message_detach()

Arguments:

dpp

The dispatch handle, as returned by a successful call to dispatch_create().

low, high

The range of messages that you want to detach the handler from. This range must be the same one that you passed to message_attach().

flags

0 or MSG_FLAG_DEFAULT_FUNC. This flag removes the default function, which was the one set in the func argument given to message_attach() when it was called with attr->flags set to MSG_FLAG_DEFAULT_FUNC also.

Library:

libc

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

Description:

The message_detach() function detaches the message type [low, high], for dispatch handle dpp, that was attached with message_attach().

Returns:

Zero on success. If an error occurs, -1 or the following error constant:

EINVAL

The range [low, high] doesn't match the range that you attached with message_attach(), or you called message_detach() for an active dpp with DISPATCH_FLAG_NOLOCK set.

Examples:

#include <sys/dispatch.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

int my_func( … ) {

   …

}
        
int main( int argc, char **argv ) {
   dispatch_t    *dpp;
   int           lo=0x2000, hi=0x2fff, flags=0;
    
   if( ( dpp = dispatch_create() ) == NULL ) {
     fprintf( stderr, 
       "%s: Unable to allocate dispatch handle.\n",
       argv[0] );
     return EXIT_FAILURE;
   }

   …

   if( message_attach( dpp, NULL, lo, hi,
                       &my_func, NULL) == -1 ) {
     fprintf( stderr, 
       "%s: Failed to attach message range.\n",
        argv[0] );
     return 1;
   }
    
   …

   if ( message_detach ( dpp, lo, hi, flags ) == -1 ) {
      fprintf ( stderr, 
        "Failed to detach message range from %d to %d.\n",
        lo, hi );
      return 1;
   }
   /* else message was detached */
            
   …
}

For examples using the dispatch interface, see dispatch_create(), message_attach(), resmgr_attach(), and thread_pool_create().

Classification:

QNX OS