osf1 man page for bufcall

bufcall(9r)															       bufcall(9r)

NAME
       bufcall - STREAMS: Gets a buffer when allocb fails

SYNOPSIS
       #include <sys/stream.h>

       int bufcall(
	       int size,
	       int pri,
	       int (*function) (),
	       long argument );

ARGUMENTS
       Specifies the number of bytes in the buffer.  Specifies the priority of the allocb allocation request (no longer used).	Specifies a kernel
       or driver interface to be called when a buffer becomes available.  Specifies an argument to be passed to the  kernel  or  driver  interface
       specified in the function argument.

DESCRIPTION
       The  bufcall  interface	serves	as  a timeout call of indeterminate length. When a buffer allocation request fails, you can use bufcall to
       schedule the interface passed to the function argument to be called with the argument passed to argument when a buffer  becomes	available.
       The interface passed to function can be a routine that calls allocb or it can be implemented to perform something else.

NOTES
       Even  when the bufcall interface calls the interface passed to the function argument, the allocb interface can still fail if another module
       or device driver allocated the memory before the interface in function was able to call allocb.

RETURN VALUES
       Upon successful completion, the bufcall interface returns a bufcall id that you can use in a call to the unbufcall interface to cancel  the
       request. If the bufcall scheduling fails (that is, a buffer is not available), the interface passed to function is never called and bufcall
       returns the value zero(0).

SEE ALSO
       Kernel Routines: allocb(9r), esballoc(9r), testb(9r)

       Programmer's Guide: STREAMS

																       bufcall(9r)