X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/3f617f15b3e35f4212d1ba8c1ea62f20057e9714..9a41b5fa634b7df7f823f57c4b2a3e27874df28f:/src/xbt/context.c

diff --git a/src/xbt/context.c b/src/xbt/context.c
index 93f7b9c248..67d95f75f9 100644
--- a/src/xbt/context.c
+++ b/src/xbt/context.c
@@ -16,6 +16,11 @@
 #include "gras_config.h"
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
 
+/* #define WARNING(format, ...) (fprintf(stderr, "[%s , %s : %d] ", __FILE__, __FUNCTION__, __LINE__),\ */
+/*                               fprintf(stderr, format, ## __VA_ARGS__), \ */
+/*                               fprintf(stderr, "\n")) */
+/* #define VOIRP(expr) WARNING("  {" #expr " = %p }", expr) */
+
 #ifndef HAVE_UCONTEXT_H
 /* don't want to play with conditional compilation in automake tonight, sorry.
    include directly the c file from here when needed. */
@@ -23,19 +28,86 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
 #endif
 
 static xbt_context_t current_context = NULL;
-static xbt_dynar_t context_to_destroy = NULL;
+static xbt_context_t init_context = NULL;
+static xbt_swag_t context_to_destroy = NULL;
+static xbt_swag_t context_living = NULL;
+
+static void __xbt_context_yield(xbt_context_t context)
+{
+  int return_value = 0;
+
+  xbt_assert0(current_context,"You have to call context_init() first.");
+  
+/*   WARNING("--------- current_context (%p) is yielding to context(%p) ---------",current_context,context); */
+/*   VOIRP(current_context); */
+/*   if(current_context) VOIRP(current_context->save); */
+/*   VOIRP(context); */
+/*   if(context) VOIRP(context->save); */
+
+  if (context) {
+    if(context->save==NULL) {
+/*       WARNING("**** Yielding to somebody else ****"); */
+/*       WARNING("Saving current_context value (%p) to context(%p)->save",current_context,context); */
+      context->save = current_context ;
+/*       WARNING("current_context becomes  context(%p) ",context); */
+      current_context = context ;
+/*       WARNING("Current position memorized (context->save). Jumping to context (%p)",context); */
+      return_value = swapcontext (&(context->save->uc), &(context->uc));
+      xbt_assert0((return_value==0),"Context swapping failure");
+/*       WARNING("I am (%p). Coming back\n",context); */
+    } else {
+      xbt_context_t old_context = context->save ;
+/*       WARNING("**** Back ! ****"); */
+/*       WARNING("Setting current_context (%p) to context(%p)->save",current_context,context); */
+      current_context = context->save ;
+/*       WARNING("Setting context(%p)->save to NULL",context); */
+      context->save = NULL ;
+/*       WARNING("Current position memorized (%p). Jumping to context (%p)",context,old_context); */
+      return_value = swapcontext (&(context->uc), &(old_context->uc));
+      xbt_assert0((return_value==0),"Context swapping failure");
+/*       WARNING("I am (%p). Coming back\n",context); */
+    }
+  }
+
+  return;
+}
+
+static void xbt_context_destroy(xbt_context_t context)
+{
+  xbt_free(context);
 
+  return;
+}
+
+/** \name Functions 
+ *  \ingroup XBT_context
+ */
+/*@{*/
+/** Context module initialization
+ *
+ * \warning It has to be called before using any other function of this module.
+ */
 void xbt_context_init(void)
 {
   if(!current_context) {
-    current_context = xbt_new0(s_xbt_context_t,1);
-    context_to_destroy = xbt_dynar_new(sizeof(xbt_context_t),xbt_free);
+    current_context = init_context = xbt_new0(s_xbt_context_t,1);
+    context_to_destroy = xbt_swag_new(xbt_swag_offset(*current_context,hookup));
+    context_living = xbt_swag_new(xbt_swag_offset(*current_context,hookup));
+    xbt_swag_insert(init_context, context_living);
   }
 }
 
+/** Garbage collection
+ *
+ * Should be called some time to time to free the memory allocated for contexts
+ * that have finished executing their main functions.
+ */
 void xbt_context_empty_trash(void)
 {
-  xbt_dynar_reset(context_to_destroy);
+  xbt_context_t context=NULL;
+
+  while((context=xbt_swag_extract(context_to_destroy)))
+    xbt_context_destroy(context);
 }
 
 static void *__context_wrapper(void *c)
@@ -45,101 +117,148 @@ static void *__context_wrapper(void *c)
 
 /*   msg_global->current_process = process; */
 
+  if(context->startup_func)
+    context->startup_func(context->startup_arg);
+
   /*  WARNING("Calling the main function"); */
+  /*   xbt_context_yield(context); */
   (context->code) (context->argc,context->argv);
 
   for(i=0;i<context->argc; i++) 
     if(context->argv[i]) xbt_free(context->argv[i]);
   if(context->argv) xbt_free(context->argv);
 
-  xbt_dynar_push(context_to_destroy, &context);
+  if(context->cleanup_func)
+    context->cleanup_func(context->cleanup_arg);
 
-  xbt_context_yield(context);
+  xbt_swag_remove(context, context_living);
+  xbt_swag_insert(context, context_to_destroy);
 
+  __xbt_context_yield(context);
+  xbt_assert0(0,"You're cannot be here!");
   return NULL;
 }
 
+/** 
+ * \param context the context to start
+ * 
+ * Calling this function prepares \a context to be run. It will 
+   however run effectively only when calling #xbt_context_schedule
+ */
 void xbt_context_start(xbt_context_t context) 
 {
+/*   xbt_fifo_insert(msg_global->process, process); */
+/*   xbt_fifo_insert(msg_global->process_to_run, process); */
 
-/*   TBX_FIFO_insert(msg_global->process, process); */
-/*   TBX_FIFO_insert(msg_global->process_to_run, process); */
-
-  /*  WARNING("Assigning __MSG_process_launcher to context (%p)",context); */
   makecontext (&(context->uc), (void (*) (void)) __context_wrapper,
 	       1, context);
-
   return;
 }
 
-xbt_context_t xbt_context_new(xbt_context_function_t code,
-			 int argc, char *argv[])
+/** 
+ * \param code a main function
+ * \param startup_func a function to call when running the context for
+ *      the first time and just before the main function \a code
+ * \param startup_arg the argument passed to the previous function (\a startup_func)
+ * \param cleanup_func a function to call when running the context, just after 
+        the termination of the main function \a code
+ * \param cleanup_arg the argument passed to the previous function (\a cleanup_func)
+ * \param argc first argument of function \a code
+ * \param argv seconde argument of function \a code
+ */
+xbt_context_t xbt_context_new(xbt_context_function_t code, 
+			      void_f_pvoid_t startup_func, void *startup_arg,
+			      void_f_pvoid_t cleanup_func, void *cleanup_arg,
+			      int argc, char *argv[])
 {
   xbt_context_t res = NULL;
 
   res = xbt_new0(s_xbt_context_t,1);
 
-  /*  WARNING("Initializing context (%p)",res); */
-
   xbt_assert0(getcontext(&(res->uc))==0,"Error in context saving.");
 
-  /*  VOIRP(res->uc); */
   res->code = code;
-  res->uc.uc_link = &(current_context->uc); /* FIXME LATER */
+  res->uc.uc_link = NULL;
+  res->argc = argc;
+  res->argv = argv;
+/*   res->uc.uc_link = &(current_context->uc); */
   /* WARNING : when this context is over, the current_context (i.e. the 
-     father), is awaken... May result in bugs later.*/
+     father), is awaken... Theorically, the wrapper should prevent using 
+     this feature. */
   res->uc.uc_stack.ss_sp = res->stack;
   res->uc.uc_stack.ss_size = STACK_SIZE;
+  res->startup_func = startup_func;
+  res->startup_arg = startup_arg;
+  res->cleanup_func = cleanup_func;
+  res->cleanup_arg = cleanup_arg;
+
+  xbt_swag_insert(res, context_living);
+
   return res;
 }
 
-static void xbt_context_destroy(xbt_context_t context)
-{
-  xbt_free(context);
 
-  return;
+/** 
+ * Calling this function makes the current context yield. The context
+ * that scheduled it returns from xbt_context_schedule as if nothing
+ * had happened.
+ */
+void xbt_context_yield(void)
+{
+  __xbt_context_yield(current_context);
 }
 
-void xbt_context_yield(xbt_context_t context)
+
+/** 
+ * \param context the winner
+ *
+ * Calling this function blocks the current context and schedule \a context.  
+ * When \a context will call xbt_context_yield, it will return
+ * to this function as if nothing had happened.
+ */
+void xbt_context_schedule(xbt_context_t context)
 {
+  xbt_assert0((current_context==init_context),
+	      "You are not supposed to run this function here!");
+  __xbt_context_yield(context);
+}
 
-  xbt_assert0(current_context,"You have to call context_init() first.");
+/** 
+ * This function kill all existing context and free all the memory
+ * that has been allocated in this module.
+ */
+void xbt_context_exit(void) {
+  xbt_context_t context=NULL;
 
-  /*   __MSG_context_init(); */
-  /*  fprintf(stderr,"\n"); */
-  /*  WARNING("--------- current_context (%p) is yielding to context(%p) ---------",current_context,context); */
-  /*  VOIRP(current_context); */
-  /*  if(current_context) VOIRP(current_context->save); */
-  /*  VOIRP(context); */
-  /*  if(context) VOIRP(context->save); */
+  xbt_context_empty_trash();
+  xbt_swag_free(context_to_destroy);
 
-  if (context) {
-/*     m_process_t self = msg_global->current_process; */
-    if(context->save==NULL) {
-      /*      WARNING("**** Yielding to somebody else ****"); */
-      /*      WARNING("Saving current_context value (%p) to context(%p)->save",current_context,context); */
-      context->save = current_context ;
-      context->uc.uc_link = &(current_context->uc);
-      /*      WARNING("current_context becomes  context(%p) ",context); */
-      current_context = context ;
-      /*      WARNING("Current position memorized (context->save). Jumping to context (%p)",context); */
-      if(!swapcontext (&(context->save->uc), &(context->uc))) 
-	xbt_assert0(0,"Context swapping failure");
-      /*      WARNING("I am (%p). Coming back\n",context); */
-    } else {
-      xbt_context_t old_context = context->save ;
-      /*      WARNING("**** Back ! ****"); */
-      /*      WARNING("Setting current_context (%p) to context(%p)->save",current_context,context); */
-      current_context = context->save ;
-      /*      WARNING("Setting context(%p)->save to NULL",current_context,context); */
-      context->save = NULL ;
-      /*      WARNING("Current position memorized (%p). Jumping to context (%p)",context,old_context); */
-      if(!swapcontext (&(context->uc), &(old_context->uc)) ) 
-	xbt_assert0(0,"Context swapping failure");
-      /*      WARNING("I am (%p). Coming back\n",context); */
-    }
-/*     msg_global->current_process = self; */
-  }
+  while((context=xbt_swag_extract(context_living)))
+    xbt_context_free(context);
+
+  xbt_swag_free(context_living);
+
+  init_context = current_context = NULL ;
+}
+
+/** 
+ * \param context poor victim
+ *
+ * This function simply kills \a context... scarry isn't it ?
+ */
+void xbt_context_free(xbt_context_t context)
+{
+  int i ;
+
+  xbt_swag_remove(context, context_living);  
+  for(i=0;i<context->argc; i++) 
+    if(context->argv[i]) xbt_free(context->argv[i]);
+  if(context->argv) xbt_free(context->argv);
+  
+  if(context->cleanup_func)
+    context->cleanup_func(context->cleanup_arg);
+  xbt_context_destroy(context);
 
   return;
 }
+/*@}*/