rsrcdbmgr_query()

Query the resource database

Synopsis:

#include <sys/rsrcdbmgr.h>
#include <sys/rsrcdbmsg.h>

int rsrcdbmgr_query( rsrc_alloc_t *list,
                     int listcnt,
                     int start,
                     uint32_t type );

Arguments:

list

NULL, or an array of rsrc_alloc_t structures that the function can fill with information about the resources that it finds. For more information about this structure, see the documentation for rsrcdbmgr_create().

listcnt

The number of entries in the array.

start

The index that you want to start searching at.

type

The type of resource that you want to query; one of the following (defined in <sys/rsrcdbmgr.h>):

• RSRCDBMGR_DMA_CHANNEL -- DMA channel
• RSRCDBMGR_IO_PORT -- I/O port address
• RSRCDBMGR_IRQ or RSRCMGR_IRQ -- interrupt address
• RSRCDBMGR_MEMORY -- Memory address
• RSRCDBMGR_PCI_MEMORY -- PCI memory address

Library:

libc

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

Description:

The rsrcdbmgr_query() function queries the database for listcnt count of type resources in use, beginning at the index start. If you make the query with a non-NULL list, then the function stores a maximum of found listcnt resources in the array.

Returns:

If list is NULL or listcnt is 0, then the function returns the number of resources of type in the database.

If list is non-NULL, then the function returns the number of type resources available in the system.

If an error occurs, the function returns -1 and sets errno.

Errors:

EINVAL

Invalid argument

ENOMEM

Insufficient memory to allocate internal data structures.

Examples:

List all of the memory resource blocks available in the system:

rsrc_alloc_t  list[20];
int           size, count = 0, start = 0;

while (1) {
   count = rsrcdbmgr_query( list, 20, start, RSRCDBMGR_MEMORY );
   if (count == -1) 
   break;

   size = min( count-start, 20 );  /* In case more than 20 blocks
                                      were returned. */
   printf( "Retrieved %d of a possible %d resource blocks", \
            size, count);

   for (count=0; count<size; count++) {
       printf( "RSRC[%d] Start %d End %d \n",  \
                start+count, list[count].start, list[count].end);
   }
   start += size;  /* Loop again, in case there are more than
                      20 blocks. */
}

Classification:

QNX Neutrino

See also:

rsrcdbmgr_attach()