src/xbt/xbt_ucontext.c

   1 \r
   2 #include "ucontext_stack.h"\r
   3 \r
   4 /* callback: context fetching */\r
   5 static ex_ctx_t*\r
   6 xbt_jcontext_ex_ctx(void);\r
   7 \r
   8 /* callback: termination */\r
   9 static void \r
  10 xbt_jcontext_ex_terminate(xbt_ex_t *e);\r
  11 \r
  12 static xbt_context_t \r
  13 xbt_ucontext_factory_create_context(const char* name, xbt_main_func_t code, void_f_pvoid_t startup_func, void* startup_arg, void_f_pvoid_t cleanup_func, void* cleanup_arg, int argc, char** argv);\r
  14 \r
  15 static int\r
  16 xbt_ucontext_factory_finalize(xbt_context_factory_t* factory);\r
  17 \r
  18 static int \r
  19 xbt_ucontext_factory_create_maestro_context(xbt_context_t* maestro);\r
  20 \r
  21 static void \r
  22 xbt_ucontext_free(xbt_context_t context);\r
  23 \r
  24 static void \r
  25 xbt_ucontext_kill(xbt_context_t context);\r
  26 \r
  27 static void \r
  28 xbt_ucontext_schedule(xbt_context_t context);\r
  29 \r
  30 static void \r
  31 xbt_ucontext_yield(void);\r
  32 \r
  33 static void \r
  34 xbt_ucontext_start(xbt_context_t context);\r
  35 \r
  36 static void \r
  37 xbt_ucontext_stop(int exit_code);\r
  38 \r
  39 static void \r
  40 xbt_ucontext_swap(xbt_context_t context);\r
  41 \r
  42 static void\r
  43 xbt_ucontext_schedule(xbt_context_t context);\r
  44 \r
  45 static void\r
  46 xbt_ucontext_yield(void);\r
  47 \r
  48 static void\r
  49 xbt_ucontext_suspend(xbt_context_t context);\r
  50 \r
  51 static void\r
  52 xbt_ucontext_resume(xbt_context_t context);\r
  53 \r
  54 static void* \r
  55 xbt_ucontext_wrapper(void* param);\r
  56 \r
  57 /* callback: context fetching */\r
  58 static ex_ctx_t*\r
  59 xbt_ucontext_ex_ctx(void) \r
  60 {\r
  61         return current_context->exception;\r
  62 }\r
  63 \r
  64 /* callback: termination */\r
  65 static void \r
  66 xbt_ucontext_ex_terminate(xbt_ex_t *e) \r
  67 {\r
  68         xbt_ex_display(e);\r
  69         abort();\r
  70 }\r
  71 \r
  72 \r
  73 int\r
  74 xbt_ucontext_factory_init(xbt_context_factory_t* factory)\r
  75 {\r
  76         /* context exception */\r
  77         *factory = xbt_new0(s_xbt_context_factory_t,1);\r
  78         \r
  79         (*factory)->create_context = xbt_ucontext_factory_create_context;\r
  80         (*factory)->finalize = xbt_ucontext_factory_finalize;\r
  81         (*factory)->create_maestro_context = xbt_ucontext_factory_create_maestro_context;\r
  82         (*factory)->name = "ucontext_context_factory";\r
  83         \r
  84         /* context exception handlers */\r
  85         __xbt_ex_ctx       = xbt_ucontext_ex_ctx;\r
  86     __xbt_ex_terminate = xbt_ucontext_ex_terminate;     \r
  87     \r
  88         return 0;\r
  89 }\r
  90 \r
  91 static int \r
  92 xbt_ucontext_factory_create_maestro_context(xbt_context_t* maestro)\r
  93 {\r
  94                 \r
  95         xbt_ucontext_t context = xbt_new0(s_xbt_ucontext_t, 1);\r
  96         \r
  97         context->exception = xbt_new(ex_ctx_t,1);\r
  98     XBT_CTX_INITIALIZE(context->exception);\r
  99     \r
 100     *maestro = (xbt_context_t)context;\r
 101     \r
 102     return 0;\r
 103     \r
 104 }\r
 105 \r
 106 \r
 107 static int\r
 108 xbt_ucontext_factory_finalize(xbt_context_factory_t* factory)\r
 109 {\r
 110         free(maestro_context->exception);\r
 111         free(*factory);\r
 112         *factory = NULL;\r
