libobjc/thr-win32.c

   1 /* GNU Objective C Runtime Thread Interface - Win32 Implementation
   2    Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   3    Contributed by Galen C. Hunt (gchunt@cs.rochester.edu)
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify it under the
   8 terms of the GNU General Public License as published by the Free Software
   9 Foundation; either version 2, or (at your option) any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  13 FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  14 details.
  15
  16 You should have received a copy of the GNU General Public License along with
  17 GNU CC; see the file COPYING.  If not, write to the Free Software
  18 Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* As a special exception, if you link this library with files compiled with
  22    GCC to produce an executable, this does not cause the resulting executable
  23    to be covered by the GNU General Public License. This exception does not
  24    however invalidate any other reasons why the executable file might be
  25    covered by the GNU General Public License.  */
  26
  27 #include <objc/thr.h>
  28 #include "runtime.h"
  29
  30 #ifndef __OBJC__
  31 #define __OBJC__
  32 #endif
  33 #include <windows.h>
  34
  35 /* Key structure for maintaining thread specific storage */
  36 static DWORD    __objc_data_tls = (DWORD)-1;
  37
  38 /* Backend initialization functions */
  39
  40 /* Initialize the threads subsystem. */
  41 int
  42 __objc_init_thread_system(void)
  43 {
  44   /* Initialize the thread storage key */
  45   if ((__objc_data_tls = TlsAlloc()) != (DWORD)-1)
  46     return 0;
  47   else
  48     return -1;
  49 }
  50
  51 /* Close the threads subsystem. */
  52 int
  53 __objc_close_thread_system(void)
  54 {
  55   if (__objc_data_tls != (DWORD)-1)
  56     TlsFree(__objc_data_tls);
  57   return 0;
  58 }
  59
  60 /* Backend thread functions */
  61
  62 /* Create a new thread of execution. */
  63 objc_thread_t
  64 __objc_thread_detach(void (*func)(void *arg), void *arg)
  65 {
  66   DWORD thread_id = 0;
  67   HANDLE win32_handle;
  68
  69   if (!(win32_handle = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)func,
  70                                    arg, 0, &thread_id)))
  71     thread_id = 0;
  72
  73   return (objc_thread_t)thread_id;
  74 }
  75
  76 /* Set the current thread's priority. */
  77 int
  78 __objc_thread_set_priority(int priority)
  79 {
  80   int sys_priority = 0;
  81
  82   switch (priority)
  83     {
  84     case OBJC_THREAD_INTERACTIVE_PRIORITY:
  85       sys_priority = THREAD_PRIORITY_NORMAL;
  86       break;
  87     default:
  88     case OBJC_THREAD_BACKGROUND_PRIORITY:
  89       sys_priority = THREAD_PRIORITY_BELOW_NORMAL;
  90       break;
  91     case OBJC_THREAD_LOW_PRIORITY:
  92       sys_priority = THREAD_PRIORITY_LOWEST;
  93       break;
  94     }
  95
  96   /* Change priority */
  97   if (SetThreadPriority(GetCurrentThread(), sys_priority))
  98     return 0;
  99   else
 100     return -1;
 101 }
 102
 103 /* Return the current thread's priority. */
 104 int
 105 __objc_thread_get_priority(void)
 106 {
 107   int sys_priority;
 108
 109   sys_priority = GetThreadPriority(GetCurrentThread());
 110
 111   switch (sys_priority)
 112     {
 113     case THREAD_PRIORITY_HIGHEST:
 114     case THREAD_PRIORITY_TIME_CRITICAL:
 115     case THREAD_PRIORITY_ABOVE_NORMAL:
 116     case THREAD_PRIORITY_NORMAL:
 117       return OBJC_THREAD_INTERACTIVE_PRIORITY;
