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aio_req(9s) [bsd man page]

aio_req(9S)						    Data Structures for Drivers 					       aio_req(9S)

aio_req - asynchronous I/O request structure SYNOPSIS
#include <sys/uio.h> #include <sys/aio_req.h> #include <sys/ddi.h> #include <sys/sunddi.h> INTERFACE LEVEL
Solaris DDI specific (Solaris DDI) DESCRIPTION
An aio_req structure describes an asynchronous I/O request. STRUCTURE MEMBERS
struct uio*aio_uio; /* uio structure describing the I/O request */ The aio_uio member is a pointer to a uio(9S) structure, describing the I/O transfer request. SEE ALSO
aread(9E), awrite(9E), aphysio(9F), uio(9S) SunOS 5.10 28 Mar 1997 aio_req(9S)

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aread(9E)							Driver Entry Points							 aread(9E)

aread - asynchronous read from a device SYNOPSIS
#include <sys/uio.h> #include <sys/aio_req.h> #include <sys/cred.h> #include <sys/ddi.h> #include <sys/sunddi.h> intprefix aread(dev_t dev, struct aio_req *aio_reqp, cred_t *cred_p); INTERFACE LEVEL
Solaris DDI specific (Solaris DDI). This entry point is optional. Drivers that do not support an aread() entry point should use nodev(9F) PARAMETERS
dev Device number. aio_reqp Pointer to the aio_req(9S) structure that describes where the data is to be stored. cred_p Pointer to the credential structure. DESCRIPTION
The driver's aread() routine is called to perform an asynchronous read. getminor(9F) can be used to access the minor number component of the dev argument. aread() may use the credential structure pointed to by cred_p to check for superuser access by calling drv_priv(9F). The aread() routine may also examine the uio(9S) structure through the aio_req structure pointer, aio_reqp. aread() must call aphysio(9F) with the aio_req pointer and a pointer to the driver's strategy(9E) routine. No fields of the uio(9S) structure pointed to by aio_req, other than uio_offset or uio_loffset, may be modified for non-seekable devices. RETURN VALUES
The aread() routine should return 0 for success, or the appropriate error number. CONTEXT
This function is called from user context only. EXAMPLES
Example 1: The following is an example of an aread() routine: static int xxaread(dev_t dev, struct aio_req *aio, cred_t *cred_p) { int instance; struct xxstate *xsp; instance = getminor(dev); xsp = ddi_get_soft_state(statep, instance); /*Verify soft state structure has been allocated */ if (xsp == NULL) return (ENXIO); return (aphysio(xxstrategy, anocancel, dev, B_READ, xxminphys, aio)); } SEE ALSO
read(2), aioread(3AIO), awrite(9E), read(9E), strategy(9E), write(9E), anocancel(9F), aphysio(9F), ddi_get_soft_state(9F), drv_priv(9F), getminor(9F), minphys(9F), nodev(9F), aio_req(9S), cb_ops(9S), uio(9S) Writing Device Drivers BUGS
There is no way other than calling aphysio(9F) to accomplish an asynchronous read. SunOS 5.10 28 Mar 1997 aread(9E)

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