utils/rpctrace: fix output so that replies can be attributed to requests

Currently, it is impossible to properly attribute response messages to
requests.  Even though rpctrace is single-threaded, its tracee may
not.  Or there might be more than one tracee.  In any such case it is
not guaranteed that the reply message we just processed is for the
request we just printed.  Fix this by printing ellipsis with the port
name, so that reply messages can be properly attributed:

task129(pid3312)->mach_port_allocate (3) ...134
task129(pid3312)->mach_port_deallocate (pn{  1}) ...160
134... = 0 pn{ 30}
160... = 0

* utils/rpctrace.c (last_reply_port): New variable.
(print_ellipsis): New function.
(print_request_header): Optionally print ellipsis and update
last_reply_port.
(print_reply_header): Likewise.

0 files changed, 0 insertions, 0 deletions