iofunc_ocb_detach()
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.
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(), iofunc_mmap_ext(), iofunc_mmap_default(), or iofunc_mmap_default_ext(), 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:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |