1. ChannelTest::MultipleSendersReceivers
- Add C++14-compatible latch implementation (similar to C++20 std::latch)
- Ensure receivers are ready before senders start sending messages
- This prevents race condition where senders might send before receivers are listening
2. RWLockTest::ReadWriteReadPattern
- Fix test logic: lock_shared allows multiple concurrent readers
- Previous test had race condition where both threads could read same value
- New test: each thread writes based on thread id (1 or 2), then reads
- Expected result: 1*20 + 2*20 = 60
3. ShmTest::ReleaseMemory
- Correct return value semantics: release() returns ref count before decrement, or -1 on error
- Must call get_mem() to map memory and set ref count to 1 before release
- Expected: release() returns 1 (ref count before decrement)
4. ShmTest::ReferenceCount
- Correct semantics: ref count is 0 after acquire (memory not mapped)
- get_mem() maps memory and sets ref count to 1
- Second acquire+get_mem increases ref count to 2
- Test now properly validates reference counting behavior
5. ShmTest::SubtractReference
- sub_ref() only works after get_mem() has mapped the memory
- Must call get_mem() first to initialize ref count to 1
- sub_ref() then decrements it to 0
- Test now follows correct API usage pattern
- Test spin_lock basic operations and mutual exclusion
- Test spin_lock critical section protection
- Test spin_lock concurrent access and contention
- Test rw_lock write lock (exclusive access)
- Test rw_lock read lock (shared access)
- Test multiple concurrent readers
- Test writers have exclusive access
- Test readers and writers don't overlap
- Test various read-write patterns
- Test rapid lock/unlock operations
- Test mixed concurrent operations
- Test write lock blocks readers correctly
