From 4241dd5673566a61add85bd9eb52d4ae7db2750a Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Sat, 23 Nov 2013 16:12:55 +0100
Subject: libports: use protected payloads to optimize the object lookup

* NEWS: Mention protected payloads.
* libports/Makefile (SRCS): Add `port-deref-deferred.c'.
* libports/create-internal.c (_ports_create_port_internal): Set the
protected payload to the objects address.
* libports/import-port.c (ports_import_port): Likewise.
* libports/reallocate-from-external.c (ports_reallocate_from_external):
Likewise.
* libports/reallocate-port.c (ports_reallocate_port): Likewise.
* libports/transfer-right.c (ports_transfer_right): Likewise.
* libports/manage-multithread.c (ports_manage_port_operations_multithread):
Use the protected payload for the object lookup if provided.  Add
thread pool management calls.
* libports/manage-one-thread.c (ports_manage_port_operations_one_thread):
Likewise.
* libports/destroy-right.c (ports_destroy_right): Defer the
dereferencing of outstanding send rights to avoid a port_info
use-after-free.
* libports/port-deref-deferred.c: New file.
* libports/port-deref-deferred.h: Likewise.
* libports/ports.h (struct port_bucket): New field `threadpool'.
(ports_lookup_payload): Check `port_right'.
---
 libports/create-internal.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

(limited to 'libports/create-internal.c')

diff --git a/libports/create-internal.c b/libports/create-internal.c
index 2d85931c..d79dc78f 100644
--- a/libports/create-internal.c
+++ b/libports/create-internal.c
@@ -99,7 +99,11 @@ _ports_create_port_internal (struct port_class *class,
   bucket->count++;
   class->count++;
   pthread_mutex_unlock (&_ports_lock);
-  
+
+  /* This is an optimization.  It may fail.  */
+  mach_port_set_protected_payload (mach_task_self (), port,
+				   (unsigned long) pi);
+
   if (install)
     {
       err = mach_port_move_member (mach_task_self (), pi->port_right,
-- 
cgit v1.2.3