X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/9d1a487722431c76f5861a1490d9469de8af8f7e..54037339d01e1596cf2b97ba56e142bce5bce42e:/src/simix/smx_context.c diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c index 70a41babaf..707cf7708d 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) 2009-2013. 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. */ @@ -9,149 +9,214 @@ #include "portable.h" #include "xbt/log.h" #include "xbt/swag.h" -#include "private.h" -#include - - -#ifdef HAVE_RUBY -/* Damn Ruby. They load their full config.h, which breaks since we also load ours. - * So, we undef the offending defines - */ -#undef PACKAGE_VERSION -#undef PACKAGE_NAME -#undef PACKAGE_TARNAME -#undef PACKAGE_STRING -#undef PACKAGE_BUGREPORT -#undef _GNU_SOURCE -#include - void SIMIX_ctx_ruby_factory_init(smx_context_factory_t *factory); -#include "smx_context_ruby.c" -#endif - -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mecanism"); - -const char *xbt_ctx_factory_to_use = NULL; +#include "xbt/xbt_os_thread.h" +#include "smx_private.h" +#include "simgrid/sg_config.h" +#include "internal_config.h" + +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, + "Context switching mechanism"); + +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; +int smx_context_stack_size_was_set = 0; +#ifdef HAVE_THREAD_LOCAL_STORAGE +static __thread smx_context_t smx_current_context_parallel; +#else +static xbt_os_thread_key_t smx_current_context_key = 0; +#endif +static smx_context_t smx_current_context_serial; +static int smx_parallel_contexts = 1; +static int smx_parallel_threshold = 2; +static e_xbt_parmap_mode_t smx_parallel_synchronization_mode = XBT_PARMAP_DEFAULT; /** - * This function is call by SIMIX_global_init() to initialize the context module. + * This function is called by SIMIX_global_init() to initialize the context module. */ - void SIMIX_context_mod_init(void) { +#if defined(CONTEXT_THREADS) && !defined(HAVE_THREAD_LOCAL_STORAGE) + /* the __thread storage class is not available on this platform: + * use getspecific/setspecific instead to store the current context in each thread */ + xbt_os_thread_key_create(&smx_current_context_key); +#endif if (!simix_global->context_factory) { - /* select context factory to use to create the context(depends of the macro definitions) */ - if (xbt_ctx_factory_to_use) { - SIMIX_context_select_factory(xbt_ctx_factory_to_use); - } else { -#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); + /* 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 (!strcmp(smx_context_factory_name, "thread")) { + /* use os threads (either pthreads or windows ones) */ + SIMIX_ctx_thread_factory_init(&simix_global->context_factory); + } +#ifdef CONTEXT_UCONTEXT + else if (!strcmp(smx_context_factory_name, "ucontext")) { + /* use ucontext */ + SIMIX_ctx_sysv_factory_init(&simix_global->context_factory); + } +#endif +#ifdef HAVE_RAWCTX + else if (!strcmp(smx_context_factory_name, "raw")) { + /* use raw contexts */ + SIMIX_ctx_raw_factory_init(&simix_global->context_factory); + } +#endif + else { + XBT_ERROR("Invalid context factory specified. Valid factories on this machine:"); +#ifdef HAVE_RAWCTX + XBT_ERROR(" raw: high performance context factory implemented specifically for SimGrid"); #else - /* context switch is not allowed on Windows */ -#error ERROR [__FILE__, line __LINE__]: no context based implementation specified. + XBT_ERROR(" (raw contexts are disabled at compilation time on this machine -- check configure logs for details)"); #endif +#ifdef CONTEXT_UCONTEXT + XBT_ERROR(" ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)"); +#else + XBT_ERROR(" (ucontext is disabled at compilation time on this machine -- check configure logs for details)"); +#endif + XBT_ERROR(" thread: slow portability layer using system threads (pthreads on UNIX, CreateThread() on windows)"); + xbt_die("Please use a valid factory."); + } } } } /** - * This function is call by SIMIX_clean() to finalize the context module. + * This function is called by SIMIX_clean() to finalize the context module. */ void SIMIX_context_mod_exit(void) { if (simix_global->context_factory) { smx_pfn_context_factory_finalize_t finalize_factory; - + /* finalize the context factory */ finalize_factory = simix_global->context_factory->finalize; - (*finalize_factory) (&simix_global->context_factory); + finalize_factory(&simix_global->context_factory); } + xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory"); } /** - * This function is used to change the context factory. - * Warning: it destroy all the existing processes (even for maestro), and it - * will create a new maestro