X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/15f9e0adbd11d2a0736440004a2f71ef9cfccab8..ccf671a80a47f0489c33fb1dc2a8aadfc28b5b88:/src/kernel/context/ContextSwapped.cpp diff --git a/src/kernel/context/ContextSwapped.cpp b/src/kernel/context/ContextSwapped.cpp index 2d53c8e4cf..bd913fb87c 100644 --- a/src/kernel/context/ContextSwapped.cpp +++ b/src/kernel/context/ContextSwapped.cpp @@ -1,17 +1,19 @@ -/* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2009-2021. 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/Exception.hpp" #include "simgrid/modelchecker.h" #include "src/internal_config.h" -#include "src/kernel/context/context_private.hpp" -#include "src/simix/ActorImpl.hpp" +#include "src/kernel/actor/ActorImpl.hpp" #include "src/simix/smx_private.hpp" #include "xbt/parmap.hpp" #include "src/kernel/context/ContextSwapped.hpp" -#include "src/kernel/context/ContextUnix.hpp" // FIXME: temporary reverse import + +#include +#include #ifdef _WIN32 #include @@ -28,92 +30,56 @@ #if HAVE_VALGRIND_H #include #endif +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT +#include +#endif +#if HAVE_SANITIZER_THREAD_FIBER_SUPPORT +#include +#endif XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); -namespace simgrid { -namespace kernel { -namespace context { - -/* Parallel execution */ -simgrid::xbt::Parmap* SwappedContext::parmap_; -std::atomic SwappedContext::threads_working_; /* number of threads that have started their work */ -thread_local uintptr_t SwappedContext::worker_id_; /* thread-specific storage for the thread id */ -std::vector SwappedContext::workers_context_; /* space to save the worker's context in each thread */ - -SwappedContextFactory::SwappedContextFactory(std::string name) - : ContextFactory(name), parallel_(SIMIX_context_is_parallel()) -{ - SwappedContext::set_maestro(nullptr); - SwappedContext::initialize(parallel_); -} -SwappedContextFactory::~SwappedContextFactory() -{ - SwappedContext::finalize(); -} -/** Maestro wants to run all ready actors */ -void SwappedContextFactory::run_all() -{ - /* This function is called by maestro at the beginning of a scheduling round to get all working threads executing some - * stuff It is much easier to understand what happens if you see the working threads as bodies that swap their soul - * for the ones of the simulated processes that must run. - */ - if (parallel_) { - SwappedContext::threads_working_ = 0; - - // We lazily create the parmap so that all options are actually processed when doing so. - if (SwappedContext::parmap_ == nullptr) - SwappedContext::parmap_ = - new simgrid::xbt::Parmap(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode()); - - // Usually, Parmap::apply() executes the provided function on all elements of the array. - // Here, the executed function does not return the control to the parmap before all the array is processed: - // - suspend() should switch back to the worker_context (either maestro or one of its minions) to return - // the control to the parmap. Instead, it uses parmap_->next() to steal another work, and does it directly. - // It only yields back to worker_context when the work array is exhausted. - // - So, resume() is only launched from the parmap for the first job of each minion. - SwappedContext::parmap_->apply( - [](smx_actor_t process) { - SwappedContext* context = static_cast(process->context_); - context->resume(); - }, - simix_global->process_to_run); - } else { // sequential execution - if (simix_global->process_to_run.empty()) - return; - smx_actor_t first_actor = simix_global->process_to_run.front(); - process_index_ = 1; - /* execute the first actor; it will chain to the others when using suspend() */ - static_cast(first_actor->context_)->resume(); - } -} - -void SwappedContext::initialize(bool parallel) +// The name of this function is currently hardcoded in MC (as string). +// Do not change it without fixing those references as well. +void smx_ctx_wrapper(simgrid::kernel::context::SwappedContext* context) { - parmap_ = nullptr; // will be created lazily with the right parameters if needed (ie, in parallel) - if (parallel) { - workers_context_.clear(); - workers_context_.resize(SIMIX_context_get_nthreads(), nullptr); +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT + __sanitizer_finish_switch_fiber(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_); +#endif + try { + (*context)(); + context->Context::stop(); + } catch (simgrid::ForcefulKillException const&) { + XBT_DEBUG("Caught a ForcefulKillException"); + } catch (simgrid::Exception const& e) { + XBT_INFO("Actor killed by an uncaught exception %s", boost::core::demangle(typeid(e).name()).c_str()); + throw; } +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT + context->asan_stop_ = true; +#endif + context->suspend(); + THROW_IMPOSSIBLE; } -void SwappedContext::finalize() -{ - delete parmap_; - parmap_ = nullptr; - workers_context_.clear(); -} +namespace simgrid { +namespace kernel { +namespace context { -SwappedContext* SwappedContext::maestro_context_ = nullptr; +/* thread-specific storage for the worker's context */ +thread_local SwappedContext* SwappedContext::worker_context_ = nullptr; -SwappedContext::SwappedContext(std::function code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process, - SwappedContextFactory* factory) - : Context(std::move(code), cleanup_func, process), factory_(factory) +SwappedContext::SwappedContext(std::function&& code, smx_actor_t actor, SwappedContextFactory* factory) + : Context(std::move(code), actor), factory_(*factory) { + // Save maestro (=first created context) in preparation for run_all + if (not SIMIX_context_is_parallel() && factory_.maestro_context_ == nullptr) + factory_.maestro_context_ = this; + if (has_code()) { + xbt_assert((actor->get_stacksize() & 0xf) == 0, "Actor stack size should be multiple of 16"); if (smx_context_guard_size > 0 && not MC_is_active()) { - -#if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1) +#if PTH_STACKGROWTH != -1 xbt_die( "Stack overflow protection is known to be broken on your system: you stacks grow upwards (or detection is " "broken). " @@ -122,18 +88,20 @@ SwappedContext::SwappedContext(std::function code, void_pfn_smxprocess_t * 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; + size_t size = actor->get_stacksize() + 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; + auto* alloc = static_cast(xbt_malloc0(size + xbt_pagesize)); + stack_ = alloc - (reinterpret_cast(alloc) & (xbt_pagesize - 1)) + xbt_pagesize; + reinterpret_cast(stack_)[-1] = alloc; #elif !defined(_WIN32) - if (posix_memalign(&this->stack_, xbt_pagesize, size) != 0) + void* alloc; + if (posix_memalign(&alloc, xbt_pagesize, size) != 0) xbt_die("Failed to allocate stack."); + this->stack_ = static_cast(alloc); #else - this->stack_ = _aligned_malloc(size, xbt_pagesize); + this->stack_ = static_cast(_aligned_malloc(size, xbt_pagesize)); #endif #ifndef _WIN32 @@ -142,21 +110,32 @@ SwappedContext::SwappedContext(std::function code, void_pfn_smxprocess_t "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.", + "Please see " + "https://simgrid.org/doc/latest/Configuring_SimGrid.html#configuring-the-user-code-virtualization for more " + "information.", strerror(errno)); /* This is fatal. We are going to fail at some point when we try reusing this. */ } #endif - this->stack_ = (char*)this->stack_ + smx_context_guard_size; + this->stack_ = this->stack_ + smx_context_guard_size; } else { - this->stack_ = xbt_malloc0(smx_context_stack_size); + this->stack_ = static_cast(xbt_malloc0(actor->get_stacksize())); } #if HAVE_VALGRIND_H - unsigned int valgrind_stack_id = - VALGRIND_STACK_REGISTER(this->stack_, (char*)this->stack_ + smx_context_stack_size); - memcpy((char*)this->stack_ + smx_context_usable_stack_size, &valgrind_stack_id, sizeof valgrind_stack_id); + if (RUNNING_ON_VALGRIND) + this->valgrind_stack_id_ = VALGRIND_STACK_REGISTER(this->stack_, this->stack_ + actor->get_stacksize()); +#endif +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT + this->asan_stack_ = get_stack_bottom(); +#endif +#if HAVE_SANITIZER_THREAD_FIBER_SUPPORT + this->tsan_fiber_ = __tsan_create_fiber(0); +#endif + } else { + // not has_code(): in maestro context +#if HAVE_SANITIZER_THREAD_FIBER_SUPPORT + this->tsan_fiber_ = __tsan_get_current_fiber(); #endif } } @@ -166,22 +145,24 @@ SwappedContext::~SwappedContext() if (stack_ == nullptr) // maestro has no extra stack return; +#if HAVE_SANITIZER_THREAD_FIBER_SUPPORT + __tsan_destroy_fiber(tsan_fiber_); +#endif #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); + if (RUNNING_ON_VALGRIND) + 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; + stack_ = 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); + stack_ = reinterpret_cast(stack_)[-1]; #endif } #endif /* not windows */ @@ -189,48 +170,140 @@ SwappedContext::~SwappedContext() xbt_free(stack_); } -/** Maestro wants to yield back to a given actor */ -void SwappedContext::resume() +unsigned char* SwappedContext::get_stack_bottom() const { - if (factory_->parallel_) { - THROW_IMPOSSIBLE; + // Depending on the stack direction, its bottom (that make_fcontext needs) may be the lower or higher end +#if PTH_STACKGROWTH == 1 + return stack_; +#else + return stack_ + get_actor()->get_stacksize(); +#endif +} + +void SwappedContext::stop() +{ + Context::stop(); + /* We must cut the actor execution using an exception to properly free the C++ RAII variables */ + throw ForcefulKillException(); +} + +void SwappedContext::swap_into(SwappedContext* to) +{ +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT + void* fake_stack = nullptr; + to->asan_ctx_ = this; + __sanitizer_start_switch_fiber(this->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_); +#endif +#if HAVE_SANITIZER_THREAD_FIBER_SUPPORT + __tsan_switch_to_fiber(to->tsan_fiber_, 0); +#endif + + swap_into_for_real(to); + +#if HAVE_SANITIZER_ADDRESS_FIBER_SUPPORT + __sanitizer_finish_switch_fiber(fake_stack, &this->asan_ctx_->asan_stack_, &this->asan_ctx_->asan_stack_size_); +#endif +} + +/** Maestro wants to run all ready actors */ +void SwappedContextFactory::run_all() +{ + /* This function is called by maestro at the beginning of a scheduling round to get all working threads executing some + * stuff It is much easier to understand what happens if you see the working threads as bodies that swap their soul + * for the ones of the simulated processes that must run. + */ + if (SIMIX_context_is_parallel()) { + // We lazily create the parmap so that all options are actually processed when doing so. + if (parmap_ == nullptr) + parmap_ = std::make_unique>(SIMIX_context_get_nthreads(), + SIMIX_context_get_parallel_mode()); + + // Usually, Parmap::apply() executes the provided function on all elements of the array. + // Here, the executed function does not return the control to the parmap before all the array is processed: + // - suspend() should switch back to the worker_context (either maestro or one of its minions) to return + // the control to the parmap. Instead, it uses parmap_->next() to steal another work, and does it directly. + // It only yields back to worker_context when the work array is exhausted. + // - So, resume() is only launched from the parmap for the first job of each minion. + parmap_->apply( + [](const actor::ActorImpl* process) { + auto* context = static_cast(process->context_.get()); + context->resume(); + }, + simix_global->actors_to_run); } else { // sequential execution - // Maestro is always the calling thread of this function (ie, self() == maestro) - SwappedContext* old = static_cast(self()); - Context::set_current(this); - old->swap_into(this); + if (simix_global->actors_to_run.empty()) + return; + + /* maestro is already saved in the first slot of workers_context_ */ + const actor::ActorImpl* first_actor = simix_global->actors_to_run.front(); + process_index_ = 1; + /* execute the first actor; it will chain to the others when using suspend() */ + static_cast(first_actor->context_.get())->resume(); } } -/** The actor wants to yield back to maestro */ +/** Maestro wants to yield back to a given actor, so awake it on the current thread + * + * In parallel, it is only applied to the N first elements of the parmap array, + * where N is the amount of worker threads in the parmap. + * See SwappedContextFactory::run_all for details. + */ +void SwappedContext::resume() +{ + auto* old = static_cast(self()); + if (SIMIX_context_is_parallel()) { + // Save my current soul (either maestro, or one of the minions) in a thread-specific area + worker_context_ = old; + } + // Switch my soul and the actor's one + Context::set_current(this); + old->swap_into(this); + // No body runs that soul anymore at this point, but it is stored in a safe place. + // When the executed actor will do a blocking action, ActorImpl::yield() will call suspend(), below. +} + +/** The actor wants to yield back to maestro, because it is blocked in a simcall (i.e., in ActorImpl::yield()) + * + * Actually, it does not really yield back to maestro, but directly into the next executable actor. + * + * This makes the parmap::apply awkward (see SwappedContextFactory::run_all()) because it only apply regularly + * on the few first elements of the array, but it saves a lot of context switches back to maestro, + * and directly forth to the next executable actor. + */ void SwappedContext::suspend() { - if (factory_->parallel_) { - THROW_IMPOSSIBLE; + SwappedContext* next_context; + if (SIMIX_context_is_parallel()) { + // Get some more work to directly swap into the next executable actor instead of yielding back to the parmap + boost::optional next_work = factory_.parmap_->next(); + if (next_work) { + // There is a next soul to embody (ie, another executable actor) + XBT_DEBUG("Run next process"); + next_context = static_cast(next_work.get()->context_.get()); + } else { + // All actors were run, go back to the parmap context + XBT_DEBUG("No more actors to run"); + // worker_context_ is my own soul, stored in thread_local when starting the scheduling round + next_context = worker_context_; + // When given that soul, the body will wait for the next scheduling round + } } else { // sequential execution /* determine the next context */ - SwappedContext* next_context; - unsigned long int i = factory_->process_index_; - factory_->process_index_++; + unsigned long int i = factory_.process_index_; + factory_.process_index_++; - if (i < simix_global->process_to_run.size()) { + if (i < simix_global->actors_to_run.size()) { /* Actually swap into the next actor directly without transiting to maestro */ - XBT_DEBUG("Run next process"); - next_context = static_cast(simix_global->process_to_run[i]->context_); + XBT_DEBUG("Run next actor"); + next_context = static_cast(simix_global->actors_to_run[i]->context_.get()); } else { /* all processes were run, actually return to maestro */ - XBT_DEBUG("No more process to run"); - next_context = static_cast(get_maestro()); + XBT_DEBUG("No more actors to run"); + next_context = factory_.maestro_context_; } - Context::set_current(next_context); - this->swap_into(next_context); } -} - -void SwappedContext::stop() -{ - Context::stop(); - throw StopRequest(); + Context::set_current(next_context); + this->swap_into(next_context); } } // namespace context