src/xbt/xbt_ucontext.c

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