+++ /dev/null
-/* a fast and simple context switching library */
-
-/* Copyright (c) 2004-2008 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. */
-
-#include "portable.h"
-#include "xbt/log.h"
-#include "xbt/swag.h"
-#include "xbt_context_private.h"
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_context, xbt,
- "Context switching mecanism");
-
-/* the context associated with the current process */
-xbt_context_t current_context = NULL;
-
-/* the context associated with the maestro */
-xbt_context_t maestro_context = NULL;
-
-
-/* this list contains the contexts to destroy */
-xbt_swag_t context_to_destroy = NULL;
-
-/* this list contains the contexts in use */
-xbt_swag_t context_living = NULL;
-
-/* the context factory used to create the appropriate context
- * each context implementation define its own context factory
- * a context factory is responsable of the creation of the context
- * associated with the maestro and of all the context based on
- * the selected implementation.
- *
- * for example, the context switch based on java thread use the
- * java implementation of the context and the java factory build
- * the context depending of this implementation.
- */
-static xbt_context_factory_t context_factory = NULL;
-
-/**
- * This function is call by the xbt_init() function to initialize the context module.
- */
-void xbt_context_mod_init(void)
-{
- if (!context_factory) {
- /* select context factory to use to create the context(depends of the macro definitions) */
-
-#ifdef CONTEXT_THREADS
- /* context switch based os thread */
- xbt_ctx_thread_factory_init(&context_factory);
-#elif !defined(WIN32)
- /* context switch based ucontext */
- xbt_ctx_sysv_factory_init(&context_factory);
-#else
- /* context switch is not allowed on Windows */
-#error ERROR [__FILE__, line __LINE__]: no context based implementation specified.
-#endif
-
- /* maestro context specialisation (this create the maestro with the good implementation */
- (*(context_factory->create_maestro_context)) (&maestro_context);
-
- /* the current context is the context of the maestro */
- current_context = maestro_context;
-
- /* the current context doesn't want to die */
- current_context->iwannadie = 0;
-
- /* intantiation of the lists containing the contexts to destroy and the contexts in use */
- context_to_destroy =
- xbt_swag_new(xbt_swag_offset(*current_context, hookup));
- context_living = xbt_swag_new(xbt_swag_offset(*current_context, hookup));
-
- /* insert the current context in the list of the contexts in use */
- xbt_swag_insert(current_context, context_living);
-
- }
-}
-
-/**
- * This function is call by the xbt_exit() function to finalize the context module.
- */
-void xbt_context_mod_exit(void)
-{
- if (context_factory) {
- xbt_context_t context = NULL;
- xbt_pfn_context_factory_finalize_t finalize_factory;
-
- /* finalize the context factory */
- finalize_factory = context_factory->finalize;
-
- (*finalize_factory) (&context_factory);
-
- /* destroy all contexts in the list of contexts to destroy */
- xbt_context_empty_trash();
-
- /* remove the context of the scheduler from the list of the contexts in use */
- xbt_swag_remove(maestro_context, context_living);
-
- /*
- * kill all the contexts in use :
- * the killed contexts are added in the list of the contexts to destroy
- */
- while ((context = xbt_swag_extract(context_living)))
- (*(context->kill)) (context);
-
-
- /* destroy all contexts in the list of contexts to destroy */
- xbt_context_empty_trash();
-
- free(maestro_context);
- maestro_context = current_context = NULL;
-
- /* destroy the lists */
- xbt_swag_free(context_to_destroy);
- xbt_swag_free(context_living);
- }
-}
-
-/*******************************/
-/* Object creation/destruction */
-/*******************************/
-/**
- * \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(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[]
- )
-{
- /* use the appropriate context factory to create the appropriate context */
- xbt_context_t context =
- (*(context_factory->create_context)) (name, code, startup_func,
- startup_arg, cleanup_func,
- cleanup_arg, argc, argv);
-
- /* add the context in the list of the contexts in use */
- xbt_swag_insert(context, context_living);
-
- return context;
-}
-
-/* Scenario for the end of a context:
- *
- * CASE 1: death after end of function
- * __context_wrapper, called by os thread, calls xbt_context_stop after user code stops
- * xbt_context_stop calls user cleanup_func if any (in context settings),
- * add current to trashbin
- * yields back to maestro (destroy os thread on need)
- * From time to time, maestro calls xbt_context_empty_trash,
- * which maps xbt_context_free on the content
- * xbt_context_free frees some more memory,
- * joins os thread
- *
- * CASE 2: brutal death
- * xbt_context_kill (from any context)
- * set context->wannadie to 1
- * yields to the context
- * the context is awaken in the middle of __yield.
- * At the end of it, it checks that wannadie == 1, and call xbt_context_stop
- * (same than first case afterward)
- */
-
-
-/* Argument must be stopped first -- runs in maestro context */
-void xbt_context_free(xbt_context_t context)
-{
- (*(context->free)) (context);
-}
-
-
-void xbt_context_kill(xbt_context_t context)
-{
- (*(context->kill)) (context);
-}
-
-/**
- * \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)
-{
- (*(context->start)) (context);
-}
-
-/**
- * Calling this function makes the current context yield. The context
- * that scheduled it returns from xbt_context_schedule as if nothing
- * had happened.
- *
- * Only the processes can call this function, giving back the control
- * to the maestro
- */
-void xbt_context_yield(void)
-{
- (*(current_context->yield)) ();
-}
-
-/**
- * \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.
- *
- * Only the maestro can call this function to run a given process.
- */
-void xbt_context_schedule(xbt_context_t context)
-{
- (*(context->schedule)) (context);
-}
-
-void xbt_context_stop(int exit_code)
-{
-
- (*(current_context->stop)) (exit_code);
-}
-
-int xbt_context_select_factory(const char *name)
-{
- /* if a factory is already instantiated (xbt_context_mod_init() was called) */
- if (NULL != context_factory) {
- /* if the desired factory is different of the current factory, call xbt_context_mod_exit() */
- if (strcmp(context_factory->name, name))
- xbt_context_mod_exit();
- else
- /* the same context factory is requested return directly */
- return 0;
- }
-
- /* get the desired factory */
- xbt_context_init_factory_by_name(&context_factory, name);
-
- /* maestro context specialisation */
- (*(context_factory->create_maestro_context)) (&maestro_context);
-
- /* the current context is the context of the maestro */
- current_context = maestro_context;
-
- /* the current context doesn't want to die */
- current_context->iwannadie = 0;
-
- /* intantiation of the lists containing the contexts to destroy and the contexts in use */
- context_to_destroy =
- xbt_swag_new(xbt_swag_offset(*current_context, hookup));
- context_living = xbt_swag_new(xbt_swag_offset(*current_context, hookup));
-
- /* insert the current context in the list of the contexts in use */
- xbt_swag_insert(current_context, context_living);
-
- return 0;
-}
-
-void
-xbt_context_init_factory_by_name(xbt_context_factory_t * factory,
- const char *name)
-{
- if (!strcmp(name, "java"))
- xbt_ctx_java_factory_init(factory);
-#ifdef CONTEXT_THREADS
- else if (!strcmp(name, "thread"))
- xbt_ctx_thread_factory_init(factory);
-#elif !defined(WIN32)
- else if (!strcmp(name, "sysv"))
- xbt_ctx_sysv_factory_init(factory);
-#endif
- else
- THROW1(not_found_error, 0, "Factory '%s' does not exist", name);
-}
-
-/** 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_context_t context = NULL;
-
- while ((context = xbt_swag_extract(context_to_destroy)))
- (*(context->free)) (context);
-}