/* a fast and simple context switching library */
-/* Copyright (c) 2009-2017. 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 <cerrno>
-#include <cstring>
-
-#include <utility>
-#include <string>
-
-#include <xbt/config.hpp>
-#include <xbt/log.h>
-#include <xbt/range.hpp>
-#include <xbt/sysdep.h>
-
-#include "simgrid/modelchecker.h"
-#include "simgrid/sg_config.h"
-#include "smx_private.hpp"
#include "src/internal_config.h"
-#include "xbt/log.h"
-#include "xbt/swag.h"
-#include "xbt/xbt_os_thread.h"
-
-#ifdef _WIN32
-#include <windows.h>
-#include <malloc.h>
-#else
-#include <sys/mman.h>
-#endif
+#include "src/simix/smx_private.hpp"
+#include "src/smpi/include/smpi_config.hpp"
+#include "xbt/config.hpp"
-#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
+#include <thread>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mechanism");
#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");
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;
{
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) {
+#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 defined(__FreeBSD__)
- if (context_factory_name == std::string("thread") && strcmp(xbt_cfg_get_string("smpi/privatization"), "no") != 0) {
+
+#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) { // Give Java a chance to hijack the factory mechanism
+ 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;
}
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)
+ * @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
+ * @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);
+ nb_threads = std::thread::hardware_concurrency();
+ 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.
+ * @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() {
}
/**
- * \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) {
}
/**
- * \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() {
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()
-{
- 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;
- }
-}
