LSMP(1) General Commands Manual LSMP(1)

lsmp — Display mach port information for processes on the system

lsmp -h


lsmp -p <pid> Show mach port usage for <pid>. Run with root privileges to see detailed info about port destinations etc.


lsmp -v Show information in detail for Kernel object based ports. Including thread ports and special ports attached to it.


lsmp -a Show mach port usage for all tasks in the system


lsmp -j <path> Save output as JSON to <path>.

The lsmp command prints information about every active right in a task's port space, giving a view into the inter-process communication behavior of that task.

Following is an explanation of each symbol and values from the output.
name        : Task unique name for a port. A "-" signifies that this is a member of a port-set
ipc-object  : A unique identifier for a kernel object. A "+" sign implies that this entry is expanded from above ipc-object.
rights      : Rights corresponding to this name. Possible values are recv, send, send-once and port-set.
flags       : Flags indicating port status.
                T : Port has tempowner set
                G : Port is guarded
                S : Port has strict guarding restrictions
                I : Port has importance donation flag set
                R : Port is marked reviving
                P : Port has task pointer set
boost       : Importance boost count
reqs        : Notifications armed on this port.
                D : Dead name notification
                N : No sender notification
                P : Port Destroy requests
recv        : Number of recv rights for this name.
send        : Number of send rights stored at this name. This does NOT reflect the total number of send rights for this recv right.
sonce       : Number of outstanding send-once rights for this receive right.
oref        : Do send rights exist somewhere for this receive right?
qlimit      : Queue limit for this port. If orefs column shows -> then it indicates the queue limit on the destination port. And a <- indicates this port right is destined to receive messages from process referred in identifier column.
msgcount    : Number of messages enqueued on this port. See qlimit for -> and <- explanations.
context     : Mach port context value.
identifier  : A unique identifier for a kernel object or task's name for this right. This field is described by the type column.

ddt(1), top(1)

July 24, 2012 macOS