X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/a001b13d7aa269a90f035f58c71778c6812b07f6..HEAD:/src/simix/smx_context.cpp diff --git a/src/simix/smx_context.cpp b/src/simix/smx_context.cpp deleted file mode 100644 index e3991634b7..0000000000 --- a/src/simix/smx_context.cpp +++ /dev/null @@ -1,362 +0,0 @@ -/* a fast and simple context switching library */ - -/* Copyright (c) 2009-2017. 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 -#include - -#include -#include - -#include -#include -#include -#include - -#include "src/internal_config.h" -#include "xbt/log.h" -#include "xbt/swag.h" -#include "xbt/xbt_os_thread.h" -#include "smx_private.h" -#include "simgrid/sg_config.h" -#include "src/internal_config.h" -#include "simgrid/modelchecker.h" - - -#ifdef _WIN32 -#include -#include -#else -#include -#endif - -#ifdef __MINGW32__ -#define _aligned_malloc __mingw_aligned_malloc -#define _aligned_free __mingw_aligned_free -#endif /*MINGW*/ - -#if HAVE_VALGRIND_H -# include -#endif - -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 -#if HAVE_THREAD_CONTEXTS - { "thread", &simgrid::kernel::context::thread_factory }, -#endif -}; - -static_assert(sizeof(context_factories) != 0, "No context factories are enabled for this build"); - -// 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; -} - -static simgrid::config::Flag context_factory_name( - "contexts/factory", - (std::string("Possible values: ")+contexts_list()).c_str(), - context_factories[0].first); - -unsigned smx_context_stack_size; -int smx_context_stack_size_was_set = 0; -unsigned smx_context_guard_size; -int smx_context_guard_size_was_set = 0; -#if 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; -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() -{ - xbt_assert(simix_global->context_factory == nullptr); - -#if HAVE_THREAD_CONTEXTS && not 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 defined(__APPLE__) || defined(__NetBSD__) - if (context_factory_name == std::string("thread") && - strcmp(xbt_cfg_get_string("smpi/privatization"), "dlopen") == 0) { - XBT_WARN("dlopen+thread broken on Apple and BSD. Switching to raw contexts."); - context_factory_name = "raw"; - } -#endif -#if defined(__FreeBSD__) - if (context_factory_name == std::string("thread") && strcmp(xbt_cfg_get_string("smpi/privatization"), "no") != 0) { - XBT_WARN("mmap broken on FreeBSD, but dlopen+thread broken too. Switching to dlopen+raw contexts."); - context_factory_name = "raw"; - } -#endif - - /* select the context factory to use to create the contexts */ - if (simgrid::kernel::context::factory_initializer) { // 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)"); -#endif -#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)"); -#endif -#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?)"); -#endif - 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() -{ - delete simix_global->context_factory; - simix_global->context_factory = nullptr; -} - -void *SIMIX_context_stack_new() -{ - 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 && not MC_is_active()) { - -#if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1) - static int warned_once = 0; - if (not warned_once) { - XBT_WARN("Stack overflow protection is known to be broken on your system. Either stack grows upwards, or it was not even tested properly."); - warned_once = 1; - } -#endif - - size_t size = smx_context_stack_size + smx_context_guard_size; -#if SIMGRID_HAVE_MC - /* Cannot use posix_memalign when SIMGRID_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.\n" - "If you are running a lot of actors, you may be exceeding the amount of mappings allowed per process.\n" - "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n" - "Please see http://simgrid.gforge.inria.fr/simgrid/latest/doc/html/options.html#options_virt for more info.", - strerror(errno)); - /* This is fatal. We are going to fail at some point when we try reusing this. */ - } -#endif - stack = (char *)stack + smx_context_guard_size; - } else { - stack = xbt_malloc0(smx_context_stack_size); - } - -#if HAVE_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 (not stack) - return; - -#if HAVE_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 && not 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 */ - } -#if SIMGRID_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() { - 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) - */ -int SIMIX_context_get_nthreads() { - return smx_parallel_contexts; -} - -/** - * \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); - } -#if !HAVE_THREAD_CONTEXTS - xbt_assert(nb_threads == 1, "Parallel runs are impossible when the pthreads are missing."); -#endif - smx_parallel_contexts = nb_threads; -} - -/** - * \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 - */ -int SIMIX_context_get_parallel_threshold() { - 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 - */ -void SIMIX_context_set_parallel_threshold(int threshold) { - smx_parallel_threshold = threshold; -} - -/** - * \brief Returns the synchronization mode used when 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() { - 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 - */ -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() -{ - if (SIMIX_context_is_parallel()) { -#if 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()) { -#if 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; - } -}