X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/244d7851457bfd373983edfb00c80760239dc8ab..b9945098e2ba4e7b639e0c2245835d44800c1b29:/src/kernel/context/ContextUnix.cpp diff --git a/src/kernel/context/ContextUnix.cpp b/src/kernel/context/ContextUnix.cpp index ea21e2579e..70a87d20ca 100644 --- a/src/kernel/context/ContextUnix.cpp +++ b/src/kernel/context/ContextUnix.cpp @@ -1,41 +1,53 @@ -/* 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. */ /* \file UContext.cpp Context switching with ucontexts from System V */ -#include "ContextUnix.hpp" +#include "context_private.hpp" #include "mc/mc.h" -#include "src/mc/mc_ignore.h" -#include "src/simix/ActorImpl.hpp" +#include "simgrid/Exception.hpp" +#include "src/kernel/actor/ActorImpl.hpp" +#include "src/mc/mc_ignore.hpp" +#include "src/simix/smx_private.hpp" + +#include "ContextUnix.hpp" XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); -/** Many integers are needed to store a pointer - * - * Support up to two ints. */ +/** Up to two integers may be needed to store a pointer on the system we target */ constexpr int CTX_ADDR_LEN = 2; static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int), - "Ucontexts are not supported on this arch yet"); + "Ucontexts are not supported on this arch yet. Please increase CTX_ADDR_LEN."); + +/* Make sure that this symbol is easy to recognize by name, even on exotic platforms */ +extern "C" { +static void smx_ctx_wrapper(int i1, int i2); +} -// The name of this function is currently hardcoded in the code (as string). +// The name of this function is currently hardcoded in MC (as string). // Do not change it without fixing those references as well. -static void smx_ctx_sysv_wrapper(int i1, int i2) +static void smx_ctx_wrapper(int i1, int i2) { // Rebuild the Context* pointer from the integers: int ctx_addr[CTX_ADDR_LEN] = {i1, i2}; simgrid::kernel::context::UContext* context; memcpy(&context, ctx_addr, sizeof context); + ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_); try { (*context)(); context->Context::stop(); - } catch (simgrid::kernel::context::Context::StopRequest const&) { - XBT_DEBUG("Caught a StopRequest"); + } catch (simgrid::ForcefulKillException const&) { + XBT_DEBUG("Caught a ForcefulKillException"); + } catch (simgrid::Exception const& e) { + XBT_INFO("Actor killed by an uncatched exception %s", simgrid::xbt::demangle(typeid(e).name()).get()); + throw; } + ASAN_ONLY(context->asan_stop_ = true); context->suspend(); } @@ -44,246 +56,49 @@ namespace kernel { namespace context { // UContextFactory - -UContextFactory::UContextFactory() : ContextFactory("UContextFactory"), parallel_(SIMIX_context_is_parallel()) +Context* UContextFactory::create_context(std::function&& code, smx_actor_t actor) { - UContext::setMaestro(nullptr); - if (parallel_) { -#if HAVE_THREAD_CONTEXTS - ParallelUContext::initialize(); -#else - xbt_die("No thread support for parallel context execution"); -#endif - } + return new_context(std::move(code), actor, this); } -UContextFactory::~UContextFactory() -{ -#if HAVE_THREAD_CONTEXTS - if (parallel_) - ParallelUContext::finalize(); -#endif -} - -Context* UContextFactory::create_context(std::function code, void_pfn_smxprocess_t cleanup, smx_actor_t process) -{ -#if HAVE_THREAD_CONTEXTS - if (parallel_) - return new_context(std::move(code), cleanup, process); - else -#endif - return new_context(std::move(code), cleanup, process); -} - -/* 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. - */ -void UContextFactory::run_all() -{ -#if HAVE_THREAD_CONTEXTS - if (parallel_) - ParallelUContext::run_all(); - else -#endif - SerialUContext::run_all(); -} // UContext -UContext* UContext::maestro_context_ = nullptr; - -UContext::UContext(std::function code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : Context(std::move(code), cleanup_func, process) +UContext::UContext(std::function&& code, smx_actor_t