ExchangeContext remove unused flags (#17731)

* ExchangeContext remove unused flags

* Update src/messaging/ReliableMessageContext.h

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Resolve comments: do not rename HasPiggybackAckPending

* Update comments

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

src/messaging/ExchangeContext.cpp

@@ -302,7 +302,6 @@ ExchangeContext::ExchangeContext(ExchangeManager * em, uint16_t ExchangeId, cons
  mFlags.Set(Flags::kFlagInitiator, Initiator);
  mDelegate = delegate;
 
- SetDropAckDebug(false);
  SetAckPending(false);
 
  // Do not request Ack for multicast

src/messaging/ReliableMessageContext.cpp

@@ -103,10 +103,6 @@ void ReliableMessageContext::HandleRcvdAck(uint32_t ackMessageCounter)
 CHIP_ERROR ReliableMessageContext::HandleNeedsAck(uint32_t messageCounter, BitFlags<MessageFlagValues> messageFlags)
 
 {
- // Skip processing ack if drop ack debug is enabled.
- if (ShouldDropAckDebug())
- return CHIP_NO_ERROR;
-
  CHIP_ERROR err = HandleNeedsAckInner(messageCounter, messageFlags);
 
  // Schedule next physical wakeup on function exit

src/messaging/ReliableMessageContext.h

@@ -67,9 +67,9 @@ class ReliableMessageContext
  }
 
  /**
- * Check whether we have an ack to piggyback on the message we are sending.
- * If true, TakePendingPeerAckMessageCounter will return a valid value that
- * should be included as an ack in the message.
+ * Check whether we have a mPendingPeerAckMessageCounter. The counter is
+ * valid once we receive a message which requests an ack. Once
+ * mPendingPeerAckMessageCounter is valid, it never stops being valid.
  */
  bool HasPiggybackAckPending() const;
 
@@ -102,26 +102,6 @@ class ReliableMessageContext
  */
  void SetAutoRequestAck(bool autoReqAck);
 
- /**
- * Determine whether the ChipExchangeManager should not send an
- * acknowledgement.
- *
- * For internal, debug use only.
- */
- bool ShouldDropAckDebug() const;
-
- /**
- * Set whether the ChipExchangeManager should not send acknowledgements
- * for this context.
- *
- * For internal, debug use only.
- *
- * @param[in] inDropAckDebug A Boolean indicating whether (true) or not
- * (false) the acknowledgements should be not
- * sent for the exchange.
- */
- void SetDropAckDebug(bool inDropAckDebug);
-
  /**
  * Determine whether there is already an acknowledgment pending to be sent to the peer on this exchange.
  *
@@ -159,29 +139,25 @@ class ReliableMessageContext
  /// When set, automatically request an acknowledgment whenever a message is sent via UDP.
  kFlagAutoRequestAck = (1u << 2),
 
- /// Internal and debug only: when set, the exchange layer does not send an acknowledgment.
- kFlagDropAckDebug = (1u << 3),
-
  /// When set, signifies there is a message which hasn't been acknowledged.
- kFlagMessageNotAcked = (1u << 4),
+ kFlagMessageNotAcked = (1u << 3),
 
  /// When set, signifies that there is an acknowledgment pending to be sent back.
- kFlagAckPending = (1u << 5),
+ kFlagAckPending = (1u << 4),
 
- /// When set, signifies that there has once been an acknowledgment
- /// pending to be sent back. In that case,
- /// mPendingPeerAckMessageCounter is a valid message counter value for
- /// some message we have needed to acknowledge in the past.
- kFlagAckMessageCounterIsValid = (1u << 6),
+ /// When set, signifies that mPendingPeerAckMessageCounter is valid.
+ /// The counter is valid once we receive a message which requests an ack.
+ /// Once mPendingPeerAckMessageCounter is valid, it never stops being valid.
+ kFlagAckMessageCounterIsValid = (1u << 5),
 
  /// When set, signifies that this exchange is waiting for a call to SendMessage.
- kFlagWillSendMessage = (1u << 7),
+ kFlagWillSendMessage = (1u << 6),
 
  /// When set, we have had Close() or Abort() called on us already.
- kFlagClosed = (1u << 8),
+ kFlagClosed = (1u << 7),
 
  /// When set, signifies that the exchange is requesting Sleepy End Device active mode.
- kFlagActiveMode = (1u << 9),
+ kFlagActiveMode = (1u << 8),
  };
 
  BitFlags<Flags> mFlags; // Internal state flags
@@ -228,11 +204,6 @@ inline bool ReliableMessageContext::IsMessageNotAcked() const
  return mFlags.Has(Flags::kFlagMessageNotAcked);
 }
 
-inline bool ReliableMessageContext::ShouldDropAckDebug() const
-{
- return mFlags.Has(Flags::kFlagDropAckDebug);
-}
-
 inline bool ReliableMessageContext::HasPiggybackAckPending() const
 {
  return mFlags.Has(Flags::kFlagAckMessageCounterIsValid);
@@ -253,11 +224,6 @@ inline void ReliableMessageContext::SetAckPending(bool inAckPending)
  mFlags.Set(Flags::kFlagAckPending, inAckPending);
 }
 
-inline void ReliableMessageContext::SetDropAckDebug(bool inDropAckDebug)
-{
- mFlags.Set(Flags::kFlagDropAckDebug, inDropAckDebug);
-}
-
 inline void ReliableMessageContext::SetMessageNotAcked(bool messageNotAcked)
 {
  mFlags.Set(Flags::kFlagMessageNotAcked, messageNotAcked);