fix(server): notify characteristics on client disconnect#393
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m-mcgowan wants to merge 1 commit intoh2zero:masterfrom
Open
fix(server): notify characteristics on client disconnect#393m-mcgowan wants to merge 1 commit intoh2zero:masterfrom
m-mcgowan wants to merge 1 commit intoh2zero:masterfrom
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When a client disconnects, iterate through all services and characteristics and call processSubRequest with subValue=0 for any that had subscriptions from the disconnecting client. This ensures that application callbacks (onSubscribe) are properly notified when a client disconnects, allowing them to clean up their subscription state. Previously, the onSubscribe callback was only called when the client explicitly unsubscribed by writing to the CCCD, not when the connection was terminated. This fixes issues where: - Subscriber counts would not decrement on disconnect - Blocking reads would hang forever waiting for unsubscribe notification - Applications could not detect client disconnection via characteristic callbacks
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Summary
When a BLE client disconnects, characteristics with active subscriptions are not notified. This leaves applications with stale subscription state, causing issues with reconnection.
This PR adds code to the
BLE_GAP_EVENT_DISCONNECThandler to iterate through all characteristics and callprocessSubRequest(peerInfo, 0)for any that had active subscriptions from the disconnecting client.Problem
Applications using wrappers like NuS-NimBLE-Serial track subscriber counts via the
onSubscribecallback. Without this fix:onSubscribe(subValue=1)called → count = 1Solution
In
BLE_GAP_EVENT_DISCONNECT, before callingonDisconnect:processSubRequest(peerInfo, 0)to trigger theonSubscribecallback withsubValue=0This ensures:
onSubscribecallback is called withsubValue=0Testing
Tested with ESP32-S3 using the ESP-IDF framework (with Arduino as a component) and NuS-NimBLE-Serial. Before the fix, reconnection after disconnect would fail. After the fix, reconnection works reliably.
Note
An equivalent fix has been submitted to NimBLE-Arduino (#1081 in h2zero/NimBLE-Arduino) for Arduino-only builds.