process using the new context factory. + * \brief Returns whether some parallel threads are used + * for the user contexts. + * \return 1 if parallelism is used */ -int SIMIX_context_select_factory(const char *name) -{ - /* if a context factory is already instantiated and it is different from the - newly selected one, then kill all the processes, exit the context module - and initialize the new factory. - */ - - - if (simix_global->context_factory != NULL) { - if (strcmp(simix_global->context_factory->name, name)){ +XBT_INLINE int SIMIX_context_is_parallel(void) { + return smx_parallel_contexts > 1; +} - SIMIX_process_killall(); - - /* kill maestro process */ - SIMIX_context_free(simix_global->maestro_process->context); - free(simix_global->maestro_process); - simix_global->maestro_process = NULL; +/** + * \brief Returns the number of parallel threads used + * for the user contexts. + * \return the number of threads (1 means no parallelism) + */ +XBT_INLINE int SIMIX_context_get_nthreads(void) { + return smx_parallel_contexts; +} - SIMIX_context_mod_exit(); - } - else - /* the same context factory is requested return directly */ - return 0; - } +/** + * \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 (1 thread only). + * If the value is greater than 1, the thread support must be enabled. + * + * \param nb_threads the number of threads to use + */ +void SIMIX_context_set_nthreads(int nb_threads) { + if (nb_threads<=0) { + nb_threads = xbt_os_get_numcores(); + XBT_INFO("Auto-setting contexts/nthreads to %d",nb_threads); + } - /* init the desired factory */ - SIMIX_context_init_factory_by_name(&simix_global->context_factory, name); + if (nb_threads > 1) { +#ifndef CONTEXT_THREADS + THROWF(arg_error, 0, "The thread factory cannot be run in parallel"); +#endif + } + smx_parallel_contexts = nb_threads; +} - SIMIX_create_maestro_process (); +/** + * \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. + * + * \return when the number of user processes ready to run is above + * this threshold, they are run in parallel + */ +XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { + return smx_parallel_threshold; +} +/** + * \brief Sets 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. + * + * \param threshold when the number of user processes ready to run is above + * this threshold, they are run in parallel + */ +XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) { + smx_parallel_threshold = threshold; +} - - return 0; +/** + * \brief Returns the synchronization mode used when processes are run in + * parallel. + * \return how threads are synchronized if processes are run in parallel + */ +XBT_INLINE e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode(void) { + return smx_parallel_synchronization_mode; +} + +/** + * \brief Sets the synchronization mode to use when processes are run in + * parallel. + * \param mode how to synchronize threads if processes are run in parallel + */ +XBT_INLINE void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) { + smx_parallel_synchronization_mode = mode; } /** - * Initializes a context factory given by its name + * \brief Returns the current context of this thread. + * \return the current context of this thread */ -void SIMIX_context_init_factory_by_name(smx_context_factory_t * factory, - const char *name) +XBT_INLINE smx_context_t SIMIX_context_get_current(void) { - - 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); + if (SIMIX_context_is_parallel()) { +#ifdef HAVE_THREAD_LOCAL_STORAGE + return smx_current_context_parallel; #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 if (!strcmp(name, "lua")) -#ifdef HAVE_LUA - SIMIX_ctx_lua_factory_init(factory); -#else - - THROW0(not_found_error, 0, "Factory 'lua' does not exist: Lua support was not compiled in the SimGrid library"); -#endif /* HAVE_LUA */ + return xbt_os_thread_get_specific(smx_current_context_key); +#endif + } + else { + return smx_current_context_serial; + } +} - else if (!strcmp(name,"ruby")) -#ifdef HAVE_RUBY - SIMIX_ctx_ruby_factory_init(factory); +/** + * \brief Sets the current context of this thread. + * \param context the context to set + */ +XBT_INLINE void SIMIX_context_set_current(smx_context_t context) +{ + if (SIMIX_context_is_parallel()) { +#ifdef HAVE_THREAD_LOCAL_STORAGE + smx_current_context_parallel = context; #else - THROW0(not_found_error, 0, "Factory 'ruby' does not exist: Ruby support was not compiled in the SimGrid library"); + xbt_os_thread_set_specific(smx_current_context_key, context); #endif - else - THROW1(not_found_error, 0, "Factory '%s' does not exist", name); + } + else { + smx_current_context_serial = context; + } }