 113         return 0;\r
 114 }\r
 115 \r
 116 static xbt_context_t \r
 117 xbt_ucontext_factory_create_context(const char* name, xbt_main_func_t code, void_f_pvoid_t startup_func, void* startup_arg, void_f_pvoid_t cleanup_func, void* cleanup_arg, int argc, char** argv)\r
 118 {\r
 119         xbt_ucontext_t context = xbt_new0(s_xbt_ucontext_t, 1);\r
 120         \r
 121         context->code = code;\r
 122         context->name = xbt_strdup(name);\r
 123         \r
 124         xbt_assert2(getcontext(&(context->uc)) == 0,"Error in context saving: %d (%s)", errno, strerror(errno));\r
 125         context->uc.uc_link = NULL;\r
 126         context->uc.uc_stack.ss_sp = pth_skaddr_makecontext(context->stack, STACK_SIZE);\r
 127         context->uc.uc_stack.ss_size = pth_sksize_makecontext(context->stack, STACK_SIZE);\r
 128         \r
 129         context->exception = xbt_new(ex_ctx_t, 1);\r
 130         XBT_CTX_INITIALIZE(context->exception);\r
 131         context->iwannadie = 0;           /* useless but makes valgrind happy */\r
 132         context->argc = argc;\r
 133         context->argv = argv;\r
 134         context->startup_func = startup_func;\r
 135         context->startup_arg = startup_arg;\r
 136         context->cleanup_func = cleanup_func;\r
 137         context->cleanup_arg = cleanup_arg;\r
 138         \r
 139         \r
 140         context->free = xbt_ucontext_free;                      \r
 141         context->kill = xbt_ucontext_kill;                      \r
 142         context->schedule = xbt_ucontext_schedule;\r
 143         context->yield = xbt_ucontext_yield;                    \r
 144         context->start = xbt_ucontext_start;                    \r
 145         context->stop = xbt_ucontext_stop;                      \r
 146         \r
 147         return (xbt_context_t)context;\r
 148 }\r
 149 \r
 150 static void \r
 151 xbt_ucontext_free(xbt_context_t context)\r
 152 {\r
 153         if(context)\r
 154         {\r
 155                 free(context->name);\r
 156                 \r
 157                 if(context->argv)\r
 158                 {\r
 159                         int i;\r
 160                         \r
 161                         for(i = 0; i < context->argc; i++)\r
 162                                 if(context->argv[i])\r
 163                                         free(context->argv[i]);\r
 164                                         \r
 165                         free(context->argv);\r
 166                 }\r
 167                 \r
 168                 if(context->exception) \r
 169                         free(context->exception);\r
 170                 \r
 171                 /* finally destroy the context */\r
 172                 free(context);\r
 173         }\r
 174 }\r
 175 \r
 176 static void \r
 177 xbt_ucontext_kill(xbt_context_t context)\r
 178 {\r
 179         context->iwannadie = 1;\r
 180         xbt_ucontext_swap(context);\r
 181 }\r
 182 \r
 183 /** \r
 184  * \param context the winner\r
 185  *\r
 186  * Calling this function blocks the current context and schedule \a context.  \r
 187  * When \a context will call xbt_context_yield, it will return\r
 188  * to this function as if nothing had happened.\r
 189  * \r
 190  * Only the maestro can call this function to run a given process.\r
 191  */\r
 192 static void \r
 193 xbt_ucontext_schedule(xbt_context_t context)\r
 194 {\r
