X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/ecc6d28bb4d0c9a96be2265db664a9170e9471d1..96920215fe6b67ec41f9e9dee856b5157a67f6d2:/src/simix/smx_context.c diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c index 978629b543..e5e48ce071 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. */ @@ -9,39 +9,66 @@ #include "portable.h" #include "xbt/log.h" #include "xbt/swag.h" -#include "smx_context_private.h" +#include "private.h" +#include "simix/context.h" +#include "gras_config.h" -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smx_context, simix, "Context switching mecanism"); +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, + "Context switching mecanism"); -/* 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. - */ +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; +static int smx_parallel_threshold = 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) */ + /* 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 */ -#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); + if (smx_context_factory_name == NULL) { + /* use the default factory */ +#ifdef CONTEXT_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. + SIMIX_ctx_thread_factory_init(&simix_global->context_factory); #endif + } + else if (!strcmp(smx_context_factory_name, "ucontext")) { + /* use ucontext */ +#ifdef CONTEXT_UCONTEXT + SIMIX_ctx_sysv_factory_init(&simix_global->context_factory); +#else + xbt_die("The ontext factory 'ucontext' unavailable on your system"); +#endif + } + 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"); + } + } } } @@ -53,191 +80,77 @@ 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"); } -/*******************************/ -/* Object creation/destruction */ -/*******************************/ /** - * \param smx_process the simix process that contains this context - * \param code a main function - */ -int SIMIX_context_new(smx_process_t *process, xbt_main_func_t code) -{ - /* use the appropriate context factory to create the appropriate context */ - return (*(simix_global->context_factory->create_context)) (process, code); -} - - -int SIMIX_context_create_maestro(smx_process_t *process) -{ - return (*(simix_global->context_factory->create_maestro_context)) (process); -} - -/* Scenario for the end of a context: + * \brief Sets the number of parallel threads to use + * for the user contexts. * - * CASE 1: death after end of function - * __context_wrapper, called by os thread, calls smx_context_stop after user code stops - * smx_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 smx_context_empty_trash, - * which maps smx_context_free on the content - * smx_context_free frees some more memory, - * joins os thread + * 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. * - * CASE 2: brutal death - * smx_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 smx_context_stop - * (same than first case afterward) + * \param nb_threads the number of threads to use */ +XBT_INLINE void SIMIX_context_set_nthreads(int nb_threads) { + xbt_assert(nb_threads > 0, "Invalid number of parallel threads: %d", nb_threads); -/* Argument must be stopped first -- runs in maestro context */ -void SIMIX_context_free(smx_process_t process) -{ - (*(simix_global->context_factory->free)) (process); -} + if (nb_threads > 1) { +#ifndef CONTEXT_THREADS + THROWF(arg_error, 0, "No thread support for parallel context execution"); +#endif + } -void SIMIX_context_kill(smx_process_t process) -{ - (*(simix_global->context_factory->kill)) (process); + smx_parallel_contexts = nb_threads; } /** - * \param context the context to start - * - * Calling this function prepares \a process to be run. It will - however run effectively only when calling #SIMIX_context_schedule + * \brief Returns the number of parallel threads used + * for the user contexts. + * \return the number of threads (1 means no parallelism) */ -void SIMIX_context_start(smx_process_t process) -{ - (*(simix_global->context_factory->start)) (process); +XBT_INLINE int SIMIX_context_get_nthreads(void) { + return smx_parallel_contexts; } /** - * Calling this function makes the current process yield. The process - * that scheduled it returns from SIMIX_context_schedule as if nothing - * had happened. - * - * Only the processes can call this function, giving back the control - * to the maestro + * \brief Returns whether some parallel threads are used + * for the user contexts. + * \return 1 if parallelism is used */ -void SIMIX_context_yield(void) -{ - (*(simix_global->context_factory->yield)) (); +XBT_INLINE int SIMIX_context_is_parallel(void) { + return smx_parallel_contexts > 1; } /** - * \param process to be scheduled + * \brief Sets the threshold above which user processes are run in parallel. * - * Calling this function blocks the current process and schedule \a process. - * When \a process would call SIMIX_context_yield, it will return - * to this function as if nothing had happened. + * If the number of threads is set to 1, there is no parallelism and this + * threshold has no effect. * - * Only the maestro can call this function to run a given process. + * \param threshold when the number of user processes ready to run is above + * this threshold, they are run in parallel */ -void SIMIX_context_schedule(smx_process_t process) -{ - (*(simix_global->context_factory->schedule)) (process); -} - -void SIMIX_context_stop(int exit_code) -{ - (*(simix_global->context_factory->stop)) (exit_code); -} - -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); - - /* maestro process specialisation */ - (*(simix_global->context_factory->create_maestro_context)) (&simix_global->maestro_process); - - /* 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); - - return 0; -} - -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); +XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) { + smx_parallel_threshold = threshold; } -/** Garbage collection +/** + * \brief Returns the threshold above which user processes are run in parallel. + * + * If the number of threads is set to 1, there is no parallelism and this + * threshold has no effect. * - * Should be called some time to time to free the memory allocated for processes - * that have finished (or killed). + * \return when the number of user processes ready to run is above + * this threshold, they are run in parallel */ -void SIMIX_context_empty_trash(void) -{ - smx_process_t process = NULL; - int i; - - while ((process = xbt_swag_extract(simix_global->process_to_destroy))){ - free(process->name); - process->name = NULL; - - if (process->argv) { - for (i = 0; i < process->argc; i++) - if (process->argv[i]) - free(process->argv[i]); - - free(process->argv); - } - - free(process); - } +XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { + return smx_parallel_threshold; } +