(void)
 {
     if (mWiFiAPMode == kWiFiAPMode_OnDemand || mWiFiAPMode == kWiFiAPMode_OnDemand_NoStationProvision)
     {
-        mLastAPDemandTime = System::Clock::Zero;
+        mLastAPDemandTime = System::Clock::kZero;
         DeviceLayer::SystemLayer().ScheduleWork(DriveAPState, NULL);
     }
 }
@@ -334,8 +334,8 @@ CHIP_ERROR ConnectivityManagerImpl::_GetAndLogWifiStatsCounters(void)
 
 CHIP_ERROR ConnectivityManagerImpl::_Init()
 {
-    mLastStationConnectFailTime   = System::Clock::Zero;
-    mLastAPDemandTime             = System::Clock::Zero;
+    mLastStationConnectFailTime   = System::Clock::kZero;
+    mLastAPDemandTime             = System::Clock::kZero;
     mWiFiStationMode              = kWiFiStationMode_Disabled;
     mWiFiStationState             = kWiFiStationState_NotConnected;
     mWiFiAPMode                   = kWiFiAPMode_Disabled;
@@ -462,7 +462,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             ChangeWiFiStationState(kWiFiStationState_Connected);
             ChipLogProgress(DeviceLayer, "WiFi station interface connected");
-            mLastStationConnectFailTime = System::Clock::Zero;
+            mLastStationConnectFailTime = System::Clock::kZero;
             OnStationConnected();
         }
 
@@ -499,7 +499,7 @@ void ConnectivityManagerImpl::DriveStationState()
             if (prevState != kWiFiStationState_Connecting_Failed)
             {
                 ChipLogProgress(DeviceLayer, "WiFi station interface disconnected");
-                mLastStationConnectFailTime = System::Clock::Zero;
+                mLastStationConnectFailTime = System::Clock::kZero;
                 OnStationDisconnected();
             }
             else
@@ -514,7 +514,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             // Initiate a connection to the AP if we haven't done so before, or if enough
             // time has passed since the last attempt.
-            if (mLastStationConnectFailTime == System::Clock::Zero ||
+            if (mLastStationConnectFailTime == System::Clock::kZero ||
                 now >= mLastStationConnectFailTime + mWiFiStationReconnectInterval)
             {
                 ChipLogProgress(DeviceLayer, "Attempting to connect WiFi station interface");

src/platform/ESP32/ConnectivityManagerImpl_WiFi.cpp

@@ -142,7 +142,7 @@ void ConnectivityManagerImpl::_StopOnDemandWiFiAP(void)
 {
     if (mWiFiAPMode == kWiFiAPMode_OnDemand || mWiFiAPMode == kWiFiAPMode_OnDemand_NoStationProvision)
     {
-        mLastAPDemandTime = System::Clock::Zero;
+        mLastAPDemandTime = System::Clock::kZero;
         DeviceLayer::SystemLayer().ScheduleWork(DriveAPState, NULL);
     }
 }
@@ -375,8 +375,8 @@ CHIP_ERROR ConnectivityManagerImpl::_GetAndLogWifiStatsCounters(void)
 
 CHIP_ERROR ConnectivityManagerImpl::InitWiFi()
 {
-    mLastStationConnectFailTime   = System::Clock::Zero;
-    mLastAPDemandTime             = System::Clock::Zero;
+    mLastStationConnectFailTime   = System::Clock::kZero;
+    mLastAPDemandTime             = System::Clock::kZero;
     mWiFiStationMode              = kWiFiStationMode_Disabled;
     mWiFiStationState             = kWiFiStationState_NotConnected;
     mWiFiAPMode                   = kWiFiAPMode_Disabled;
@@ -551,7 +551,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             ChangeWiFiStationState(kWiFiStationState_Connected);
             ChipLogProgress(DeviceLayer, "WiFi station interface connected");
-            mLastStationConnectFailTime = System::Clock::Zero;
+            mLastStationConnectFailTime = System::Clock::kZero;
             OnStationConnected();
         }
 
@@ -588,7 +588,7 @@ void ConnectivityManagerImpl::DriveStationState()
             if (prevState != kWiFiStationState_Connecting_Failed)
             {
                 ChipLogProgress(DeviceLayer, "WiFi station interface disconnected");
-                mLastStationConnectFailTime = System::Clock::Zero;
+                mLastStationConnectFailTime = System::Clock::kZero;
                 OnStationDisconnected();
             }
             else
@@ -604,7 +604,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             // Initiate a connection to the AP if we haven't done so before, or if enough
             // time has passed since the last attempt.
-            if (mLastStationConnectFailTime == System::Clock::Zero ||
+            if (mLastStationConnectFailTime == System::Clock::kZero ||
                 now >= mLastStationConnectFailTime + mWiFiStationReconnectInterval)
             {
                 ChipLogProgress(DeviceLayer, "Attempting to connect WiFi station interface");
@@ -740,7 +740,7 @@ void ConnectivityManagerImpl::DriveAPState()
         {
             System::Clock::Timestamp now = System::SystemClock().GetMonotonicTimestamp();
 
-            if (mLastAPDemandTime != System::Clock::Zero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
+            if (mLastAPDemandTime != System::Clock::kZero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
             {
                 targetState = kWiFiAPState_Active;
 

src/platform/ESP32/PlatformManagerImpl.h

@@ -70,7 +70,7 @@ class PlatformManagerImpl final : public PlatformManager, public Internal::Gener
     friend PlatformManager & PlatformMgr(void);
     friend PlatformManagerImpl & PlatformMgrImpl(void);
 
