X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/87c589b94e563580e8e0585079cdba97914d791d..0d638e1070f68f783639288b8f0799679fad87cf:/src/kernel/context/ContextUnix.cpp diff --git a/src/kernel/context/ContextUnix.cpp b/src/kernel/context/ContextUnix.cpp index 4e204b0f71..97e8a5170f 100644 --- a/src/kernel/context/ContextUnix.cpp +++ b/src/kernel/context/ContextUnix.cpp @@ -1,227 +1,83 @@ -/* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2009-2023. 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 "context_private.hpp" - #include "mc/mc.h" #include "simgrid/Exception.hpp" -#include "src/mc/mc_ignore.hpp" -#include "src/simix/ActorImpl.hpp" -#include "src/simix/smx_private.hpp" +#include "src/kernel/actor/ActorImpl.hpp" +#include "src/mc/remote/AppSide.hpp" #include "ContextUnix.hpp" -XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); +XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(ker_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"); - -namespace simgrid { -namespace kernel { -namespace context { - -// UContextFactory + "Ucontexts are not supported on this arch yet. Please increase CTX_ADDR_LEN."); -UContextFactory::UContextFactory() : ContextFactory("UContextFactory"), parallel_(SIMIX_context_is_parallel()) +// This function is called by makecontext(3): use extern "C" to have C language linkage for its type +extern "C" { +XBT_ATTRIB_NORETURN static void sysv_ctx_wrapper(int i1, int i2) { - UContext::set_maestro(nullptr); - if (parallel_) - ParallelUContext::initialize(); + // 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); + smx_ctx_wrapper(context); } - -UContextFactory::~UContextFactory() -{ - if (parallel_) - ParallelUContext::finalize(); } -Context* UContextFactory::create_context(std::function code, void_pfn_smxprocess_t cleanup, smx_actor_t process) -{ - if (parallel_) - return new_context(std::move(code), cleanup, process); - else - return new_context(std::move(code), cleanup, process); -} +namespace simgrid::kernel::context { -/* 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() +// UContextFactory +UContext* UContextFactory::create_context(std::function&& code, actor::ActorImpl* actor) { - if (parallel_) - ParallelUContext::run_all(); - else - SwappedContext::run_all(); + return new_context(std::move(code), actor, this); } + // UContext -UContext::UContext(std::function code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : SwappedContext(std::move(code), cleanup_func, process) +UContext::UContext(std::function&& code, actor::ActorImpl* 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 */ + XBT_VERB("Creating a context of stack %uMb", actor->get_stacksize() / 1024 / 1024); + /* if the user provided a function for the actor then use it. If not, nothing to do for maestro. */ if (has_code()) { 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_size = sg_makecontext_stack_size(smx_context_usable_stack_size); -#if PTH_STACKGROWTH == -1 - ASAN_ONLY(this->asan_stack_ = static_cast(this->stack_) + smx_context_usable_stack_size); -#else - ASAN_ONLY(this->asan_stack_ = this->stack_); -#endif - UContext::make_ctx(&this->uc_, UContext::smx_ctx_sysv_wrapper, this); - } else { - if (process != nullptr && get_maestro() == nullptr) - set_maestro(this); - } + this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(get_stack()); + this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(actor->get_stacksize()); + // Makecontext expects integer arguments; we want to pass a pointer. + // This context address is decomposed into a series of integers, which are passed as arguments to makecontext. + + int ctx_addr[CTX_ADDR_LEN]{}; + UContext* arg = this; + memcpy(ctx_addr, &arg, sizeof arg); + makecontext(&this->uc_, (void (*)())sysv_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()) + simgrid::mc::AppSide::get()->declare_stack(get_stack(), stack_size, &uc_); #endif -} - -UContext::~UContext() = default; - -// The name of this function is currently hardcoded in the code (as string). -// Do not change it without fixing those references as well. -void UContext::smx_ctx_sysv_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)(); - } catch (simgrid::kernel::context::Context::StopRequest const&) { - XBT_DEBUG("Caught a StopRequest"); - } catch (simgrid::Exception const& e) { - XBT_INFO("Actor killed by an uncatched exception %s", simgrid::xbt::demangle(typeid(e).name()).get()); - throw; } - context->Context::stop(); - ASAN_ONLY(context->asan_stop_ = true); - context->suspend(); } -/** 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) +void UContext::swap_into_for_real(SwappedContext* to_) { - 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::swap_into(SwappedContext* to_) -{ - UContext* to = static_cast(to_); - ASAN_ONLY(void* fake_stack = nullptr); - ASAN_ONLY(to->asan_ctx_ = from); - ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_); + const UContext* to = static_cast(to_); swapcontext(&this->uc_, &to->uc_); - ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_); -} - -void UContext::stop() -{ - Context::stop(); - throw StopRequest(); } -// ParallelUContext - -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(); - SwappedContext* 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"); - // worker_id_ is the identity of my body, stored in thread_local when starting the scheduling round - // 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 - } - - Context::set_current(next_context); - // Get the next soul to run, either simulated or initial minion's one: - this->swap_into(next_context); -} - -/** Run one particular simulated process on the current thread. */ -void ParallelUContext::resume() -{ - // What is my containing body? Store its number in os-thread-specific area : - worker_id_ = threads_working_.fetch_add(1, std::memory_order_relaxed); - // Get my current soul: - ParallelUContext* worker_context = static_cast(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 - Context::set_current(this); - // Actually do that using the relevant library call: - worker_context->swap_into(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 -} XBT_PRIVATE ContextFactory* sysv_factory() { XBT_VERB("Activating SYSV context factory"); return new UContextFactory(); } -}}} // namespace simgrid::kernel::context +} // namespace simgrid::kernel::context