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[] critical vs aSemaphore critical: []

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Louis LaBrunda

[] critical vs aSemaphore critical: []

Hi All,

I realized I need to protect the ordered collections from being changed by a fork while in the middle of a change from another fork (see my other post about makeFixed/makeFree).

Is there any reason I need more than [] critical like using aSemaphore critical: []? See the code below.

I don't think so but sometimes the reasons are not obvious.

Lou

inputBuffer: receiveType
	"Answer an input buffer for the receive type (String or ByteArray).  Put the buffer in fixed space."
	"Buffers are freed by #freeInputBuffer: and are cleared it that time."

	^[ | buffer pool bufferSize |
		StringInputBuffers isNil ifTrue: [StringInputBuffers := OrderedCollection new: 100].
		ByteArrayInputBuffers isNil ifTrue: [ByteArrayInputBuffers := OrderedCollection new: 100].
		bufferSize := 32768.					"32 * 1024"
		pool := (receiveType == String) ifTrue: [StringInputBuffers] ifFalse: [ByteArrayInputBuffers].
		buffer := pool notEmpty ifTrue: [pool removeLast] ifFalse: [receiveType new: bufferSize].
		buffer makeFixed.
	] critical.

freeInputBuffer: buffer
	"Clear and then put the input buffer for the receive type (String or ByteArray) into a pool for reuse."

	[
		buffer isString ifTrue: [
			buffer replaceFrom: 1 to: buffer size withObject: Nul.
			StringInputBuffers add: buffer.
		] ifFalse: [
			buffer replaceFrom: 1 to: buffer size withObject: 0.
			ByteArrayInputBuffers add: buffer.
		].
	] critical.

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