actor, SwappedContextFactory* factory) + : SwappedContext(std::move(code), actor, factory) { - /* if the user provided a function for the process then use it, otherwise it is the context for maestro */ + /* if the user provided a function for the actor then use it. If not, nothing to do for maestro. */ if (has_code()) { - this->stack_ = SIMIX_context_stack_new(); getcontext(&this->uc_); this->uc_.uc_link = nullptr; - this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(this->stack_); + this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(get_stack()); this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_usable_stack_size); - UContext::make_ctx(&this->uc_, UContext::wrapper, this); - } else { - if (process != nullptr && maestro_context_ == nullptr) - maestro_context_ = this; - } + // Makecontext expects integer arguments; we want to pass a pointer. + // This context address is decomposed into a serie of integers, which are passed as arguments to makecontext. + + int ctx_addr[CTX_ADDR_LEN]{}; + UContext* arg = this; + memcpy(ctx_addr, &arg, sizeof this); + makecontext(&this->uc_, (void (*)())smx_ctx_wrapper, 2, ctx_addr[0], ctx_addr[1]); #if SIMGRID_HAVE_MC - if (MC_is_active() && has_code()) { - MC_register_stack_area(this->stack_, process, &(this->uc_), smx_context_usable_stack_size); - } + if (MC_is_active()) { + MC_register_stack_area(get_stack(), actor, &(this->uc_), smx_context_usable_stack_size); + } #endif -} - -UContext::~UContext() -{ - SIMIX_context_stack_delete(this->stack_); -} - -void UContext::wrapper(int i1, int i2) -{ - smx_ctx_sysv_wrapper(i1, i2); -} - -/** A better makecontext - * - * Makecontext expects integer arguments, we the context variable is decomposed into a serie of integers and each - * integer is passed as argument to makecontext. - */ -void UContext::make_ctx(ucontext_t* ucp, void (*func)(int, int), UContext* arg) -{ - int ctx_addr[CTX_ADDR_LEN]{}; - memcpy(ctx_addr, &arg, sizeof arg); - makecontext(ucp, (void (*)())func, 2, ctx_addr[0], ctx_addr[1]); -} - -void UContext::stop() -{ - Context::stop(); - throw StopRequest(); -} - -// SerialUContext - -unsigned long SerialUContext::process_index_; /* index of the next process to run in the list of runnable processes */ - -void SerialUContext::suspend() -{ - /* determine the next context */ - SerialUContext* next_context; - unsigned long int i = process_index_; - process_index_++; - - if (i < simix_global->process_to_run.size()) { - /* execute the next process */ - XBT_DEBUG("Run next process"); - next_context = static_cast(simix_global->process_to_run[i]->context); - } else { - /* all processes were run, return to maestro */ - XBT_DEBUG("No more process to run"); - next_context = static_cast(UContext::getMaestro()); } - SIMIX_context_set_current(next_context); - UContext::swap(this, next_context); } -void SerialUContext::resume() +void UContext::swap_into(SwappedContext* to_) { - SIMIX_context_set_current(this); - UContext::swap(UContext::getMaestro(), this); + UContext* to = static_cast(to_); + ASAN_ONLY(void* fake_stack = nullptr); + ASAN_ONLY(to->asan_ctx_ = this); + ASAN_START_SWITCH(this->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_); + swapcontext(&this->uc_, &to->uc_); + ASAN_FINISH_SWITCH(fake_stack, &this->asan_ctx_->asan_stack_, &this->asan_ctx_->asan_stack_size_); } -void SerialUContext::run_all() -{ - if (simix_global->process_to_run.empty()) - return; - smx_actor_t first_process = simix_global->process_to_run.front(); - process_index_ = 1; - static_cast(first_process->context)->resume(); -} - -// ParallelUContext - -#if HAVE_THREAD_CONTEXTS - -simgrid::xbt::Parmap* ParallelUContext::parmap_; -uintptr_t ParallelUContext::threads_working_; /* number of threads that have started their work */ -xbt_os_thread_key_t ParallelUContext::worker_id_key_; /* thread-specific storage for the thread id */ -std::vector ParallelUContext::workers_context_; /* space