 118
 119     default:
 120     case THREAD_PRIORITY_BELOW_NORMAL:
 121       return OBJC_THREAD_BACKGROUND_PRIORITY;
 122
 123     case THREAD_PRIORITY_IDLE:
 124     case THREAD_PRIORITY_LOWEST:
 125       return OBJC_THREAD_LOW_PRIORITY;
 126     }
 127
 128   /* Couldn't get priority. */
 129   return -1;
 130 }
 131
 132 /* Yield our process time to another thread. */
 133 void
 134 __objc_thread_yield(void)
 135 {
 136   Sleep(0);
 137 }
 138
 139 /* Terminate the current thread. */
 140 int
 141 __objc_thread_exit(void)
 142 {
 143   /* exit the thread */
 144   ExitThread(__objc_thread_exit_status);
 145
 146   /* Failed if we reached here */
 147   return -1;
 148 }
 149
 150 /* Returns an integer value which uniquely describes a thread. */
 151 objc_thread_t
 152 __objc_thread_id(void)
 153 {
 154   return (objc_thread_t)GetCurrentThreadId();
 155 }
 156
 157 /* Sets the thread's local storage pointer. */
 158 int
 159 __objc_thread_set_data(void *value)
 160 {
 161   if (TlsSetValue(__objc_data_tls, value))
 162     return 0;
 163   else
 164     return -1;
 165 }
 166
 167 /* Returns the thread's local storage pointer. */
 168 void *
 169 __objc_thread_get_data(void)
 170 {
 171   return TlsGetValue(__objc_data_tls);          /* Return thread data.      */
 172 }
 173
 174 /* Backend mutex functions */
 175
 176 /* Allocate a mutex. */
 177 int
 178 __objc_mutex_allocate(objc_mutex_t mutex)
 179 {
 180   if ((mutex->backend = (void *)CreateMutex(NULL, 0, NULL)) == NULL)
 181     return -1;
 182   else
 183     return 0;
 184 }
 185
 186 /* Deallocate a mutex. */
 187 int
 188 __objc_mutex_deallocate(objc_mutex_t mutex)
 189 {
 190   CloseHandle((HANDLE)(mutex->backend));
 191   return 0;
 192 }
 193
 194 /* Grab a lock on a mutex. */
 195 int
 196 __objc_mutex_lock(objc_mutex_t mutex)
 197 {
 198   int status;
 199
 200   status = WaitForSingleObject((HANDLE)(mutex->backend), INFINITE);
 201   if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED)
 202     return -1;
 203   else
 204     return 0;
 205 }
 206
 207 /* Try to grab a lock on a mutex. */
 208 int
 209 __objc_mutex_trylock(objc_mutex_t mutex)
 210 {
 211   int status;
 212
 213   status = WaitForSingleObject((HANDLE)(mutex->backend), 0);
 214   if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED)
 215     return -1;
 216   else
 217     return 0;
 218 }
 219
 220 /* Unlock the mutex */
 221 int
 222 __objc_mutex_unlock(objc_mutex_t mutex)
 223 {
 224   if (ReleaseMutex((HANDLE)(mutex->backend)) == 0)
 225     return -1;
 226   else
 227     return 0;
 228 }
 229
 230 /* Backend condition mutex functions */
 231
 232 /* Allocate a condition. */
 233 int
 234 __objc_condition_allocate(objc_condition_t condition)
 235 {
 236   /* Unimplemented. */
 237   return -1;
 238 }
 239
 240 /* Deallocate a condition. */
 241 int
 242 __objc_condition_deallocate(objc_condition_t condition)
 243 {
 244   /* Unimplemented. */
 245   return -1;
 246 }
 247
 248 /* Wait on the condition */
 249 int
 250 __objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
 251 {
 252   /* Unimplemented. */
 253   return -1;
 254 }
 255
 256 /* Wake up all threads waiting on this condition. */
 257 int
 258 __objc_condition_broadcast(objc_condition_t condition)
 259 {
 260   /* Unimplemented. */
 261   return -1;
 262 }
 263
 264 /* Wake up one thread waiting on this condition. */
 265 int
 266 __objc_condition_signal(objc_condition_t condition)
 267 {
 268   /* Unimplemented. */
 269   return -1;
 270 }
 271
 272 /* End of File */