-    chip::System::Clock::Timestamp mStartTime = System::Clock::Zero;
+    chip::System::Clock::Timestamp mStartTime = System::Clock::kZero;
 
     static PlatformManagerImpl sInstance;
 };

src/platform/Linux/ConnectivityManagerImpl.cpp

@@ -452,7 +452,7 @@ void ConnectivityManagerImpl::_StopOnDemandWiFiAP()
     if (mWiFiAPMode == kWiFiAPMode_OnDemand || mWiFiAPMode == kWiFiAPMode_OnDemand_NoStationProvision)
     {
         ChipLogProgress(DeviceLayer, "wpa_supplicant: Demand stop WiFi AP");
-        mLastAPDemandTime = System::Clock::Zero;
+        mLastAPDemandTime = System::Clock::kZero;
         DeviceLayer::SystemLayer().ScheduleWork(DriveAPState, NULL);
     }
     else
@@ -769,7 +769,7 @@ void ConnectivityManagerImpl::DriveAPState()
         {
             System::Clock::Timestamp now = System::SystemClock().GetMonotonicTimestamp();
 
-            if (mLastAPDemandTime != System::Clock::Zero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
+            if (mLastAPDemandTime != System::Clock::kZero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
             {
                 targetState = kWiFiAPState_Active;
 

src/platform/Linux/PlatformManagerImpl.h

@@ -76,7 +76,7 @@ class PlatformManagerImpl final : public PlatformManager, public Internal::Gener
     friend PlatformManagerImpl & PlatformMgrImpl();
     friend class Internal::BLEManagerImpl;
 
-    System::Clock::Timestamp mStartTime = System::Clock::Zero;
+    System::Clock::Timestamp mStartTime = System::Clock::kZero;
 
     static PlatformManagerImpl sInstance;
 

src/platform/P6/ConnectivityManagerImpl.cpp

@@ -131,7 +131,7 @@ void ConnectivityManagerImpl::_StopOnDemandWiFiAP(void)
 {
     if (mWiFiAPMode == kWiFiAPMode_OnDemand || mWiFiAPMode == kWiFiAPMode_OnDemand_NoStationProvision)
     {
-        mLastAPDemandTime = System::Clock::Zero;
+        mLastAPDemandTime = System::Clock::kZero;
         DeviceLayer::SystemLayer().ScheduleWork(DriveAPState, NULL);
     }
 }
@@ -182,8 +182,8 @@ CHIP_ERROR ConnectivityManagerImpl::_Init()
 {
     CHIP_ERROR err                = CHIP_NO_ERROR;
     cy_rslt_t result              = CY_RSLT_SUCCESS;
-    mLastStationConnectFailTime   = System::Clock::Zero;
-    mLastAPDemandTime             = System::Clock::Zero;
+    mLastStationConnectFailTime   = System::Clock::kZero;
+    mLastAPDemandTime             = System::Clock::kZero;
     mWiFiStationMode              = kWiFiStationMode_Disabled;
     mWiFiStationState             = kWiFiStationState_NotConnected;
     mWiFiAPMode                   = kWiFiAPMode_Disabled;
@@ -404,7 +404,7 @@ void ConnectivityManagerImpl::DriveAPState()
         {
             System::Clock::Timestamp now = System::SystemClock().GetMonotonicTimestamp();
 
-            if (mLastAPDemandTime != System::Clock::Zero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
+            if (mLastAPDemandTime != System::Clock::kZero && now < (mLastAPDemandTime + mWiFiAPIdleTimeout))
             {
                 targetState = kWiFiAPState_Active;
 
@@ -502,7 +502,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             ChangeWiFiStationState(kWiFiStationState_Connected);
             ChipLogProgress(DeviceLayer, "WiFi station interface connected");
-            mLastStationConnectFailTime = System::Clock::Zero;
+            mLastStationConnectFailTime = System::Clock::kZero;
         }
 
         // If the WiFi station interface is no longer enabled, or no longer provisioned,
@@ -537,7 +537,7 @@ void ConnectivityManagerImpl::DriveStationState()
             if (prevState != kWiFiStationState_Connecting_Failed)
             {
                 ChipLogProgress(DeviceLayer, "WiFi station interface disconnected");
-                mLastStationConnectFailTime = System::Clock::Zero;
+                mLastStationConnectFailTime = System::Clock::kZero;
             }
             else
             {
@@ -551,7 +551,7 @@ void ConnectivityManagerImpl::DriveStationState()
         {
             // Initiate a connection to the AP if we haven't done so before, or if enough
             // time has passed since the last attempt.
-            if (mLastStationConnectFailTime == System::Clock::Zero ||
+            if (mLastStationConnectFailTime == System::Clock::kZero ||
                 now >= mLastStationConnectFailTime + mWiFiStationReconnectInterval)
             {
                 ChangeWiFiStationState(kWiFiStationState_Connecting);

src/platform/Tizen/ConnectivityManagerImpl.cpp

@@ -55,7 +55,7 @@ CHIP_ERROR ConnectivityManagerImpl::_Init(void)
     mWiFiStationMode              = kWiFiStationMode_Disabled;
     mWiFiAPMode                   = kWiFiAPMode_Disabled;
     mWiFiAPState                  = kWiFiAPState_NotActive;
-    mLastAPDemandTime             = System::Clock::Zero;
+    mLastAPDemandTime             = System::Clock::kZero;
     mWiFiStationReconnectInterval = System::Clock::Milliseconds32(CHIP_DEVICE_CONFIG_WIFI_STATION_RECONNECT_INTERVAL);
     mWiFiAPIdleTimeout            = System::Clock::Milliseconds32(CHIP_DEVICE_CONFIG_WIFI_AP_IDLE_TIMEOUT);