to save the worker's context - * in each thread */ - -void ParallelUContext::initialize() -{ - parmap_ = nullptr; - workers_context_.clear(); - workers_context_.resize(SIMIX_context_get_nthreads(), nullptr); - xbt_os_thread_key_create(&worker_id_key_); -} - -void ParallelUContext::finalize() -{ - delete parmap_; - parmap_ = nullptr; - workers_context_.clear(); - xbt_os_thread_key_destroy(worker_id_key_); -} - -void ParallelUContext::run_all() -{ - threads_working_ = 0; - // Parmap_apply ensures that every working thread get an index in the process_to_run array (through an atomic - // fetch_and_add), and runs the ParallelUContext::resume function on that index - - // We lazily create the parmap because the parmap creates context with simix_global->context_factory (which might not - // be initialized when bootstrapping): - if (parmap_ == nullptr) - parmap_ = new simgrid::xbt::Parmap(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode()); - parmap_->apply( - [](smx_actor_t process) { - ParallelUContext* context = static_cast(process->context); - context->resume(); - }, - simix_global->process_to_run); -} - -/** Yield - * - * This function is called when a simulated process wants to yield back to the maestro in a blocking simcall. This - * naturally occurs within SIMIX_context_suspend(self->context), called from SIMIX_process_yield() Actually, it does not - * really yield back to maestro, but into the next process that must be executed. If no one is to be executed, then it - * yields to the initial soul that was in this working thread (that was saved in resume_parallel). - */ -void ParallelUContext::suspend() -{ - /* determine the next context */ - // Get the next soul to embody now: - boost::optional next_work = parmap_->next(); - ParallelUContext* next_context; - if (next_work) { - // There is a next soul to embody (ie, a next process to resume) - XBT_DEBUG("Run next process"); - next_context = static_cast(next_work.get()->context); - } else { - // All processes were run, go to the barrier - XBT_DEBUG("No more processes to run"); - // Get back the identity of my body that was stored when starting the scheduling round - uintptr_t worker_id = reinterpret_cast(xbt_os_thread_get_specific(worker_id_key_)); - // Deduce the initial soul of that body - next_context = workers_context_[worker_id]; - // When given that soul, the body will wait for the next scheduling round - } - - SIMIX_context_set_current(next_context); - // Get the next soul to run, either simulated or initial minion's one: - UContext::swap(this, next_context); -} - -/** Run one particular simulated process on the current thread. */ -void ParallelUContext::resume() -{ - // What is my containing body? - uintptr_t worker_id = __sync_fetch_and_add(&threads_working_, 1); - // Store the number of my containing body in os-thread-specific area : - xbt_os_thread_set_specific(worker_id_key_, reinterpret_cast(worker_id)); - // Get my current soul: - ParallelUContext* worker_context = static_cast(SIMIX_context_self()); - // Write down that this soul is hosted in that body (for now) - workers_context_[worker_id] = worker_context; - // Write in simix that I switched my soul - SIMIX_context_set_current(this); - // Actually do that using the relevant library call: - UContext::swap(worker_context, this); - // No body runs that soul anymore at this point. Instead the current body took the soul of simulated process The - // simulated process wakes back after the call to "SIMIX_context_suspend(self->context);" within - // smx_process.c::SIMIX_process_yield() - - // From now on, the simulated processes will change their soul with the next soul to execute (in suspend_parallel, - // below). When nobody is to be executed in this scheduling round, the last simulated process will take back the - // initial soul of the current working thread -} - -#endif XBT_PRIVATE ContextFactory* sysv_factory() {