DBTAdapter, Device, HCIHandler: SEND (manual) EVENTs off-thread, mimic normal event delivered via HCIHandler's reader threadalt_sendevent

3 files changed, 13 insertions, 12 deletions

diff --git a/src/direct_bt/DBTAdapter.cpp b/src/direct_bt/DBTAdapter.cpp
index 5e76c705..f210a4bd 100644
--- a/src/direct_bt/DBTAdapter.cpp
+++ b/src/direct_bt/DBTAdapter.cpp
@@ -561,10 +561,10 @@ exit:
     if( discoveryTempDisabled || !res ) {
         // In case of discoveryTempDisabled, power-off, le_enable_scane failure
         // or already pulled HCIHandler, send the event directly.
-        mgmtEvDeviceDiscoveringHCI(
-                std::shared_ptr<MgmtEvent>(
-                        new MgmtEvtDiscovering(dev_id, ScanType::LE, false)
-                ) );
+        // SEND_EVENT: Perform off-thread to avoid potential deadlock w/ application callbacks (similar when sent from HCIHandler's reader-thread)
+        std::thread bg(&DBTAdapter::mgmtEvDeviceDiscoveringHCI, this, std::shared_ptr<MgmtEvent>( new MgmtEvtDiscovering(dev_id, ScanType::LE, false) ) );
+        bg.detach();
+        // mgmtEvDeviceDiscoveringHCI( std::shared_ptr<MgmtEvent>( new MgmtEvtDiscovering(dev_id, ScanType::LE, false) ) );
     }
     DBG_PRINT("DBTAdapter::stopDiscovery: End: Result %d, keepAlive %d, currentScanType[native %s, meta %s], discoveryTempDisabled %d ...",
             res, keepDiscoveringAlive.load(),
diff --git a/src/direct_bt/DBTDevice.cpp b/src/direct_bt/DBTDevice.cpp
index b1f1dccb..95af4dd8 100644
--- a/src/direct_bt/DBTDevice.cpp
+++ b/src/direct_bt/DBTDevice.cpp
@@ -426,8 +426,6 @@ void DBTDevice::disconnectGATT() noexcept {
 }
 
 HCIStatusCode DBTDevice::disconnect(const HCIStatusCode reason) noexcept {
-    // ioErrorCause only true: pingGATT failure or GATTHandler::disconnect(..) called on failure
-
     // Avoid disconnect re-entry -> potential deadlock
     bool expConn = true; // C++11, exp as value since C++20
     if( !allowDisconnect.compare_exchange_strong(expConn, false) ) {
@@ -480,10 +478,11 @@ exit:
         // In case of an already pulled or disconnected HCIHandler (e.g. power-off)
         // or in case the hci->disconnect() itself fails,
         // send the DISCONN_COMPLETE event directly.
-        adapter.mgmtEvDeviceDisconnectedHCI(
-                std::shared_ptr<MgmtEvent>(
-                        new MgmtEvtDeviceDisconnected(adapter.dev_id, address, addressType, reason, hciConnHandle.load())
-                ) );
+        // SEND_EVENT: Perform off-thread to avoid potential deadlock w/ application callbacks (similar when sent from HCIHandler's reader-thread)
+        std::thread bg(&DBTAdapter::mgmtEvDeviceDisconnectedHCI, &adapter, std::shared_ptr<MgmtEvent>(
+                 new MgmtEvtDeviceDisconnected(adapter.dev_id, address, addressType, reason, hciConnHandle.load()) ) );
+        bg.detach();
+        // adapter.mgmtEvDeviceDisconnectedHCI( std::shared_ptr<MgmtEvent>( new MgmtEvtDeviceDisconnected(adapter.dev_id, address, addressType, reason, hciConnHandle.load()) ) );
     }
     WORDY_PRINT("DBTDevice::disconnect: End: status %s, handle 0x%X, isConnected %d/%d on %s",
             getHCIStatusCodeString(res).c_str(), hciConnHandle.load(),
diff --git a/src/direct_bt/HCIHandler.cpp b/src/direct_bt/HCIHandler.cpp
index 6affc1d3..6359ab83 100644
--- a/src/direct_bt/HCIHandler.cpp
+++ b/src/direct_bt/HCIHandler.cpp
@@ -606,8 +606,10 @@ HCIStatusCode HCIHandler::le_enable_scan(const bool enable, const bool filter_du
     std::shared_ptr<HCIEvent> ev = processCommandComplete(req0, &ev_status, &status);
 
     if( HCIStatusCode::SUCCESS == status ) {
-        MgmtEvtDiscovering *e = new MgmtEvtDiscovering(dev_id, ScanType::LE, enable);
-        sendMgmtEvent(std::shared_ptr<MgmtEvent>(e));
+        // SEND_EVENT: Perform off-thread to avoid potential deadlock w/ application callbacks (similar when sent from HCIHandler's reader-thread)
+        std::thread bg(&HCIHandler::sendMgmtEvent, this, std::shared_ptr<MgmtEvent>( new MgmtEvtDiscovering(dev_id, ScanType::LE, enable) ) );
+        bg.detach();
+        // sendMgmtEvent(std::shared_ptr<MgmtEvent>( new MgmtEvtDiscovering(dev_id, ScanType::LE, enable) ) );
     }
     return status;
 }