qbufcall(9f) [freebsd man page]
qbufcall(9F) Kernel Functions for Drivers qbufcall(9F) NAME
qbufcall - call a function when a buffer becomes available SYNOPSIS
#include <sys/stream.h> #include <sys/ddi.h> bufcall_id_t qbufcall(queue_t *q, size_t size, uint_t pri, void(*func)(void *arg), void *arg); INTERFACE LEVEL
Solaris DDI specific (Solaris DDI). PARAMETERS
q Pointer to STREAMS queue structure. size Number of bytes required for the buffer. pri Priority of the allocb(9F) allocation request (not used). func Function or driver routine to be called when a buffer becomes available. arg Argument to the function to be called when a buffer becomes available. DESCRIPTION
qbufcall() serves as a qtimeout(9F) call of indeterminate length. When a buffer allocation request fails, qbufcall() can be used to sched- ule the routine func to be called with the argument arg when a buffer becomes available. func may call allocb() or it may do something else. The qbufcall() function is tailored to be used with the enhanced STREAMS framework interface, which is based on the concept of perimeters. (See mt-streams(9F).) qbufcall() schedules the specified function to execute after entering the perimeters associated with the queue passed in as the first parameter to qbufcall(). All outstanding timeouts and bufcalls must be cancelled (using, respectively, quntimeout(9F) and qunbufcall(9F)) before a driver close routine can block and before the close routine calls qprocsoff(9F). qprocson(9F) must be called before calling either qbufcall() or qtimeout(9F). RETURN VALUES
If successful, qbufcall() returns a qbufcall ID that can be used in a call to qunbufcall(9F) to cancel the request. If the qbufcall() scheduling fails, func is never called and 0 is returned. CONTEXT
qbufcall() can be called from user or interrupt context. SEE ALSO
allocb(9F), mt-streams(9F), qprocson(9F), qtimeout(9F), qunbufcall(9F), quntimeout(9F) Writing Device Drivers STREAMS Programming Guide WARNINGS
Even when func is called by qbufcall(), allocb(9F) can fail if another module or driver had allocated the memory before func was able to call allocb(9F). SunOS 5.10 17 Oct 2002 qbufcall(9F)
Check Out this Related Man Page
qbufcall(9F) Kernel Functions for Drivers qbufcall(9F) NAME
qbufcall - call a function when a buffer becomes available SYNOPSIS
#include <sys/stream.h> #include <sys/ddi.h> bufcall_id_t qbufcall(queue_t *q, size_t size, uint_t pri, void(*func)(void *arg), void *arg); INTERFACE LEVEL
Solaris DDI specific (Solaris DDI). PARAMETERS
q Pointer to STREAMS queue structure. size Number of bytes required for the buffer. pri Priority of the allocb(9F) allocation request (not used). func Function or driver routine to be called when a buffer becomes available. arg Argument to the function to be called when a buffer becomes available. DESCRIPTION
qbufcall() serves as a qtimeout(9F) call of indeterminate length. When a buffer allocation request fails, qbufcall() can be used to sched- ule the routine func to be called with the argument arg when a buffer becomes available. func may call allocb() or it may do something else. The qbufcall() function is tailored to be used with the enhanced STREAMS framework interface, which is based on the concept of perimeters. (See mt-streams(9F).) qbufcall() schedules the specified function to execute after entering the perimeters associated with the queue passed in as the first parameter to qbufcall(). All outstanding timeouts and bufcalls must be cancelled (using, respectively, quntimeout(9F) and qunbufcall(9F)) before a driver close routine can block and before the close routine calls qprocsoff(9F). qprocson(9F) must be called before calling either qbufcall() or qtimeout(9F). RETURN VALUES
If successful, qbufcall() returns a qbufcall ID that can be used in a call to qunbufcall(9F) to cancel the request. If the qbufcall() scheduling fails, func is never called and 0 is returned. CONTEXT
qbufcall() can be called from user or interrupt context. SEE ALSO
allocb(9F), mt-streams(9F), qprocson(9F), qtimeout(9F), qunbufcall(9F), quntimeout(9F) Writing Device Drivers STREAMS Programming Guide WARNINGS
Even when func is called by qbufcall(), allocb(9F) can fail if another module or driver had allocated the memory before func was able to call allocb(9F). SunOS 5.10 17 Oct 2002 qbufcall(9F)