Struct readerWriter

chapter7/patterns/semaphore/semaphore.go:28–54

readerWriter provides a structure for safely reading and writing a shared resource. It supports multiple readers and a single writer goroutine using a semaphore construct.

	// readerWriter provides a structure for safely reading and writing a shared resource.
	// It supports multiple readers and a single writer goroutine using a semaphore construct.
	readerWriter struct {
		// The name of this object.
		name string

		// write forces reading to stop to allow the write to occur safely.
		write sync.WaitGroup

		// readerControl is a semaphore that allows a fixed number of reader goroutines
		// to read at the same time. This is our semaphore.
		readerControl semaphore

		// shutdown is used to signal to running goroutines to shutdown.
		shutdown chan struct{}

		// reportShutdown is used by the goroutines to report they are shutdown.
		reportShutdown sync.WaitGroup

		// maxReads defined the maximum number of reads that can occur at a time.
		maxReads int

		// maxReaders defines the number of goroutines launched to perform read operations.
		maxReaders int

		// currentReads keeps a safe count of the current number of reads occurring
		// at any give time.
		currentReads int32
	}
)

// init is called when the package is initialized. This code runs first.