Writing Monitors for the Event Monitoring Service (December 1999)

38 Chapter2

The EMS Application Programming Interface (API)

Function Descriptions

rm_get

Used by resource monitors and target applications to retrieve data from

an object. The caller passes the object and ﬁeld identiﬁer of interest, and

rm_get() uses the supplied address to store the data.

Function Prototype

int rm_get ( const rm_object_addr obj,

rm_field_type field,

void *addr,

rm_error_type *error_code );

Parameters

addr

An address where the result will be stored. Note that addr is

always speciﬁed as the address of a variable. The type of the variable

must match the TYPE speciﬁed in the chapters, “Creating a Resource

Monitor” or “Writing a Target Application.”

For example, to retrieve the message tag from a Monitor Request object,

a resource monitor should set addr to the address of an unsigned 32-bit

integer.

ubit32 msg_tag;

rm_error_type error_code;

rm_get(obj, RmMsgTag, &msg_tag, &error_code);

To retrieve the resource name from a Subclass Request object, the

monitor should set addr to the address of a character pointer, not the

address of a character array.

The following example correctly sets a character pointer to point to the

resource name:

char *resource_name;

rm_error_type error_code;

rm_get(obj, RmResourceName, &resource_name,

&error_code); /* CORRECT */

Following is an incorrect example of getting a resource name:

char resource_name[256];

rm_error_type error_code;

rm_get(obj, RmResourceName, resource_name,

&error_code); /* WRONG */

error_code

Provides additional information about failure conditions of