X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b266c9f9b644f15f1d397e60f5affa12cf0167d8..e816186fdeaf53fa5abf6886f157c499e09c4622:/src/simix/smx_context.cpp diff --git a/src/simix/smx_context.cpp b/src/simix/smx_context.cpp index a75367fefd..533669351a 100644 --- a/src/simix/smx_context.cpp +++ b/src/simix/smx_context.cpp @@ -1,260 +1,172 @@ /* a fast and simple context switching library */ -/* Copyright (c) 2009-2015. The SimGrid Team. - * All rights reserved. */ +/* Copyright (c) 2009-2019. 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 "src/portable.h" -#include "xbt/log.h" -#include "xbt/swag.h" -#include "xbt/xbt_os_thread.h" -#include "smx_private.h" -#include "smx_private.hpp" -#include "simgrid/sg_config.h" -#include "src/internal_config.h" -#include "simgrid/modelchecker.h" +#include "src/simix/smx_private.hpp" +#include "xbt/config.hpp" +#include -#ifdef _WIN32 -#include -#include -#else -#include +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mechanism"); + +static std::pair context_factories[] = { +#if HAVE_RAW_CONTEXTS + { "raw", &simgrid::kernel::context::raw_factory }, +#endif +#if HAVE_UCONTEXT_CONTEXTS + { "ucontext", &simgrid::kernel::context::sysv_factory }, +#endif +#if HAVE_BOOST_CONTEXTS + { "boost", &simgrid::kernel::context::boost_factory }, #endif + { "thread", &simgrid::kernel::context::thread_factory }, +}; -#ifdef __MINGW32__ -#define _aligned_malloc __mingw_aligned_malloc -#define _aligned_free __mingw_aligned_free -#endif //MINGW +static_assert(sizeof(context_factories) != 0, "No context factories are enabled for this build"); -#ifdef HAVE_VALGRIND_VALGRIND_H -# include -#endif +// Create the list of possible contexts: +static inline +std::string contexts_list() +{ + std::string res; + const std::size_t n = sizeof(context_factories) / sizeof(context_factories[0]); + for (std::size_t i = 1; i != n; ++i) { + res += ", "; + res += context_factories[i].first; + } + return res; +} -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mechanism"); +static simgrid::config::Flag context_factory_name( + "contexts/factory", + (std::string("Possible values: ")+contexts_list()).c_str(), + context_factories[0].first); -char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contexts/factory:value */ -int smx_context_stack_size; -int smx_context_stack_size_was_set = 0; -int smx_context_guard_size; -int smx_context_guard_size_was_set = 0; -#ifdef HAVE_THREAD_LOCAL_STORAGE -static XBT_THREAD_LOCAL 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; +unsigned smx_context_stack_size; +unsigned smx_context_guard_size; 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) +void SIMIX_context_mod_init() { -#if defined(HAVE_THREAD_CONTEXTS) && !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 (simgrid::simix::factory_initializer) - simix_global->context_factory = simgrid::simix::factory_initializer(); - else { /* use the factory specified by --cfg=contexts/factory:value */ -#if defined(HAVE_THREAD_CONTEXTS) - if (!strcmp(smx_context_factory_name, "thread")) - simix_global->context_factory = simgrid::simix::thread_factory(); -#else - if (0); -#endif -#ifdef HAVE_UCONTEXT_CONTEXTS - else if (!strcmp(smx_context_factory_name, "ucontext")) - simix_global->context_factory = simgrid::simix::sysv_factory(); -#endif -#ifdef HAVE_RAW_CONTEXTS - else if (!strcmp(smx_context_factory_name, "raw")) - simix_global->context_factory = simgrid::simix::raw_factory(); + xbt_assert(simix_global->context_factory == nullptr); + +#if HAVE_SMPI && (defined(__APPLE__) || defined(__NetBSD__)) + std::string priv = simgrid::config::get_value("smpi/privatization"); + if (context_factory_name == "thread" && (priv == "dlopen" || priv == "yes" || priv == "default" || priv == "1")) { + XBT_WARN("dlopen+thread broken on Apple and BSD. Switching to raw contexts."); + context_factory_name = "raw"; + } #endif -#ifdef HAVE_BOOST_CONTEXTS - else if (!strcmp(smx_context_factory_name, "boost")) - simix_global->context_factory = simgrid::simix::boost_factory(); + +#if HAVE_SMPI && defined(__FreeBSD__) + if (context_factory_name == "thread" && simgrid::config::get_value("smpi/privatization") != "no") { + XBT_WARN("mmap broken on FreeBSD, but dlopen+thread broken too. Switching to dlopen+raw contexts."); + context_factory_name = "raw"; + } #endif - else { - XBT_ERROR("Invalid context factory specified. Valid factories on this machine:"); -#ifdef HAVE_RAW_CONTEXTS - XBT_ERROR(" raw: high performance context factory implemented specifically for SimGrid"); + + /* select the context factory to use to create the contexts */ + if (simgrid::kernel::context::factory_initializer != nullptr) { // Give Java a chance to hijack the factory mechanism + simix_global->context_factory = simgrid::kernel::context::factory_initializer(); + return; + } + /* use the factory specified by --cfg=contexts/factory:value */ + for (auto const& factory : context_factories) + if (context_factory_name == factory.first) { + simix_global->context_factory = factory.second(); + break; + } + + if (simix_global->context_factory == nullptr) { + XBT_ERROR("Invalid context factory specified. Valid factories on this machine:"); +#if HAVE_RAW_CONTEXTS + XBT_ERROR(" raw: high performance context factory implemented specifically for SimGrid"); #else - XBT_ERROR(" (raw contexts were disabled at compilation time on this machine -- check configure logs for details)"); + XBT_ERROR(" (raw contexts were disabled at compilation time on this machine -- check configure logs for details)"); #endif -#ifdef HAVE_UCONTEXT_CONTEXTS - XBT_ERROR(" ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)"); +#if HAVE_UCONTEXT_CONTEXTS + XBT_ERROR(" ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)"); #else - XBT_ERROR(" (ucontext was disabled at compilation time on this machine -- check configure logs for details)"); + XBT_ERROR(" (ucontext was disabled at compilation time on this machine -- check configure logs for details)"); #endif -#ifdef HAVE_BOOST_CONTEXTS - XBT_ERROR(" boost: this uses the boost libraries context implementation"); +#if HAVE_BOOST_CONTEXTS + XBT_ERROR(" boost: this uses the boost libraries context implementation"); #else - XBT_ERROR(" (boost was disabled at compilation time on this machine -- check configure logs for details. Did you install the libboost-context-dev package?)"); + XBT_ERROR(" (boost was disabled at compilation time on this machine -- check configure logs for details. Did you install the libboost-context-dev package?)"); #endif - XBT_ERROR(" thread: slow portability layer using pthreads as provided by gcc"); - xbt_die("Please use a valid factory."); - } - } + XBT_ERROR(" thread: slow portability layer using pthreads as provided by gcc"); + xbt_die("Please use a valid factory."); } } /** * This function is called by SIMIX_clean() to finalize the context module. */ -void SIMIX_context_mod_exit(void) +void SIMIX_context_mod_exit() { delete simix_global->context_factory; simix_global->context_factory = nullptr; } -void *SIMIX_context_stack_new(void) -{ - void *stack; - - /* FIXME: current code for stack overflow protection assumes that stacks are - * growing downward (PTH_STACKGROWTH == -1). Protected pages need to be put - * after the stack when PTH_STACKGROWTH == 1. */ - - if (smx_context_guard_size > 0 && !MC_is_active()) { - -#if defined(_WIN32) || (PTH_STACKGROWTH != -1) - static int warned_once = 0; - if (!warned_once) { - XBT_WARN("Stack overflow protection is known to be broken on your system. Either you're on Windows or PTH_STACKGROWTH != -1 (current value is %d).", - PTH_STACKGROWTH); - warned_once = 1; - } -#endif - - size_t size = smx_context_stack_size + smx_context_guard_size; -#ifdef HAVE_MC - /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the - * pointer returned by xbt_malloc0. */ - char *alloc = (char*)xbt_malloc0(size + xbt_pagesize); - stack = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize; - *((void **)stack - 1) = alloc; -#elif !defined(_WIN32) - if (posix_memalign(&stack, xbt_pagesize, size) != 0) - xbt_die("Failed to allocate stack."); -#else - stack = _aligned_malloc(size, xbt_pagesize); -#endif - -#ifndef _WIN32 - if (mprotect(stack, smx_context_guard_size, PROT_NONE) == -1) { - xbt_die("Failed to protect stack: %s", strerror(errno)); - /* This is fatal. We are going to fail at some point when - we tryi reusing this. */ - } -#endif - stack = (char *)stack + smx_context_guard_size; - } else { - stack = xbt_malloc0(smx_context_stack_size); - } - -#ifdef HAVE_VALGRIND_VALGRIND_H - unsigned int valgrind_stack_id = VALGRIND_STACK_REGISTER(stack, (char *)stack + smx_context_stack_size); - memcpy((char *)stack + smx_context_usable_stack_size, &valgrind_stack_id, sizeof valgrind_stack_id); -#endif - - return stack; -} - -void SIMIX_context_stack_delete(void *stack) -{ - if (!stack) - return; - -#ifdef HAVE_VALGRIND_VALGRIND_H - unsigned int valgrind_stack_id; - memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size, sizeof valgrind_stack_id); - VALGRIND_STACK_DEREGISTER(valgrind_stack_id); -#endif - -#ifndef _WIN32 - if (smx_context_guard_size > 0 && !MC_is_active()) { - stack = (char *)stack - smx_context_guard_size; - if (mprotect(stack, smx_context_guard_size, PROT_READ | PROT_WRITE) == -1) { - XBT_WARN("Failed to remove page protection: %s", strerror(errno)); - /* try to pursue anyway */ - } -#ifdef HAVE_MC - /* Retrieve the saved pointer. See SIMIX_context_stack_new above. */ - stack = *((void **)stack - 1); -#endif - } -#endif /* not windows */ - - xbt_free(stack); -} - /** @brief Returns whether some parallel threads are used for the user contexts. */ -int SIMIX_context_is_parallel(void) { +int SIMIX_context_is_parallel() { 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) + * @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) { +int SIMIX_context_get_nthreads() { return smx_parallel_contexts; } /** - * \brief Sets the number of parallel threads to use + * @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 + * @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); - } - - if (nb_threads > 1) { -#ifndef HAVE_THREAD_CONTEXTS - THROWF(arg_error, 0, "The thread factory cannot be run in parallel"); -#endif + if (nb_threads<=0) { + nb_threads = std::thread::hardware_concurrency(); + XBT_INFO("Auto-setting contexts/nthreads to %d", nb_threads); } smx_parallel_contexts = nb_threads; } /** - * \brief Returns the threshold above which user processes are run in parallel. + * @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 + * @return when the number of user processes ready to run is above * this threshold, they are run in parallel */ -int SIMIX_context_get_parallel_threshold(void) { +int SIMIX_context_get_parallel_threshold() { return smx_parallel_threshold; } /** - * \brief Sets the threshold above which user processes are run in parallel. + * @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 + * @param threshold when the number of user processes ready to run is above * this threshold, they are run in parallel */ void SIMIX_context_set_parallel_threshold(int threshold) { @@ -262,55 +174,19 @@ void SIMIX_context_set_parallel_threshold(int threshold) { } /** - * \brief Returns the synchronization mode used when processes are run in + * @brief Returns the synchronization mode used when processes are run in * parallel. - * \return how threads are synchronized if processes are run in parallel + * @return how threads are synchronized if processes are run in parallel */ -e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode(void) { +e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode() { return smx_parallel_synchronization_mode; } /** - * \brief Sets the synchronization mode to use when processes are run in + * @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 + * @param mode how to synchronize threads if processes are run in parallel */ void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) { smx_parallel_synchronization_mode = mode; } - -/** - * \brief Returns the current context of this thread. - * \return the current context of this thread - */ -smx_context_t SIMIX_context_get_current(void) -{ - if (SIMIX_context_is_parallel()) { -#ifdef HAVE_THREAD_LOCAL_STORAGE - return smx_current_context_parallel; -#else - return xbt_os_thread_get_specific(smx_current_context_key); -#endif - } - else { - return smx_current_context_serial; - } -} - -/** - * \brief Sets the current context of this thread. - * \param context the context to set - */ -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 - xbt_os_thread_set_specific(smx_current_context_key, context); -#endif - } - else { - smx_current_context_serial = context; - } -}