Default unblock handler


#include <sys/iofunc.h>

int iofunc_unblock_default( resmgr_context_t * ctp,
                            io_pulse_t * msg,
                            iofunc_ocb_t * ocb );


A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.
A pointer to the io_pulse_t structure that describes the pulse that the resource manager received.
A pointer to the iofunc_ocb_t structure for the Open Control Block that was created when the client opened the resource.



Use the -l c option to qcc to link against this library. This library is usually included automatically.


The iofunc_unblock_default() function is the default routine that a resource manager calls when a client requests to be unblocked (e.g., because of a signal or timeout). It unblocks any clients that are blocked on any internal resource manager structures, calling iofunc_unblock() to do the actual work.

You can place this function directly into the io_funcs table passed to resmgr_attach(), at the unblock position, or you can call iofunc_func_init() to initialize all of the functions to their default values.

The unblock message is synthesized by the resource-manager shared library when a client wishes to unblock from its MsgSendv() to the resource manager. The iofunc_unblock_default() function takes care of freeing up any locks that the client may have placed on the resource.


No client connection was found.
A client connection has been unblocked.


If you're calling iofunc_lock_default(), your unblock handler should call iofunc_unblock_default():

if((status = iofunc_unblock_default(...)) != _RESMGR_DEFAULT) {
   return status;

/* Do your own thing to look for a client to unblock */


QNX Neutrino

Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes

See also:

iofunc_func_init(), iofunc_lock_default(), iofunc_ocb_t, resmgr_attach(), resmgr_context_t, resmgr_io_funcs_t

Writing a Resource Manager

Resource Managers chapter of Getting Started with QNX Neutrino