+++ /dev/null
-/* a fast and simple context switching library */
-
-/* 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/internal_config.h"
-#include "src/simix/smx_private.hpp"
-#include "xbt/config.hpp"
-
-#include <thread>
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mechanism");
-
-static std::pair<const char*, simgrid::kernel::context::ContextFactoryInitializer> 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 },
-};
-
-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<std::string> context_factory_name(
- "contexts/factory",
- (std::string("Possible values: ")+contexts_list()).c_str(),
- context_factories[0].first);
-
-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()
-{
- xbt_assert(simix_global->context_factory == nullptr);
-
-#if HAVE_SMPI && (defined(__APPLE__) || defined(__NetBSD__))
- smpi_init_options();
- std::string priv = simgrid::config::get_value<std::string>("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
-
-#if HAVE_SMPI && defined(__FreeBSD__)
- smpi_init_options();
- if (context_factory_name == "thread" && simgrid::config::get_value<std::string>("smpi/privatization") != "no") {
- 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 != 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)");
-#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;
-}
-
-/** @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 = 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.
- *
- * 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;
-}
