Release Open Control Block resources
Synopsis:
#include <sys/iofunc.h>
int iofunc_ocb_detach( resmgr_context_t * ctp,
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.
- 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_ocb_detach() function releases any resources allocated to the
passed ocb, such as any memory map (mmap) entries.
Note:
This function doesn't free the memory associated with the OCB itself.
The iofunc_ocb_detach() function also updates the time structure, by calling
iofunc_time_update(),
and decrements the read, write, lock, and use counters, according to
the mode that was used to open the resource (from ocb->ioflag).
The counters are incremented in
iofunc_ocb_attach(),
and represent the number of OCBs that are using the managed
resource in the respective manners (e.g.:
ocb->attr->rcount keeps count of how many
OCBs are using the resource specified by attr for read access).
If you're using
iofunc_mmap()
or
iofunc_mmap_default(),
you must call iofunc_ocb_detach() to clean up.
This function is called by
iofunc_close_ocb().
Returns:
A bitwise OR of flags describing the state of the managed resource:
- IOFUNC_OCB_LAST_READER
- This OCB was the last one performing read operations on the resource.
This flag is set when the
ocb->attr->rcount flag is
decremented to zero.
- IOFUNC_OCB_LAST_WRITER
- This OCB was the last one performing write operations on the resource.
This flag is set when the
ocb->attr->wcount flag is
decremented to zero.
- IOFUNC_OCB_LAST_RDLOCK
- This OCB was the last one holding a read lock on the resource.
This flag is set when the
ocb->attr->rlocks flag is
decremented to zero.
- IOFUNC_OCB_LAST_WRLOCK
- This OCB was the last one holding a write lock on the resource.
This flag is set when the
ocb->attr->wlocks flag is
decremented to zero.
- IOFUNC_OCB_LAST_INUSE
- This OCB was the last one using the resource.
This flag is set when the
ocb->attr->count flag is
decremented to zero.
Classification:
QNX Neutrino
Safety: |
|
Cancellation point |
No |
Interrupt handler |
No |
Signal handler |
Yes |
Thread |
Yes |