X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/66b0686fe441796325c3b5738b1b880d15ce1ea6..c1ef47e48c471626332e7df2506356db3bbdf868:/src/simix/smx_context.c diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c index 9fc1b5d3e7..88c5a4fac9 100644 --- a/src/simix/smx_context.c +++ b/src/simix/smx_context.c @@ -1,6 +1,6 @@ /* a fast and simple context switching library */ -/* Copyright (c) 2009, 2010. The SimGrid Team. +/* Copyright (c) 2009-2013. The SimGrid Team. * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it @@ -10,80 +10,82 @@ #include "xbt/log.h" #include "xbt/swag.h" #include "xbt/xbt_os_thread.h" -#include "src/simix/private.h" -#include "simix/context.h" -#include "gras_config.h" +#include "smx_private.h" +#include "simgrid/sg_config.h" +#include "internal_config.h" XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, - "Context switching mecanism"); + "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 -__thread smx_context_t smx_current_context; +static __thread smx_context_t smx_current_context_parallel; #else -smx_context_t smx_current_context; /* define it anyway, will be used in non-parallel mode */ 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 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 the context factory to use to create the contexts */ if (smx_factory_initializer_to_use) { - (*smx_factory_initializer_to_use)(&(simix_global->context_factory)); + 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) { - /* use the default factory */ - #ifdef HAVE_RAWCTX - SIMIX_ctx_raw_factory_init(&simix_global->context_factory); - #elif CONTEXT_UCONTEXT - SIMIX_ctx_sysv_factory_init(&simix_global->context_factory); - #else - SIMIX_ctx_thread_factory_init(&simix_global->context_factory); - #endif - } - else if (!strcmp(smx_context_factory_name, "ucontext")) { - /* use ucontext */ + + 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); -#else - xbt_die("The context 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); } +#endif +#ifdef HAVE_RAWCTX else if (!strcmp(smx_context_factory_name, "raw")) { - /* use raw contexts */ - SIMIX_ctx_raw_factory_init(&simix_global->context_factory); + /* use raw contexts */ + SIMIX_ctx_raw_factory_init(&simix_global->context_factory); } +#endif else { - xbt_die("Invalid context factory specified"); + 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 + XBT_ERROR(" (raw contextes are disabled at compilation time on this machine -- check configure logs for details)"); +#endif +#ifdef CONTEXT_UCONTEXT + XBT_ERROR(" ucontext: classical system V contextes (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."); } } } - -#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 } /** - * 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) { @@ -92,9 +94,27 @@ void SIMIX_context_mod_exit(void) /* 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) _surf_cfg_set,"contexts/factory"); + xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory"); +} + +/** + * \brief Returns whether some parallel threads are used + * for the user contexts. + * \return 1 if parallelism is used + */ +XBT_INLINE int SIMIX_context_is_parallel(void) { + return smx_parallel_contexts > 1; +} + +/** + * \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; } /** @@ -102,40 +122,36 @@ void SIMIX_context_mod_exit(void) * for the user contexts. * * This function should be called before initializing SIMIX. - * A value of 1 means no parallelism. + * 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 */ XBT_INLINE void SIMIX_context_set_nthreads(int nb_threads) { - - xbt_assert(nb_threads > 0, "Invalid number of parallel threads: %d", nb_threads); - + if (nb_threads<=0) { + nb_threads = xbt_os_get_numcores(); + XBT_INFO("Auto-setting contexts/nthreads to %d",nb_threads); + } + if (nb_threads > 1) { #ifndef CONTEXT_THREADS - THROWF(arg_error, 0, "No thread support for parallel context execution"); + THROWF(arg_error, 0, "The thread factory cannot be run in parallel"); #endif } - smx_parallel_contexts = nb_threads; } /** - * \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; -} - -/** - * \brief Returns whether some parallel threads are used - * for the user contexts. - * \return 1 if parallelism is used + * \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_is_parallel(void) { - return smx_parallel_contexts > 1; +XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { + return smx_parallel_threshold; } /** @@ -152,16 +168,21 @@ XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) { } /** - * \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 + * \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 int SIMIX_context_get_parallel_threshold(void) { - return smx_parallel_threshold; +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; } /** @@ -170,11 +191,16 @@ XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { */ XBT_INLINE smx_context_t SIMIX_context_get_current(void) { + if (SIMIX_context_is_parallel()) { #ifdef HAVE_THREAD_LOCAL_STORAGE - return smx_current_context; + return smx_current_context_parallel; #else - return xbt_os_thread_get_specific(smx_current_context_key); + return xbt_os_thread_get_specific(smx_current_context_key); #endif + } + else { + return smx_current_context_serial; + } } /** @@ -183,10 +209,15 @@ XBT_INLINE smx_context_t SIMIX_context_get_current(void) */ XBT_INLINE void SIMIX_context_set_current(smx_context_t context) { + if (SIMIX_context_is_parallel()) { #ifdef HAVE_THREAD_LOCAL_STORAGE - smx_current_context = context; + smx_current_context_parallel = context; #else - xbt_os_thread_set_specific(smx_current_context_key, context); + xbt_os_thread_set_specific(smx_current_context_key, context); #endif + } + else { + smx_current_context_serial = context; + } }