IOCLASSCOUNT(8) BSD System Manager's Manual IOCLASSCOUNT(8)NAMEioclasscountSYNOPSISioclasscount [classname] [...]
DESCRIPTIONioclasscount displays the instance counts of OSObject-based C++ classes
in the kernel, incremented by the number of direct subclasses that have
an instance count of at least 1. For example, if IONetworkController is
not directly instantiated, but its direct subclass IOEthernetController
has any instances, then IONetworkController's instance count will be at
least 1; if another direct subclass such as IOFWController has any
instances, then IONetworkController's instance count will be at least 2;
and so on. (This modification of instance counts prevents unloading of
kexts defining superclasses that have no instances, but whose subclasses
in other kexts have instances.)
If classes are specified, instance counts are printed as a comma-sepa‐
rated list in the order specified. If no classes are specified, instance
counts for all classes are printed, one per line of output and sorted by
name.
This information is useful for tracking leaks. Instance counts can also
found in the root of the IORegistry in the “IOKitDiagnostics” property.
EXAMPLES
Display instance counts for IOPCIDevice and AppleTestPCI:
/usr/sbin/ioclasscount IOPCIDevice AppleTestPCI
IOPCIDevice = 2, AppleTestPCI = 1
SEE ALSOioalloccount(8), ioreg(8)Darwin November 06, 2008 Darwin
