uisimulator/sdl/thread-sdl.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 Dan Everton
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include <time.h>
  21 #include <SDL.h>
  22 #include <SDL_thread.h>
  23 #include <stdlib.h>
  24 #include "thread-sdl.h"
  25 #include "kernel.h"
  26 #include "thread.h"
  27 #include "debug.h"
  28
  29 SDL_Thread          *threads[256];
  30 int                 threadCount = 0;
  31 volatile long       current_tick = 0;
  32 SDL_mutex *m;
  33
  34 void yield(void)
  35 {
  36     static int counter = 0;
  37
  38     SDL_mutexV(m);
  39     if (counter++ >= 50)
  40     {
  41         SDL_Delay(1);
  42         counter = 0;
  43     }
  44     SDL_mutexP(m);
  45 }
  46
  47 void sim_sleep(int ticks)
  48 {
  49     SDL_mutexV(m);
  50     SDL_Delay((1000/HZ) * ticks);
  51     SDL_mutexP(m);
  52 }
  53
  54 int runthread(void *data)
  55 {
  56     SDL_mutexP(m);
  57     ((void(*)())data) ();
  58     SDL_mutexV(m);
  59     return 0;
  60 }
  61
  62 struct thread_entry*
  63     create_thread(void (*function)(void), void* stack, int stack_size,
  64                   const char *name)
  65 {
  66     /** Avoid compiler warnings */
  67     (void)stack;
  68     (void)stack_size;
  69     (void)name;
  70     SDL_Thread* t;
  71
  72     if (threadCount == 256) {
  73         return NULL;
  74     }
  75
  76     t = SDL_CreateThread(runthread, function);
  77     threads[threadCount++] = t;
  78
  79     yield();
  80
  81     /* The return value is never de-referenced outside thread.c so this
  82        nastiness should be fine.  However, a better solution would be nice.
  83       */
  84     return (struct thread_entry*)t;
  85 }
  86
  87 void init_threads(void)
  88 {
  89     m = SDL_CreateMutex();
  90
  91     if (SDL_mutexP(m) == -1) {
  92         fprintf(stderr, "Couldn't lock mutex\n");
  93         exit(-1);
  94     }
  95 }
  96
  97 void remove_thread(struct thread_entry *thread)
  98 {
  99     SDL_KillThread((SDL_Thread*) thread);
 100 }