image.lock - Function

Acquire a lock on the image

Synopsis
lock(write, nattempts)

Arguments

write	in	Acquire a read/write (T) or a readonly (F) lock
		Allowed:	T or F
		Default:	T
nattempts	in	Number of attempts
		Allowed:	Non-negative integer
		Default:	Forever

Returns
T or fail

Description

This function can be used to acquire a Read or a Read/Write lock on the image file. It is not of general user interest.

In general locking is handled automatically, with a built in lock release cycle. However, this function can be useful in scripts when a file is being shared between more than one process. See also functions unlock and haslock.

Example

- im := image('xx')
- im.lock(write=T)
- im.unlock()
- im.lock(write=F)

This acquires a read/write lock on the file. Then we unlock it and acquire a readonly lock.

Next: image.makecomplex - Function Up: image - Tool Previous: image.ispersistent - Function Contents Index

	Package	general
	Module	images
	Tool	image