Sun Microsystems S16A s16aconfigureringbuffers, Description, Syntax, Arguments, s16ap, bufsize

S16A User’s Guide Input and Output

s16a_configure_ring_buffers

Description

Configures the SBus 16-bit Dual Analog Interface ring buffers. Any previous configuration is replaced, and previously allocated buffers are released.

Buffers can be allocated and maintained within the SBus 16-bit Dual Analog Interface library or within the user application itself.

Syntax

int s16a_configure_ring_buffers(S16aDev *s16a_p, int bufsize, int nbufs, void *bufarray[], int data_output);

Arguments
s16a_p	S16A device handle returned from s16a_open
bufsize	size of each buffer. For optimal efficiency, allocate a value approximating throughput
	divided by 20: that is, if transfer occurs at 20 MB per second, allocate 1 MB per buffer.
	Buffers significantly larger or smaller can overuse memory or lock the system up in
	processing interrupts.
nbufs	number of buffers. Must be 1 or greater. Four is recommended.
bufarray	array of pointers to individual buffers if the buffers are allocated by the application. Must
	be NULL if in library, or have nbufs elements.
	library	Must be NULL.
	user	This array must be filled with the addresses of the buffers allocated by
		the application for the library to use.
data_direction	Indicates whether this connection is to be used for input or output. Only one direction is
	possible per device or subdevice:
	EDT_READ = 0
	EDT_WRITE = 1

Return

0 on success; –1 on error. If all buffers cannot be allocated, none are allocated and an error is returned.

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