Open [& Connect] @ ctor (RAII): HCIComm, L2CAPComm, GATTHandler, simplifying 'connect' lifecycle

Further:
- L2CAPComm
-- disconnect(): Only lock mtw_write if connected and mark noexcept
-- Added '~L2CAPComm() noexcept' for RAII
-- Removed unsued accessors

- GATTHandler
-- Similar treatment as L2CAPComm

- DBTDevice
-- Remove mtx_gatt and its locks, they were not consistent.
   Rely on mtx_connect (connectGATT/getGATTServices/disconnect)
   and atomic local GATTHandler copy when using.

-- disconnect GATTHandler directly in disconnect, remove explicit method.

-- pingGATT uses local gattHandler copy to avoid parallel disconnect nullptr,
   however, it will fail immediately due to disconnection.

3 files changed, 5 insertions, 6 deletions

diff --git a/examples/direct_bt_scanner00/dbt_scanner00.cpp b/examples/direct_bt_scanner00/dbt_scanner00.cpp
index 63eb61c4..5cf9f996 100644
--- a/examples/direct_bt_scanner00/dbt_scanner00.cpp
+++ b/examples/direct_bt_scanner00/dbt_scanner00.cpp
@@ -267,7 +267,7 @@ int main(int argc, char *argv[])
                 }
                 {
                     std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
-                    if( nullptr != gatt && gatt->isOpen() ) {
+                    if( nullptr != gatt && gatt->getIsConnected() ) {
                         std::shared_ptr<DeviceInformation> di = gatt->getDeviceInformation(primServices);
                         if( nullptr != di ) {
                             fprintf(stderr, "  DeviceInformation: %s\n\n", di->toString().c_str());
diff --git a/examples/direct_bt_scanner01/dbt_scanner01.cpp b/examples/direct_bt_scanner01/dbt_scanner01.cpp
index 653e5eab..4d791050 100644
--- a/examples/direct_bt_scanner01/dbt_scanner01.cpp
+++ b/examples/direct_bt_scanner01/dbt_scanner01.cpp
@@ -277,19 +277,19 @@ int main(int argc, char *argv[])
                 if( nullptr != ga ) {
                     fprintf(stderr, "  GenericAccess: %s\n\n", ga->toString().c_str());
                 }
-                if( nullptr != gatt && gatt->isOpen() ) {
+                if( nullptr != gatt && gatt->getIsConnected() ) {
                     std::shared_ptr<DeviceInformation> di = gatt->getDeviceInformation(primServices);
                     if( nullptr != di ) {
                         fprintf(stderr, "  DeviceInformation: %s\n\n", di->toString().c_str());
                     }
                 }
 
-                for(size_t i=0; i<primServices.size() && gatt->isOpen(); i++) {
+                for(size_t i=0; i<primServices.size() && gatt->getIsConnected(); i++) {
                     GATTService & primService = *primServices.at(i);
                     fprintf(stderr, "  [%2.2d] Service %s\n", (int)i, primService.toString().c_str());
                     fprintf(stderr, "  [%2.2d] Service Characteristics\n", (int)i);
                     std::vector<GATTCharacteristicRef> & serviceCharacteristics = primService.characteristicList;
-                    for(size_t j=0; j<serviceCharacteristics.size() && gatt->isOpen(); j++) {
+                    for(size_t j=0; j<serviceCharacteristics.size() && gatt->getIsConnected(); j++) {
                         GATTCharacteristic & serviceChar = *serviceCharacteristics.at(j);
                         fprintf(stderr, "  [%2.2d.%2.2d] Decla: %s\n", (int)i, (int)j, serviceChar.toString().c_str());
                         if( serviceChar.hasProperties(GATTCharacteristic::PropertyBitVal::Read) ) {
@@ -312,7 +312,6 @@ int main(int argc, char *argv[])
                 }
                 // FIXME sleep 1s for potential callbacks ..
                 sleep(1);
-                device->disconnectGATT(); // redundant: also done at gatt->disconnect()
             } else {
                 fprintf(stderr, "GATT connect failed: %s\n", gatt->getStateString().c_str());
             }
diff --git a/examples/direct_bt_scanner10/dbt_scanner10.cpp b/examples/direct_bt_scanner10/dbt_scanner10.cpp
index 1a0bbf5a..20a0c7ee 100644
--- a/examples/direct_bt_scanner10/dbt_scanner10.cpp
+++ b/examples/direct_bt_scanner10/dbt_scanner10.cpp
@@ -307,7 +307,7 @@ static void processConnectedDevice(std::shared_ptr<DBTDevice> device) {
         }
         {
             std::shared_ptr<GATTHandler> gatt = device->getGATTHandler();
-            if( nullptr != gatt && gatt->isOpen() ) {
+            if( nullptr != gatt && gatt->getIsConnected() ) {
                 std::shared_ptr<DeviceInformation> di = gatt->getDeviceInformation(primServices);
                 if( nullptr != di && !SILENT_GATT ) {
                     fprintf(stderr, "  DeviceInformation: %s\n\n", di->toString().c_str());