+++ /dev/null
-/* a fast and simple context switching library */
-
-/* Copyright (c) 2009-2018. 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 "simgrid/modelchecker.h"
-#include "src/internal_config.h"
-#include "src/simix/smx_private.hpp"
-#include "xbt/config.hpp"
-
-#include <thread>
-
-#ifdef _WIN32
-#include <windows.h>
-#include <malloc.h>
-#else
-#include <sys/mman.h>
-#endif
-
-#ifdef __MINGW32__
-#define _aligned_malloc __mingw_aligned_malloc
-#define _aligned_free __mingw_aligned_free
-#endif /*MINGW*/
-
-#if HAVE_VALGRIND_H
-# include <valgrind/valgrind.h>
-#endif
-
-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;
-int smx_context_stack_size_was_set = 0;
-unsigned smx_context_guard_size;
-int smx_context_guard_size_was_set = 0;
-static thread_local smx_context_t smx_current_context;
-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);
-
- smx_context_stack_size_was_set = not simgrid::config::is_default("contexts/stack-size");
- smx_context_guard_size_was_set = not simgrid::config::is_default("contexts/guard-size");
-
-#if HAVE_SMPI && (defined(__APPLE__) || defined(__NetBSD__))
- 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__)
- 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;
-}
-
-void *SIMIX_context_stack_new()
-{
- void *stack;
-
- if (smx_context_guard_size > 0 && not MC_is_active()) {
-
-#if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1)
- xbt_die("Stack overflow protection is known to be broken on your system: you stacks grow upwards (or detection is "
- "broken). "
- "Please disable stack guards with --cfg=contexts:guard-size:0");
- /* 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. */
-#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 = 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;
-}
-
-/**
- * @brief Returns the current context of this thread.
- * @return the current context of this thread
- */
-smx_context_t SIMIX_context_get_current()
-{
- return smx_current_context;
-}
-
-/**
- * @brief Sets the current context of this thread.
- * @param context the context to set
- */
-void SIMIX_context_set_current(smx_context_t context)
-{
- smx_current_context = context;
-}
