[Tizen] Properly implement BLEManagerImpl::_NumConnections #39965
+2
−1
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
There was a problem hiding this comment.
Code Review
The pull request implements _NumConnections to return the actual number of BLE connections. The review focuses on a potential race condition when accessing the shared connection map and suggests adding thread synchronization using the platform's locking mechanism to ensure data integrity.
Comment on lines
+1068
to
+1069
| VerifyOrReturnValue(mConnectionMap != nullptr, 0); | ||
| return g_hash_table_size(mConnectionMap); |
There was a problem hiding this comment.
There's a potential race condition here. mConnectionMap can be modified by BLE event callbacks (like GattConnectionStateChangedCb) on a different thread, while this function could be called from any application thread. Accessing mConnectionMap without synchronization can lead to undefined behavior, such as crashes or returning an incorrect value.
To ensure thread safety, you should wrap the access to mConnectionMap with PlatformMgr().LockChipStack() and PlatformMgr().UnlockChipStack().
Additionally, g_hash_table_size returns a guint (usually 32-bit), while this function returns a uint16_t. It's good practice to use an explicit static_cast for the conversion to make the intent clear and prevent potential compiler warnings, even though it's unlikely for the number of connections to exceed the uint16_t limit.
Suggested change
| VerifyOrReturnValue(mConnectionMap != nullptr, 0); | |
| return g_hash_table_size(mConnectionMap); | |
| PlatformMgr().LockChipStack(); | |
| const guint size = mConnectionMap ? g_hash_table_size(mConnectionMap) : 0; | |
| PlatformMgr().UnlockChipStack(); | |
| return static_cast<uint16_t>(size); |
|
PR #39965: Size comparison from c0a78ce to 0258186 Full report (70 builds for bl602, bl702, bl702l, cc13x4_26x4, cc32xx, cyw30739, efr32, esp32, linux, nrfconnect, nxp, psoc6, qpg, stm32, telink)
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
The
chip::DeviceLayer::ConnectivityMgr().NumBLEConnections()always returns 0 because underlying implementation was incorrect.Testing
Locally verified that the application can check whether there is an ongoing BLE connection.