/* a fast and simple context switching library */
-/* Copyright (c) 2009-2015. The SimGrid Team.
- * All rights reserved. */
+/* 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 "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/internal_config.h"
+#include "src/simix/smx_private.hpp"
+#include "xbt/config.hpp"
+#include <thread>
#ifdef _WIN32
#include <windows.h>
#include <sys/mman.h>
#endif
-#ifdef __MINGW32__
-#define _aligned_malloc __mingw_aligned_malloc
-#define _aligned_free __mingw_aligned_free
-#endif //MINGW
+#ifdef __MINGW32__
+#define _aligned_malloc __mingw_aligned_malloc
+#define _aligned_free __mingw_aligned_free
+#endif /*MINGW*/
-#ifdef HAVE_VALGRIND_VALGRIND_H
+#if HAVE_VALGRIND_H
# include <valgrind/valgrind.h>
#endif
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
- "Context switching mechanism");
+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
+#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<std::string> 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;
+unsigned smx_context_stack_size;
int smx_context_stack_size_was_set = 0;
-int smx_context_guard_size;
+unsigned 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 thread_local smx_context_t smx_current_context_parallel;
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(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);
+
+ 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
-#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<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
- 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) { // 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 system threads (pthreads on UNIX, CreateThread() on windows)");
- 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;
- xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory");
}
-void *SIMIX_context_stack_new(void)
+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 (smx_context_guard_size > 0 && !MC_is_active()) {
-
-#if defined(_XBT_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;
- }
+#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;
-#ifdef HAVE_MC
- /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the
+#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(_XBT_WIN32)
+#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 _XBT_WIN32
+#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. */
+ 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;
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);
+#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 (!stack)
+ if (not stack)
return;
-#ifdef HAVE_VALGRIND_VALGRIND_H
+#if HAVE_VALGRIND_H
unsigned int valgrind_stack_id;
- memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size,
- sizeof 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()) {
+#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) {
+ 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
+#if SIMGRID_HAVE_MC
/* Retrieve the saved pointer. See SIMIX_context_stack_new above. */
stack = *((void **)stack - 1);
#endif
}
-#endif
+#endif /* not windows */
xbt_free(stack);
}
-/**
- * \brief Returns whether some parallel threads are used
- * for the user contexts.
- * \return 1 if parallelism is used
- */
-int SIMIX_context_is_parallel(void) {
+/** @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)
+ * @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);
}
+#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(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) {
}
/**
- * \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
+ * @brief Returns the current context of this thread.
+ * @return the current context of this thread
*/
-smx_context_t SIMIX_context_get_current(void)
+smx_context_t SIMIX_context_get_current()
{
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
+ * @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;
