lib/igt_core: Track child process pid and tid

Introduce variables which can decrease number of getpid()/gettid()
calls, especially for allocator which must be aware of method
acquiring addresses.

When child is spawned using igt_fork() we can control its initialization
and prepare child_pid implicitly. Tracking child_tid requires our
intervention in the code and do something like this:

if (child_tid == -1)
	child_tid = gettid()

Variable was created for using in TLS so each thread is created
with variable set to -1. This will give each thread it's own "copy"
and there's no risk to use other thread tid. For each forked child
we reassign -1 to child_tid to avoid using already set variable.

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Cc: Dominik Grzegorzek <dominik.grzegorzek@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Petri Latvala <petri.latvala@intel.com>
Acked-by: Arjun Melkaveri <arjun.melkaveri@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Petri Latvala <petri.latvala@intel.com>

0 files changed, 0 insertions, 0 deletions