native_client_sdk/src/libraries/third_party/pthreads-win32/pthread_self.c

   1 /*
   2  * pthread_self.c
   3  *
   4  * Description:
   5  * This translation unit implements miscellaneous thread functions.
   6  *
   7  * --------------------------------------------------------------------------
   8  *
   9  *      Pthreads-win32 - POSIX Threads Library for Win32
  10  *      Copyright(C) 1998 John E. Bossom
  11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@callisto.canberra.edu.au
  14  *
  15  *      The current list of contributors is contained
  16  *      in the file CONTRIBUTORS included with the source
  17  *      code distribution. The list can also be seen at the
  18  *      following World Wide Web location:
  19  *      http://sources.redhat.com/pthreads-win32/contributors.html
  20  *
  21  *      This library is free software; you can redistribute it and/or
  22  *      modify it under the terms of the GNU Lesser General Public
  23  *      License as published by the Free Software Foundation; either
  24  *      version 2 of the License, or (at your option) any later version.
  25  *
  26  *      This library is distributed in the hope that it will be useful,
  27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29  *      Lesser General Public License for more details.
  30  *
  31  *      You should have received a copy of the GNU Lesser General Public
  32  *      License along with this library in the file COPYING.LIB;
  33  *      if not, write to the Free Software Foundation, Inc.,
  34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  35  */
  36
  37 #include "pthread.h"
  38 #include "implement.h"
  39
  40 pthread_t
  41 pthread_self (void)
  42      /*
  43       * ------------------------------------------------------
  44       * DOCPUBLIC
  45       *      This function returns a reference to the current running
  46       *      thread.
  47       *
  48       * PARAMETERS
  49       *      N/A
  50       *
  51       *
  52       * DESCRIPTION
  53       *      This function returns a reference to the current running
  54       *      thread.
  55       *
  56       * RESULTS
  57       *              pthread_t       reference to the current thread
  58       *
  59       * ------------------------------------------------------
  60       */
  61 {
  62   pthread_t self;
  63   pthread_t nil = {NULL, 0};
  64   ptw32_thread_t * sp;
  65
  66 #if defined(_UWIN)
  67   if (!ptw32_selfThreadKey)
  68     return nil;
  69 #endif
  70
  71   sp = (ptw32_thread_t *) pthread_getspecific (ptw32_selfThreadKey);
  72
  73   if (sp != NULL)
  74     {
  75       self = sp->ptHandle;
  76     }
  77   else
  78     {
  79       /*
  80        * Need to create an implicit 'self' for the currently
  81        * executing thread.
  82        */
  83       self = ptw32_new ();
  84       sp = (ptw32_thread_t *) self.p;
  85
  86       if (sp != NULL)
  87         {
  88           /*
  89            * This is a non-POSIX thread which has chosen to call
  90            * a POSIX threads function for some reason. We assume that
  91            * it isn't joinable, but we do assume that it's
  92            * (deferred) cancelable.
  93            */
  94           sp->implicit = 1;
  95           sp->detachState = PTHREAD_CREATE_DETACHED;
  96           sp->thread = GetCurrentThreadId ();
  97
  98 #if defined(NEED_DUPLICATEHANDLE)
  99           /*
 100            * DuplicateHandle does not exist on WinCE.
 101            *
 102            * NOTE:
 103            * GetCurrentThread only returns a pseudo-handle
 104            * which is only valid in the current thread context.
 105            * Therefore, you should not pass the handle to
 106            * other threads for whatever purpose.
 107            */
 108           sp->threadH = GetCurrentThread ();
 109 #else
 110           if (!DuplicateHandle (GetCurrentProcess (),
 111                                 GetCurrentThread (),
 112                                 GetCurrentProcess (),
 113                                 &sp->threadH,
 114                                 0, FALSE, DUPLICATE_SAME_ACCESS))
 115             {
 116               /*
 117                * Should not do this, but we have no alternative if
 118                * we can't get a Win32 thread handle.
 119                * Thread structs are never freed.
 120                */
 121               ptw32_threadReusePush (self);
 122               /*
 123                * As this is a win32 thread calling us and we have failed,
 124                * return a value that makes sense to win32.
 125                */
 126               return nil;
 127             }
 128 #endif
 129
 130           /*
 131            * No need to explicitly serialise access to sched_priority
 132            * because the new handle is not yet public.
 133            */
 134           sp->sched_priority = GetThreadPriority (sp->threadH);
 135           pthread_setspecific (ptw32_selfThreadKey, (void *) sp);
 136         }
 137     }
 138
 139   return (self);
 140
 141 }                               /* pthread_self */