Revert #724e1a7 and replace with stack checks.

Replaces `NimBLEDevice::setConnectionInProgress` and `NimBLEDevice::isConnectionInProgress()` with lower level checks to avoid potential incorrect state reporting.
`NimBLEClient::connect` will instead call `NimBLEScan::stop` if it stopped the scan to release any resources waiting, the call the callback if set.

src/NimBLEClient.cpp

@@ -176,11 +176,6 @@ bool NimBLEClient::connect(const NimBLEAddress& address, bool deleteAttributes,
         return false;
     }
 
-    if (NimBLEDevice::isConnectionInProgress()) {
-        NIMBLE_LOGE(LOG_TAG, "Connection already in progress");
-        return false;
-    }
-
     const ble_addr_t* peerAddr = address.getBase();
     if (ble_gap_conn_find_by_addr(peerAddr, NULL) == 0) {
         NIMBLE_LOGE(LOG_TAG, "A connection to %s already exists", address.toString().c_str());
@@ -202,9 +197,6 @@ bool NimBLEClient::connect(const NimBLEAddress& address, bool deleteAttributes,
     m_config.asyncConnect = asyncConnect;
     m_config.exchangeMTU  = exchangeMTU;
 
-    // Set the connection in progress flag to prevent a scan from starting while connecting.
-    NimBLEDevice::setConnectionInProgress(true);
-
     do {
 # if CONFIG_BT_NIMBLE_EXT_ADV
         rc = ble_gap_ext_connect(NimBLEDevice::m_ownAddrType,
@@ -258,7 +250,6 @@ bool NimBLEClient::connect(const NimBLEAddress& address, bool deleteAttributes,
 
     if (rc != 0) {
         m_lastErr = rc;
-        NimBLEDevice::setConnectionInProgress(false);
         return false;
     }
 
@@ -985,7 +976,6 @@ int NimBLEClient::handleGapEvent(struct ble_gap_event* event, void* arg) {
                 return 0;
             }
 
-            NimBLEDevice::setConnectionInProgress(false);
             rc = event->connect.status;
             if (rc == 0) {
                 pClient->m_connHandle = event->connect.conn_handle;

src/NimBLEDevice.cpp

@@ -101,10 +101,6 @@ std::vector<NimBLEAddress> NimBLEDevice::m_ignoreList{};
 std::vector<NimBLEAddress> NimBLEDevice::m_whiteList{};
 uint8_t                    NimBLEDevice::m_ownAddrType{BLE_OWN_ADDR_PUBLIC};
 
-# if defined(CONFIG_BT_NIMBLE_ROLE_CENTRAL) || defined(CONFIG_BT_NIMBLE_ROLE_PERIPHERAL)
-bool NimBLEDevice::m_connectionInProgress{false};
-# endif
-
 # ifdef ESP_PLATFORM
 #  ifdef CONFIG_BTDM_BLE_SCAN_DUPL
 uint16_t NimBLEDevice::m_scanDuplicateSize{CONFIG_BTDM_SCAN_DUPL_CACHE_SIZE};
@@ -1238,23 +1234,6 @@ bool NimBLEDevice::setCustomGapHandler(gap_event_handler handler) {
     return rc == 0;
 } // setCustomGapHandler
 
-/**
- * @brief Set the connection in progress flag.
- * @param [in] inProgress The connection in progress flag.
- * @details This is used to prevent a scan from starting while a connection is in progress.
- */
-void NimBLEDevice::setConnectionInProgress(bool inProgress) {
-    m_connectionInProgress = inProgress;
-} // setConnectionInProgress
-
-/**
- * @brief Check if a connection is in progress.
- * @return True if a connection is in progress.
- */
-bool NimBLEDevice::isConnectionInProgress() {
-    return m_connectionInProgress;
-} // isConnectionInProgress
-
 /**
  * @brief Return a string representation of the address of this device.
  * @return A string representation of this device address.

src/NimBLEDevice.h

@@ -184,8 +184,6 @@ class NimBLEDevice {
     static bool          isBonded(const NimBLEAddress& address);
     static bool          deleteAllBonds();
     static NimBLEAddress getBondedAddress(int index);
-    static void          setConnectionInProgress(bool inProgress);
-    static bool          isConnectionInProgress();
 # endif
 
   private:
@@ -197,10 +195,6 @@ class NimBLEDevice {
     static uint8_t                    m_ownAddrType;
     static std::vector<NimBLEAddress> m_whiteList;
 
-# if defined(CONFIG_BT_NIMBLE_ROLE_CENTRAL) || defined(CONFIG_BT_NIMBLE_ROLE_PERIPHERAL)
-    static bool m_connectionInProgress;
-# endif
-
 # if defined(CONFIG_BT_NIMBLE_ROLE_OBSERVER)
     static NimBLEScan* m_pScan;
 # endif

src/NimBLEScan.cpp

@@ -291,7 +291,7 @@ bool NimBLEScan::isScanning() {
 bool NimBLEScan::start(uint32_t duration, bool is_continue) {
     NIMBLE_LOGD(LOG_TAG, ">> start: duration=%" PRIu32, duration);
 
-    if (NimBLEDevice::isConnectionInProgress()) {
+    if (ble_gap_conn_active()) {
         NIMBLE_LOGE(LOG_TAG, "Connection in progress, cannot start scan");
         return false;
     }