cpu/native/mtarch.c

   1 /*
   2  * Copyright (c) 2007, Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is part of the Contiki operating system.
  30  *
  31  * Author: Oliver Schmidt <ol.sc@web.de>
  32  *
  33  * $Id: mtarch.c,v 1.2 2007/04/03 18:37:15 oliverschmidt Exp $
  34  */
  35
  36 #ifdef __CYGWIN__
  37
  38 #define WIN32_LEAN_AND_MEAN
  39 #include <windows.h>
  40
  41 static void *main_fiber;
  42
  43 #else /* __CYGWIN__ */
  44
  45 #include <stdlib.h>
  46 #include <signal.h>
  47 #include <ucontext.h>
  48
  49 struct mtarch_t {
  50   char stack[4096];
  51   ucontext_t context;
  52 };
  53
  54 static ucontext_t main_context;
  55 static ucontext_t *running_context;
  56
  57 #endif /* __CYGWIN__ */
  58
  59 #include "mtarch.h"
  60
  61 /*--------------------------------------------------------------------------*/
  62 void
  63 mtarch_init(void)
  64 {
  65 #ifdef __CYGWIN__
  66
  67   main_fiber = ConvertThreadToFiber(NULL);
  68
  69 #endif /* __CYGWIN__ */
  70 }
  71 /*--------------------------------------------------------------------------*/
  72 void
  73 mtarch_remove(void)
  74 {
  75 #ifdef __CYGWIN__
  76
  77   ConvertFiberToThread();
  78
  79 #endif /* __CYGWIN__ */
  80 }
  81 /*--------------------------------------------------------------------------*/
  82 void
  83 mtarch_start(struct mtarch_thread *thread,
  84              void (* function)(void *data),
  85              void *data)
  86 {
  87 #ifdef __CYGWIN__
  88
  89   thread->mt_thread = CreateFiber(0, (LPFIBER_START_ROUTINE)function, data);
  90
  91 #else /* __CYGWIN__ */
  92
  93   thread->mt_thread = malloc(sizeof(struct mtarch_t));
  94
  95   getcontext(&((struct mtarch_t *)thread->mt_thread)->context);
  96
  97   ((struct mtarch_t *)thread->mt_thread)->context.uc_link = NULL;
  98   ((struct mtarch_t *)thread->mt_thread)->context.uc_stack.ss_sp =
  99                         ((struct mtarch_t *)thread->mt_thread)->stack;
 100   ((struct mtarch_t *)thread->mt_thread)->context.uc_stack.ss_size =
 101                         sizeof(((struct mtarch_t *)thread->mt_thread)->stack);
 102
 103   /* Some notes:
 104      - If a CPU needs stronger alignment for the stack than malloc()
 105        guarantees (like i.e. IA64) then makecontext() is supposed to
 106        add that alignment internally.
 107      - According to POSIX the arguments to function() are of type int
 108        and there are in fact 64-bit implementations which support only
 109        32 bits per argument meaning that a pointer argument has to be
 110        splitted into two arguments.
 111      - Most implementations interpret context.uc_stack.ss_sp on entry
 112        as the lowest stack address even if the CPU stack actually grows
 113        downwards. Although this means that ss_sp does NOT represent the
 114        CPU stack pointer this behaviour makes perfectly sense as it is
 115        the only way to stay independent from the CPU architecture. But
 116        Solaris prior to release 10 interprets ss_sp as highest stack
 117        address thus requiring special handling. */
 118   makecontext(&((struct mtarch_t *)thread->mt_thread)->context,
 119               (void (*)(void))function, 1, data);
 120
 121 #endif /* __CYGWIN__ */
 122 }
 123 /*--------------------------------------------------------------------------*/
 124 void
 125 mtarch_yield(void)
 126 {
 127 #ifdef __CYGWIN__
 128
 129   SwitchToFiber(main_fiber);
 130
 131 #else /* __CYGWIN__ */
 132
 133   swapcontext(running_context, &main_context);
 134
 135 #endif /* __CYGWIN__ */
 136 }
 137 /*--------------------------------------------------------------------------*/
 138 void
 139 mtarch_exec(struct mtarch_thread *thread)
 140 {
 141 #ifdef __CYGWIN__
 142
 143   SwitchToFiber(thread->mt_thread);
 144
 145 #else /* __CYGWIN__ */
 146
 147   running_context = &((struct mtarch_t *)thread->mt_thread)->context;
 148   swapcontext(&main_context, running_context);
 149   running_context = NULL;
 150
 151 #endif /* __CYGWIN__ */
 152 }
 153 /*--------------------------------------------------------------------------*/
 154 void
 155 mtarch_stop(struct mtarch_thread *thread)
 156 {
 157 #ifdef __CYGWIN__
 158
 159   DeleteFiber(thread->mt_thread);
 160
 161 #else /* __CYGWIN__ */
 162
 163   free(thread->mt_thread);
 164
 165 #endif /* __CYGWIN__ */
 166 }
 167 /*--------------------------------------------------------------------------*/
 168 void
 169 mtarch_pstart(void)
 170 {
 171 }
 172 /*--------------------------------------------------------------------------*/
 173 void
 174 mtarch_pstop(void)
 175 {
 176 }
 177 /*--------------------------------------------------------------------------*/