iofunc_sync_verify()

Updated: October 26, 2022

Verify permissions to sync

Synopsis:

#include <sys/iofunc.h>

int iofunc_sync_verify( resmgr_context_t *ctp,
                        io_sync_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_sync_t structure that contains the message that the resource manager received; see below.
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_sync_verify() function verifies that the client has permission to synchronize.

io_sync_t structure

The io_sync_t structure holds the _IO_SYNC message received by the resource manager:

struct _io_sync {
    uint16_t                    type;
    uint16_t                    combine_len;
    uint32_t                    flag;
};

typedef union {
    struct _io_sync             i;
} io_sync_t;

The I/O message structures are unions of an input message (coming to the resource manager) and an output or reply message (going back to the client). In this case, there's only an input message, i.

The i member is a structure of type _io_sync that contains the following members:

type
_IO_SYNC.
combine_len
If the message is a combine message, _IO_COMBINE_FLAG is set in this member. For more information, see Combine Messages chapter of Writing a Resource Manager.
flag
One of:
  • O_DSYNC
  • O_SYNC

For more information about these flags, see open().

Returns:

EOK
The resource supports synchronizing.
EINVAL
The resource doesn't support synchronizing (i.e, IOFUNC_PC_SYNC_IO isn't set in the device's mount configuration).

Classification:

QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes