Default handler for _IO_LSEEK messages
Synopsis:
#include <sys/iofunc.h>
int iofunc_lseek_default( resmgr_context_t* ctp,
io_lseek_t* msg,
iofunc_ocb_t* ocb );
Arguments:
- ctp
- A pointer to a
resmgr_context_t
structure that the resource-manager library uses to pass context information
between functions.
- msg
- A pointer to the
io_lseek_t
structure that contains the message that the resource manager received.
For more information, see the documentation for iofunc_lseek().
- ocb
- A pointer to the
iofunc_ocb_t
structure for the Open Control Block that was created when the
client opened the resource.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The iofunc_lseek_default() function
implements POSIX semantics for the client's
lseek()
call, which is received as an _IO_LSEEK message by the resource manager.
You can place this function directly into the
resmgr_io_funcs_t
table passed as the io_funcs argument to
resmgr_attach(),
at the lseek position, or you can call
iofunc_func_init()
to initialize all of the functions to their default values.
The iofunc_lseek_default() function calls
iofunc_lseek()
to do the actual work.
Returns:
- -1
- Success; the resource manager library should return a one-part IOV to the client.
- EOK
- The message is a combine message, and no error occurred.
- EINVAL
- The whence member in the _IO_LSEEK message wasn't one of
SEEK_SET, SEEK_CUR, or SEEK_END,
or the resulting position after the offset was applied resulted in a negative number (overflow).
- EOVERFLOW
- The resulting file offset is a value that can't be represented
correctly in an object of type off_t.
Classification:
QNX Neutrino
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |