X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1cde906ff21eb6a3dd34cce742b544e1ddcb8994..dbfa5606c9912e09908b3343ec7a56b283ec82b9:/src/simix/smx_context.c

diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c
index 7101a1ab19..2da152b007 100644
--- a/src/simix/smx_context.c
+++ b/src/simix/smx_context.c
@@ -1,7 +1,7 @@
 /* a fast and simple context switching library                              */
 
-/* Copyright (c) 2004-2008 the SimGrid team.                                */
-/* All rights reserved.                                                     */
+/* Copyright (c) 2009, 2010. The SimGrid Team.
+ * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -10,28 +10,51 @@
 #include "xbt/log.h"
 #include "xbt/swag.h"
 #include "private.h"
+#include "simix/context.h"
+#include "gras_config.h"
 
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mecanism");
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
+                                "Context switching mecanism");
 
+char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contexts/factory:value */
+smx_ctx_factory_initializer_t smx_factory_initializer_to_use = NULL;
+int smx_context_stack_size = 128 * 1024;
 
-/**
- * This function is call by SIMIX_global_init() to initialize the context module.
+#ifdef CONTEXT_THREADS
+__thread smx_context_t smx_current_context;
+#else
+smx_context_t smx_current_context;
+#endif
+
+static int smx_parallel_contexts = 1;
+
+/** 
+ * This function is called by SIMIX_global_init() to initialize the context module.
  */
 void SIMIX_context_mod_init(void)
 {
   if (!simix_global->context_factory) {
-  /* select context factory to use to create the context(depends of the macro definitions) */
-
-#ifdef CONTEXT_THREADS
-    /* context switch based os thread */
-    SIMIX_ctx_thread_factory_init(&simix_global->context_factory);
-#elif !defined(WIN32)
-    /* context switch based ucontext */
-    SIMIX_ctx_sysv_factory_init(&simix_global->context_factory);
-#else
-    /* context switch is not allowed on Windows */
-#error ERROR [__FILE__, line __LINE__]: no context based implementation specified.
-#endif
+    /* select the context factory to use to create the contexts */
+    if (smx_factory_initializer_to_use) {
+      (*smx_factory_initializer_to_use)(&(simix_global->context_factory));
+    }
+    else { /* use the factory specified by --cfg=contexts/factory:value */
+      if (smx_context_factory_name == NULL || !strcmp(smx_context_factory_name, "ucontext")) {
+        /* use ucontext */
+        SIMIX_ctx_sysv_factory_init(&simix_global->context_factory);
+      }
+      else if (!strcmp(smx_context_factory_name, "thread")) {
+	/* use os threads (either pthreads or windows ones) */
+        SIMIX_ctx_thread_factory_init(&simix_global->context_factory);
+      }
+      else if (!strcmp(smx_context_factory_name, "raw")) {
+	/* use raw contexts */
+	SIMIX_ctx_raw_factory_init(&simix_global->context_factory);
+      }
+      else {
+        xbt_die("Invalid context factory specified");
+      }
+    }
   }
 }
 
@@ -43,76 +66,44 @@ void SIMIX_context_mod_exit(void)
   if (simix_global->context_factory) {
     smx_pfn_context_factory_finalize_t finalize_factory;
 
-    /* if there are living processes then kill them (except maestro) */
-    if(simix_global->process_list != NULL)
-      SIMIX_process_killall();
-    
     /* finalize the context factory */
     finalize_factory = simix_global->context_factory->finalize;
     (*finalize_factory) (&simix_global->context_factory);
   }
+  xbt_dict_remove((xbt_dict_t) _surf_cfg_set,"contexts/factory");
 }
 
 /**
- * This function is used to change the context factory.
- * Warning: it destroy all the existing contexts
+ * \brief Sets the number of parallel threads to use
+ * for the user contexts.
+ *
+ * This function should be called before initializing SIMIX.
+ * A value of 1 means no parallelism.
+ * If the value is greater than 1, the thread support must be enabled.
+ *
+ * \param nb_threads the number of threads to use
  */
-int SIMIX_context_select_factory(const char *name)
-{
-  /* if a factory is already instantiated (SIMIX_context_mod_init() was called) */
-  if (simix_global->context_factory != NULL) {
-    /* if the desired factory is different of the current factory, call SIMIX_context_mod_exit() */
-    if (strcmp(simix_global->context_factory->name, name))
-      SIMIX_context_mod_exit();
-    else
-      /* the same context factory is requested return directly */
-      return 0;
-  }
-
-  /* get the desired factory */
-  SIMIX_context_init_factory_by_name(&simix_global->context_factory, name);
+void SIMIX_context_set_nthreads(int nb_threads) {
 
-  /* maestro process specialisation */
-  simix_global->maestro_process->context = SIMIX_context_create_maestro ();
-
-  /* the current process is the process of the maestro */
-  simix_global->current_process = simix_global->maestro_process;
-
-  /* the current context doesn't want to die */
-  simix_global->current_process->iwannadie = 0;
-
-  /* insert the current context in the list of the contexts in use */
-  xbt_swag_insert(simix_global->current_process, simix_global->process_list);
+  xbt_assert1(nb_threads > 0, "Invalid number of parallel threads: %d", nb_threads);
+  smx_parallel_contexts = nb_threads;
+}
 
-  return 0;
+/**
+ * \brief Returns the number of parallel threads used
+ * for the user contexts.
+ * \return the number of threads (1 means no parallelism)
+ */
+int SIMIX_context_get_nthreads(void) {
+  return smx_parallel_contexts;
 }
 
 /**
- * Initializes a context factory given by its name
+ * \brief Returns whether some parallel threads are used
+ * for the user contexts.
+ * \return 1 if parallelism is used
  */
-void SIMIX_context_init_factory_by_name(smx_context_factory_t * factory,
-                                        const char *name)
-{
-  if (!strcmp(name, "java"))
-#ifdef HAVE_JAVA     
-    SIMIX_ctx_java_factory_init(factory);
-#else
-    THROW0(not_found_error, 0, "Factory 'Java' does not exist: Java support was not compiled in the SimGrid library");
-#endif /* HAVE_JAVA */
-   
-  else if (!strcmp(name, "thread"))
-#ifdef CONTEXT_THREADS
-    SIMIX_ctx_thread_factory_init(factory);
-#else
-    THROW0(not_found_error, 0, "Factory 'thread' does not exist: thread support was not compiled in the SimGrid library");
-#endif /* CONTEXT_THREADS */
-   
-  else if (!strcmp(name, "sysv"))
-#if !defined(WIN32) && !defined(CONTEXT_THREADS)
-    SIMIX_ctx_sysv_factory_init(factory);
-#else
-    THROW0(not_found_error, 0, "Factory 'sysv' does not exist: no System V thread support under Windows");
-#endif   
-  else
-    THROW1(not_found_error, 0, "Factory '%s' does not exist", name);
+int SIMIX_context_is_parallel(void) {
+  return smx_parallel_contexts > 1;
 }
+