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C Library Reference
I
iofunc_sync_default()
Default handler for _IO_SYNC messages

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        Lock the attribute structure
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        I/O attribute structure
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        Try to lock the attribute structure
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        Unlock the attribute structure
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        Check access permissions
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        Check a message
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        Handle an _IO_CHMOD message
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        Default handler for _IO_CHMOD messages
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        Handle an _IO_CHOWN message
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        Default handler for _IO_CHOWN messages
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        Return information about a client connection, including abilities
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        Return information about a client connection
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        Free the structure used for information about a client connection
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        Free all locks allocated for the client process
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        Default handler for _IO_CLOSE messages
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        Return the memory allocated for an OCB
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        Return the memory allocated for an OCB
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        Handle an _IO_DEVCTL message
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        Default handler for _IO_DEVCTL messages
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        Perform validation that's common to all handlers for _IO_DEVCTL messages
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        Handle an _IO_FDINFO message
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        Default handler for _IO_FDINFO messages
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        Initialize the default POSIX-layer function tables
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        Link two directory entries
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        Lock a resource
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        Default handler for _IO_LOCK messages
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        Default handler for the lock_ocb callout
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        Handle an _IO_LSEEK message
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        Default handler for _IO_LSEEK messages
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        Verify a client's ability to make a new filesystem entry point
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        Handle an _IO_MMAP message
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        Default handler for _IO_MMAP messages
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        Handle an _IO_MMAP message
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        Clean up the IOFUNC_MOUNT_T structure
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        Set the timestamp resolution for iofunc functions and structures
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        Remove notification entries from a list
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        Initialize an Open Control Block (OCB)
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        Allocate an iofunc Open Control Block
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        Release Open Control Block resources
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        Deallocate an iofunc Open Control Block's memory
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        Open Control Block structure
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        Verify a client's ability to open or to create a resource
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        Default handler for _IO_CONNECT messages
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        Increment count and locking flags
      - iofunc_openfd_default()
        Default handler for _IO_OPENFD messages
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        Support pathconf() requests
      - iofunc_pathconf_default()
        Default handler for _IO_PATHCONF messages
      - iofunc_read_default()
        Default handler for _IO_READ messages
      - iofunc_read_verify()
        Verify a client's read access to a resource
      - iofunc_readlink()
        Verify the attributes being used to read a link
      - iofunc_rename()
        Do permission checks for a _IO_CONNECT_RENAME message
      - iofunc_space_verify()
        Do permission checks for the _IO_SPACE message
      - iofunc_stat(), iofunc_stat_format()
        Populate a stat structure
      - iofunc_stat_default()
        Default handler for _IO_STAT messages
      - iofunc_sync()
        Indicate if synchronization is needed
      - iofunc_sync_default()
        Default handler for _IO_SYNC messages
      - iofunc_sync_verify()
        Verify permissions to sync
      - iofunc_time_update()
        Update time stamps
      - iofunc_unblock()
        Unblock OCBs
      - iofunc_unblock_default()
        Default unblock handler
      - iofunc_unlink()
        Verify that an entry can be unlinked
      - iofunc_unlock_ocb_default()
        Default handler for the unlock_ocb callout
      - iofunc_utime()
        Update time stamps
      - iofunc_utime_default()
        Default handler for _IO_UTIME messages
      - iofunc_write_default()
        Default handler for _IO_WRITE messages
      - iofunc_write_verify()
        Verify a client's write access to a resource
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        Arm a resource manager
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        Test a character to see if it's alphanumeric
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        Test a character to see if it's alphabetic
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        Test a character to see if it's a 7-bit ASCII character
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        Test to see if a file descriptor is associated with a terminal
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        Test a character to see if it's a blank character
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        Test a character to see if it's a control character
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        Test a character to see if it's a decimal digit
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        Test the file type of a file descriptor
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        Determine if a number is finite
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        Test a character to see if it's any printable character except a space
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        Determine whether one floating-point number is greater than another
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        Determine whether one floating-point number is greater than or equal to another
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        Test for infinity
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        Determine whether one floating-point number is less than another
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        Determine whether one floating-point number is less than or equal to another
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        Determine whether one floating-point number is less than or greater than another
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        Test a character to see if it's a lowercase letter
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        Test for not-a-number (NaN)
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        Determine whether a floating-point number is normal
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        Test a character to see if it's any printable character, including a space
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        Test a character to see if it's any punctuation character
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        Test a character to see if it's a whitespace character
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        Determine whether two floating-point numbers are unordered
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        Test a character to see if it's an uppercase letter
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        Test a wide character to see if it's alphanumeric
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iofunc_sync_default()

QNX SDP8.0C Library ReferenceAPIDeveloper

Default handler for _IO_SYNC messages

Synopsis:

#include <sys/iofunc.h>

int iofunc_sync_default( 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. For more information, see iofunc_sync_verify().
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_default() function implements POSIX semantics for the client's fsync() call, which is received as an _IO_SYNC 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 sync position, or you can call iofunc_func_init() to initialize all of the functions to their default values.

The iofunc_sync_default() function calls iofunc_sync_verify() to see if the client can synchronize the resource.

Returns:

EINVAL: The resource doesn't support synchronizing.
EOK: The client can synchronize the resource.

Classification:


Safety:
Cancellation point	No
Signal handler	Yes
Thread	Yes

Page updated: August 11, 2025