NAME
port_set_backlog - changes a port’s backlog value

SYNOPSIS
#include <mach.h>

kern_return_t port_set_backlog(task, port_name, backlog)
task_t task;
port_name_t port_name;
int backlog;

ARGUMENTS
task The task owning the named port right.

port_name task’s name for the port right.

backlog The new backlog to be set.

DESCRIPTION
The port’s backlog value is the number of unreceived messages that
are allowed in its message queue before the kernel will refuse to
accept any more sends to that port. port_set_backlog changes the
backlog value on the specified port.

task must have receive rights for the named port.

The file <sys/mach_param.h> exports the system default value for a
port’s backlog as the constant PORT_BACKLOG_DEFAULT and the maximum
backlog value as the constant PORT_BACKLOG_MAX.

DIAGNOSTICS
KERN_SUCCESS The call succeeded.

KERN_NOT_RECEIVER port_name doesn’t name receive rights
in task.

KERN_INVALID_ARGUMENT task was invalid or port_name does
not name a valid port or the desired
backlog was non-positive or the
desired backlog was greater than
PORT_BACKLOG_MAX.

SEE ALSO
msg_send(2), port_status(2)