Retrieving
Selected Data
Retrieving
the performance data is not without cost to the system, especially in terms of
processor and memory requirements. In cases where your application does not
need all the performance data, you can use the lpszValueName parameter
of the RegQueryValueEx function to indicate the amount of information to
retrieve. The following table lists the values you can specify for lpszValueName.
Note that the value strings are case-sensitive, and if a string includes more
than one word, your words must be separated by a space.
|
Value |
Description |
|
Global |
The
function returns all data for counters on the local computer, except those
included in the Costly category. |
|
nnn
xx yyy |
Each of
these is a Unicode string representing the decimal value for an object name
index. The function only returns data about the specified object types on the
local computer. For example, if your program were to use 2 4 , the System
and Memory objects would be retrieved. Note that
more object types can be returned than are requested. This occurs when the
requested object type depends on another object type. For example, processes
are needed to identify threads, so information for the Process object is also
returned when you request information for the Thread object. |
|
Foreign ssss |
The string ssss
is the name of a foreign computer, such as a Novell NetWare server or a UNIX
system. If your system is capable of collecting data from a foreign computer,
the function returns all data for counters on the foreign computer. Try this
approach if the RegConnectRegistry function fails to connect to a foreign
computer. |
|
Foreign ssss
nnn xx yyy |
This format
combines Foreign ssss and nnn xx yyy. |
|
Costly |
The
function returns data for object types whose data is expensive to collect in
terms of processor time or memory usage. Start a worker thread if your
application needs to respond to the user during this lengthy data collection.
|