Use pthread_mach_thread_np(pthread_self()) instead of mach_thread_self()

src/trusted/service_runtime/osx/nacl_thread_nice.c

 /*
  * Copyright 2009 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can
  * be found in the LICENSE file.
  */
 /*
  * Mac OSX thread priority support.
  */
 
 #include <mach/mach_init.h>
 #include <mach/mach_time.h>
 #include <mach/thread_policy.h>
 #include <mach/thread_act.h>
+#include <pthread.h>
 
 #include "native_client/src/shared/platform/nacl_log.h"
 #include "native_client/src/trusted/service_runtime/include/sys/nacl_nice.h"
 
 /* MyConvertToHostTime converts nanoseconds to the time base used by MacOS.
  * Typically the time base is nanoseconds, and the conversion is trivial.
  * To avoid having to drag in the entire CoreAudio framework just for this
  * subroutine, it is reimplemented here in terms of mach_timebase_info which
  * is in the MacOS core.
  * To understand that this implementation is correct, have a look at
@@ skipping 17 matching lines @@
   double math_tmp = 0.0;
 
   math_tmp = gTimeBase.numer;
   math_tmp *= nanos;
   math_tmp /= gTimeBase.denom;
   return (uint64_t)math_tmp;
 }
 
 int nacl_thread_nice(int nacl_nice) {
   kern_return_t kr;
-  thread_act_t mthread = mach_thread_self();
+
+  /*
+   * Don't use mach_thread_self() because it requires a separate
+   * mach_port_deallocate() system call to release it. Instead, rely on
+   * pthread's cached copy of the port.
+   */
+  thread_act_t mthread = pthread_mach_thread_np(pthread_self());
 
   switch (nacl_nice) {
     case NICE_REALTIME: {
       struct thread_time_constraint_policy tcpolicy;
       const int kPeriodInNanoseconds = 2902490;
       const float kDutyCycle = 0.5;
       const float kDutyMax = 0.85;
       tcpolicy.period = MyConvertToHostTime(kPeriodInNanoseconds);
       tcpolicy.computation = kDutyCycle * tcpolicy.period;
       tcpolicy.constraint = kDutyMax * tcpolicy.period;
@@ skipping 31 matching lines @@
       return -1;
       break;
   }
   if (kr != KERN_SUCCESS) {
     NaClLog(LOG_WARNING, "nacl_thread_nice() failed.\n");
     return -1;
   } else {
     return 0;
   }
 }