I provide synchronized communication of a single bit of information (a "signal") between Processes. A signal is sent by sending the message signal and received by sending the message wait. If no signal has been sent when a wait message is sent, the sending Process will be suspended until a signal is sent.

	comparing
	= hash

	initialize-release
	initSignals terminateProcess

	mutual exclusion
	critical: critical:ifError:

	testing
	isSignaled

	communication	top
	signal Primitive. Send a signal through the receiver. If one or more processes have been suspended trying to receive a signal, allow the first one to proceed. If no process is waiting, remember the excess signal. Essential. See Object documentation whatIsAPrimitive.
	wait Primitive. The active Process must receive a signal through the receiver before proceeding. If no signal has been sent, the active Process will be suspended until one is sent. Essential. See Object documentation whatIsAPrimitive.
	waitTimeoutMSecs: Wait on this semaphore for up to the given number of milliseconds, then timeout. It is up to the sender to determine the difference between the expected event and a timeout.
	waitTimeoutSeconds: Wait on this semaphore for up to the given number of seconds, then timeout. It is up to the sender to determine the difference between the expected event and a timeout.

	comparing	top
	= Answer true if the receiver is equivalent to the otherCollection. First test for identity, then rule out different species and sizes of collections. As a last resort, examine each element of the receiver and the otherCollection.
	hash Answer an integer hash value for the receiver such that, -- the hash value of an unchanged object is constant over time, and -- two equal objects have equal hash values

	initialize-release	top
	initSignals Consume any excess signals the receiver may have accumulated.
	terminateProcess Terminate the process waiting on this semaphore, if any.

	mutual exclusion	top
	critical: Evaluate mutuallyExcludedBlock only if the receiver is not currently in the process of running the critical: message. If the receiver is, evaluate mutuallyExcludedBlock after the other critical: message is finished.
	critical:ifError: Evaluate mutuallyExcludedBlock only if the receiver is not currently in the process of running the critical: message. If the receiver is, evaluate mutuallyExcludedBlock after the other critical: message is finished.

	testing	top
	isSignaled Return true if this semaphore is currently signaled

	instance creation	top
	forMutualExclusion Answer an instance of me that contains a single signal. This new instance can now be used for mutual exclusion (see the critical: message to Semaphore).
	new Answer a new instance of Semaphore that contains no signals.