Serialized output I/O

Collaboration diagram for Serialized output I/O:

Files
file	CheckpointHdf5.cpp
	Native-descriptor VFD and platform checkpoint HDF5 access wrappers.
file	CheckpointHdf5.hpp
	Checkpoint result-file access with rename-sharing descriptor support.
file	IOThread.cpp
	IOThread — producer/consumer output writer implementation.
file	IOThread.hpp
	Separate IO writer thread with a bounded task queue (Phase 5, R17).
file	WriteTask.hpp
	Ring-buffer task descriptor for the IO thread (Phase 5, R17).

Classes
class	openswmm::IOThread
	Producer-consumer IO thread for writing simulation snapshots. More...
struct	openswmm::WriteTask
	One item in the IOThread write queue. More...

Detailed Description

Bounded asynchronous write queues and native file/archive helpers. The caller owns producer shutdown, borrowed immutable metadata lifetime and accepted-state boundaries; individual contracts describe locking and partial-failure behavior.