 195         xbt_assert0((current_context == maestro_context),"You are not supposed to run this function here!");\r
 196         xbt_ucontext_swap(context);\r
 197 }\r
 198 \r
 199 /** \r
 200  * Calling this function makes the current context yield. The context\r
 201  * that scheduled it returns from xbt_context_schedule as if nothing\r
 202  * had happened.\r
 203  * \r
 204  * Only the processes can call this function, giving back the control\r
 205  * to the maestro\r
 206  */\r
 207 static void \r
 208 xbt_ucontext_yield(void)\r
 209 {\r
 210         xbt_assert0((current_context != maestro_context),"You are not supposed to run this function here!");\r
 211         xbt_ucontext_swap(current_context);\r
 212 }\r
 213 \r
 214 static void \r
 215 xbt_ucontext_start(xbt_context_t context)\r
 216 {\r
 217         makecontext(&(((xbt_ucontext_t)context)->uc), (void (*)(void)) xbt_ucontext_wrapper, 1, context);\r
 218 }\r
 219 \r
 220 static void \r
 221 xbt_ucontext_stop(int exit_code)\r
 222 {\r
 223         if(current_context->cleanup_func) \r
 224                 ((*current_context->cleanup_func))(current_context->cleanup_arg);\r
 225         \r
 226         xbt_swag_remove(current_context, context_living);\r
 227         xbt_swag_insert(current_context, context_to_destroy);   \r
 228         \r
 229         xbt_ucontext_swap(current_context);\r
 230 }\r
 231 \r
 232 static void \r
 233 xbt_ucontext_swap(xbt_context_t context)\r
 234 {\r
 235         xbt_assert0(current_context, "You have to call context_init() first.");\r
 236         xbt_assert0(context, "Invalid argument");\r
 237         \r
 238         if(((xbt_ucontext_t)context)->prev == NULL) \r
 239                 xbt_ucontext_resume(context);\r
 240         else \r
 241                 xbt_ucontext_suspend(context);\r
 242         \r
 243         if(current_context->iwannadie)\r
 244                 xbt_ucontext_stop(1);\r
 245 }\r
 246 \r
 247 static void* \r
 248 xbt_ucontext_wrapper(void* param)\r
 249 {\r
 250         if (current_context->startup_func)\r
 251                 (*current_context->startup_func)(current_context->startup_arg);\r
 252         \r
 253         xbt_ucontext_stop((*(current_context->code))(current_context->argc, current_context->argv));\r
 254         return NULL;\r
 255 }\r
 256 \r
 257 static void\r
 258 xbt_ucontext_suspend(xbt_context_t context)\r
 259 {\r
 260         int rv;\r
 261         \r
 262         xbt_ucontext_t prev_context = ((xbt_ucontext_t)context)->prev;\r
 263         \r
 264         current_context = (xbt_context_t)(((xbt_ucontext_t)context)->prev);\r
 265         \r
 266         ((xbt_ucontext_t)context)->prev = NULL;\r
 267         \r
 268         rv = swapcontext(&(((xbt_ucontext_t)context)->uc), &(prev_context->uc));\r
 269                 \r
 270         xbt_assert0((rv == 0), "Context swapping failure");\r
 271 }\r
 272 \r
 273 static void\r
 274 xbt_ucontext_resume(xbt_context_t context)\r
 275 {\r
 276         int rv;\r
 277         \r
 278         ((xbt_ucontext_t)context)->prev = (xbt_ucontext_t)current_context;\r
 279         \r
 280         current_context = context;\r
 281         \r
 282         rv = swapcontext(&(((xbt_ucontext_t)context)->prev->uc), &(((xbt_ucontext_t)context)->uc));\r
 283                 \r
 284         xbt_assert0((rv == 0), "Context swapping failure");\r
 285 }\r
 286 \r
 287 \r
 288 \r